IXC COMMUNICATIONS INC
10-Q/A, 1997-12-10
TELEPHONE COMMUNICATIONS (NO RADIOTELEPHONE)
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<PAGE>   1
 
================================================================================
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                            ------------------------
 
                                  FORM 10-Q/A
   
                               (AMENDMENT NO. 2)
    
                            ------------------------
 
[X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
    ACT OF 1934
 
                  FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1997
 
                                       OR
 
[ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
    ACT OF 1934
 
     FOR THE TRANSITION PERIOD FROM                   TO
 
                         COMMISSION FILE NUMBER 0-20803
 
                            ------------------------
 
                            IXC COMMUNICATIONS, INC.
              (EXACT NAME OF REGISTRANT SPECIFIED IN ITS CHARTER)
 
                            ------------------------
 
<TABLE>
<S>                                           <C>
                   DELAWARE                                     75-2644120
       (STATE OR OTHER JURISDICTION OF                       (I.R.S. EMPLOYER
        INCORPORATION OR ORGANIZATION)                      IDENTIFICATION NO.)
      5000 PLAZA ON THE LAKE, SUITE 200,
                AUSTIN, TEXAS                                      78746
   (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                     (ZIP CODE)
</TABLE>
 
      (REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE) (512) 328-1112
 
     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes [X]  No [ ]
 
     The number of shares of Common Stock, $.01 par value, outstanding (the only
class of common stock of the Company outstanding) was 30,898,841 on July 31,
1997.
 
================================================================================
<PAGE>   2
 
   
     This Amendment No. 2 to the Quarterly Report on Form 10-Q is being filed to
amend certain exhibits to the Quarterly Report on Form 10-Q for the quarter
ended June 30, 1997, that was filed with the Securities and Exchange Commission
on August 6, 1997, as amended on August 8, 1997 ("Form 10-Q").
    
 
   
     IXC Communications, Inc. hereby amends its Form 10-Q by amending Exhibits
10.19 and 10.20 to the exhibits contained under Item 6 (Exhibits and Reports on
Form 8-K), which are being filed in redacted form pursuant to a request for
confidential treatment filed separately pursuant to Rule 24b-2, contained in
Part II of the Form 10-Q for the quarter ended June 30, 1997, as set forth
below:
    
 
ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K
 
(A) EXHIBITS
 
<TABLE>
<CAPTION>
EXHIBIT
NUMBER                                         DESCRIPTION
- ------      ---------------------------------------------------------------------------------
<C>         <S>
  3.1 +     Restated Certificate of Incorporation of IXC Communications, Inc., as amended
  3.2       Bylaws of IXC Communications, Inc., as amended (incorporated by reference to
            Exhibit 3.2 of IXC Communications, Inc. Quarterly Report on Form 10-Q for the
            quarter ended March 31, 1997 (the "10-Q")).
  4.1       Specimen certificate representing shares of Common Stock of IXC Communications,
            Inc. (incorporated by reference to Exhibit 4.1 of IXC Communications, Inc.
            Registration Statement on Form S-1 filed with the Commission on May 20, 1996, as
            amended (File No. 333-4061) (the "S-1")).
  4.2       Indenture dated as of October 5, 1995 by and among IXC Communications, Inc., on
            its behalf and as successor-in-interest to I-Link Holdings, Inc. and IXC Carrier
            Group, Inc., each of IXC Carrier, Inc., on its behalf and as
            successor-in-interest to I-Link, Inc., CTI Investments, Inc., Texas Microwave,
            Inc. and WTM Microwave, Inc., Atlantic States Microwave Transmission Company,
            Central States Microwave Transmission Company, Telcom Engineering, Inc., on its
            behalf and as successor-in-interest to SWTT Company and Microwave Network, Inc.,
            Tower Communication Systems Corp., West Texas Microwave Company, Western States
            Microwave Transmission Company, Rio Grande Transmission, Inc., IXC Long Distance,
            Inc., Link Net International, Inc. (collectively, the "Guarantors") and IBJ
            Schroder Bank & Trust Company, as Trustee, with respect to the 12 1/2% Series A
            and Series B Senior Notes due 2005 (incorporated by reference to Exhibit 4.1 of
            IXC Communications, Inc.'s and each of the Guarantor's Registration Statement on
            Form S-4 filed with the Commission on April 1, 1996, as amended (File No.
            333-2936) (the "S-4")).
  4.3       Purchase Agreement dated October 5, 1995 by and among IXC Communications, Inc.,
            and the Purchasers named therein (incorporated by reference to Exhibit 4.2 of the
            S-4).
  4.4       A/B Exchange Registration Rights Agreement dated as of October 5, 1995 by and
            among IXC Communications, Inc., the Guarantors and the Purchasers named therein
            (incorporated by reference to Exhibit 4.3 of the S-4).
  4.5       Escrow Account and Disbursement Agreement dated as of October 5, 1995 by and
            among IXC Communications, Inc., IBJ Schroder Bank & Trust Company, as Escrow
            Holder, and IBJ Schroder Bank & Trust Company, as Collateral Agent (incorporated
            by reference to Exhibit 4.4 of the S-4).
  4.6       Escrow Account Security Agreement dated as of October 5, 1995 by and between IXC
            Communications, Inc. and IBJ Schroder Bank & Trust Company (incorporated by
            reference to Exhibit 4.5 of the S-4).
  4.7       Form of 12 1/2% Series A Senior Notes due 2005 (incorporated by reference to
            Exhibit 4.6 of the S-4).
  4.8       Form of 12 1/2% Series B Senior Notes due 2005 and Subsidiary Guarantee
            (incorporated by reference to Exhibit 4.8 of the S-1).
  4.9       Amendment No. 1 to Indenture and Subsidiary Guarantee dated as of June 4, 1996 by
            and among IXC Communications, Inc., the Guarantors and the Trustee (incorporated
            by reference to Exhibit 4.11 of the S-1).
</TABLE>
 
                                        1
<PAGE>   3
 
   
<TABLE>
<CAPTION>
EXHIBIT
NUMBER                                         DESCRIPTION
- ------      ---------------------------------------------------------------------------------
<C>         <S>
 4.10       Stock Exchange Agreement dated as of June 10, 1996 by and between IXC
            Communications, Inc., and Trustees of General Electric Pension Trust ("GEPT")
            (incorporated by reference to Exhibit 4.12 of the S-1).
 4.11       Registration Rights Agreement dated as of June 10, 1996 by and among IXC
            Communications, Inc., GEPT and certain stockholders of IXC Communications, Inc.
            (incorporated by reference to Exhibit 4.13 of the S-1).
 4.12       Purchase Agreement dated as of March 25, 1997 by and among IXC Communications,
            Inc., Credit Suisse First Boston Corporation ("CS First Boston") and Dillon Read
            & Co. Inc. ("Dillon Read") incorporated by reference to Exhibit 4.12 of the
            10-Q).
 4.13       Registration Rights Agreement dated as of March 25, 1997 by and among IXC
            Communications, Inc., CS First Boston and Dillon Read (incorporated by reference
            to Exhibit 4.13 of the 10-Q).
 4.14       Amendment to Registration Rights Agreement dated as of March 25, 1995 between IXC
            Communications, Inc. and GEPT (incorporated by reference to Exhibit 4.14 of the
            10-Q).
 4.15 +     Registration Rights Agreement dated as of July 8, 1997 among IXC Communications,
            Inc. and each of William G. Rodi, Gordon Hutchins, Jr. and William F. Linsmeier.
 4.16 +     Registration Rights Agreement dated as of July 8, 1997 among IXC Communications,
            Inc. and each of William G. Rodi, Gordon Hutchins, Jr. and William F. Linsmeier.
 10.1       Office Lease dated June 21, 1989 with USAA Real Estate Company, as amended
            (incorporated by reference to Exhibit 10.1 of the S-4).
 10.2       Equipment Lease dated as of December 1, 1994 by and between DSC Finance
            Corporation and Switched Services Communications, L.L.C.; Assignment Agreement
            dated as of December 1, 1994 by and between Switched Services Communications,
            L.L.C. and DSC Finance Corporation; and Guaranty dated December 1, 1994 made in
            favor of DSC Finance Corporation by IXC Communications, Inc. (incorporated by
            reference to Exhibit 10.2 of the S-4).
 10.3 +     Amended and Restated 1994 Stock Plan of IXC Communications, Inc., as amended.
 10.4       Form of Non-Qualified Stock Option Agreement under the 1994 Stock Plan of IXC
            Communications, Inc. (incorporated by reference to Exhibit 10.4 of the S-4).
 10.5       Form of IXC Communications, Inc. Restricted Stock Agreement (incorporated by
            reference to Exhibit 10.5 of the S-4).
 10.6       Form of IXC Communications, Inc. Restricted Stock Agreement (incorporated by
            reference to Exhibit 10.6 of the S-4).
 10.7       Amended and Restated Development Agreement by and between Intertech Management
            Group, Inc. and IXC Long Distance, Inc. (incorporated by reference to Exhibit
            10.7 of the S-4).
 10.8       Second Amended and Restated Service Agreement dated as of January 1, 1996 by and
            between Switched Services Communications, L.L.C. and Excel Telecommunications,
            Inc. (incorporated by reference to Exhibit 10.8 of the S-4).
 10.9       Equipment Purchase Agreement dated as of January 16, 1996 by and between Siecor
            Corporation and IXC Carrier, Inc. (incorporated by reference to Exhibit 10.9 of
            the S-4).
10.10       1996 Stock Plan of IXC Communications, Inc., as amended (incorporated by
            reference to Exhibit 10.10 of IXC Communications, Inc. Annual Report on Form 10-K
            for the year ended December 31, 1996 (the "10-K")).
10.11       IRU Agreement dated as of November 1995 between WorldCom, Inc. and IXC Carrier,
            Inc. (incorporated by reference to Exhibit 10.11 of the S-4).
10.12       Outside Directors' Phantom Stock Plan of IXC Communications, Inc., as amended
            (incorporated by reference to Exhibit 10.12 of the 10-K).
</TABLE>
    
 
                                        2
<PAGE>   4
 
   
<TABLE>
<CAPTION>
EXHIBIT
NUMBER                                         DESCRIPTION
- ------      ---------------------------------------------------------------------------------
<C>         <S>
10.13       Business Consultant and Management Agreement dated as of January 3, 1995 by and
            between IXC Communications, Inc. and Culp Communications Associates (incorporated
            by reference to Exhibit 10.13 of the S-1).
10.14       Employment Agreement dated December 28, 1995 by and between IXC Communications,
            Inc. and James F. Guthrie (incorporated by reference to Exhibit 10.14 of the
            S-1).
10.15       Employment Agreement dated August 28, 1995, by and between IXC Communications,
            Inc. and David J. Thomas (incorporated by reference to Exhibit 10.15 of the S-1).
10.16       Special Stock Plan of IXC Communications, Inc. (incorporated by reference to
            Exhibit 10.16 of the 10-K).
10.17 +     Lease dated as of June 4, 1997 between IXC Communications, Inc. and Carramerica
            Realty, L.P.
10.18 +     Loan and Security Agreement dated as of July 18, 1997 among IXC Communications,
            Inc., IXC Carrier, Inc. and NTFC Capital Corporation
10.19 *     IRU and Stock Purchase Agreement dated as of July 22, 1997 between IXC Internet
            Services, Inc. and PSINet Inc.
10.20 *     Joint Marketing and Services Agreement dated on July 22, 1997 between IXC
            Internet Services, Inc. and PSINet Inc.
 11.1 +     Statement of Computation of Earnings per Share.
 27.1 +     Financial Data Schedule.
</TABLE>
    
 
- ---------------
 
+ Previously filed.
 
   
* Filed herewith in redacted form pursuant to a request for confidential
  treatment filed separately with the Commission pursuant to Rule 24b-2.
    
 
(B) REPORTS ON FORM 8-K.
 
(1) Form 8-K dated April 1, 1997 and filed with the Commission on April 3, 1997
    with respect to the Company's notice of offering of unregistered securities
    pursuant to Rule 135c(d) of the Securities Act of 1933, as amended, with
    respect to the sale of Convertible Preferred Stock, which occurred on April
    1, 1997.
 
                                        3
<PAGE>   5
 
                                   SIGNATURE
 
   
     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this Amendment No. 2 to the report to be signed on
its behalf by the undersigned thereunto duly authorized.
    
 
                                          IXC Communications, Inc.,
                                          a Delaware corporation
 
   
December 9, 1997                          By: /s/ JAMES F. GUTHRIE
    
                                            ------------------------------------
                                            James F. Guthrie
                                            Executive Vice President and
                                            Chief Financial Officer
                                            (Duly Authorized Officer and
                                            Principal Financial Officer)
 
                                        4

<PAGE>   1
                                                                   EXHIBIT 10.19

                        IRU AND STOCK PURCHASE AGREEMENT

                                     BETWEEN

                           IXC INTERNET SERVICES, INC.

                                       AND

                                   PSINET INC.





                            DATED AS OF JULY 22, 1997

<PAGE>   2

                        IRU AND STOCK PURCHASE AGREEMENT
                                     BETWEEN
                           IXC INTERNET SERVICES, INC.
                                       AND
                                   PSINET INC.
                            DATED AS OF JULY 22, 1997


<TABLE>
<CAPTION>
                                         TABLE OF CONTENTS
<S>            <C>    <C>                                                                    <C>
SECTION 1.     RIGHTS GRANTED TO PSINet....................................................  1
               1.1    Fiber IRU............................................................  1
               1.2    IRU Capacity.........................................................  1
               1.3    Security Interest....................................................  2
               1.4    Additional Rights After the Closing..................................  2
               1.5    Quiet Enjoyment......................................................  3

SECTION 2.     USE OF BANDWIDTH............................................................  3
               2.1    Permitted Doubling...................................................  3
               2.2    Additional Mileage...................................................  3
               2.3    Additional Routes....................................................  3
               2.4    Term of IRU..........................................................  4

SECTION 3.     CONSIDERATION...............................................................  4
               3.1    Reincorporation......................................................  4
               3.2    Issuance of Shares...................................................  4
               3.3    Adjustments Relating to Stock Splits and Other Events................  4
               3.4    Certificates.........................................................  5
               3.5    Issuance of Additional Shares........................................  5
               3.6    Tax Reporting........................................................  6

SECTION 4.     ORDERING BANDWIDTH..........................................................  6
               4.1    Type of Bandwidth....................................................  6
               4.2    Ordering Bandwidth...................................................  6
               4.3    Bandwidth Delivery...................................................  7
               4.4    Existing Arrangements................................................  7
               4.5    Bandwidth Forecasts..................................................  7
               4.6    Initial Order........................................................  7

SECTION 5.     OTHER SERVICES..............................................................  8
               5.1    Multiplexing.........................................................  8
               5.2    Reconfiguration......................................................  8

SECTION 6.     TERM OF AGREEMENT...........................................................  8
               6.1    Term of the Agreement................................................  8

SECTION 7.     PAYMENT, CPI AND DEFAULT....................................................  8
               7.1    Payment..............................................................  8
               7.2    Late Payment.........................................................  8
               7.3    CPI..................................................................  9
               7.4    Default/Termination..................................................  9

SECTION 8.     SYSTEM MAINTENANCE AND POPs................................................. 10
               8.1    Maintenance.......................................................... 10
               8.2    Repair or Replacement................................................ 10
               8.3    Consideration........................................................ 10
               8.4    POPs................................................................. 11
               8.5    Other Party's Equipment.............................................. 11
</TABLE>


                                              i

<PAGE>   3


<TABLE>

<S>            <C>    <C>                                                                    <C>
SECTION 9.     INDEMNIFICATION............................................................. 11
               9.1    Indemnification Obligations.......................................... 11
               9.2    Notice of Indemnification............................................ 12
               9.3    Defense Obligations.................................................. 12

SECTION 10.    ADMINISTRATION OF AGREEMENT................................................. 13
               10.1   Representatives...................................................... 13
               10.2   Responsibilities..................................................... 13
               10.3   Form of Actions...................................................... 13
               10.4   Fees and Expenses.................................................... 13

SECTION 11.    FORCE MAJEURE............................................................... 13

SECTION 12.    LIMITATION OF LIABILITY; INDEMNIFICATION.................................... 14
               12.1   Limitation of Liability.............................................. 14
               12.2   Release; Indemnification............................................. 14

SECTION 13.    REPRESENTATIONS AND WARRANTIES OF PSINet.................................... 14
               13.1   Organization......................................................... 14
               13.2   Authorization........................................................ 14
               13.3   Shares............................................................... 15
               13.4   Capitalization....................................................... 15
               13.5   PSINet Filings; No Material Adverse Change........................... 15
               13.6   Effect of Transactions............................................... 15
               13.7   Litigation........................................................... 16
               13.8   Brokers.............................................................. 16
               13.9   No Other Agreements To Sell.......................................... 16
               13.10  Full Disclosure...................................................... 16

SECTION 14.    REPRESENTATIONS AND WARRANTIES OF IXC....................................... 16
               14.1   Organization......................................................... 16
               14.2   Authorization........................................................ 17
               14.3   Effect of Transactions............................................... 17
               14.4   Litigation........................................................... 17
               14.5   Brokers.............................................................. 17
               14.6   Investment Representations........................................... 17
               14.7   Disclosure; No Material Adverse Change............................... 18
               14.8   IRUs................................................................. 19
               14.9   Available System..................................................... 19
               14.10Stock Ownership 19

SECTION 15.    COVENANTS................................................................... 19
               15.1   Hart-Scott-Rodino.................................................... 19
               15.2   Consents............................................................. 19
               15.3   Other Actions........................................................ 20
               15.4   Board Seat........................................................... 20
               15.5   Restriction on Resale................................................ 20
               15.6   No Solicitation...................................................... 21
               15.7   Transfer Matters..................................................... 21
               15.8   Standstill Agreement................................................. 22
               15.9   Registration Rights Agreement........................................ 23
               15.10  Non-Interference..................................................... 23
               15.11  Use of Marks......................................................... 23

SECTION 16.    CONDITIONS PRECEDENT TO CLOSING............................................. 24
               16.1   Approvals............................................................ 24
               16.2   Reincorporation...................................................... 24
               16.3   Shareholder Approval................................................. 24
               16.4   Appraisal Rights..................................................... 24
               16.5   Fairness Opinions.................................................... 24
               16.6   Consent of Bondholders............................................... 24
               16.7   Contribution Agreement............................................... 25

</TABLE>


                                              ii

<PAGE>   4


<TABLE>

<S>            <C>    <C>                                                                    <C>
               16.8   Material Adverse Effect.............................................. 25
               16.9   Acquisition of PSINet................................................ 25
               16.10  Preferred Stock Purchase Plan Amendment.............................. 25

SECTION 17.    THE CLOSING................................................................. 25
               17.1   Deliveries by PSINet................................................. 26
               17.2   Deliveries by IXC.................................................... 26
               17.3   Survival of Representations and Warranties........................... 26

SECTION 18.    TERMINATION................................................................. 26
               18.1   Termination.......................................................... 26
               18.2   Effect of Termination................................................ 27

SECTION 19.    GENERAL PROVISIONS.......................................................... 27
               19.1   Definitions.......................................................... 27
               19.2   Amendments, Waivers and Consents..................................... 32
               19.3   Section Headings..................................................... 32
               19.4   Counterparts......................................................... 32
               19.5   Notices.............................................................. 32
               19.6   Binding Effect; Assignment........................................... 33
               19.7   Severability; Specific Performance................................... 34
               19.8   Expenses............................................................. 34
               19.9   Integration.......................................................... 34
               19.10  Schedules............................................................ 35
               19.11  Public Announcements................................................. 35
               19.12  Interpretation....................................................... 35
               19.13  Governing Law........................................................ 35
               19.14  Dispute Resolution................................................... 35
               19.16  Laws and Licenses.................................................... 36
               19.17  Facsimile Delivery................................................... 36

</TABLE>


                                             iii

<PAGE>   5

                        IRU AND STOCK PURCHASE AGREEMENT


        IRU AND STOCK PURCHASE AGREEMENT made as of this 22nd day of July, 1997
by and between PSINet Inc., a New York corporation ("PSINet"), and IXC Internet
Services, Inc., a Delaware corporation ("IXC").

        WHEREAS, IXC and its Affiliates have constructed or are planning to
construct a fiber optic telecommunications system. Pursuant to a Contribution
Agreement to be dated prior to the Closing Date between IXC Carrier, Inc.
("Carrier") and IXC, IXC will acquire a non-cancellable, indefeasible right of
use ("IRU") in two fibers and in certain capacity in that system (such IRU, the
"Base IRU") from Carrier (the "Contribution Agreement").

        WHEREAS, IXC and PSINet have entered into a Joint Marketing and Services
Agreement dated as of the date hereof (the "Internet Services Agreement"),
pursuant to which IXC will acquire from PSINet, and PSINet will deliver to IXC,
Internet services.

        WHEREAS, IXC is willing to grant PSINet a noncancellable indefeasible
right of use in two fibers on the IXC fiber optic telecommunications system to
the extent necessary to secure certain capacity thereon, and a noncancellable
indefeasible right of use in such capacity on such fibers, and PSINet is willing
to exchange therefor shares of its common stock on the terms and subject to the
conditions set forth below.

        WHEREAS, as a condition to the effectiveness of this Agreement, among
other things, PSINet will use reasonable efforts to reincorporate in the State
of Delaware, subject to obtaining all required shareholder consents, by merging
into a Delaware corporation to be formed as a wholly-owned subsidiary of PSINet
which will be named the same name as PSINet upon consummation of such merger
("Newco"; prior to the Closing Date, references in this Agreement to "PSINet"
shall be deemed to refer to PSINet, a New York corporation, and on and after the
Closing Date, references herein to PSINet shall be deemed to refer to Newco).

        NOW, THEREFORE, in consideration of the mutual promises set forth below,
and other good and valuable considerations, the receipt and sufficiency of which
are hereby acknowledged, the parties, intending to be legally bound, hereby
agree as follows:


SECTION 1.     RIGHTS GRANTED TO PSINET

        1.1 Fiber IRU. At the Closing, IXC, as the owner of the Base IRU, shall
grant to PSINet a noncancellable IRU in two fibers in the portion of the
Available System completed at the Closing (the "IXC Fibers") to the extent
necessary to carry one OC-48 (the "PSINet Fiber IRU"). At or prior to the
Closing, IXC shall specify the fibers in the applicable routes in which such IRU
is granted. Except as set forth in the Collocation Agreement and Section 7.4(b)
below, at no time shall PSINet be entitled to have physical access to the IXC
Fibers. IXC agrees that it has no right to use the portion of the IXC Fibers
comprising the PSINet Fiber IRU during the Term (as defined).

        1.2 IRU Capacity. At the Closing, IXC shall grant to PSINet a
noncancellable IRU in the IRU Capacity. As used herein, the "IRU Capacity" shall
mean the use of capacity as permitted by this Agreement on that portion of the
IXC fiber optic telecommunications system as described in Exhibit A hereto (such
portion of such system, together with additional portions made Available by IXC
to PSINet after the date hereof, is referred to as the "Available System"). The
total amount of the IRU Capacity will be 10,000 OC-48 Equivalent Miles.
Notwithstanding anything in this Agreement to the contrary, IXC will have no
obligation under this Agreement or otherwise to extend the Available System
except as set forth in Exhibit A, into new geographic areas or to complete a



<PAGE>   6

total 10,000 Route Miles on the Available System. IXC agrees that it has no
right to use the IRU Capacity during the Term.

        1.3 Security Interest. At the Closing, IXC shall grant, assign and
transfer to PSINet a continuing, first priority, perfected and exclusive
security interest in and to all of IXC' right, title and interest in and to the
following, whether now existing or hereafter coming into existence
(collectively, the "Collateral"): (a) a portion of the Base IRU in the IXC
Fibers granted to IXC by Carrier, such portion (the "Long-Term Indivisible IRU")
being an IRU in the IXC Fibers for the purpose of the transmission of OC-48
capacity pursuant to IXC' grant of the PSINet Fiber IRU to PSINet, which
security interest shall secure IXC' obligation to provide the PSINet Fiber IRU
pursuant to Section 1.1; (b) a portion (separate from the Long-Term Indivisible
IRU) of the Base IRU in the IXC Fibers granted to IXC by Carrier, such portion
(the "Short-Term Indivisible IRU") being an IRU in the IXC Fibers which supports
OC-48 capacity and (c) the Access Right (as defined). The Short-Term Indivisible
IRU shall be a right of use of fiber only and shall not include any rights in
electronics or optronics. The security interest in the Short-Term Indivisible
IRU shall secure IXC' obligations to provide the PSINet Fiber IRU over 10,000
OC-48 Equivalent Miles. At the Closing, IXC and PSINet shall enter into a
security agreement in substantially the form attached hereto as Exhibit B (the
"Security Agreement") and such UCC statements and other instruments reasonably
necessary to grant, perfect and maintain the security interests contemplated by
this Agreement.

        1.4 Additional Rights After the Closing. After the Closing, in the event
IXC completes additional portions of the Available System, (a) IXC hereby
grants, without further action on its part, rights to PSINet so that each of the
PSINet Fiber IRU and the Base IRU in the IXC Fibers is extended to cover such
completed portions of the Available System (but only up to a total of 10,000
Route Miles) effective immediately upon completion of each portion, and (b) IXC
hereby grants, without further action on its part, and will execute the
necessary documents to evidence such grant of, additional security interests so
that PSINet has a continuing, first priority, perfected and exclusive security
interest in (i) the Long- Term Indivisible IRU (with such defined phrase being
extended to cover such completed portions of the Available System) and the
products and proceeds thereof, and (ii) the Short-Term Indivisible IRU (with
such defined phrase being extended to cover such completed portion of the
Available System) and the products and proceeds thereof, and the Long-Term
Indivisible IRU and the Short-Term Indivisible IRU, as so extended, will
thereupon become part of the Collateral. Notwithstanding the foregoing, however,
commencing in respect of any completed portion of the Available System, after
the date on which such completed portion of the Available System shall have been
completed, the length of the Short-Term Indivisible IRU shall not exceed the
excess, if any, of 10,000 Route Miles over the number of completed Route Miles
on the Available System Accepted by PSINet. To the extent completion of
additional portions of the Available System requires shortening the length of
the Short-Term Indivisible IRU (which is subject to the security interest
pursuant to the preceding sentence) by a certain number of Route Miles (the
"Reduction Miles"), the Short-Term Indivisible IRU shall be deemed to be
shortened 30 days after the date on which such completed portion of the
Available System shall have been completed, by changing its definition to
exclude a number of Route Miles equal to the number of Reduction Miles. The
specific Route Miles excluded shall be determined by excluding that number of
Route Miles of the Available System most recently completed beginning with the
eastern most portion along the applicable route, all as set forth in a written
notice from IXC to PSINet pursuant to the Security Agreement. The security
interest in the Short-Term Indefeasible IRU shall terminate upon the first to
occur of the following: (i) IXC's making Available and PSINet's Acceptance of
all of the IRU Capacity, and granting an IRU therein, to PSINet on the terms and
subject to the conditions of this Agreement, and (ii) the written consent of the
parties.



                                        2

<PAGE>   7

        1.5 Quiet Enjoyment. IXC covenants that, at the Closing, it will have
the full right and authority to grant to PSINet the PSINet Fiber IRU and
capacity IRUs hereunder. IXC shall assure that Carrier has obtained or will
obtain all Rights-of-Way necessary for the installation and use of the IXC
Fibers comprising the PSINet Fiber IRU and the fibers underlying the capacity
IRUs granted hereunder, and cause such Rights-of-Way to remain in effect or be
adequately replaced during the Term. IXC shall be responsible for, and timely
pay, any and all (i) taxes and franchises, license and permit fees
(collectively, "Taxes") imposed because of the physical location of the IXC
Fibers and the fibers underlying the IRU Capacity and (ii) Rights-of-Way
payments on the IXC Fibers and the fibers underlying the IRU Capacity. Failure
to pay such taxes or payments shall authorize, but not obligate, PSINet to make
such payments, and IXC will immediately reimburse PSINet for any amounts paid.
PSINet will reimburse IXC for (or at IXC's option, pay directly to the proper
authority) any Taxes based on the revenues or capacity usage of PSINet. IXC and
PSINet will each notify the other party of the assertion of any Taxes which
could reasonably be the responsibility of the other party and, as reasonably
requested by the other party, will cooperate with each other to contest any such
Taxes with the proper authorities.


SECTION 2.     USE OF BANDWIDTH

        2.1 Permitted Doubling. IXC shall make Available, but not be obligated
to make Available more than, a single OC-48 Equivalent on any part of the
Available System, provided, however, that to the extent the length of the
Available System is less than 10,000 Route Miles, IXC will make Available to
PSINet, at PSINet's option, up to two OC-48 Equivalents on a portion of the
Available System selected by PSINet that is equal in length to the Shortfall
Mileage. For example, if the length of the Available System is 8,000 route
miles, PSINet would be allowed to have up to two OC-48 Equivalents on up to
2,000 miles and no more than one OC-48 Equivalent on the then remaining 6,000
miles. In the event IXC completes portions of the Available System and, as a
consequence the Shortfall Mileage is reduced, IXC, upon six months' notice to
PSINet, shall have the right to require PSINet to reconfigure Bandwidth so that
the length of the portion of the Available System where PSINet has capacity in
excess of one OC-48 does not exceed the then current Shortfall Mileage. After
IXC' completion of 10,000 miles of the Available System, PSINet will be limited
to a maximum of one OC-48 Equivalent on any particular portion of the Available
System.

        2.2 Additional Mileage. Subject to the overall IRU Capacity limitation
set forth herein, PSINet, at its option, may order Bandwidth on portions of the
Available System in excess of 10,000 Route Miles (the "Excess Miles") provided
that: (a) the aggregate Route Mileage covered by Bandwidth Units, regardless of
the level or type of Bandwidth which is then being provided by IXC to PSINet
thereon, does not exceed 15,000 Route Miles; (b) pursuant to the Collocation
Agreement in the form attached hereto as Exhibit C, PSINet will pay the market
rate for cabinet space used in connection with the Excess Miles; and (c) PSINet
will pay IXC' fees for add/drop, multiplexing and reconfiguration on the Excess
Miles, as set forth herein. To the extent PSINet orders Bandwidth on Excess
Miles, the parties will in good faith attempt to negotiate and effect
adjustments in PSINet's rights in the PSINet Fiber IRU and in the security
interest in the Long-Term Indefeasible IRU, with such rights to be expanded to
cover such Bandwidth in the Excess Miles and to be reduced so as not to cover
PSINet's usage of Bandwidth to the extent less than an OC-48 on any portion of
the original 10,000 Route Miles of the Available System.

        2.3 Additional Routes. Notwithstanding anything herein to the contrary,
in the event IXC or any of its Affiliates adds or acquires an additional route
to its system in the United States during the Reconfiguration Period, (a) the
route will be deemed to be a part of the Available System if: (i) IXC or any of
its Affiliates has at least 18 fibers in such route, net of the number of fibers
in which IXC or any of its Affiliates shall have granted IRU's to nonaffiliated



                                        3

<PAGE>   8


third parties pursuant to cost-saving or joint build arrangements in connection
with the construction of such route (the "Net Fiber Number"), or (ii) IXC gives
notice to PSINet that IXC has elected to include such route as a part of the
Available System even though the Net Fiber Number in the route is less than 18;
and (b)(i) if the Net Fiber Number in the route is less than 18 but more than
11, IXC shall not be obligated to provide more than two OC-12's to PSINet on the
route; (ii) if the Net Fiber Number in the route is less than 12 but greater
than 3, IXC will not be obligated to provide PSINet with more than one OC-3 (or
at IXC's option, three DS-3's) to PSINet on the route, which OC-3 or DS-3s are
subject to availability (that is, IXC may, at its option, not deliver such OC-3
or DS-3s if needed for IXC's business or if the applicable fibers have not been
lit); and (iii) if the Net Fiber Number in the route is 3 or less, then IXC will
not be obligated to provide PSINet with any capacity on the route. In the event
IXC provides PSINet with an OC-3 pursuant to subsection b(ii) of the preceding
sentence, no multiplexing charge will apply to such OC-3.

        2.4 Term of IRU. The term of each Bandwidth Unit of the IRU Capacity
will end on the earlier of: (a) 20 years from the Original Service Activation
Date of the Bandwidth Unit, or (b) 24 years from the Closing Date; provided,
however, that the term of each Bandwidth Unit will be extended by (i) the length
of time, if any, that such Bandwidth Unit commences after the fourth anniversary
of the Closing Date, but only to the extent such delay is attributable to the
completion of the applicable portion of the Available System occurring after
such date, and (ii) the length of time performance by IXC is excused pursuant to
Section 11, below, in the event such performance shall have been so excused for
any period of at least 12 consecutive months.


SECTION 3.     CONSIDERATION

        3.1 Reincorporation. Prior to the Closing Date, PSINet will use
reasonable efforts to reincorporate in the State of Delaware by merging into
Newco, subject to PSINet obtaining all required shareholder and third-party
approvals and consents therefor.

        3.2 Issuance of Shares. In consideration of the execution and delivery
of this Agreement, the grant of the IRUs hereunder by IXC to PSINet and IXC's
other obligations to PSINet hereunder, subject to Section 3.3 below, PSINet (as
merged into Newco) agrees to issue and deliver to IXC at the Closing, 10,155,536
shares of Common Stock of Newco, par value $.0001 per share (such shares, as
adjusted for post-issuance stock splits, stock dividends, recapitalization or
similar events, the "IXC Initial Common Shares"), and at the Additional Shares
Determination Date (as defined) or no later than 30 days after the Additional
Shares Acceleration Date (as defined), certain additional shares of Newco Common
Stock (such shares, as adjusted for post-issuance stock splits, stock dividends,
recapitalization or similar events, the "Additional Shares" and, collectively
with the IXC Initial Common Shares, the "IXC Shares") and/or cash, other
securities or property, if any, as may be issued and delivered as set forth in
Section 3.5. The IXC Shares shall be issued and delivered by PSINet to IXC,
together with corresponding rights under PSINet's preferred stock purchase
rights plan, as amended, modified or supplemented (the "preferred stock purchase
rights plan") as those held by other holders of Common Stock (subject to the
terms of such plan), free and clear of any and all claims, liens, pledges,
options, charges, security interests, restrictions, encumbrances or other rights
of third parties other than (a) the rights created in favor of PSINet pursuant
to this Agreement, and (b) restrictions on transferability generally imposed on
securities under federal or state securities laws.

        3.3 Adjustments Relating to Stock Splits and Other Events. It is the
intent of the parties that the number of the IXC Initial Common Shares to be
issued by Newco to IXC hereunder shall, at the Closing Date, be equal to
19.99999% of the outstanding shares of Common Stock of Newco, as determined in



                                        4

<PAGE>   9

the manner set forth on Exhibit D hereto. If after the date hereof and before
the Closing Date, the number of outstanding shares of Newco Common Stock (as
determined in the same manner set forth on Exhibit D hereto) shall have changed
or if such shares shall have been changed into or exchanged for a different
number or kind of shares or other securities through any issuance,
reorganization, recapitalization, reclassification, merger, consolidation, share
exchange or similar transaction, then a proportionate adjustment in the number
and an appropriate adjustment in the kind of securities issuable hereunder shall
be made.

        3.4 Certificates. At the Closing, PSINet agrees to deliver to IXC
certificates issued in IXC's name for all of the IXC Initial Common Shares.

        3.5    Issuance of Additional Shares.

               (a) Subject to Section 15.7(c) and the last sentence of this
Section 3.5(a), on the earlier of (i) the first anniversary of the date on which
the Total Bandwidth has been Accepted and/or Deemed Accepted by PSINet or (ii)
the fourth anniversary of the Closing, (such earlier date, the "Additional
Shares Determination Date"), IXC shall be entitled to receive such number of
Additional Shares, based on the Common Stock Price determined as of the
Additional Shares Determination Date, or, at the sole discretion of PSINet, such
amount of cash, or any combination of Additional Shares and cash, as shall have
an Aggregate Fair Market Value equal to the Additional Shares Value as of the
Additional Shares Determination Date; provided, however, that PSINet shall be
entitled, at its sole option, to accelerate IXC's right to receive Additional
Shares and/or cash pursuant to this Section 3.5(a) at any time after the Closing
Date to a date prior to the Additional Shares Determination Date pursuant to a
notice to such effect given by PSINet to IXC in accordance with the terms of
Section 19.5 of this Agreement (the "Additional Shares Acceleration Date") by
delivering to IXC not later than 30 days after the Additional Shares
Acceleration Date, such number of Additional Shares, based on the Common Stock
Price determined as of the Additional Shares Acceleration Date, or, at the sole
discretion of PSINet, such amount of cash, or any combination of Additional
Shares and cash, as shall have an Aggregate Fair Market Value equal to the
Additional Shares Value as of the Additional Shares Acceleration Date.
Notwithstanding the foregoing, (i) the right of IXC to receive any Additional
Shares and/or cash pursuant to this Section 3.5 shall terminate and be of no
further force or effect on such date as the calculation of the IXC Common Shares
Value would result in a value equal to or greater than $240,000,000 and (ii) the
obligations of IXC under this Agreement shall not be altered, diminished,
modified or impaired by any delivery or payment of Additional Shares and/or cash
pursuant to this Section 3.5.

 (b) If at any time or from time to time prior to the Additional Shares
Determination Date, there shall occur a Merger or Other Reorganization Event,
then, as a part of and as a condition to the effectiveness of such Merger or
Other Reorganization Event, lawful and adequate provision shall be made so that
IXC shall thereafter be entitled to receive pursuant to Section 3.5(a) in lieu
of any Additional Shares IXC may be entitled to receive under Section 3.5(a),
the number of shares of Successor Stock or other securities or property, if any,
of PSINet or of the successor Person resulting from such Merger or Other
Reorganization Event to which a holder of such number of shares of Common Stock
as is equal to the number of Additional Shares that would otherwise be
deliverable pursuant to Section 3.5(a) would have been entitled to receive in
connection with such Merger or Other Reorganization Event. In any such case,
appropriate provisions shall be made with respect to the rights of IXC under
this Section 3.5 in connection with the Merger or Other Reorganization Event to
the end that the provisions of this Section 3.5 shall thereafter be applicable,
as nearly as may be, with respect to any shares of Successor Stock, securities
or property that may be deliverable thereafter upon the Additional Shares
Determination Date or the Additional Shares Acceleration Date, as applicable.



                                        5

<PAGE>   10

        3.6 Tax Reporting. The parties acknowledge that PSINet's issuance of IXC
Shares under this Agreement will be a taxable payment for income tax purposes
and not part of a tax-free acquisition for income tax purposes and not part of a
tax-free reorganization, tax-free incorporation or other tax-free transaction
for income tax purposes, and that PSINet's tax acquisition cost and IXC's gross
receipts for federal income tax purposes with respect to PSINet's payments under
this Agreement will be equal to the value of the IXC Shares upon issuance,
together with the cash or other payments, if any, under Section 3.5. The parties
shall report such issuance of IXC Shares and such cash or other payments, if
any, consistent with the prior sentence in connection with the determination of
their income, franchise or other taxes measured by net income.


SECTION 4.     ORDERING BANDWIDTH

        4.1 Type of Bandwidth. Subject to the terms and conditions of this
Agreement, PSINet may order Bandwidth in increments from OC-12 to OC-48 along
any portion of the Available System. PSINet may order DS-3's or OC-3's on the
Available System or DS-3's on Barter Capacity (in either case, subject to the
capacity limitations set forth herein), but shall be obligated to pay the
multiplexing fees set forth herein (except on the Barter Capacity). IXC will use
good faith efforts to provision DS-3's on the Barter Capacity subject to
availability and subject to IXC's use for its own network requirements.
Furthermore, IXC will cause IXC Carrier to provide off-net capacity such as
DS-1's and greater, pursuant to the Digital Service Agreement dated as of
December 23, 1994, as amended, between IXC Carrier and PSINet, as the exhibits
thereto shall be revised by IXC Carrier from time to time, on the same payment
terms and subject to the same material conditions by which IXC acquires such
capacity (including the cost thereof, including, without limitation, third party
cross-connect fees, if any) plus an administrative fee (payable once per
circuit) in the amount of * per circuit. PSINet, at its option and subject to
availability, may order other associated services as and at such rates as set
forth on Exhibit E hereto. The rates for such associated services are subject to
change by IXC upon 30 days' notice.

        4.2 Ordering Bandwidth. If ordered by PSINet, IXC will make Available to
PSINet at least 10,000 OC-12 Equivalent Miles in each Six-Month Period. To order
Bandwidth on the Available System, PSINet shall submit a completed, dated and
signed Bandwidth Order to IXC. IXC will then accept or reject the Bandwidth
Order within 45 days following the date of the Bandwidth Order by returning the
countersigned Bandwidth Order to PSINet or setting forth the reason for the
rejection on the returned Bandwidth Order. In accepting a Bandwidth Order, IXC
may change the Requested Delivery Date as reasonably necessary to ensure timely
delivery. PSINet shall specify a Requested Delivery Date in each Bandwidth
Order. The sole reasons for rejection of a Bandwidth Order (other than for
Barter Capacity, which is subject to the conditions set forth above) are (i) the
Bandwidth Order pertains to a portion of the Available System that has not yet
been completed, (ii) IXC shall have provided PSINet with 10,000 OC-12 Equivalent
Miles during the applicable Six-Month Period, (iii) IXC shall have provided
PSINet with 10,000 OC-48 Equivalent Miles in the aggregate, or (iv) PSINet shall
have been determined to be in default of a Material Provision pursuant to
arbitration proceedings conducted under Section 19.14(b) and such default
remains uncured. In the event PSINet orders less than 10,000 OC-12 Equivalent
Miles over the Available System during any Six-Month Period, IXC, at its option,
can require that PSINet order Primary Additional Bandwidth (as defined), as
Available, so


- --------

     *  Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                                        6

<PAGE>   11



that up to a total of 10,000 OC-12 Equivalent Miles are ordered during the
Six-Month Period.

"Primary Additional Bandwidth" shall mean the Bandwidth, if any, Available to
PSINet on a Major Route (as defined), which, together with the Bandwidth, if
any, already being used on the route by PSINet, adds up to one OC-48 Equivalent.
* shall mean any route between two metropolitan statistical areas with
populations of at least *. On or before the date 41 months after the Closing,
IXC shall give notice to PSINet of which portions of the Available System will
be Available by the date four years after the Closing and PSINet shall order, on
or before the date 42 months after the Closing, and IXC shall make Available,
Bandwidth so that, at the fourth anniversary of the Closing, PSINet's total
capacity (as measured in OC-48 Equivalent Miles) in use hereunder will be at
least equal to the smaller of: (i) twice the total length of the Available
System at that date or (ii) 10,000.

        4.3 Bandwidth Delivery. IXC will use commercially reasonable efforts to
make the requested Bandwidth Available to PSINet by the Requested Delivery Date.
Within five business days of the date on which Bandwidth is made Available to
PSINet, PSINet shall test it in accordance with the standards set forth in
Exhibit F hereto. In the event IXC fails to make the requested Bandwidth
Available to PSINet by the Requested Delivery Date, other than by reason of (i)
a force majeure event provided in Section 11, below, or (ii) the affected
portion of the Available System having not yet been completed, then, in any
other event, IXC shall pay PSINet, within 30 days after invoice by PSINet, an
amount equal to (a) * IXC will notify PSINet as quickly as reasonably
practicable upon learning of any circumstances that will cause a delay in
delivery of capacity beyond the Requested Delivery Date. In the event of a late
delivery, IXC will use commercially reasonable efforts to assist PSINet in
obtaining temporary replacement capacity.

        4.4 Existing Arrangements. As soon as practicable after the Closing
Date, but in no event later than 30 days thereafter, IXC shall, and shall cause
its Affiliates to, deliver any On-net or Barter Capacity bandwidth leased by
PSINet from IXC or any Affiliate immediately prior to Closing, collocation in
the POP's and related cross-connects (but only those cross-connects within the
Available System) and interconnect facilities with IXC existing at the Closing,
to be transferred to and covered by this Agreement. Bandwidth on order at the
Closing Date will also be covered by this Agreement, including, without
limitation this Section 4.4. Furthermore, with respect to off-net bandwidth
leased or on order prior to the Closing, IXC will use commercially reasonable
best efforts to provide such bandwidth On-net if and when the Available System
covers the applicable routes of such off-net bandwidth. This transfer will be
without penalty and without credit for prior payments, so that all payments for
such bandwidth and facilities for the period commencing on the Closing Date will
cease as of such transfer, provided, however, that maintenance fees as set forth
in Section 8.3 will apply to such bandwidth. Multiplexing charges as set forth
herein will not apply to any bandwidth so transferred unless and until PSINet
reconfigures such bandwidth concurrently with such transfer or, with respect to
a particular route, PSINet orders OC-12 capacity on such route.

        4.5 Bandwidth Forecasts. Attached as Exhibit G hereto is PSINet's good
faith, non-binding three-year forecast of the anticipated amount of Bandwidth
that will be required by PSINet under this Agreement, which good faith,
non-binding forecast shall be updated by PSINet quarterly and delivered to IXC
by no later than the 20th day following the end of each calendar quarter.

- --------

     *  Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                                        7

<PAGE>   12

        4.6 Initial Order. Effective upon the Closing, IXC accepts the Bandwidth
Orders attached hereto as Exhibit G-1 as PSINet's initial Bandwidth Orders for
the Requested Delivery dates specified therein.


SECTION 5.     OTHER SERVICES

        5.1 Multiplexing. In the event PSINet requires capacity in units other
than OC-48 or OC-12 (for example, an OC-3 or DS-3) it will pay IXC's fees for
multiplexing as set forth in Exhibit H hereto (except as set forth in the last
sentence of Section 2.3). PSINet will also pay IXC's fees for multiplexing for
Barter Capacity DS-3's. IXC may change its fees for multiplexing at any time in
its sole and absolute discretion; provided, however, that such changed fees will
only be effective against PSINet on the tenth business day after PSINet's
receipt of written notice from IXC of such changed fees.

        5.2 Reconfiguration. During the first four years of this Agreement (or
until one year after the Delivery Completion Date, whichever comes first),
PSINet can Reconfigure Bandwidth. PSINet will pay IXC's fee for reconfiguration
as set forth on Exhibit I hereto, which shall include a fee for reconfiguring
from OC-12 to OC-48 or for moving an OC-48. IXC may change its fees for
reconfiguration at any time in its sole and absolute discretion; provided,
however, that such changed fees will only be effective against PSINet on the
tenth business day after PSINet's receipt of written notice from IXC of such
changed fees. In the event of a reconfiguration that leaves OC-12 equipment (for
which PSINet has previously paid a multiplexing or reconfiguration charge) which
is not being utilized, IXC will either (i) utilize the equipment elsewhere for
PSINet's capacity (without charging a multiplexing fee for such OC-12), (ii)
deliver the OC-12 equipment to PSINet, or (iii) purchase the equipment from
PSINet at a mutually agreeable price.


SECTION 6.     TERM OF AGREEMENT

        6.1 Term of the Agreement. This Agreement shall commence on the Closing
Date and shall automatically terminate upon the termination of the
last-to-expire term of the Bandwidth delivered hereunder (the "Term").


SECTION 7.     PAYMENT, CPI AND DEFAULT

        7.1 Payment. PSINet agrees to pay IXC in advance, as billed by IXC, each
month during the Term, all fees and other charges payable hereunder for such
month, for maintenance, off-net capacity, multiplexing and add/drops. PSINet
agrees to pay IXC in arrears, as billed by IXC, each month all fees and other
charges payable hereunder for such months for other services, including for
reconfiguration.

        7.2 Late Payment. IXC invoices for amounts payable hereunder shall be
due within 30 days of the date of invoice. If a dispute arises as to any portion
of an invoice, PSINet shall pay the undisputed amount of such invoice when due
and shall notify IXC in writing of the disputed amount no later than 30 days
from the date of invoice. The IXC Authorized Representative and the PSINet
Authorized Representative will first attempt in good faith to promptly resolve
the dispute. If the matter has not been resolved by the IXC Authorized
Representative and the PSINet Authorized Representative within 14 days after
PSINet' notice, or if either party will not agree to meet within such 14-day
period, the matter will be referred to the Chief Executive Officer of IXC and
the Chief Executive Officer of PSINet, who will attempt in good faith to
promptly resolve the dispute. If the dispute has not been resolved by the Chief
Executive Officer of IXC and the Chief Executive Officer of PSINet within an
additional 14-day period, or if either party will not agree to meet within such
14-day period, then the dispute shall



                                        8

<PAGE>   13

be submitted to arbitration pursuant to Section 19.14. In any such arbitration,
the prevailing party shall be awarded such party's costs and expenses incurred
in bringing such action.

        In the event that any payment remains unpaid after its due date, such
payment shall be subject to an interest charge equal to the lesser of one and
one-half percent of the unpaid balance per month or the maximum rate allowed
under applicable state law and, if a payment shall not have been paid in full
within five business days of the applicable due date when no bona fide dispute
exists, IXC may, without any liability to PSINet, at its option, suspend the
provision of maintenance and other services hereunder until such payment is made
in full. Notwithstanding anything herein to the contrary, in no event shall IXC
have the right to terminate, modify or otherwise affect its grant to PSINet of,
or PSINet's right, title and interest in, the IRU Capacity and the PSINet Fiber
IRU.

        7.3 CPI. In addition to any other adjustment permitted or contemplated
herein, IXC has the right to make adjustments to the fees and charges hereunder
on each anniversary of the expiration of the Closing Date (the "Adjustment
Date") by multiplying the applicable fee or charge for the immediately preceding
twelve (12) month period (the "Prior Period") by a factor equal to one (1) plus
or minus the decimal equivalent of the total percentage change, if any, in the
U.S. Department of Labor Price Index for Urban Consumers, All Items, 1982-84 =
100 for the period from three (3) months prior to the commencement of such Prior
Period to three (3) months prior to the Adjustment Date. IXC shall deliver to
PSINet prior to each Adjustment Date notice of the adjustment in the applicable
fee or charge, setting forth the calculation of such adjustment.

        7.4    Default/Termination.

               (a) A party may deliver to the other party a written "Notice of
Default" for: (i) failing to make any payment owed hereunder, when no bona fide
dispute exists (a "Monetary Default"); or (ii) the breaching by either party or
its agents, assigns or affiliates of any Material Provision; or (iii) the filing
or initiating of proceedings by or against a party seeking liquidation,
reorganization or other such relief under any federal or state bankruptcy or
insolvency law (a "Bankruptcy Proceeding"). Such Notice of Default must
prominently contain the following sentences in capital letters: "THIS IS A
FORMAL NOTICE OF A BREACH OF CONTRACT. FAILURE TO CURE SUCH BREACH WILL HAVE
SIGNIFICANT LEGAL CONSEQUENCES." A party that has received a Notice of Default
shall have five (5) business days to cure a Monetary Default, thirty (30) days
to cure the alleged breach of any other Material Provision (other than Section
15.8(a) or the Standstill Agreement, which shall be required to be cured upon
demand by PSINet, provided, however, that IXC Communications, Inc. and/or IXC
shall have five (5) business days to cure a nonintentional breach of clause (vi)
of Section 15.8(a) or clause (vi) of Section 2 of the Standstill Agreement) and,
if the defaulting party shall have commenced actions in good faith to cure such
defaults which are not susceptible of being cured during such 30-day period,
such period shall be extended (but not in excess of 90 additional days) while
such party continues such actions to cure, and shall be given ninety (90) days
to remove, have dismissed or stay any involuntary Bankruptcy Proceeding (each
such cure period, a "Cure Period"). If such party fails to cure the breach
within the applicable Cure Period or, in the case of Section 15.8(a) (other than
clause (vi) thereof) or the Standstill Agreement (other than clause (vi) of
Section 2 thereof), upon demand by PSINet, as long as such default shall be
continuing, the non-defaulting party shall have the right to either (a) suspend
its performance or payment obligations under this Agreement and/or any of the
Transaction Documents (other than obligations under Section 15.8(a) and the
Standstill Agreement), (b) seek an order of specific performance or, in the case
of a breach of Section 15.8(a) or the Standstill Agreement, specific
performance, injunctive relief or other equitable remedy, and/or (c) seek the
award of compensatory damages. Notwithstanding anything herein to the contrary,
in no event, shall IXC have the



                                        9

<PAGE>   14

right to terminate, modify or otherwise affect its grant to PSINet of, or
PSINet's right, title and interest in, the IRU Capacity and the PSINet Fiber
IRU, provided, however, that, during the continuance of any breach (as
determined by an arbitration pursuant to Section 19.14) by PSINet of a Material
Provision, IXC shall have the rights set forth in the preceding sentence with
respect to matters other than those affecting PSINet's right, title or interest
in the IRU capacity or the PSINet Fiber IRU; such IXC rights to include, without
limitation, the right to disconnect PSINet's access, and to suspend performance
of its obligations hereunder to allow PSINet access, to IXC's POPs, the IXC
Fibers, electronics, and optronics (whether by way of direct connection,
interconnection, or other means), and the right to suspend maintenance. In the
event IXC does not allow PSINet access to IXC's POPs as set forth in the
preceding sentence, IXC will allow PSINet, upon reasonable notice, to remove
PSINet's equipment and any equipment leased to PSINet or provided by a third
party to PSINet from the POPs.

               (b) In the event of, and during the continuance of, a breach by
IXC of any Material Provision (subject to the last sentence of this section), so
long as PSINet shall not have been determined pursuant to arbitration
proceedings conducted under Section 19.14(b) to be in breach of a Material
Provision hereunder which remains continuing, PSINet shall be entitled to engage
an Approved Subcontractor to access the Maintainable Equipment (as defined) in
IXC's POPs as reasonably necessary to assure its continued uninterrupted use of
the PSINet Fiber IRU and the IRU in the IRU Capacity granted to PSINet
hereunder. Such access shall be subject to applicable rights-of-way and lessor
rights; provided, however, that in the event PSINet exercises its rights
pursuant to this Section 7.4(b), IXC shall use reasonable efforts to obtain any
necessary third party consents to such access. Such access is referred to as the
"Access Right." PSINet shall use its best efforts to assure that no damage is
caused to IXC's equipment, fibers or systems in connection with such maintenance
and access. IXC shall use its commercially reasonable best efforts to assure
that the applicable rights-of-way and lessors' rights are maintained and
exercised at all times in a manner consistent with PSINet's ability pursuant to
this Section 7.4(b) to access all relevant premises to install and/or maintain
equipment associated with or to be associated with the PSINet Fiber IRU or the
IRU in the IRU Capacity granted to PSINet hereunder. Notwithstanding the
foregoing, however, PSINet shall have no rights under this Section 7.4(b) by
reason of an IXC Bankruptcy Proceeding if IXC is not also at such time in breach
of a Material Provision.


SECTION 8.     SYSTEM MAINTENANCE AND POPS

        8.1 Maintenance. IXC shall provide all maintenance and repair functions
on the Available System as well as on the optical and electronic equipment owned
or leased by IXC used to provide the Bandwidth. IXC agrees it will provide all
maintenance and repair functions in the same manner and with at least the same
degree of care and timeliness utilized by IXC or IXC Communications with respect
to other portions of their telecommunications systems, but at no time shall such
maintenance and repair functions be conducted in a manner which does not equal
or exceed that which is normal and customary in the telecommunications industry.

        8.2 Repair or Replacement. In the event that all or any part of the
Available System or optical or electronic equipment owned by IXC requires
replacement during the term of this Agreement, such replacement shall be on a
timely basis, and at the expense of IXC. This replacement will be scheduled at
IXC's reasonable discretion upon adequate notice to PSINet or at PSINet's
reasonable request.


                                       10

<PAGE>   15



        8.3 Consideration. In consideration of IXC's maintenance obligations
hereunder, PSINet shall pay IXC a monthly fee of * per OC-12 Equivalent Mile per
month (on lower capacity, * per DS-3 Mile per month) for each OC-12 (or its
equivalent) provided by IXC to PSINet hereunder.

        8.4 POPs. PSINet may only interconnect to IXC Fibers to utilize the IRU
Capacity at IXC's POPs. IXC shall provide PSINet with the applicable Bandwidth
only between IXC's POPs and IXC shall provide POP space to PSINet (including,
without limitation, cabinet space for equipment), all as set forth in the
Collocation Agreement. PSINet's right to occupy any POP will expire upon the
earlier of: (i) 20 years after the first date of occupancy in such POP or (ii)
the termination of the last Bandwidth Unit which terminates in such POP. PSINet
shall pay for all costs associated with connecting its system and POPs to IXC's
POPs. IXC will allow PSINet light-to-light and copper-to-copper connections
within IXC's POPs so that PSINet, at its own expense, can make interconnections
to its own POPs. Notwithstanding the foregoing, if necessary, and where
applicable, IXC shall use commercially reasonable efforts to provide PSINet, at
PSINet's expense, access to existing building entrance facilities, if available,
to access and exit IXC POPs. PSINet will pay IXC time and material agreed upon
on a case by case basis for: (a) equipment installation and tech-assists and (b)
for build-outs for power, cabling and HVAC for PSINet's needs in excess of *
cabinet spaces in the applicable POP. Interconnect facilities to interconnect to
other parties within IXC's POPs shall be installed and maintained under the
terms and conditions that are specified in the Collocation Agreement.

        8.5 Other Party's Equipment. IXC shall be required to exercise
reasonable care with respect to any equipment located in any of IXC's POPs or
any portion or component thereof. IXC shall promptly notify PSINet of any
matters pertaining to damage or impending damage, or loss of any portion of the
Available System that are known to it, which may adversely affect PSINet's use
of the PSINet IRU or the IRU Capacity.


SECTION 9.     INDEMNIFICATION.

        9.1 Indemnification Obligations. IXC and PSINet (hereinafter where
either has undertaken the action or inaction to be indemnified against shall be
known as the "Indemnifying Party") agree to assume all liability for and
indemnify, defend and hold harmless the other party or any third party claiming
through the other party, from and against all liability, loss, cost, damage,
expense or cause of action, of whatsoever character, or injury or death of any
person and damage to or destruction of any property, including, without
limitation, third parties and all related expenses, including, but not limited
to, reasonable attorneys' fees, investigators' fees and litigation expenses and
costs of enforcing this Section 9 arising out of or relating to, in whole or in
part, any of the following:

        (i)           claims for libel, slander, infringement of copyright or
                      unauthorized use of a trade secret, trade name or service
                      mark that results from the transmission of material over
                      the Available System by the Indemnifying Party, authorized
                      representatives of the Indemnifying Party or other persons
                      not associated with, or related to, either IXC or PSINet;
                      or

        (ii)          claims of any person not a party to this Agreement arising
                      out of the negligent or willful act or omission of the
                      Indemnifying Party or its agents, servants, employees,

- --------

     *  Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                                       11

<PAGE>   16



                      contractors or representatives (other than IXC, if PSINet
                      is the Indemnifying Party, or PSINet, if IXC is the 
                      Indemnifying Party); or

        (iii)         claims for patent infringement arising out of the use of
                      the Available System by the Indemnifying Party or any
                      person authorized by the Indemnifying Party or resulting
                      from the acts of the Indemnifying Party or the
                      Indemnifying Party's representatives in combining the
                      Available System with the facilities of the Indemnifying
                      Party or others, or using the Available System either
                      alone or in connection with that of the Indemnifying Party
                      or others; or

        (iv)          claims, except as otherwise set forth herein, for the
                      material breach of or failure to comply, in any material
                      respect, with any term or condition of this Agreement by
                      the Indemnifying Party or its officers, employees or
                      invitees; or

        (v)           claims resulting from patent or trade secret infringement
                      or infringement or unauthorized use of trade secrets or
                      trade name by the Indemnifying Party in connection with
                      this Agreement;

        PROVIDED, HOWEVER, IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER
(OR TO ANY THIRD PARTY CLAIMING THROUGH SUCH OTHER PARTY) FOR CONSEQUENTIAL,
INCIDENTAL, EXEMPLARY OR PUNITIVE DAMAGES, AND THE FOREGOING INDEMNITIES SHALL
NOT APPLY WITH RESPECT TO SUCH DAMAGES.

        9.2 Notice of Indemnification. Upon receipt by the Indemnifying Party of
a notice from the other party with respect to any claim of a third party against
the other party, the Indemnifying Party shall, within 30 days of the mailing of
the other party's notice setting forth such request for indemnification, either
(i) agree in writing to assume the defense of such third party claim, or (ii)
provide the other party with written notice setting forth the basis for such
objection in reasonable detail. In the event the Indemnifying Party fails to
respond to the other party's written request within such 30 day period, the
other party's right to indemnification, as set forth in the other party's
notice, shall be deemed agreed to by the Indemnifying Party. In the event the
Indemnifying Party timely objects to the other party's request for
indemnification, the dispute shall be settled in accordance with the procedures
set forth in Section 7.2, above.

        9.3 Defense Obligations. In the event it is determined that the
Indemnifying Party is required to indemnify the other party, the Indemnifying
Party shall assume the defense of such claim with counsel reasonably
satisfactory to the other party, and the other party shall cooperate to the
extent reasonably requested by the Indemnifying Party in defense or prosecution
thereof. If the Indemnifying Party has agreed to indemnify the other party and
has assumed the defense of any such third party claim, the other party shall
have the right to employ its own counsel in any such case, but the fees and
expenses of such counsel shall be at the expense of the other party, and the
Indemnifying Party shall have the right to settle any claim for which
indemnification has been sought and is available hereunder; provided, however,
that, to the extent that such settlement requires the other party to take, or
prohibits the other party from taking, any action or purports to obligate the
other party, then the Indemnifying Party shall not settle such claim without the
prior written consent of the other party, which shall not be unreasonably
withheld, delayed or conditioned.

If the Indemnifying Party does not assume the defense of any third party claim
for which it is obligated to provide indemnification hereunder, the other party
may assume control of the defense of such claim through counsel of its choice at



                                       12

<PAGE>   17

the Indemnifying Party's expense and shall have control over the litigation and
authority to resolve such claim. If action is required to be taken with respect
to any third party claim prior to the determination of the Indemnifying Party's
obligations hereunder, the other party may assume control of the defense of such
claim through counsel of its choice until such time as the Indemnifying Party's
obligations hereunder are determined; provided, however, that the Indemnifying
Party shall not be liable hereunder for any settlement of such claim without the
Indemnifying Party's prior written consent unless and until it is determined
that the Indemnifying Party is obligated hereunder to provide indemnification
with respect thereto and refuses or fails to assume the defense of such claim.


SECTION 10.    ADMINISTRATION OF AGREEMENT

        10.1 Representatives. Within 30 days after the Closing Date, IXC and
PSINet shall each designate, by written notice to the other party, a
representative (each, an "Authorized Representative") who is authorized to act
on the respective party's behalf with respect to those matters delegated to the
Authorized Representative. Each party may designate an alternate representative
with full authority to act in the absence of the Authorized Representative. Each
party shall have the right to change its Authorized Representative or
alternative by written notice to the other party.

        10.2 Responsibilities. The Authorized Representatives shall provide
liaison between the parties in order to provide effective cooperation, exchange
of information and consultation on a prompt and orderly manner concerning the
various matters which may arise, from time to time, in connection with this
Agreement. In addition, the Authorized Representatives shall have the following
responsibilities, among others:

                1.      Perform those functions and duties assigned to them in
                        this Agreement;

                2.      Review and attempt to resolve any disputes between the
                        parties arising under this Agreement. Should the
                        Authorized Representatives be unable to resolve a
                        dispute, the matter shall be resolved in accordance with
                        the provisions of Section 19.14, below; and

                3.      Arrange for the development and completion of procedures
                        to implement the provisions of this Agreement.

        10.3 Form of Actions. All actions, agreements, resolutions,
determinations or reports made by the Authorized Representatives shall be in
writing and shall become effective when signed by both Authorized
Representatives.

        10.4 Fees and Expenses. Any and all fees and expenses incurred by an
Authorized Representative in connection with his or her duties shall be paid by
the party he or she represents.


SECTION 11.    FORCE MAJEURE

        Notwithstanding any provision in this Agreement to the contrary, neither
party shall be liable to the other for any failure of performance under this
Agreement (except with respect to payment or other monetary obligations or as
otherwise specifically set forth herein) due to causes beyond the reasonable
control of a party, including, by way of illustration and not limitation, acts
of God, flood, fire, explosion, storm, acts of public enemies, insurrection,
war, national emergency, riots, strikes, labor disputes, disturbances, lockouts,
labor or material shortages (not resulting from the responsible party's failure
to place reasonable orders therefor), breakdown of or damage to plants or
equipment



                                       13

<PAGE>   18



or facilities (other than arising out of the neglect or mishandling by such
party), failure of a supplier to supply necessary materials or equipment or
labor in a timely manner (including warranty replacements), destruction of
property, embargoes, boycotts, governmental legislation or regulations, orders
or acts of civil or military authorities, governmental acts, or orders of courts
or administrative agencies. Any party excused from performance pursuant to this
Section 11 shall use commercially reasonable efforts to minimize the time during
which such performance is excused pursuant to this Section 11.


SECTION 12.    LIMITATION OF LIABILITY; INDEMNIFICATION

        12.1 Limitation of Liability. Except for direct damages otherwise
specifically provided for in this Agreement, in no event shall IXC or PSINet be
liable for any special, incidental, direct, indirect, punitive, reliance or
consequential damages, whether foreseeable or not, arising under this Agreement
or from any breach or partial breach of the provisions of this Agreement or
occasioned by any defect in the Bandwidth or other service provided hereunder,
delay in availability of the Bandwidth or any service provided hereunder,
failure of the Bandwidth or other service provided hereunder, interruptions or
outages of the Available System or any other cause whatsoever or arising out of
any act or omission by IXC or PSINet, as applicable, its employees, servants
and/or agents, including but not limited to, damage or loss of property or
equipment, loss of profits or revenue, cost of capital, cost of replacement
services, or claims of customers for service interruptions or transmission
problems.

        12.2 Release; Indemnification. Each party (each party in such capacity
being referred to as the "Releasing Party") releases, assumes and agrees to
indemnify, defend, protect and save the other party harmless from and against
any claim, damage, loss, liability, cost and expense (including reasonable
attorneys' fees) in connection with any loss or damage to any physical property
or facilities of the Releasing Party or any injury to or death of any person
arising out of or resulting in any way from the negligence or misconduct of the
Releasing Party or its employees, servants, contractors and/or agents.


SECTION 13.    REPRESENTATIONS AND WARRANTIES OF PSINET

        PSINet represents and warrants to IXC that, except as set forth in the
PSINet Disclosure Schedule set forth as Exhibit L hereto, as of the date hereof
and as of the Closing Date, except where a representation and warranty is made
as of a specified date, in which case it is made as of such date:

        13.1 Organization. On the date hereof PSINet is a corporation duly
organized, validly existing and in good standing under the laws of the State of
New York. On the Closing Date, PSINet, as merged into Newco, will be a
corporation duly organized, validly existing and in good standing under the laws
of the State of Delaware. PSINet is qualified to do business as a foreign
corporation in each jurisdiction in which such qualification is required except
in those jurisdictions where the failure to be so qualified would not have a
Material Adverse Effect on PSINet and its subsidiaries taken as a whole. PSINet
has delivered to IXC true and correct copies of its Certificate of Incorporation
and Bylaws and, prior to the Closing, will deliver true and correct copies of
Newco's Certificate of Incorporation (which does not include the documents
required to effect the Reincorporation) and Bylaws in substantially the form as
set forth as Exhibit J hereto (with such changes thereto as may be required in
order for such Certificate of Incorporation and Bylaws to comply with Delaware
General Corporation Law while providing the parties with substantially
equivalent economic benefits as provided therein).

        13.2 Authorization. The execution, delivery and performance of this
Agreement and the Transaction Documents to which PSINet is or will be a party
has



                                       14

<PAGE>   19



been or, on the Closing Date, will be, duly authorized by all necessary
corporate action on the part of PSINet. This Agreement and the Transaction
Documents to which PSINet is or will be a party are or, when executed and
delivered, will be valid and binding obligations of PSINet, enforceable against
PSINet in accordance with their terms, except as such enforceability may be
limited by bankruptcy, insolvency or other laws relating to or affecting
creditors' rights generally and the exercise of judicial discretion in
accordance with general equitable principles. Except as set forth in Section
13.2 of the PSINet Disclosure Schedule, no material consent, approval or
authorization of, or designation, declaration or filing with, any governmental
authority is required of PSINet in connection with the execution, delivery and
performance of this Agreement or the consummation of the transactions
contemplated hereby.

        13.3 Shares. Upon the issuance of the IXC Initial Common Shares on the
Closing Date in accordance with this Agreement, the IXC Initial Common Shares
will be duly authorized, validly issued, fully paid and nonassessable. Upon the
issuance, if any, of the Additional Shares, the Additional Shares will be duly
authorized, validly issued, fully paid and nonassessable.

        13.4 Capitalization. As of the date of this Agreement, the authorized
capital stock of PSINet consists of 100,000,000 shares of Common Stock, $.01 par
value per share, 29,000,000 shares of undesignated Preferred Stock, $.01 par
value per share, and 1,000,000 shares of Series A Junior Participating Preferred
Stock, $.01 par value per share, of which approximately 40,397,876 shares of
Common Stock are issued and outstanding, 99,556 shares of Common Stock are held
as treasury shares and no shares of Preferred Stock are issued or outstanding.
Upon the Closing Date, after giving effect to the Reincorporation, the
authorized capital stock of Newco will be as set forth in Section 13.4 of the
PSINet Disclosure Schedule and each share of Common Stock of PSINet issued and
outstanding on the date hereof will have been exchanged for one share of Common
Stock of Newco. Except as set forth on the PSINet Disclosure Schedule, as of the
date of this Agreement, there is not outstanding any subscription, option,
warrant, call, right or other agreement or commitment obligating PSINet to
issue, sell, deliver or transfer (including any right of conversion or exchange
under any outstanding security or other instrument) any shares of Common Stock
or any other shares of capital stock of PSINet. PSINet does not have outstanding
any bonds, debentures, notes or other obligations, under the terms of which the
holders of which have the rights to vote with the shareholders of PSINet.

        13.5 PSINet Filings; No Material Adverse Change. Neither PSINet's Annual
Report on Form 10-K for the year ended December 31, 1996 nor any other of
PSINet's periodic reports filed with the U.S. Securities and Exchange Commission
(the "Commission") pursuant to the 1934 Act on or after March 31, 1997 (each, a
"PSINet Filing"), taken as a whole, as of the date of filing thereof, contained
any untrue statement of material facts or omitted to state any material fact
necessary in order to make the statements contained therein not misleading in
light of the circumstances under which such statements were made. PSINet used
reasonable efforts, in good faith, to comply in all material respects with the
requirements of the Commission as to the contents of such filings. Such PSINet
Filings, when they were filed with the Commission, conformed as to form in all
material respects to the requirements of the 1934 Act and the rules and
regulations of the Commission thereunder. Except as disclosed by PSINet in
public announcements or otherwise set forth in the PSINet Disclosure Schedule,
there has been no material and adverse change to the business, financial
condition or results of operation of PSINet and its subsidiaries taken as a
whole since the date of the most recent PSINet Filing.

        13.6 Effect of Transactions. Except as set forth in Section 13.6 of the
PSINet Disclosure Schedule, the execution, delivery and performance by PSINet of
this Agreement and the Transaction Documents to which PSINet is a party and the
consummation of the transactions contemplated hereby and thereby will not
conflict with or result in any default or require the consent of any person or



                                       15

<PAGE>   20



entity under the Articles or Certificate of Incorporation, By-laws or any
material agreement of PSINet, or result in the creation of any lien, charge or
encumbrance of any nature upon any of the properties or assets of PSINet except
pursuant to this Agreement. The execution, delivery and performance of this
Agreement by PSINet will not violate, in any material respect, any judgment,
decree, order, statute, rule or regulation of any federal, state or local
government or agency applicable to PSINet or to which PSINet is a party.

        13.7 Litigation. Except as disclosed in Section 13.7 of the PSINet
Disclosure Schedule, there is no litigation or governmental proceeding or
investigation pending or, to the knowledge of PSINet, threatened against PSINet
which (i) may call into question the validity or hinder the enforceability or
the performance of this Agreement, the Transaction Documents to which PSINet is
a party or the transactions contemplated hereby and thereby, or (ii) could
reasonably be expected to give rise to a Material Adverse Effect on PSINet and
its subsidiaries taken as a whole.

        13.8 Brokers. Except for the fees of Merrill Lynch & Co. in connection
with any fairness or valuation opinions to be provided by it to PSINet as
contemplated by this Agreement, no broker, finder, agent or similar intermediary
has acted on behalf of PSINet in connection with this Agreement or the
transactions contemplated hereby, and there are no brokerage commissions,
finder's fees or similar fees or commissions payable by PSINet in connection
with this Agreement or the transactions contemplated hereby.

        13.9 No Other Agreements To Sell. Except as set forth in this Agreement
or as disclosed in Section 13.9 of the PSINet Disclosure Schedule, neither
PSINet nor any of its subsidiaries has any commitment to (i) sell, assign or
transfer a material portion of the assets or capital stock of PSINet or an
Affiliate, (ii) to effect any merger, consolidation or other reorganization of
PSINet or an Affiliate that could affect the transactions contemplated by this
Agreement, or (iii) to enter into any agreement with respect to any of the
foregoing.

        13.10 Full Disclosure. No representation, warranty or other statement of
PSINet contained in this Agreement, or any other document or certificate
delivered at Closing or, to PSINet's knowledge, other written statement
furnished to IXC in connection with the transactions contemplated by this
Agreement (other than any interim financial statements of PSINet not filed with
the Securities and Exchange Commission) contains any untrue statement of a
material fact or omits to state a material fact necessary in order to make the
statements contained herein or therein relating to this Agreement and the
transactions contemplated hereby or to the business or financial condition of
PSINet not materially misleading when taken as a whole in the light of the
circumstances under which they were made. There is no fact known to PSINet which
could reasonably be expected to have, in light of the circumstances in which it
is made, a Material Adverse Effect on PSINet and its subsidiaries, taken as a
whole, that has not been disclosed herein or in such other documents,
certificates and statements furnished to IXC for use in connection with the
transactions contemplated hereby. All interim financial statements furnished by
PSINet to IXC in connection with this Agreement were prepared in good faith.

        EXCEPT FOR THE REPRESENTATIONS AND WARRANTIES SPECIFICALLY SET FORTH IN
THIS SECTION 13, PSINET MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND
WHATSOEVER, WHETHER EXPRESS, IMPLIED OR STATUTORY, AND PSINET EXPRESSLY
DISCLAIMS AND EXCLUDES ALL OTHER REPRESENTATIONS AND WARRANTIES OF ANY KIND.


SECTION 14.    REPRESENTATIONS AND WARRANTIES OF IXC

        IXC hereby represents and warrants to PSINet that, except as set forth
in the IXC Disclosure Schedule set forth as Exhibit M hereto, as of the date
hereof



                                       16

<PAGE>   21



and as of the Closing Date, except where a representation and warranty is made
as of a specified date, in which case it is made as of such date:

        14.1 Organization. IXC is a corporation duly organized, validly existing
and in good standing under the laws of the State of Delaware, and is qualified
to do business as a foreign corporation in each jurisdiction in which such
qualification is required except in those jurisdictions where the failure to be
so qualified would not have a Material Adverse Effect on IXC and its
subsidiaries taken as a whole.

        14.2 Authorization. The execution, delivery and performance of this
Agreement, the Transaction Documents to which IXC is or will be a party and the
Contribution Agreement have been duly authorized by all necessary corporate
action on the part of IXC and IXC Carrier, as applicable. This Agreement, the
Transaction Documents to which IXC is or will be a party, and the Contribution
Agreement are or, when executed and delivered, will be valid and binding
obligations of IXC and IXC Carrier, as applicable, enforceable against IXC or
IXC Carrier, as applicable, in accordance with their terms, except as such
enforceability may be limited by bankruptcy, insolvency or other laws relating
to or affecting creditors' rights generally and the exercise of judicial
discretion in accordance with general equitable principles. Except as set forth
in Section 14.2 of the IXC Disclosure Schedule, no consent, approval or
authorization of, or designation, declaration or filing with, any governmental
authority is required of IXC or IXC Carrier, as applicable, in connection with
the execution, delivery and performance of this Agreement, the Transaction
Documents to which IXC is or will be a party, and the Contribution Agreement by
IXC or IXC Carrier, as applicable, or the performance or consummation of any
other transaction contemplated hereby or thereby.

        14.3 Effect of Transactions. Except as set forth in Section 14.3 of the
IXC Disclosure Schedule, the execution and delivery of this Agreement, the
Transaction Documents to which IXC is or will be a party, and the Contribution
Agreement by IXC and IXC Carrier, as applicable, and the performance by IXC and
IXC Carrier, as applicable, of the transactions contemplated hereby and thereby
will not conflict with or result in any default or require the consent of any
person or entity under the Certificate of Incorporation, By-laws or any material
agreement of IXC or IXC Carrier, as applicable, or result in the creation of any
lien, charge or encumbrance of any nature upon any of the properties or assets
of IXC except pursuant to this Agreement. The execution and delivery of this
Agreement, the Transaction Documents to which IXC is or will be a party, and the
Contribution Agreement by IXC or IXC Carrier, as applicable, and the performance
by IXC and IXC Carrier, as applicable, of the transactions contemplated hereby
and thereby will not violate, in any material respect, any judgment, decree,
order, statute, rule or regulation of any federal, state or local government or
agency applicable to IXC or IXC Carrier, as applicable, is a party.

        14.4 Litigation. Except as set forth in Section 14.4 of the IXC
Disclosure Schedule, there is no litigation or governmental proceeding or
investigation pending or, to the knowledge of IXC, threatened against IXC or IXC
Carrier which (i) may call into question the validity or hinder the
enforceability or performance of this Agreement, the Transaction Documents to
which IXC or IXC Carrier is a party or the transactions contemplated hereby or
thereby or (ii) could reasonably be expected to give rise to a Material Adverse
Effect on IXC and its subsidiaries taken as a whole or IXC Carrier.

        14.5 Brokers. No broker, finder, agent or similar intermediary has acted
on behalf of IXC or any of its Affiliates in connection with this Agreement or
the transactions contemplated hereby and, there are no brokerage commissions,
finder's fees or similar fees or commissions payable by IXC or any of its
Affiliates in connection with this Agreement or the transactions contemplated
hereby.


                                       17

<PAGE>   22

        14.6   Investment Representations.

               (a) IXC (i) has received and reviewed this Agreement, including
all schedules and exhibits hereto and the PSINet Disclosure Schedule, and has
had the opportunity to review the PSINet Filings, the Certificate of
Incorporation, as amended, and By-laws of PSINet, PSINet's preferred stock
purchase rights plan and the proposed Certificate of Incorporation and By-laws
of Newco which are proposed to be in effect on the Closing Date and (ii) has had
the opportunity to ask questions of, and has received answers from, PSINet
concerning the transactions contemplated hereby and to obtain additional
information which PSINet possesses or could acquire without unreasonable effort
or expense.

               (b) IXC is acquiring or will acquire, as the case may be, the IXC
Shares (collectively the "Acquired Shares") for its own account, for investment,
and not with a view to any resale or "distribution" thereof within the meaning
of the Securities Act. IXC was not formed or organized for the purpose of
acquiring the Acquired Shares.

               (c) IXC understands that because the Acquired Shares have not
been and will not be at the time of issuance registered under the Securities
Act, it cannot dispose of any or all of the Acquired Shares unless the Acquired
Shares are subsequently registered under the Securities Act or exemptions from
such registration are available. IXC understands that each certificate
representing the Acquired Shares will bear the following legend or one
substantially similar thereto:

        THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
        UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR ANY
        APPLICABLE STATE OR FOREIGN SECURITIES LAWS. THESE SECURITIES HAVE BEEN
        ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO DISTRIBUTION OR RESALE,
        AND MAY NOT BE SOLD, MORTGAGED, PLEDGED, HYPOTHECATED OR OTHERWISE
        TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT FOR SUCH
        SECURITIES UNDER THE ACT OR THE AVAILABILITY OF AN EXEMPTION FROM SUCH
        REGISTRATION REQUIREMENTS.

        THE SECURITIES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO AN IRU AND
        STOCK PURCHASE AGREEMENT, DATED AS OF JULY 22, 1997, A COPY OF WHICH IS
        AVAILABLE FOR INSPECTION, IN RELEVANT PART, AT THE PRINCIPAL OFFICES OF
        THE ISSUER.

               (d) IXC is sufficiently knowledgeable and experienced in
financial and business matters and in the making of investments so as to be able
to evaluate the risks and merits of its investment in PSINet and the Acquired
Shares and is able to bear the economic risk of loss of its entire investment in
the Acquired Shares. IXC is an "accredited investor" as such term is defined in
Rule 501 promulgated under the Securities Act.

               (e) IXC has been advised that the Acquired Shares have not been,
will not be at the time of issuance and are not being registered under the
Securities Act or under the "blue sky" laws of any jurisdiction and that PSINet
in issuing the Acquired Shares is and will be relying upon, among other things,
the representations and warranties of IXC contained in this Section 14.6.

        14.7 Disclosure; No Material Adverse Change. Neither IXC's parent's
Annual Report on Form 10-K for the year ended December 31, 1996 nor any of IXC's
parent's periodic reports filed with the Commission pursuant to the 1934 Act on
or after March 31, 1997 (each, a "IXC Filing"), taken as a whole, as of the date
of filing thereof, contained any untrue statement of a material fact or omitted
to state any material fact necessary in order to make the statements contained
therein not misleading in light of the circumstances under which such statements
were made. IXC's parent used reasonable efforts, in good faith, to comply in all
material respects with the requirements of the Commission as to the contents of



                                       18

<PAGE>   23


such filings. Such filings, when they were filed with the Commission, conformed
as to form in all material respects to the requirements of the 1934 Act and the
rules and regulations of the Commission thereunder. IXC and IXC Carrier have
sufficient net worth and capital resources and expect to have sufficient cash
flow from their businesses in order for IXC to be able to perform its
obligations under this Agreement, the other Transaction Documents and the
Contribution Agreement and for IXC Carrier to be able to perform its obligations
under the Contribution Agreement. Except as disclosed by IXC in public
announcements or otherwise set forth in the IXC Disclosure Schedule, there has
been no material and adverse change to the business, financial condition or
results of operation of IXC and its subsidiaries taken as a whole since the date
of the most recent IXC Filing.

        14.8 IRUs. At the Closing and throughout the Term, IXC will have good
and valid title to the Base IRU free and clear of all liens and encumbrances,
and rights of third parties, except as created hereunder and those created after
the date hereof and to an indefeasible right to use related facilities and
equipment. In the case of the Long-Term Indivisible IRU and Short-Term
Indivisible IRU, IXC, at the Closing and throughout the Term, will have, good
and valid title free and clear of all liens and encumbrances, and rights of
third parties, except as created hereunder. Pursuant to the Security Agreement,
at Closing, IXC shall grant to PSINet a continuing, first priority perfected and
exclusive security interest in the Collateral.

        14.9 Available System. IXC Carrier has completed the fiber construction
of, and has installed electronics (which may not include the electronics to be
used to furnish the IRU Capacity) on, the portions of the Available System
insofar as indicated on Exhibit A hereto. The Available System will have
sufficient fiber capacity to satisfy IXC's obligations hereunder.

        14.10 Stock Ownership. From the date hereof through and including the
Closing Date and simultaneously with the Closing, neither IXC Communications,
Inc. nor any of its controlled Affiliates nor any "group" (within the meaning of
Section 13(d)(3) of the 1934 Act) of which IXC Communications, Inc. or any of
its controlled Affiliates is a member nor, to IXC's knowledge, any of its
Associates, is or will directly or indirectly be the "beneficial owner" (within
the meaning of Rule 13d-3 under the 1934 Act) of any Voting Securities of PSINet
or the "Beneficial Owner" of any PSINet securities within the meaning of
PSINet's preferred stock purchase rights plan.

        EXCEPT FOR THE REPRESENTATIONS AND WARRANTIES SPECIFICALLY SET FORTH IN
THIS SECTION 14, IXC MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND
WHATSOEVER, WHETHER EXPRESS, IMPLIED OR STATUTORY, AND IXC EXPRESSLY DISCLAIMS
AND EXCLUDES ALL OTHER REPRESENTATIONS AND WARRANTIES OF ANY KIND. WITHOUT
LIMITING THE GENERALITY OF THE FOREGOING, IXC MAKES NO WARRANTY TO PSINET OR ANY
OTHER PERSON OR ENTITY, WHETHER EXPRESS, IMPLIED OR STATUTORY, AS TO THE
DESCRIPTION, QUALITY, COMPLETENESS, MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE OF ANY CABLE OR FIBERS OR ANY SERVICE OR BANDWIDTH PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED.


SECTION 15.    COVENANTS

        15.1 Hart-Scott-Rodino. As soon as possible after the date hereof, each
of PSINet and IXC shall cause its ultimate parent to prepare and file all
documents with the Federal Trade Commission and the United States Department of
Justice as is required to comply with the Hart-Scott-Rodino Antitrust
Improvements Act of 1976 ("Hart-Scott-Rodino Act") and thereafter shall cause
its ultimate parent to promptly furnish all materials thereafter requested by
any of the regulatory agencies having jurisdiction over such filings.


                                              19

<PAGE>   24



        15.2 Consents. Each of PSINet and IXC shall use its reasonable best
efforts to obtain at the earliest practicable date all consents and approvals
required to consummate the transactions contemplated by this Agreement,
including, without limitation, the consents and approvals referred to in
Sections 13.2, 13.6, 14.2 and 14.3 hereof; provided, however, that, except for
filing fees required in connection with the parties' obligations under Section
15.1, above, neither PSINet nor IXC shall be obligated to pay any consideration
therefor to any third party from whom consent or approval is requested.

        15.3 Other Actions. Each of PSINet and IXC shall use its reasonable best
efforts to (i) take all actions necessary or appropriate to consummate the
transactions contemplated by this Agreement and (ii) cause the fulfillment at
the earliest practicable date of all of the conditions to their respective
obligations to consummate the transactions contemplated by this Agreement.

        15.4 Board Seat. So long as IXC owns 95% of all IXC Common Shares issued
to IXC hereunder, on the Closing Date, PSINet's Chairman shall recommend that
(i) PSINet's Board of Directors elect Ralph J. Swett to PSINet's Board of
Directors effective as of the Closing Date, for a term expiring in 1998 or later
and (ii) subject to the next sentence, such person be nominated to stand for
election with the other nominated Board members at the 1998 Annual Meeting of
PSINet (or, later annual meeting associated with the expiration of his term) for
a term expiring no earlier than 2000 and for reelection thereafter at the
applicable Annual Meetings of PSINet. At such time as IXC shall cease to own the
requisite amount of IXC Common Shares, a resignation letter will be executed by
Ralph J. Swett immediately and he shall immediately cease to serve as a member
of PSINet's Board of Directors.

        15.5 Restriction on Resale. PSINet shall not sell, swap, lease or
otherwise transfer (including, without limitation, by way of a pledge,
hypothecation or security interest) any Bandwidth obtained from IXC to any third
party ("Transferee") except (i) to an Affiliate, or (ii) in connection with the
offering of Internet connectivity services, as such services shall evolve and
mature, or (iii) in connection with a bona fide financing arrangement with an
unaffiliated third party and any foreclosure or similar sale in connection
therewith; provided that in any such case, the Transferee shall agree to be
subject to the terms of this Section 15.5. PSINet and each Transferee shall not
use the Bandwidth acquired from IXC pursuant to this Agreement to provide any
party (other than PSINet and its controlled U.S. affiliates for purpose of the
aggregation of the customer traffic of PSINet and its controlled U.S.
affiliates) any form of non-Internet telecommunications transport at a rate
greater than DS-3 (45mbps) without the specific written approval of IXC. PSINet
is specifically restricted from using the Bandwidth to deliver any analog or
digitized long-distance switched telephone service or any substantially similar
service, based on non-Internet telephone switching technologies, and only on
such technologies, or private line service (such as DS-0, DS-1, DS-3, T-1, T-3,
E-1, E-3, OC-3, OC- 12, OC-48, or any OC-N private line service), to any third
party. Any pledge, hypothecation or security interest of or in the Bandwidth
will be subject to the terms and conditions of this Agreement, including,
without limitation, this section. PSINet will not compete during 1997 against
IXC for * business, or for such other business opportunities introduced to
PSINet by IXC as may be reduced to writing and acknowledged by PSINet, for
services to be rendered in 1997 or thereafter, provided, however, that this
sentence will not restrict PSINet from providing services contracted for prior
to the date hereof.

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                                       20

<PAGE>   25



        Notwithstanding the foregoing, the restrictions set forth in this
Section 15.5 will not apply to any Transferee which acquires any Bandwidth in
connection with a Bankruptcy Proceeding filed or initiated by or against PSINet.

        15.6   No Solicitation.

               (a) From the date hereof until three years after the Closing
Date, neither IXC nor any of its Affiliates will, directly or indirectly, either
alone or in association with others in any part of the world induce, request,
encourage or assist any employee of PSINet or its Affiliates to terminate his or
her employment with PSINet, or to join with or become employed by, render
services to or otherwise be engaged by IXC or any of its Affiliates in any
direct or indirect capacity.

               (b) From the date hereof until three years after the Closing
Date, neither PSINet nor any of its Affiliates will, directly or indirectly,
either alone or in association with others in any part of the world induce,
request, encourage or assist any employee of IXC or its Affiliates to terminate
his or her employment with IXC, or to join with or become employed by, render
services to or otherwise be engaged by PSINet or any of its Affiliates in any
direct or indirect capacity.

               (c) If, at the time of enforcement of Section 15.6, a court shall
hold that the duration, scope, geographic area or other restrictions stated
herein are unreasonable under circumstances then existing, the parties agree
that the maximum duration, scope, geographic area or other restrictions deemed
reasonable under such circumstances by such court shall be substituted for the
stated duration, scope, geographic area or other restrictions.

        15.7 Transfer Matters. (a) If IXC or any controlled Affiliate of IXC
that beneficially owns IXC Shares (collectively, the "Selling Shareholder")
shall desire to sell or otherwise dispose of any or all of the IXC Shares
beneficially owned by it (the "Offered Shares"), other than to IXC Carrier,
after IXC Carrier has agreed in writing to be bound by the terms of this Section
15.7 and by Section 15.8, or pursuant to a pledge to an unaffiliated third-party
lender ("Lender") in connection with a bona fide lending transaction or a
foreclosure or similar sale in connection therewith (each, a "Pledge
Transaction"), such Selling Shareholder shall first give written notice (the
"Notice of Sale") to PSINet.

        Upon the giving of any Notice of Sale, PSINet shall have a
non-assignable, one-time, first option to purchase all (but not less than all)
of the Offered Shares for cash at the Current Market Price at the date the
Notice of Sale is given, which option must be exercised by giving notice of such
exercise to the Selling Shareholder within 48 hours (excluding hours on
Saturdays, Sundays or national holidays) after the receipt by PSINet of the
Notice of Sale (the "Offer Acceptance Date"). Such notice of exercise shall
constitute PSINet's binding, non-cancelable agreement to purchase the Offered
Shares.

        The closing of the purchase by PSINet of the Offered Shares shall take
place within 30 days after the Offer Acceptance Date. PSINet shall designate the
time and date of the closing which shall be held at the principal office of
PSINet or such other place as may be mutually agreed upon between PSINet and the
Selling Shareholder. At the closing, the Selling Shareholder shall duly assign
and deliver to PSINet certificates representing the Offered Shares, with
required transfer stamps attached, and PSINet shall pay the Selling Shareholder
the purchase price (plus one-half the cost of all transfer stamps required) by
wire transfer of same-day funds to an account designated by the Selling
Shareholder.

        If the right given to PSINet in this section shall not have been
exercised as to the Offered Shares as set forth above, the Selling Shareholder
shall have the right, at any time within three months after the expiration of
such 48-hour



                                       21

<PAGE>   26



period, to dispose of all of the Offered Shares. If by the end of such
three-month period, the Selling Shareholder has not sold or otherwise disposed
of all of the Offered Shares, the remaining Offered Shares shall not be sold by
the Selling Shareholder except after compliance again with the provisions of
this Section 15.7.

               (b) Notwithstanding any provision of this Agreement to the
contrary, during the six month period preceding or following the Additional
Shares Determination Date and during the six month period following the
Additional Shares Acceleration Date, neither IXC, IXC Communications, Inc. nor
any controlled Affiliate of IXC Communications, Inc. shall sell, transfer,
convey or otherwise dispose of any Common Stock of PSINet or any securities
convertible into or exchangeable or exercisable for any shares of Common Stock
of PSINet (each, an "Untimely Transfer"). PSINet's sole remedy with respect to
an Untimely Transfer occurring during the six-month period prior to the
Additional Shares Determination Date, shall be to delay payment to IXC and
suspend PSINet's obligations to IXC under Section 3.5 as set forth in Section
15.7(c). This Section 15.7(b) shall not apply to a Pledge Transaction, so long
as neither IXC nor any of its Affiliates do not intentionally breach the terms
of the applicable pledge or any related financing agreement with the purpose of
avoiding this Section 15.7(b).

               (c) Notwithstanding any provision of this Agreement to the
contrary, PSINet's obligations to pay or deliver any Additional Shares and/or
cash, other securities or property pursuant to Section 3.5 to IXC shall be
suspended in the event of, and for so long as there shall be continuing (i) a
breach by IXC of a Material Provision, or a breach of Section 15.8(a) or the
Standstill Agreement claimed by PSINet to be material and which PSINet actively
seeks to resolve through the dispute resolution procedures set forth in this
Agreement or the Standstill Agreement, as applicable, or (ii) a breach by IXC or
any of its Affiliates of the provisions of Section 15.7(a) or 15.7(b), until
such breach has been cured (in the case of a breach of Section 15.7(b), until
such breach has been cured for a period of at least fifty (50) consecutive
trading days without an Untimely Transfer after the transaction giving rise to
such breach).

        15.8   Standstill Agreement.

               (a) IXC covenants and agrees that each of it and IXC
Communications, Inc. shall not and shall not permit any controlled Affiliate of
IXC Communications, Inc. and/or IXC to, without the prior approval of the Board
of Directors of PSINet or as otherwise provided in this Agreement, (i) in any
manner acquire, agree to acquire or make any proposal to acquire, directly or
indirectly, any securities or property of PSINet or any of its subsidiaries
(except pursuant to Section 3 of this Agreement or by way of stock dividends,
stock splits or other distributions by PSINet made available to holders of
Voting Securities generally, including without limitation pursuant to a PSINet
preferred stock purchase rights plan or pursuant to any similar plan or
distribution, or as permitted pursuant to clause (ii)(C) of this Section 15.8),
(ii) propose (by itself or by or through any of its directors, executive
officers, attorneys, investment bankers or other Person duly authorized to make
such a proposal) or induce any other Person to propose, directly or indirectly,
(A) any merger or business combination involving PSINet or any of its
subsidiaries, (B) the purchase or sale of any assets of PSINet or any of its
subsidiaries or (C) the purchase of any Voting Securities, by tender offer or
otherwise (except pursuant to the exercise of rights, warrants, options or
similar securities distributed by PSINet to holders of Voting Securities
generally, including without limitation pursuant to the exercise of rights
pursuant to PSINet's preferred stock purchase rights plan), (iii) directly or
indirectly solicit "proxies" or "consents" or become a "participant" in a
"solicitation" (as such terms are defined in Regulation 14A under the 1934 Act),
or seek to advise or influence any Person with respect to the voting of any
Voting Securities of PSINet or any of its subsidiaries, (iv) form, join or in
any way participate in a "group" (within the



                                       22

<PAGE>   27


meaning of Section 13(d)(3) of the 1934 Act) with respect to any Voting
Securities of PSINet or any of its subsidiaries, (v) deposit any Voting
Securities in a voting trust or subject any Voting Securities to any arrangement
or agreement with respect to the voting of Voting Securities, (vi) otherwise
act, alone or in concert with others, to seek to control or influence (except as
a customer or supplier in the ordinary course of business) the management, Board
of Directors or policies of PSINet (provided, however, that so long as he is a
director of PSINet, this clause (vi) shall not prohibit Ralph J. Swett from
taking action and serving in his capacity as a director of PSINet in a manner
consistent with the proper exercise of his fiduciary and other duties as a
director of PSINet), (vii) disclose any intention, plan or arrangement
inconsistent with the foregoing or (viii) advise, assist or encourage any other
Person in connection with any of the foregoing. Notwithstanding anything in this
Section 15.8 to the contrary, so long as there shall not have occurred an IXC
Change of Control, IXC shall be permitted to approach the Board of Directors of
PSINet, directly or indirectly through its executive officers or its investment
bankers for purposes of obtaining a waiver of its liabilities, obligations and
commitments under clause (ii) of this Section 15.8(a). IXC agrees that the
provisions of this Section 15.8 shall be binding upon its successors and assigns
(other than resulting from a Pledge Transaction) and any permitted transferees
of the IXC Shares who are controlled Affiliates of IXC Communications, Inc.

               (b) IXC shall be entitled to acquire such number of shares of
Common Stock of PSINet which, when added to the number of shares of Common Stock
beneficially owned (excluding any rights IXC has hereunder to receive Additional
Shares) by IXC, its Affiliates and their respective successors and assigns,
would not exceed one share less than 20% of the then issued and outstanding
shares of Common Stock of PSINet and such acquisition of Common Stock of PSINet
under this Section 15.8(b) shall not, in and of itself, constitute a violation
of Section 15.8(a).

               (c) Upon the request of IXC at any time, or from time to time,
PSINet shall issue and sell to IXC up to 100 shares of Common Stock at the then
Current Market Price so long as such purchase does not cause IXC's beneficial
stock ownership to exceed 20% of the then issued and outstanding shares of
Common Stock of PSINet (it being understood that this Agreement and any action
taken in connection herewith shall not constitute a waiver under any provision
of PSINet's preferred stock purchase rights plan). Such issuance and sale of
Common Stock under this Section 15.8(c) shall not, in and of itself, constitute
a violation of Section 15.8(a).

        15.9 Registration Rights Agreement. PSINet and IXC shall each execute
and deliver to the other the Registration Rights Agreement attached hereto as
Exhibit N at the Closing.

        15.10 Non-Interference. IXC shall respect and not disturb PSINet's right
to its use and quiet enjoyment of the Bandwidth and shall take all reasonable
precautions against (and shall not knowingly use its Available System in a
manner which could reasonably be expected to result in) any interference by IXC
with respect to such use and quiet enjoyment. IXC shall have no right to use any
of the Bandwidth during the Term. Neither IXC nor PSINet shall knowingly use any
electronics or technologies which could reasonably be expected to subject risk
of damage to the other party's fibers, electronics or optronics. IXC shall use
such care in performing its obligations under this Agreement that equal or
exceed that which is normal and customary in the telecommunications industry.

        15.11 Use of Marks. Except as provided herein or by advance written
consent of the other Party, each of IXC and PSINet agrees not to (i) display or
use, in advertising or otherwise, any of the other's Marks, (ii) permit any
Affiliate to display or use any of the other's Marks, or (iii) give permission
to display or use any of the other's Marks to any Third Party. Any use by one
Party of any of the other's Marks shall be subject to such other Party's advance
approval in



                                       23

<PAGE>   28



writing, in its discretion, subject to compliance with guidelines provided by
it. Neither Party shall claim ownership or any other rights in any of the
other's Marks. Upon termination or expiration of this Agreement, any and all
rights or privileges granted by IXC or PSINet to use any Marks shall immediately
expire and each Party shall immediately discontinue the use of such Marks.
Nothing herein shall preclude either Party from making factual references to the
other in government filings, disclosure documents and other public statements,
except as otherwise set forth in the IRU Agreement.


SECTION 16.    CONDITIONS PRECEDENT TO CLOSING

        Each party shall not be obligated to proceed with the Closing, unless
and until the following conditions shall have been fulfilled or waived by the
applicable party:

        16.1 Approvals. Unless waived by each party, each of PSINet and IXC
shall have obtained all consents and approvals by (a) governmental authorities
that are necessary for the consummation of the transactions contemplated hereby
(including, without limitation, expiration or termination of all applicable
waiting periods (and any extensions thereof) under the Hart-Scott-Rodino Act,
and the effectiveness of any registration statement under the Securities Act of
1933 required prior to the Closing in connection with the reincorporation of
PSINet in the State of Delaware; and (b) any other Person necessary for the
consummation of the transactions contemplated by this Agreement. Each party
shall work with the other to acquire any permits or licenses required to be
obtained by the other party; provided, however, except as may be required
pursuant to Section 15.1, above, neither party shall be required to make any
payment or assume any liability in connection therewith.

        16.2 Reincorporation. PSINet shall have reincorporated in the State of
Delaware by merging into Newco pursuant to documents satisfactory to IXC and
PSINet.

        16.3 Shareholder Approval. Unless waived by each party, PSINet shall
have obtained all approvals of its shareholders which are required in connection
with the execution, delivery and performance of this Agreement, including,
without limitation, approval of the reincorporation of PSINet in the State of
Delaware and the issuance of the IXC Shares to IXC as provided in this
Agreement.

        16.4 Appraisal Rights. Unless waived by PSINet, the reincorporation of
PSINet in the State of Delaware shall not give rise to the exercise of statutory
appraisal rights involving an aggregate amount greater than $2,000,000.

        16.5   Fairness Opinions.

               (a) Unless waived by PSINet, there shall have been delivered to
PSINet an opinion of independent investment bankers selected by PSINet, in form
and substance satisfactory to PSINet, (i) as to the fairness to PSINet and its
stockholders from a financial point of view of the issuance of the IXC Shares
and the consummation of the transactions contemplated by, and in connection
with, this Agreement and (ii) as to the value of the IRUs being granted by IXC
to PSINet and the securities being issued or issuable by PSINet to IXC pursuant
to this Agreement.

               (b) Unless waived by IXC, there shall have been delivered to IXC
an opinion of independent investment bankers selected by IXC, in form and
substance satisfactory to IXC, as to the fairness to IXC from a financial point
of view of the transactions contemplated by, and in connection with, this
Agreement.

        16.6 Consent of Bondholders. Unless waived by IXC, IXC shall have
obtained, upon terms acceptable to IXC, all approvals of its bondholders which



                                       24

<PAGE>   29


are required in connection with the execution, delivery and performance of this
Agreement and the transactions contemplated by, and in connection with, this
Agreement.

        16.7 Contribution Agreement. The Contribution Agreement, in form and
substance satisfactory to PSINet and IXC, shall have been executed and delivered
by each of Carrier and IXC.

        16.8 Material Adverse Effect. Unless waived by each party, no Material
Adverse Effect shall have occurred with respect to either party, Carrier or IXC
Communications Inc. from the date hereof through the Closing.

        16.9 Acquisition of PSINet. Unless waived by IXC, prior to the Closing,
no Person shall have acquired or agreed to acquire more than 50% of the
outstanding common stock of PSINet.

        16.10 Preferred Stock Purchase Plan Amendment. Unless waived by each
party, PSINet shall have entered into an amendment to its preferred stock
purchase rights plan on or before August 1, 1997, satisfactory to IXC and
PSINet, providing, among other things, for purposes: (i) of the definitions of
"Acquiring Person", "Beneficial Owner" and "Beneficial Ownership"; and (ii) of
the definitions of "Associate" and Affiliate" of an Acquiring Person:

               (i) no Person shall be deemed to be an "Affiliate" or "Associate"
(as such terms are used in the preferred stock purchase rights plan) of IXC, IXC
Communications, Inc. or any controlled Affiliate of IXC or IXC Communications,
Inc. (collectively, the "IXC Parties") except for other IXC Parties and no IXC
Party will be deemed to be an "Affiliate" or "Associate" of any Person except
for other IXC Parties; and

               (ii) no Person (except for other IXC Parties) shall be deemed to
be the Beneficial Owner (as such term is used in the preferred stock purchase
rights plan) of shares of Common Stock owned by any IXC Party and no IXC Party
shall be deemed to be the Beneficial Owner of shares of Common Stock owned by
any Person (other than other IXC Parties);

unless, in any such case, any IXC Party and such Person: (A) are members of a
"group" within the meaning of Rule 13d-5 under the 1934 Act for or in
furtherance of the purpose of (x) acquiring, holding, voting or disposing of
securities of PSINet, (y) seeking to control the management, Board of Directors
or policies of PSINet, or (z) effecting or seeking to effect any action,
transaction, change or matter referred to in any one or more of clauses (a)
through (j) of Item 4 of Securities and Exchange Commission Schedule 13D as in
effect on May 8, 1996, or (B) otherwise are, or shall be deemed to be, acting in
concert for or in furtherance of any such purpose.

               Furthermore, such amendment shall provide that such amended
provisions of the preferred stock purchase rights plan cannot be further amended
without the written consent of IXC, in a way that materially adversely affects
any IXC Party (it being agreed that PSINet and its Board of Directors generally
have the right to amend, modify or waive provisions of the preferred stock
purchase rights plan insofar as they may relate to the approval of transactions
with and other matters involving parties other than IXC regardless of whether
such transaction or matter could result in a change of ownership or control of
PSINet or its businesses or operations or any of its controlled Affiliates, the
composition of the Board of Directors of PSINet or similar fundamental corporate
change or change of relative ownership of Common Stock).

               As promptly as practicable upon fulfillment or waiver of the
conditions set forth in this Section 16, PSINet and IXC agree to execute a
certificate certifying that such conditions have been satisfied or waived and
that the Closing Date has occurred.



                                       25

<PAGE>   30


SECTION 17. THE CLOSING. On the terms and subject to the satisfaction of the
conditions contained in this Agreement, the closing of the grant of the PSINet
Fiber IRU and the IRU in the IRU Capacity and the sale and purchase of the IXC
Shares hereunder (the "Closing") shall take place at the offices of PSINet or
such other place, time and date as may be mutually agreed to by the parties as
soon as possible after the conditions of Section 16 have been fulfilled.

        17.1 Deliveries by PSINet. At the Closing, PSINet shall deliver the
following:

               (a) The certificates representing the IXC Initial Common Shares;

               (b) A legal opinion of Nixon, Hargrave, Devans & Doyle LLP,
counsel to PSINet, as may be reasonably requested by IXC and mutually agreed to
by the parties;

               (c) An Officer's Certificate as may be reasonably requested by
IXC and mutually agreed to by the parties; and

               (d) The executed Registration Rights Agreement contemplated by
Section 15.9, above.

        17.2 Deliveries by IXC. At the Closing, IXC shall deliver the following:

               (a) An Officer's Certificate as may be reasonably requested by 
PSINet and mutually agreed to by the parties;

               (b) The executed Registration Rights Agreement contemplated by
Section 15.9, above;

               (c) A legal opinion of Riordan & McKinzie, counsel to IXC, as may
reasonably requested by PSINet and mutually agreed to by the parties;

               (d) The Security Agreement and such UCC statements and other
instruments as may be deemed reasonably necessary by PSINet to effect the grant
of security interests pursuant to Section 1; and

               (e) Such other instruments, documents and certificates as are
reasonably requested by PSINet to effect the grant of the indefeasible rights of
use hereunder.

        17.3 Survival of Representations and Warranties. Regardless of any
investigation at any time made by or on behalf of any party, or of any
information any party may have in respect thereof, all representations and
warranties made hereunder or pursuant hereto or in connection with the
transactions contemplated hereby shall survive the Closing for a period of two
years from the Closing; provided, however, that each party hereby represents and
warrants to the other party that it has no actual knowledge as of the date
hereof or as of the Closing of any breach of any representation or warranty by
such other party (as contrasted with knowledge solely of a fact which may give
rise to any such breach).


SECTION 18.    TERMINATION

        18.1 Termination. This Agreement may be terminated at any time prior to
the Closing Date:

               (a) by the written agreement of PSINet and IXC; or



                                       26

<PAGE>   31



               (b) by PSINet or IXC if the conditions set forth in Section 16 of
this Agreement, through no fault of the terminating party, have not been
satisfied on or prior to November 25, 1997 (as such date may be extended by
mutual agreement of the parties); or

               (c) by PSINet or IXC if any decree, permanent injunction,
judgment, order or other action by any court of competent jurisdiction or any
governmental authority preventing or prohibiting consummation of the
transactions contemplated by this Agreement shall have become final and
nonappealable.

        18.2 Effect of Termination. Upon termination of this Agreement pursuant
to Section 18.1, above, this Agreement shall thereafter become void and have no
effect, and neither party hereto shall have any liability to the other party in
respect thereof, except that nothing herein shall relieve either party from
liability for any material breach of this Agreement, including a breach covering
the failure to use reasonable efforts to satisfy the conditions set forth in
Section 16; provided, however, neither party shall have any liability arising
out of any termination by reason of the failure of the conditions set forth in
Section 16 to have been satisfied.


SECTION 19.    GENERAL PROVISIONS

        19.1 Definitions. As used in this Agreement, the following terms shall
have the following meanings:

        "Accepted": means that PSINet has tested Bandwidth and found it to
satisfy the specifications contained in Exhibit F hereto and thereafter,
accepted it in accordance with Exhibit F hereto.

        "Access Right": as defined in Section 7.4(b).

        "Additional Shares Value": means, as of the applicable date of
calculation, an amount equal to the difference, if greater than zero, between
(A) $240,000,000 and (B) the IXC Common Shares Value determined as of the
applicable date of calculation.

        "Affiliate": of a Person means any Person which directly or indirectly
controls, is under common control with, or is controlled by, such Person, where
"control" means the power and ability to direct the management and policies of
the controlled Person through the ownership of voting shares of the controlled
Person or by contract or otherwise. Notwithstanding the foregoing, Trustees of
General Electric Pension Trust and Grumman Hill Investments, L.P. and Grumman
Hill Associates, Inc. shall not be deemed to "control" or be "under common
control" with, or to be Affiliates of IXC and PSINet shall not be deemed to be
"controlled by" or "under common control with" IXC.

        "Aggregate Fair Market Value": with respect to a combination of cash and
Additional Shares as of a date of determination, means the sum of (i) such cash
and (ii) the product of the Common Stock Price as of such date and the number of
such Additional Shares.

        "Approved Subcontractor": shall mean (i) any person so approved by IXC
(which approval shall not be unreasonably withheld, conditioned or delayed),
(ii) the relevant equipment manufacturer or (iii) any authorized service agent
of the relevant equipment manufacturer.

        "Associates" shall have the meaning set forth in Rule 12b-2 promulgated
under the Securities Exchange Act of 1934, as amended, but shall exclude
Trustees of General Electric Pension Trust, Grumman Hill Investments, L.P. and
Grumman Hill Associates, Inc.


                                       27

<PAGE>   32



        "Authorized Representative": as defined in Section 10.1 of this
Agreement.

        "Available": of a Bandwidth Unit, means that IXC has tested the
Bandwidth Unit in accordance with Exhibit F hereto, the Bandwidth Unit performed
in accordance with the specifications set forth thereon, and the Bandwidth Unit
is thereafter made available for use by PSINet in accordance with such
specifications.

        "Available System": as defined in Section 1.2 of this Agreement.

        "Bandwidth": one or more Bandwidth Units.

        "Bandwidth Unit": a particular DS-3, OC-3, OC-12 or OC-48.

        "Bankruptcy Proceeding": as defined in Section 7.4(a) of this Agreement.

        "Barter Capacity": DS-3 capacity IXC has received from other carriers
through barter or swap arrangements.

        "Carrier": as defined in the recitals to this Agreement.

        "Closing": as defined in Section 17 of this Agreement.

        "Closing Date": the date of the Closing.

        "Collateral": as defined in Section 1.3 of this Agreement.

        "Collocation Agreement": the agreement in the form attached hereto as
Exhibit C which is to be executed and delivered by IXC and PSINet at the
Closing.

        "Commission": as defined in Section 13.5 of this Agreement.

        "Common Stock": Common Stock, par value $.01 per share, of PSINet or par
value $.0001 per share of Newco, as applicable.

        "Common Stock Price": means (i) the average closing market price per
share of the Common Stock or, if applicable, the Successor Stock, as reported by
The Nasdaq Stock Market or the principal securities exchange on which the Common
Stock or, if applicable, the Successor Stock, shall then be listed over the 20
trading day period immediately preceding the applicable date of calculation,
weighted by the average trading volume of the Common Stock or, if applicable,
the Successor Stock, as reported by The Nasdaq Stock Market or the principal
securities exchange on which the Common Stock or, if applicable, the Successor
Stock, shall then be listed on each day of such 20 trading day period, or (ii)
if the Common Stock, or, if applicable, the Successor Stock, is not as of the
applicable date of calculation listed on The Nasdaq Stock Market or any
securities exchange, the price per share of the Common Stock or, if applicable,
the Successor Stock, on the applicable date of calculation as determined by
mutual agreement of PSINet and IXC or, in the case of the Successor Stock, by
mutual agreement of the issuer of such Successor Stock and IXC.

        "Complete": with respect to a fiber route, means the fiber, optronics
and electronics in the route have been installed and tested and are ready for
commercial use ("completed" and "completion" have correlative meanings.)

        "Cure Period": as defined in Section 7.4(a) of this Agreement.

        "Current Market Price": as of a date means the closing price as publicly
reported on the Nasdaq Stock Market (or, if not available on such market, on the
principal trading market) of the Common Shares of PSINet as of 4:00 p.m. Eastern
Time on such date.


                                       28

<PAGE>   33


        "Deemed Accepted": means Bandwidth on the Available System made
Available to PSINet which meets the specifications for acceptance thereof by
PSINet set forth in Exhibit F to this Agreement and which has not been Accepted
by PSINet after the receipt by PSINet of a notice, given by IXC to PSINet in
accordance with the terms of Section 19.5 of this Agreement, that IXC has made
such Bandwidth so Available.

        "Delivery Completion Date": the date by which IXC has delivered to
PSINet and PSINet has Accepted 10,000 OC- 48 Equivalent Miles of Bandwidth.

        "DS-3": means a circuit meeting the specifications set forth in AT&T
Technical Reference Pub. 54014 Addendum 1, November 1992 and Bellcore
TB-NWT-608499, Issue 5, December 1993.

        "DS-3 Equivalent Mile": means one-forty eighth of an OC-48 Equivalent
Mile.

        "Excess Miles": as defined in Section 2.2 of this Agreement.

        "Hart-Scott-Rodino Act": as defined in Section 15.1 of this Agreement.

        "Indemnifying Party": as defined in Section 9 of this Agreement.

        "Internet": The global network of interconnected commercial, educational
and governmental computer networks that utilize a protocol that allow computers
with different architectures and operating system software to communicate
thereon, as the same may evolve and mature.

        "Internet Services Agreement": as defined in the recitals to this
Agreement.

        "IRU Capacity": as defined in Section 1.2 of this Agreement.

        "IXC Bankruptcy Proceeding": a Bankruptcy Proceeding filed or initiated
by or against IXC.

        "IXC Change of Control": (i) the shareholders of IXC approve an
agreement for the sale of all or substantially all of the assets of IXC; or (ii)
the shareholders of IXC approve a merger or consolidation of IXC with any other
corporation, other than (A) a merger for consideration which would result in the
voting securities of IXC outstanding immediately prior thereto continuing to
represent more than 80% of the combined voting power of the voting securities of
IXC, or such surviving entity, outstanding immediately after such merger or
consolidation, or (B) a merger or consolidation effected to implement a
recapitalization of IXC (or similar transaction) in which no "person" (as
defined below) acquires more than 20% of the combined voting power of IXC's
then-outstanding securities; or (iii) any "person," as such term is used in
Sections 13(d) and 14(d) of the 1934 Act (other than (A) IXC or (B) the
shareholders of IXC, or any corporation owned by the shareholders of IXC, in
substantially the same proportions as their ownership of stock of IXC) is or
becomes the "beneficial owner" (as defined in Rule 13d-3 under the 1934 Act),
directly or indirectly, of securities of IXC representing more of than 50% of
the combined voting power of IXC's then outstanding securities.

        "IXC Common Shares": means such number of shares of Common Stock (as
adjusted for any stock splits, stock dividends, recapitalizations or similar
events after the Closing Date) issued and sold by PSINet to IXC on the Closing
Date pursuant to this Agreement.

        "IXC Common Shares Value": means the aggregate fair market value of the
IXC Common Shares determined as of the applicable date of calculation, based on
the Common Stock Price as of such date, including, if applicable, for purposes
of such calculation, in the event a Merger or Other Reorganization Event shall
have



                                       29

<PAGE>   34



occurred on or prior to such date in connection with which there shall have been
issued or delivered to the holders of the Common Stock, in addition to or in
lieu of any Successor Stock, other securities or property, the fair market value
as of the applicable date of calculation of such other securities or property
received by IXC and/or any of its Affiliates and Associates in consideration for
the IXC Common Shares then owned by them (such fair market value to be initially
determined by the board of directors, general partners or board members, as
applicable of the successor Person resulting from such Merger or Other
Reorganization Event). In the event IXC disagrees with such determination of
fair market value, such fair market value shall be determined by arbitration
pursuant to Section 19.14.

        "IXC Initial Common Shares": as defined in Section 3.2 of this
Agreement.

        "IXC Fibers": as defined in Section 1.1 of this Agreement.

        "IXC Filing": as defined in Section 14.7 of this Agreement.

        "Long-Term Indefeasible IRU": as defined in Section 1.3 of this
Agreement.

        "Maintainable Equipment" shall mean the electrical, electronic and
optronic equipment which is utilized in delivering the PSINet Fiber IRU and the
IRU in the IRU Capacity to PSINet (a) including regeneration, op/amp, and fiber
terminating equipment, and multiplexing equipment but (b) excluding fiber in any
fiber optic cable.

        "Material Adverse Effect": a material adverse effect on the condition,
financial or otherwise, or operating results of a Person and its subsidiaries
taken as whole.

        "Material Provision": any provision of this Agreement or of any of the
Transaction Documents (including, without limitation, payment provisions but
excluding, in and of itself, any Bankruptcy Proceeding) the breach of which by
one party is determined by an arbitration pursuant to Section 19.14 to
constitute a material adverse effect on the use and enjoyment by the other party
of the benefits of such agreement.

        "Marks": shall mean trade names, logos, trademarks, trade devices, trade
dress, service marks, symbols, abbreviations or registered marks, or
contractions or simulations thereof, or any other indicia or origin.

        "Merger or Other Reorganization Event": means a capital reorganization
of the Common Stock (other than a subdivision, combination, reclassification or
exchange of shares) or a merger or consolidation of PSINet with or into another
Person or the sale of all or substantially all of PSINet's properties and assets
to any other Person.

        "Monetary Default": as defined in Section 7.4 (a) of this Agreement.

 "Newco": as defined in the recitals to this Agreement.

        "1934 Act": means the U.S. Securities Exchange of 1934, as amended, and
the rules and regulations thereunder.

        "Notice of Default": as defined in Section 7.4(a) of this Agreement.

        "Notice of Sale": as defined in Section 15.7 of this Agreement.

        "OC-3": means OC-3 SONET optical transmission capacity meeting the
applicable specifications set forth in Exhibit F hereto.



                                       30

<PAGE>   35



        "OC-12": means OC-12 SONET optical transmission capacity meeting the
applicable specifications set forth in Exhibit F hereto.

        "OC-12 Equivalent Mile": one-quarter of an OC-48 Equivalent Mile.

        "OC-48": means OC-48 SONET optical transmission capacity meeting the
applicable specifications set forth in Exhibit F.

        "OC-48 Equivalent": 1 OC-48, 4 OC-12s, 16 OC-3s or 48 DS-3s.

        "OC-48 Equivalent Mile": 1 Route Mile of OC-48 capacity, 4 Route Miles
of OC-12 capacity, 16 Route Miles of OC-3 capacity or 48 Route Miles of DS-3
capacity.

        "Offer Acceptance Date": as defined in Section 15.7 of this Agreement.

        "Offered Shares": as defined in Section 15.7 of this Agreement.

        "On-net": refers to any circuit which IXC is able to deliver on the
Available System as then completed.

        "Original Services Activation Date": the Service Activation Date of a
Bandwidth Unit, or, in the event the Bandwidth Unit is the result of the
Reconfiguring of one or more other Bandwidth Units, the earliest Service
Activation Date of any such Bandwidth Units.

        "Person": any individual, corporation, partnership, firm, joint venture,
association, limited liability company, trust, unincorporated organization or
other entity.

        "POPs": those IXC locations listed in Exhibit K hereto (as expanded by
IXC from time to time.)

        "PSINet Fiber IRU": as defined in Section 1.1 of this Agreement.

        "PSINet Filing": as defined in Section 13.5 of this Agreement.

        "Reconfigure": to swap Bandwidth between two points for lesser, equal or
greater amount of Bandwidth between such points or elsewhere.

        "Reduction Mile": as defined in Section 1.4 of this Agreement.

        "Requested Delivery Date": as to Bandwidth, the date requested by PSINet
that IXC make such Bandwidth Available, as set forth in the applicable Bandwidth
Order and as applicable as modified by IXC pursuant to Section 4.2.

        "Rights-of-Way": all rights, licenses, authorizations (including,
without limitation, any sate, local, tribal or federal authorizations or permits
(including, without limitation, environmental permits)), rights-of-way,
easements, landlord consents and other agreements now existing or hereafter
arising which are necessary for (i) the use of poles, conduit, cable, wire or
other physical plant facilities relating to or used in connection with the
PSINet Fiber IRU and the capacity IRU granted to PSINet hereunder and (ii) the
installation, use and quiet enjoyment of the PSINet Fiber IRU and the capacity
IRU granted to PSINet hereunder.

        "Route Mile": one mile of the actual geographic length of the fiber
route.

        "Securities Act": the Securities Act of 1933, as amended, and the rules
and regulations thereunder.

        "Selling Shareholder": as defined in Section 15.7 of this Agreement.



                                       31

<PAGE>   36

        "Service Activation Date": with respect to a Bandwidth Unit, the date
the Bandwidth Unit is first Accepted by PSINet.

        "Shortfall Mileage": the amount of Route Miles by which the length of
the Available System is less than 10,000 miles.

        "Short-Term Indefeasible IRU": as defined in Section 2.3 of this
Agreement.

        "Six-Month Period": any six-month period starting October 1 or April 1
of any year.

        "Standstill Agreement": the Standstill Agreement of even date hereof
from IXC Communications, Inc. to PSINet.

        "Successor Stock": means the capital stock or other equity securities of
any Person issuable to the holders of the Common Stock in connection with any
Merger or Other Reorganization Event.

        "Term": as defined in Section 6.1 of this Agreement.

        "Total Bandwidth": means 10,000 OC-48 Equivalent Miles of Bandwidth on
the Available System to be made Available to PSINet pursuant to the terms of
this Agreement.

        "Transaction Documents": this Agreement, the Registration Rights
Agreement, the Security Agreement, the Standstill Agreement, the Internet
Services Agreement and each of the agreements, instruments and documents
executed and delivered by PSINet or IXC pursuant to this Agreement, but not
including the Newco Certificate of Incorporation and By-laws, the amendment to
PSINet's preferred stock purchase rights plan or the Contribution Agreement.

        "Voting Securities" the Common Shares and any other securities of PSINet
as may from time to time be entitled to vote for the election of directors of
PSINet without regard to any event or occurrence.

        19.2 Amendments, Waivers and Consents. For purposes of this Agreement
and the Transaction Documents, except as otherwise specifically set forth herein
or therein, no course of dealing between PSINet and IXC and no delay on the part
of either party hereto in exercising any rights hereunder or thereunder shall
operate as a waiver of the rights hereof and thereof. No covenant or other
provision hereof or thereof may be waived or amended other than by a written
instrument signed by the party so waiving or amending such covenant or other
provision.

        19.3 Section Headings. The table of contents and section headings in
this Agreement have been inserted for reference purposes only and shall not be
deemed to limit or otherwise affect the construction of any provision thereof or
hereof.

        19.4 Counterparts. This Agreement may be executed simultaneously in any
number of counterparts, each of which when so executed and delivered shall be
taken to be an original, but such counterparts shall together constitute but one
and the same document.

        19.5 Notices. All notices, claims, demands and other communications
under this Agreement shall be in writing and shall be deemed given when
delivered personally, the next business day after delivered to a nationally
recognized overnight courier for next business day delivery, when transmitted by
facsimile or five (5) days after sent by registered or certified mail, return
receipt requested, to the parties (and to the Persons receiving copies thereof)
at the following addresses or facsimile numbers (or to such other address or
facsimile number as a party may have specified by notice given to the other
party pursuant to this provision):



                                       32

<PAGE>   37


               If to IXC to:

                      IXC Internet Services, Inc.
                      5000 Plaza on the Lake, Suite 200
                      Austin, TX 78746
                      Attention: Chairman
                      Facsimile: (512) 328-0239

               With copies to:

                      IXC Communications, Inc.
                      5000 Plaza on the Lake, Suite 200
                      Austin, TX 78746
                      Attention: General Counsel
                      Facsimile: (512) 328-7902

                      Riordan & McKinzie
                      695 Town Center Drive, Suite 1500
                      Costa Mesa, California 92626
                      Attention: Michael P. Whalen
                      Facsimile: (714) 549-3244

               If to PSINet to:

                      PSINet Inc.
                      510 Huntmar Park Drive
                      Herndon, Virginia 20170
                      Attention: Chairman
                      Facsimile: (703) 904-1608

               With a copy to:

                      PSINet Inc.
                      510 Huntmar Park Drive
                      Herndon, Virginia 20170
                      Attention: General Counsel
                      Facsimile: (703) 904-9527

               and to:

                      Nixon, Hargrave, Devans & Doyle LLP
                      437 Madison Avenue
                      New York, New York 10022
                      Attention: Richard F. Langan, Jr.
                      Facsimile: (212) 940-3111

        19.6 Binding Effect; Assignment. This Agreement shall be binding upon
and inure to the benefit of the parties and their respective successors and
permitted assigns. Nothing in this Agreement shall create or be deemed to create
any third party beneficiary rights in any person or entity not a party to this
Agreement except as provided below. No assignment of this Agreement or of any
rights or obligations hereunder may be made by either party without the prior
written consent of the other party hereto and any attempted assignment without
the required consent shall be void; provided, however, that notwithstanding the
foregoing, (i) as permitted by, and subject to the provisions of, Section 15.5
hereof, PSINet shall have the right to sell, swap, lease, assign or otherwise
transfer all or a portion of its rights in any of the IRU's to any person who
agrees in writing with IXC to be bound by Section 15.5 and this Section 19.6,
(ii) each party shall have the right to pledge, assign or otherwise transfer
this Agreement and its rights hereunder, in whole or in part, as collateral
security



                                       33

<PAGE>   38

to any lender, and (iii) each party shall have the right to assign or transfer
this Agreement and its rights hereunder, in whole or in part, to its parent or
to any direct or indirect wholly-owned subsidiary of that party or to any Person
into which that party may be merged or consolidated or which purchases all or
substantially all of the assets of that party; provided, however, that (a) such
parent, subsidiary or Person agrees to be bound by the terms of this Agreement
(including, without limitation, all provisions binding upon the assigning or
transferring party) and (b) any such assignment or transfer shall not relieve
that party from any liability or obligation under this Agreement.

        19.7   Severability; Specific Performance.

               (a) Whenever possible, each provision of this Agreement shall be
interpreted in such a manner as to be effective and valid under applicable law,
but if any provision of this Agreement shall be deemed prohibited or invalid
under such applicable law, such provision shall be ineffective to the extent of
such prohibition or invalidity, and such prohibition or invalidity shall not
invalidate the remainder of such provision or the other provisions of this
Agreement.

               (b) Each of PSINet and IXC recognizes and affirms that in the
event of breach by it or any controlled Affiliate of any of the provisions of
Section 15.6, 15.7, or 15.8 money damages would be inadequate and the other
party would have no adequate remedy at law. Accordingly, each party shall have
the right, in addition to any other rights and remedies existing in its favor,
to enforce its rights and the other parties' obligations under Section 15.6,
15.7 or 15.8 not only by an action or actions for damages, but also by an action
or actions for specific performance, injunction and/or other equitable relief in
order to enforce or prevent any violations (whether anticipatory, continuing or
future) of the provisions thereof (including, in the case of Section 15.6, the
extension of the 3-year period by a period equal to (i) the length of the
violation of Section 15.6 plus (ii) the length of any court proceedings
necessary to stop such violation). In the event of a breach or violation by a
party of any of the provisions of Section 15.6, the running of the 3-year period
(but not of the party's obligations under Section 15.6) shall be tolled during
the continuance of any actual breach or violation.

        19.8 Expenses. Except as otherwise provided in this Agreement, each
party shall bear its own costs and expenses (including attorney's fees), and all
taxes imposed upon it under applicable law, in connection with the negotiation,
execution and performance of this Agreement and each other agreement, document
and instrument contemplated by this Agreement and in connection with the
consummation of the transactions contemplated hereby and thereby and all
obligations required to be performed by each of them hereunder and thereunder.

        PSINet shall pay all sales, use and excise taxes related to the
Bandwidth and services provided by IXC under this Agreement and any other taxes
related to the Bandwidth and services under this Agreement which are by the
terms of the relevant statute or ordinance imposed upon PSINet; provided that,
where permitted, PSINet may provide sale or resale exemption certificates to
IXC. In no event shall PSINet be obligated to pay income taxes levied upon IXC's
income or any real or personal property taxes assessed against IXC or IXC's
property, including any gross receipts taxes assessed in lieu of income or
property taxes, provided that, if the terms of the relevant statute or ordinance
imposes such gross receipts tax upon PSINet, then PSINet shall be liable for
such tax. PSINet shall pay IXC said gross receipts taxes when they become due
provided that the taxes are invoiced and included as a separate line item on the
same invoice that is subject to such tax. IXC shall pay any such tax not
invoiced to PSINet at the time such tax is incurred.

        19.9 Integration. This Agreement, including the exhibits, documents and
instruments referred to herein constitutes the entire agreement, and supersedes



                                       34

<PAGE>   39



all other prior agreements and understandings, both written and oral, among the
parties with respect to the subject matter hereof, other than the
Confidentiality Agreement between the parties dated as of May 14, 1997.

        19.10 Schedules. The disclosure of information in the PSINet Disclosure
Schedule, the IXC Disclosure Schedule, in any other Schedule or any Exhibit
hereto shall be deemed to be disclosure in each other Schedule hereto. The
inclusion of any information in the PSINet Disclosure Schedule, the IXC
Disclosure Schedule, or any Schedule hereto shall not be deemed to be an
admission by PSINet or IXC that such information is material or outside the
ordinary course of business.

        19.11 Public Announcements. Neither party shall publish or use any
advertising, sales, promotions, or other publicity materials that use the other
party's name, logo, trademarks or service marks without the prior written
approval of the other party. Each party shall have the right to review, comment
upon and approve any publicity materials, press releases or other public
statements by the other that refer to, or that describe any aspect of, this
Agreement made prior to, or within 90 days after, the Closing; provided,
however, that with respect to IXC's consent solicitation and to disclosure
documents required under the 1934 Act, subject to the last sentence of this
Section 19.11, each party shall only have the right to prior review and to
comment upon the other party's documents. Each party agrees that it will not
issue any such publicity materials, press releases or public statements without
the prior written approval of the other party. Nothing in this Agreement
establishes a license for either party to use any of the other party's brands,
marks, or logos without the prior written approval of the other party. The
provisions of this section shall survive termination of this Agreement for a
period of two years, except for the last sentence hereof which shall survive for
the Term. IXC and PSINet shall cooperate to request confidential treatment as
may be mutually agreed by them with respect to certain terms of this Agreement,
the Transaction Documents and transactions contemplated hereby and thereby in
any filing with the Commission, any other governmental authority or any
securities exchange or stock market.

        19.12 Interpretation. The parties acknowledge and agree that: (i) each
party and its counsel reviewed and negotiated the terms and provisions of this
Agreement and have contributed to its revision; (ii) the rule of construction to
the effect that any ambiguities are resolved against the drafting party shall
not be employed in the interpretation of this Agreement; and (iii) the terms and
provisions of this Agreement shall be construed fairly as to both parties
hereto, regardless of which party was generally responsible for the preparation
of this Agreement or any provision hereof.

        19.13 Governing Law. This Agreement shall be deemed to be a contract
made under, and shall be construed in accordance with, the laws of the State of
Delaware without reference to its principles of conflicts of law.

        19.14  Dispute Resolution.

               (a) If any controversy or claim arises out of or relates to this
Agreement or with respect to an alleged breach of the terms hereof, subject to
Section 19.7, above, PSINet and IXC shall seek to resolve the matter amicably
through discussions between themselves. The parties shall attempt to resolve all
controversies, claims or breaches at the operational level, and in the event a
resolution cannot be reached, such controversy, claim or breach will be referred
progressively to higher levels within each party, to their respective
chairpersons. If the parties fail to resolve such controversy, claim or breach
within thirty (30) days by amicable arrangement and compromise, either party may
seek arbitration as set forth below but only within four years of the occurrence
of the events giving rise to, or the accrual of, such controversy, claim or
breach.



                                       35

<PAGE>   40


               (b) Except as provided in Section 19.7, above, any controversy or
claim arising out of or in relating to this Agreement, or a breach of this
Agreement, shall be finally settled by binding arbitration in Chicago, Illinois
in accordance with the J.A.M.S./ENDISPUTE Arbitration Rules and Procedures
("Endispute Rules"), as amended by this Agreement. If possible, the parties
shall appoint by mutual agreement, as the arbitrator, an attorney experienced in
telecommunications, securities law and transactional matters. If such agreement
cannot be reached, the arbitrator shall be such type of attorney and shall be
chosen under the Endispute Rules. The costs of arbitration, including the fees
and expenses of the arbitrator, shall be shared equally by the parties unless
the arbitration award provides otherwise or except as provided in Section 7.2.
Each party shall bear the cost of preparing and presenting its case. The parties
agree that this provision and the arbitrator's authority to grant relief shall
be subject to the United States Arbitration Act, 9 U.S.C. 1-16 et seq. ("USAA"),
the provisions of this Agreement, and the ABA-AAA Code of Ethics for Arbitrators
in Commercial Disputes. The parties agree that the arbitrator shall have no
power or authority to make awards or issue orders of any kind except as
expressly permitted by this Agreement, and in no event shall the arbitrator have
the authority to make any award that provides for punitive or exemplary damages.
The arbitrator's decision shall follow the plain meaning of relevant documents,
and shall be final and binding. The award may be confirmed and enforced in any
court of competent jurisdiction. All post-award proceedings shall be governed by
the USAA.

        19.15 Relationship of the Parties. This Agreement and the Transaction
Documents shall not be deemed to cause either party hereto to be deemed the
agent or partner of the other party and neither party shall have the right to
bind the other. This Agreement shall not be interpreted to impose any limitation
or restriction on IXC's ability to enter the Internet business or to acquire
Internet-related companies or to enter into agreements with other Internet
companies.

        19.16 Laws and Licenses. This Agreement is subject to all applicable
federal, state and local laws, regulations, rulings and orders of governmental
agencies, including, but not limited to, the Communications Act of 1934 as
amended by the Telecommunications Act of 1996, and the rules and regulations of
the FCC.

        19.17 Facsimile Delivery. This Agreement may be delivered by facsimile
transmission of an executed counterpart signature page hereof, and after
attachment of such transmitted signature page to a copy of this Agreement, such
copy shall have the same effect and evidentiary value as copies delivered with
original signatures. Any party delivering this Agreement by facsimile
transmission shall deliver to the other party, as soon as practicable after such
delivery, an original executed counterpart signature page of this Agreement.

        IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement
as of the day and year first above written.

                                    IXC Internet Services, Inc.

                                    By:     /s/    RALPH J. SWETT
                                       -----------------------------------------
                                            Name:  Ralph J. Swett
                                            Title: Chairman, President and CEO

                                    PSINet Inc.

                                    By:     /s/    WILLIAM L. SCHRADER
                                       -----------------------------------------
                                            Name:   William L. Schrader
                                            Title: Chairman, President and CEO


                                       36

<PAGE>   41


                                     PSINET
                                  EXHIBIT LIST


<TABLE>
<S>                   <C>
Exhibit A             Available System

Exhibit B             Security Agreement

Exhibit C             Collocation and Interconnection Agreement

Exhibit D             Newco Common Stock Percentage Determination

Exhibit E             Associated Services

Exhibit F             OC-N Specifications and Testing Standards

Exhibit G             PSINet's Bandwidth Forecast

Exhibit G-1           Initial Order

Exhibit H             Multiplexing Fees

Exhibit I             Reconfiguration Fees

Exhibit J             Newco Certificate of Incorporation

Exhibit K             POP Space

Exhibit L             PSINet Disclosure Schedule

Exhibit M             IXC Disclosure Schedule

Exhibit N             Registration Rights Agreement

</TABLE>


<PAGE>   42

                                    EXHIBIT A


                                AVAILABLE SYSTEM


                                      [MAP]



<PAGE>   43


                                    EXHIBIT B



<PAGE>   44

                                    EXHIBIT B
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT

                        SECURITY AGREEMENT AND ASSIGNMENT


        THIS SECURITY AGREEMENT AND ASSIGNMENT, dated as of __________, 1997, is
made by and between IXC Internet Services, Inc. a Delaware corporation
(hereinafter, together with its successors and assigns, "IXC"), and PSINet Inc.,
a New York corporation (hereinafter, together with its successors and assigns,
"PSINet" or the "Secured Party"). All capitalized terms used but not otherwise
defined herein shall have the meanings set forth in that certain IRU and Stock
Purchase Agreement entered into as of July 22, 1997 (as amended, supplemented or
modified, the "Purchase Agreement").

                             PRELIMINARY STATEMENTS:

        A. IXC and PSINet are parties to the Purchase Agreement pursuant to
which, among other things, PSINet has acquired the PSINet Fiber IRU and the IRU
Capacity from IXC and IXC has acquired from PSINet 19.99999% of the total
outstanding shares of Common Stock of PSINet.

        B. Pursuant to the Purchase Agreement, IXC has agreed to execute and
deliver this Security Agreement and to grant to PSINet a security interest in
the Collateral (as hereinafter defined) as security for IXC's obligation to
provide the PSINet Fiber IRU and IRU in the IRU Capacity.

        NOW, THEREFORE, in consideration of the premises and of the mutual
covenants herein contained and for other good and valuable consideration, the
receipt of which is hereby acknowledged, the parties hereto agree as follows:

                                A G R E E M E N T

        1. Defined Terms. As used in this Security Agreement the following terms
have the following meanings, unless the context otherwise requires:

               "Collateral" has the meaning assigned to it in Section 2 of this
        Security Agreement.

               "Default" means a default under the Purchase Agreement that
        remains uncured following the expiration of any applicable cure period
        and that materially and adversely affects the use and enjoyment of the
        PSINet Fiber IRU or the IRU in the IRU Capacity by PSINet.

               "GAAP" means generally accepted accounting principles in the
        United States of America from time to time in effect as set forth in the
        opinions and pronouncements of the Accounting Principles Board and the
        American Institute of Certified Public Accountants and the statements
        and pronouncements of the Financial Accounting Standards Board, or in
        such other statements by any successor entity as may be in general use
        by significant segments of the accounting profession that are applicable
        to the circumstances as of the date of determination.

               "hereby," "herein," "hereof," "hereunder" and words of similar
        import refer to this Security Agreement as a whole and not merely to the
        specific section, paragraph or clause in which the respective word
        appears.

               "Lien" means any mortgage, pledge, charge, security interest or
        other encumbrance.



<PAGE>   45


               "Permitted Liens" means (i) any Liens for taxes not yet
        delinquent or Liens for taxes being contested in good faith and by
        appropriate proceedings promptly instituted and diligently concluded,
        and (ii) materialmen's and mechanic's Liens and other similar Liens
        arising in the ordinary course of business, which are being contested in
        good faith by appropriate proceedings or are paid within 60 days from
        the creation thereof, and which do not impair the use and enjoyment by
        PSINet of the PSINet Fiber IRU and/or the IRU in the IRU Capacity.

               "Proceeds" means "proceeds," as such term is defined in section
        9-306(1) of the UCC and, in any event, shall include, without
        limitation, (i) any and all payments (in any form whatsoever) made or
        due and payable to IXC from time to time in connection with any
        requisition, confiscation, condemnation, seizure or forfeiture of all or
        any part of the Collateral by any governmental body, authority, bureau
        or agency (or any person acting under color of governmental authority),
        and (ii) any and all other amounts from time to time paid or payable to
        IXC under or in connection with any of the Collateral, excluding from
        such other amounts, amounts paid to IXC by PSINet.

               "Secured Obligations" means IXC's obligation to provide the
        PSINet Fiber IRU and the IRU in the IRU Capacity pursuant to the
        Purchase Agreement.

               "Security Agreement" means this Security Agreement and
        Assignment, as the same may from time to time be amended or
        supplemented.

               "UCC" means the Uniform Commercial Code as the same may, from
        time to time, be in effect in the State of Delaware; provided, however,
        in the event that, by reason of mandatory provisions of law, any or all
        of the attachment, perfection, priority or exercise of remedies of
        either Secured Party's security interest in any Collateral is governed
        by the Uniform Commercial Code as in effect in a jurisdiction other than
        the State of Delaware, the term "UCC" means the Uniform Commercial Code,
        as in effect in such other jurisdiction for purposes of the provisions
        hereof relating to such attachment, perfection, priority or exercise of
        remedies and for purposes of definitions related to such provisions.

        2.     Grant of Security Interest; Collateral Assignment.

        2.1 Collateral. (a) As collateral security for the prompt and complete
performance when due of the Secured Obligations, IXC hereby grants to the
Secured Party a continuing security interest in, all IXC' right, title and
interest in, to and under the following, whether now owned or hereafter acquired
and wherever located (all of which, together with the Collateral as further
defined in this Section 2.1(a) and in Section 2.1(b), being hereinafter
collectively called the "Collateral"):

               (i)    the Long-Term Indivisible IRU;

               (ii)   the Short-Term Indivisible IRU;

               (iii)  the Access Right; and

               (iv)   to the extent not otherwise included, all Proceeds of the
                      foregoing.

        As set forth in Section 1.4 of the Purchase Agreement, the PSINet Fiber
IRU and the Base IRU in the IXC Fibers shall be extended to cover additional
completed portions of the Available System effective immediately upon completion
without any further action on the part of IXC and the Long-Term Indivisible IRU
and the Short-Term Indivisible IRU shall include such completed portions of the



                                       -2-

<PAGE>   46



Available System. IXC hereby grants, without further action on its part, and
will execute the necessary documents to evidence such grant of a continuing
security interest in (i) the Long-Term Indivisible IRU (with such defined phrase
being extended to cover such completed portions of the Available System) and the
products and proceeds thereof, (ii) the Short- Term Indivisible IRU, and (iii)
the Access Right (with each such defined phrase being extended to cover such
completed portion of the Available System) and the products and proceeds
thereof, and the Long-Term Indivisible IRU, the Short-Term Indivisible IRU, and
the Access Right, as so extended, will thereupon become part of the Collateral.
Notwithstanding the foregoing, however, commencing in respect of any completed
portion of the Available System, after the date on which such completed portion
of the Available System shall have been completed, the length of the Short-Term
Indivisible IRU shall not exceed the excess, if any, of 10,000 Route Miles over
the number of completed Route Miles on the Available System Accepted by the
Secured Party. To the extent completion of additional portions of the Available
System requires shortening the length of the Short-Term Indivisible IRU (which
is subject to the security interest pursuant to the preceding sentence) by a
certain number of Route Miles (the "Reduction Miles"), the Short-Term
Indivisible IRU shall be deemed to be shortened 30 days after the date on which
such completed portion of the Available System shall have been completed by
changing its definition to exclude a number of Route Miles equal to the number
of Reduction Miles. The specific Route Miles excluded shall be determined by
excluding that number of Route Miles of the Available System most recently
completed beginning with the eastern most portion along the applicable route,
all as set forth in a written notice from IXC to the Secured Party.

        (b) IXC does hereby assign, transfer and set over unto Secured Party, as
collateral security for the prompt and complete performance of the Secured
Obligations, all of IXC's rights and interests in and to the Contribution
Agreement to the extent necessary to deliver and provide PSINet with the IRU in
the IRU Capacity and the PSINet Fiber IRU (such necessary rights and interests
in and to the Contribution Agreement being referred to as the "PSINet Rights"),
including without limitation: (i) the right to receive, use and accept the
PSINet Rights, (ii) all claims for damages in respect of the PSINet Rights
arising as a result of any default under the Contribution Agreement, (iii) any
and all rights of IXC to compel performance of the terms of the Contribution
Agreement relating to the PSINet Rights, and (iv) all rights, benefits and
claims under all warranty and indemnity provisions, if any, contained in the
Contribution Agreement relating to the PSINet Rights. Notwithstanding the
foregoing, so long as no Default shall have occurred and be continuing, Secured
Party authorizes IXC, without affecting the terms of this Agreement, to exercise
in its own name the PSINet Rights under the Contribution Agreement. The defined
term "Collateral" under this Agreement shall include the PSINet Rights.

        2.2 Non-Disturbance and Restrictions. The Secured Party and each
transferee of any Collateral pursuant to this Agreement shall not disturb the
exercise of the rights of any third party or IXC to use fibers, appurtenances or
equipment in the Available System so long as the exercise of such rights does
not interfere with the exercise by PSINet of its rights to use the PSINet Fiber
IRU, the IRU in the IRU Capacity or to enjoy the benefits thereof. The rights of
PSINet and each such transferee hereunder are subject to the obligation to
comply with Section 8, Section 15.5 and the other obligations of PSINet under
the Purchase Agreement.

        3. Representations and Warranties. IXC hereby represents and warrants
that:

        3.1 Ownership, Liens. Except for the security interest granted to the
Secured Party pursuant to this Security Agreement, IXC is the owner of each item
of the Collateral, having good title thereto, free and clear of any and all
Liens other than Permitted Liens.


                                       -3-

<PAGE>   47



        3.2 Business Locations. IXC' principal place of business and the place
where its records concerning the Collateral are kept are at the locations listed
in Schedule I hereto, and IXC will not change such principal place of business
or remove such records without at least thirty (30) days prior written notice to
each Secured Party and providing to Secured Party such documents and taking such
action as is necessary to ensure PSINet has a first priority perfected security
interest in the Collateral.

        3.3 Trade Names. Neither IXC nor any of its predecessors in interest
has, at any time within the five-year period ending on the date hereof,
conducted any business under any name other than "IXC Internet Services, Inc."
except as set forth on Schedule IV hereto.

        3.4 Identification Number. The Federal Employer Identification Number of
IXC is _________.

        4. Covenants. IXC covenants and agrees with the Secured Party that from
and after the date of this Security Agreement and until the Secured Obligations
are fully satisfied:

        4.1 Compliance with Laws. IXC will comply, in all material respects,
with all acts, rules, regulations, orders, decrees and directions of any
governmental authority, applicable to the Collateral or any part thereof;
provided, however, that IXC may contest any act, regulation, order, decree or
direction in any reasonable manner which shall not in the sole opinion of the
Secured Party adversely affect the Secured Party's right or the priority of its
security interest in the Collateral; and provided further, that nothing
contained herein shall be deemed to prohibit IXC from contesting any Lien
arising by operation of law where IXC is contesting in good faith and by
appropriate proceedings the obligations which gave rise to such Lien, provided
that such contest does not involve the material danger of the sale, forfeiture
or loss, or material restriction of, use or enjoyment of any of the Collateral.

        4.2 Payment of Obligations. IXC will pay promptly when due, all taxes,
assessments, franchises, fees and governmental charges or levies imposed upon or
payable in respect of the Collateral or in respect of its income or profits
therefrom, as well as all claims and demands of any kind (including claims for
labor, materials and supplies), except that no such charge need be paid if (i)
the validity thereof is being contested in good faith in an appropriate manner,
and (ii) such contest does not involve any material danger of the sale,
forfeiture or loss, or material restriction of, use or enjoyment of any of the
Collateral or any interest therein.

        4.3 Limitations on Liens on Collateral; Lien Waivers. IXC will not
create, permit or suffer to exist, and will defend the Collateral against and
take such other action as is necessary to remove, any Lien, claim or right, in
or to the Collateral, other than Permitted Liens, and will defend the right,
title and interest of the Secured Party in and to any of IXC's rights to the
Collateral and in and to the Proceeds and products thereof against the claims
and demands of all persons whomsoever.

        4.4 Continuous Perfection. IXC will not change its name, identity or
corporate structure in any manner which might make any financing or continuation
statement filed in connection herewith seriously misleading within the meaning
of section 9-402(7) of the UCC (or any other then applicable provision of the
UCC) unless IXC shall have given each Secured Party at least thirty (30) days'
prior written notice thereof and shall have taken all action (or made
arrangements to take such action substantially simultaneously with such change
if it is impossible to take such action in advance) necessary or reasonably
requested by each Secured Party to amend such financing statement or
continuation statement so that it is not seriously misleading.


                                       -4-

<PAGE>   48



        4.5 Further Identification of Collateral. IXC will furnish to the
Secured Party from time to time statements and schedules further identifying and
describing the Collateral and such other reports in connection with the
Collateral as the Secured Party may reasonably request, all in reasonable
detail.

        4.6 Notices. IXC will advise each Secured Party promptly, in reasonable
detail, (i) within 30 days of IXC gaining knowledge of any lien, security
interest, encumbrance or claim, other than Permitted Liens for taxes not yet due
and payable, made or asserted against any of the Collateral, (ii) of any
material change in the composition of the Collateral, and (iii) of the
occurrence of any other event which would have a material effect on the security
interests created hereunder.

        4.7 Contribution Agreement. (a) IXC agrees that, so long as this
Agreement is in effect, it will not, without the prior written consent of
Secured Party, do any of the following if such act would have a material adverse
effect on the Collateral; (i) amend, modify or permit to be amended or modified
the Contribution Agreement, (ii) waive or permit to be waived any material
provisions of the Contribution Agreement, or (iii) exercise any right to
terminate or cancel any material provision of the Contribution Agreement or
consent or agree to, or suffer or permit, the termination thereof whether or not
on account of any default therein specified.

        (b) It is expressly agreed that anything herein to the contrary
notwithstanding, IXC shall remain liable under the Contribution Agreement to
perform all of its obligations thereunder and Secured Party shall have no
obligation or liability under the Contribution Agreement by reason of, or
arising out of, this Security Agreement nor shall the Secured Party be required
or obligated in any manner to perform or fulfill any obligations of IXC under or
pursuant to any of the Contribution Agreement, or to make any payment or to make
any inquiry, as to the nature or sufficiency of any payment received by it, or
to present or file any claim or to take any other action to collect or enforce
the payment of any amounts which may have been assigned to it or to which it may
be entitled hereunder at any time or times.

        5. Remedies, Rights Upon Default. If any Default shall occur and be
continuing, the Secured Party may exercise (in addition to all other rights and
remedies granted to it in this Security Agreement) after thirty (30) days notice
to IXC (and the notice specified below of time and place of public or private
sale), may forthwith collect, receive, appropriate and realize upon the
Collateral or any part thereof, and/or may forthwith sell, lease, assign, give
option or options to purchase, or sell and deliver said Collateral (or contract
to do so), as the case may be, or any part thereof, in one or more parcels at
public sale or sales, at any exchange broker's board or at the Secured Party's
offices or elsewhere at such prices as it may deem best (subject to Section 2.2
and the last sentence of this Section 5), for cash or on credit or for future
delivery without assumption of any credit risk. The Secured Party shall have the
right upon any such public sale or sales to purchase the whole or any part of
said Collateral so sold. The Secured Party shall pay over the net proceeds of
any such collection, recovery, receipt, appropriation, realization or sale,
after deducting all reasonable costs and expenses incurred therein or incidental
to the care, safekeeping or otherwise of any or all of the Collateral or in any
way relating to the rights of the Secured Party hereunder, for application on an
equal basis to the payment in whole or in part of the Secured Obligations, and
only after such net proceeds need the Secured Party account for the surplus, if
any, to IXC. IXC agrees that neither Secured Party needs to give more than
thirty (30) days' notice (which notification shall be deemed given when mailed,
postage prepaid, addressed to IXC at its address provided pursuant to this
Security Agreement) of the time and place of any public sale may take place and
that such notice is reasonable notification of such matters. The Secured Party's
exercise of the foregoing rights and remedies is subject to the provisions of
Section 2.2

                                       -5-

<PAGE>   49



and any transferee (including the Secured Party) of any of the Collateral must
agree to be bound by such provisions.

        6. Reinstatement. This Security Agreement shall remain in full force and
effect and continue to be effective should any petition be filed by or against
IXC for liquidation or reorganization, should IXC become insolvent or make an
assignment for the benefit of creditors or should a receiver or trustee be
appointed for all or any significant part of IXC's assets, and shall continue to
be effective or be reinstated, as the case may be, if at any time payment and
performance of the Secured Obligations, or any part thereof, is, pursuant to
applicable law, rescinded or reduced in amount, or must otherwise be restored or
returned by any obligee of the Secured Obligations, whether as a "voidable
preference," "fraudulent conveyance," or otherwise, all as though such payment
or performance had not been made. In the event that any payment, or any part
thereof, is rescinded, reduced, restored or returned, the Secured Obligations
shall be reinstated and deemed reduced only by such amount paid and not so
rescinded, reduced, restored or returned.

        7. Notices. Unless otherwise provided herein, all notices and
communications concerning this Security Agreement shall be addressed to the
other party as follows:

               If to IXC:           IXC Internet Services, Inc.
                                    Attn: Chief Financial Officer
                                    5000 Plaza on the Lake
                                    Suite 200
                                    Austin, TX 78746
                                    Facsimile No.: (512) 328-0239

               with copies to:      IXC Communications, Inc.
                                    Attention: General Counsel
                                    5000 Plaza on the Lake
                                    Suite 200
                                    Austin, TX 78746
                                    Facsimile No.: (512) 328-7902

                                    Michael P. Whalen, Esq.
                                    Riordan & McKinzie
                                    695 Town Center Drive
                                    Suite 1500
                                    Costa Mesa, CA 92626
                                    Facsimile No.: (714) 549-3244

               If to PSINet:        PSINet Inc.
                                    510 Huntmar Park Drive
                                    Herndon, Virginia 20170
                                    Attention: Chairman
                                    Facsimile: (703) 904-1608

               With a copy to:

                                    PSINet Inc.
                                    510 Huntmar Park Drive
                                    Herndon, Virginia 20170
                                    Attention: General Counsel
                                    Facsimile: (703) 904-9527

               and to:              Nixon, Hargrave, Devans & Doyle LLP
                                    437 Madison Avenue
                                    New York, New York 10022
                                    Attention: Richard F. Langan, Jr.
                                    Facsimile: (212) 940-3111



                                       -6-

<PAGE>   50


        Unless otherwise provided herein, notices shall be sent by registered or
certified U.S. Mail, postage prepaid, or by commercial overnight deliver
service, or by facsimile, and shall be deemed served or delivered to the address
or its office on the date of receipt acknowledgement or, if postal claim notices
are given, on the date of this return marked "unclaimed," provided, however,
that upon receipt of a returned notice marked "unclaimed," the sending party
shall make a reasonable effort to contact and notify the other party by
facsimile.

        8. Severability. Any provision of this Security Agreement which is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render enforceable
such provision in any other jurisdiction.

        9. No Waiver; Cumulative Remedies. The Secured Party shall by any act,
delay, omission or otherwise be deemed to have waived any of its or their rights
or remedies hereunder and no waiver shall be valid unless in writing, signed by
the Secured Party, and then only to the extent therein set forth. A waiver by
the Secured Party of any right or remedy hereunder on any one occasion shall not
be construed as a bar to any right or remedy which the Secured Party would
otherwise have had on any future occasion. No failure to exercise nor any delay
in exercising on the part of the Secured Party any right, power or privilege
hereunder shall operate as a waiver thereof, nor shall any single or partial
exercise of any right, power or privilege hereunder preclude any other or future
exercise thereof or the exercise of any other right, power or privilege. The
rights and remedies hereunder provided are cumulative and may be exercised
singly or concurrently, and are not exclusive of any rights and remedies
provided by law. None of the terms or provisions of this Security Agreement may
be waived, altered, modified or amended except by an instrument in writing, duly
executed by the party against which enforcement of such waiver, alteration,
modification or amendment is sought.

        10. Successors and Assigns; Governing Law. This Security Agreement and
all obligations of IXC hereunder shall be binding upon the successors and
assigns of IXC, and shall, together with the rights, obligations and remedies of
the Secured Party hereunder inure to the benefit of and be binding upon the
successors and assigns of the Secured Party. This Security Agreement shall be
governed by, and be construed and interpreted in accordance with, the laws of
the State of Delaware.

        11.    Termination.

               11.1 Short Term Indivisible IRU. Subject to Section 6 hereof, the
Secured Party's security interest in the Short Term Indivisible IRU shall
terminate upon the Secured Party's Acceptance of 10,000 Route Miles along the
Available System.

               11.2 Agreement. Subject to Section 6 hereof, upon expiration of
the Purchase Agreement and the payment or performance of the Secured
Obligations, this Security Agreement shall terminate and PSINet will, at the
request and expense of IXC, execute and deliver to IXC a proper instrument or
instruments evidencing such termination.

        12. Dispute Resolution. Any controversy or claim between or among the
Secured Party, IXC or IXC Carrier, Inc. arising out of or relating to this
Agreement or with respect to an alleged breach of the terms hereof shall be
resolved in accordance with the provisions of Section 19.14 of the Purchase
Agreement; provided that the foregoing shall not be applicable with respect to
any matters which arise in connection with any Bankruptcy Proceeding involving
IXC or IXC Carrier, Inc., as debtor.



                                       -7-

<PAGE>   51

        13. Counterparts. This Security Agreement may be executed in any number
of counterparts, which shall, collectively and separately, constitute one
agreement.

        14. No Conflict. Nothing contained in this Security Agreement shall be
deemed to alter, modify, affect or limit any of Secured Party's rights under the
Purchase Agreement.

        IN WITNESS WHEREOF, IXC and PSINet have each caused this Security
Agreement to be executed by a duly authorized officer as of the date first set
forth above.

                                            IXC Internet Services, Inc.

                                            By:
                                            Name:
                                            Title:



                                            PSINet Inc.

                                            By:
                                            Name:
                                            Title:





                                       -8-

<PAGE>   52


                           ACKNOWLEDGEMENT AND CONSENT


        The undersigned, IXC Carrier, Inc. ("Carrier"), hereby acknowledges and
consents to the foregoing Security Agreement and Assignment and agrees not to
interfere with the rights or quiet enjoyment of the Secured Party under the
Purchase Agreement in accordance with its terms, except that IXC will have the
rights under Section 7.4(a) of the Purchase Agreement with respect to a
continuing breach (as determined by an arbitration) by Secured Party of a
Material Provision and in such event Carrier shall not be obligated to perform
any obligation which IXC is allowed pursuant to Section 7.4(a) to withhold or
suspend. Carrier hereby consents to the collateral assignment by IXC to the
Secured Party of the PSINet Rights under the Contribution Agreement as provided
in the Security Agreement and Assignment and recognizes the Secured Party as the
permitted assignee with respect to the PSINet Rights and agrees to allow the
Secured Party to exercise and obtain the benefit of such PSINet Rights. Carrier
hereby agrees to be bound by the provisions of Section 4.7 of the Security
Agreement and Assignment to the same extent as IXC and as if Carrier were a
party thereto. If Carrier gives any notices of the occurrence of a default or
event of default under the Contribution Agreement to IXC, Carrier shall
simultaneously give such notice to the Secured Party. Secured Party shall be
entitled to exercise the rights granted to IXC with respect to the PSINet Rights
and to obtain the benefits of the PSINet Rights under the Contribution Agreement
without being required or obligated to cure any default or event of default on
the part of IXC or to perform or fulfill any obligations of or make any payments
which were required to be made by IXC [except that at such time as Secured Party
exercises the PSINet Rights under the Contribution Agreement, Secured Party
shall be bound by the provisions of Sections _____ thereof].* Notwithstanding
the foregoing, upon and after the exercise by Secured Party of the PSINet Rights
under the Contribution Agreement, the Secured Party will have the same rights
and opportunity to cure the default or event of default as are given to IXC
under the Contribution Agreement. In no event shall Secured Party's obligations
with respect to the PSINet Rights under the Contribution Agreement exceed,
duplicate or be in addition to any obligation of Secured Party under the
Purchase Agreement. Carrier agrees that, with respect to the PSINet Rights, upon
a default or event of default on the part of IXC under the Contribution
Agreement, the Contribution Agreement will continue in full force and effect
between Carrier and the Secured Party in respect of the PSINet Rights to the
same extent as if Secured Party were a party thereto, subject to the fifth and
seventh sentences of this paragraph.

        In the event of a Default under the foregoing Security Agreement and
Assignment, notwithstanding Section 5 thereof, Secured Party shall not be
entitled to foreclose, collect, receive, appropriate, sell, lease, assign, give
option or options to purchase, or sell or deliver, or contract to do any of the
foregoing or otherwise realize upon the PSINet Rights under the Contribution
Agreement (except that Secured Party may deal with its IRU capacity and shall
have the rights to the PSINet Rights and use thereof as provided and permitted
under the Purchase Agreement with respect to the PSINet Fiber IRU and/or the IRU
in the IRU Capacity, including without limitation Section 15.5 of the Purchase
Agreement). Nothing contained herein shall (i) be deemed to modify, affect or
limit any of Secured Party's rights under the Purchase Agreement or (ii) prevent
Secured Party from taking any action necessary to preserve, protect, perfect or
continue its security interest in the PSINet Rights or (iii) prevent Secured
Party from using or obtaining the benefits of the PSINet Rights.

- --------

*       Such sections are subject to approval by Secured Party and shall not
        include any payment obligations.


                                       -9-

<PAGE>   53

        Capitalized terms used herein but not otherwise defined herein shall
have the respective meanings ascribed thereto in the foregoing Security
Agreement and Assignment.

                                            IXC Carrier, Inc.

                                            By:
                                            Name:
                                            Title:


        The foregoing Acknowledgment and Consent is acknowledged and agreed to
by the undersigned.

                                            PSINet Inc.

                                            By:
                                            Name:
                                            Title:

        IXC Internet Services, Inc. hereby acknowledges receipt of notice of,
consents to and agrees to be bound by the terms and provisions of the foregoing
Acknowledgment and Consent as they relate to the relative rights of PSINet Inc.
and IXC Carrier, Inc.

                           IXC Internet Services, Inc.

                                            By:
                                            Name:
                                            Title:




                                      -10-

<PAGE>   54

                                    EXHIBIT C

                   [COLLOCATION AND INTERCONNECTION AGREEMENT]



<PAGE>   55

                                    EXHIBIT C
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT



                    COLLOCATION AND INTERCONNECTION AGREEMENT


        This Collocation and Interconnection Agreement (this "Agreement") is
entered into as of the _________ day of _______________, 199_, by and between
IXC Internet Services, Inc., a Delaware corporation ("IXC"), and PSINet Inc., a
New York corporation ("PSINet"). All capitalized terms used but not otherwise
defined herein shall have the meanings set forth in that certain IRU and Stock
Purchase Agreement entered into as of July 22, 1997 by and between IXC and
PSINet (as amended, supplemented or modified, the "Purchase Agreement"). In the
event of any conflict between the terms of this Agreement and those of the
Purchase Agreement, the terms of the Purchase Agreement shall control.

                             BACKGROUND AND PURPOSE

        This Agreement is made with reference to the following facts:

        A. IXC and PSINet have entered into the Purchase Agreement pursuant to
which, among other things, PSINet has acquired from IXC the PSINet Fiber IRU,
the IRU Capacity and the option to order Bandwidth on the Available System and
IXC has acquired from PSINet shares of PSINet's common stock.

        B. In connection with the Purchase Agreement, PSINet may wish to
collocate its telecommunications equipment ("Equipment") at IXC's premises or
points-of-presence ("POPs") and, or may wish to interconnect its Equipment to
IXC's or third party's equipment. This Agreement sets forth the terms and
conditions on which PSINet may collocate and, or interconnect its Equipment on
IXC's premises.


                               TERMS OF AGREEMENT

        Accordingly, in consideration of the foregoing and of the mutual
covenants contained herein and for other good and valuable consideration, the
receipt of which is hereby acknowledged, the parties hereto agree as follows:

        1. IXC Premises. IXC's premises available for the collocation of
PSINet's Equipment or interconnection of PSINet's facilities are listed on
Exhibit K to the Purchase Agreement as it may be expanded from time to time (the
"IXC Premises" or "IXC POPs").

        2.     Collocation Rights.

               2.1 Collocation. IXC hereby grants to PSINet the right to locate,
install, maintain and operate Equipment at the IXC Premises for the duration of
the term of the Purchase Agreement. No use of the IXC Premises required or
permitted under this Agreement shall create or vest in PSINet any easements or
other ownership or property rights of any nature in IXC's real or personal
property or the IXC Premises.

               2.2 Basic Services. In consideration of the maintenance fee that
PSINet is required to pay IXC under the section entitled System Maintenance and
POPs - Consideration set forth in the Purchase Agreement, IXC shall supply HVAC
(Heating, Ventilation and Air Conditioning) for standard components, non-UPS AC
power and space for PSINet Equipment at the IXC POPs as follows:



<PAGE>   56

<TABLE>
<CAPTION>
        SITES                       # OF SPACES**                POWER PER SPACE
        -----                       -------------                ---------------

<S>                                 <C>                          <C>
        As listed on Exhibit K      *                                   *
</TABLE>

** A space adequate to contain a cabinet (measuring 2 feet (width) x 3 feet
(depth) x 70 inches (height)). PSINet shall supply its own cabinets. If PSINet
has more, or desires more, than six Spaces in the IXC POPs, PSINet shall be
required to pay for those Spaces at IXC's standard rates.

               2.3 Interface. Interface points for PSINet's IRU Capacity
provided by IXC under the Purchase Agreement shall be at fiber patch panels
("Connect Panels") located in the IXC Premises. The Connect Panel located in the
IXC Premises shall be the demarcation to establish PSINet's operational and
maintenance responsibilities. Subject to the space limitations set forth in this
Agreement, PSINet shall provide, install and maintain at its expense the
electronic equipment at the IXC Premises it desires. PSINet will pay IXC time
and materials agreed upon on a case by case basis for equipment installation,
tech-assists and build-outs for power, cabling and HVAC.

               2.4 Additional Services. In the event PSINet desires installation
services (including, but not limited to cross connect facilities needed to
access local exchange carriers' or competitive access providers' entrance
facilities), DC power, or additional space, AC power or HVAC (collectively
referred to as the "Services") at any of the IXC Premises, it shall make a
written request for such Services to IXC. Within fifteen (15) business days
after receiving such written request, IXC shall provide PSINet with the
availability of the Services and IXC's standard rates for the Services. In the
event upgrades or expansions to the IXC Premises or its facilities are necessary
to accommodate PSINet's request, IXC may include the entire cost of such
upgrades or expansions in the cost to PSINet. In the event IXC provides the
Services to PSINet by replacing its existing equipment at PSINet's expense, IXC
shall give the old, replaced equipment to PSINet. In the event PSINet chooses to
receive additional Services at the IXC Premises, PSINet shall pay any and all
(initial and continuing) costs reasonably determined by IXC to be necessary to
provide Services to PSINet. If IXC makes available and PSINet utilizes more than
20 amps of AC power per Space during any particular month during the term of
this Agreement, PSINet shall pay IXC its standard rate for each additional amp.
IXC shall provide PSINet with an invoice setting forth the costs for additional
Services within sixty (60) days of the later of: (a) IXC receiving its invoices
for such Services from subcontractors and vendors or (b) delivering the Services
to PSINet. PSINet shall pay IXC the amounts due within thirty (30) days of
receipt of an invoice from IXC.

               2.5 Back-up Power. In the event that PSINet desires back-up power
at the IXC POPs, PSINet shall submit its back-up power requirements to IXC. IXC
shall within thirty days of receipt of PSINet's request provide PSINet with a
quote as to IXC's costs for providing such back-up power; provided however, that
IXC shall only be obligated to provide such quote and the back-up power if IXC,
in its sole discretion, determines that providing such back-up power is feasible
considering available space, environmental factors, required consents from third
parties and other relevant factors.

In the event IXC does provide back-up power to PSINet: (a) IXC shall provide
PSINet with invoices setting forth the costs for such back-up power within sixty
(60) days of the later of: (i) IXC receiving its invoices from subcontractors
and vendors for installing and providing such back-up power or (ii) delivering
the back-up power to PSINet; and (b) IXC will have no liability whatsoever to
PSINet with regard to any delay, failure or defect in such back-up power and
Section 18

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                       -2-

<PAGE>   57

shall apply to such power. IXC's initial and ongoing costs for providing such
back-up power to PSINet may be included in IXC's invoices to PSINet. PSINet
shall pay IXC the amounts due within thirty (30) days of receipt of an invoice
from IXC.

               2.6 Delivery and Installation. PSINet shall, at its own expense,
deliver, install and maintain its collocated Equipment in a safe condition and
meeting or exceeding the standards set forth in Section 7.2. At no additional
charge, IXC shall provide to PSINet Spaces that are reasonably proximate to each
other in light of the type of Equipment that PSINet is installing; provided,
however, that if PSINet or its Equipment requires a specific geometric
arrangement, and IXC determines that in order to accommodate PSINet or its
Equipment, rearrangement of the existing facilities at the IXC Premises is
required, PSINet agrees to reimburse IXC for any such make-ready costs. IXC will
advise PSINet in writing of any estimated make-ready charges (including
investigation, design and engineering fees) for such rearrangement work and
PSINet shall make payment to IXC within thirty (30) days from its receipt of
IXC's invoice therefor.

        3. Interconnection with PSINet POPs.

               3.1 Construction and Installation. In the event PSINet desires to
connect any of its POPs to any IXC POP, PSINet may construct, install, operate
and maintain a connection facility (the "POP-to-POP Interconnect Facility")
between the PSINet premises and the IXC Premises so long as PSINet meets or
exceeds the standards set forth in Section 7.2. PSINet shall provide at its
expense all necessary rights-of-way, permits, equipment and IXC-approved
materials to construct and install each POP-to-POP Interconnect Facility,
including, but not limited to, cables and conduit and any labor charges
associated therewith. If necessary, and where applicable, IXC shall use
commercially reasonable efforts to provide PSINet, at PSINet's expense, access
to existing building entrance facilities, if available, to access and exit IXC
POPs. The demarcation point for PSINet shall be in the IXC POPs at the Connect
Panel or the DSX panel, as appropriate.

               3.2 Ownership. PSINet shall retain ownership of any portion of
the POP-to-POP Interconnect Facility that is located on the IXC Premises during
the term of this Agreement; provided, however, that title to any part of the
POP-to-POP Interconnect Facility within the IXC Premises shall be transferred to
IXC upon expiration or termination of this Agreement.

               3.3 Maintenance and Changes. PSINet shall be responsible for
maintenance and repair of the POP-to-POP Interconnect Facility on PSINet's side
of the point of demarcation. Any improvement, modification, addition to,
relocation, or removal of, the POP-to-POP Interconnect Facility by PSINet at the
IXC Premises is subject to prior review and written approval by IXC Transmission
Engineering Department and the cost of such improvement, modification, addition
to, relocation, or removal of, the POP-to-POP Interconnect Facility will be the
sole responsibility of PSINet. IXC's approval will not be unreasonably withheld
and in the event IXC fails to respond to PSINet's written request within thirty
(30) days of receiving PSINet's request for such changes, IXC's shall be deemed
to have approved PSINet's request.

        4. Interconnection to Third Parties. Interconnect facilities to
interconnect PSINet's equipment to other parties within IXC's POPs shall be
installed and maintained subject to available space at the IXC POPs and under
the following terms and conditions:


                                       -3-

<PAGE>   58



        (a)     IXC shall provide PSINet at each POP with * PSI and third
                parties *, as specified by PSINet, not to exceed, * PSINet has
                ordered at the POP. Such * interconnections are not transferable
                to other POPs * shall be referred to as "*" subject to the
                charges in Exhibit E to the Purchase Agreement. Should
                subsequent interconnections become necessary after initial
                installation, up to the aggregate bandwidth capacity of the
                circuits PSINet has ordered at the POP, realignment of the
                interconnections shall be subject to the preceding and to the
                reconfiguration charges as indicated in Exhibit E. All such
                interconnections shall be subject to the provisions of Section
                15.5 of the Purchase Agreement.

        (b)     PSINet shall reimburse IXC for the capital cost to establish a
                point of demarcation for Additional Interconnects that PSINet
                requests IXC to provide. This demarcation shall be in the IXC
                equipment room and shall be either the IXC standard DSX
                termination or fiber distribution frame as is applicable for the
                interconnects required.

        (c)     IXC shall charge PSINet a one time charge and a monthly
                recurring charge for each Additional Interconnect in the IXC
                POP. These charges shall be an amount equal to the then standard
                ancillary pricing for such service set forth on Exhibit E to the
                Purchase Agreement. Nothing in this Agreement shall prevent or
                in any way limit IXC's ability to charge third parties for
                interconnection.

        (d)     In the event IXC chooses to cross-connect with an Additional
                Interconnect party for which PSINet has paid a charge to IXC
                under Section 4(b), IXC shall at IXC's option: (i) refund to
                PSINet such charge or (ii) shall pay PSINet a monthly
                cross-connect fee negotiated by the parties at such time.

        (e)     IXC's maintenance responsibility shall be limited to the
                demarcation point and the associated cross connect at that
                point.

        (f)     PSINet shall not use any interconnect facility to allow third
                parties collocated in any POP to interconnect with each other at
                that POP.

        5. Notice to Interconnect or Collocate. No later than forty-five (45)
days prior to PSINet's planned installation of its Equipment or POP-to-POP
Interconnect Facilities at any IXC Premises, PSINet shall provide to IXC notice
of its desire to interconnect/locate in a particular IXC Premise, a copy of
PSINet's construction design drawings and installation schedule for IXC's review
and approval (collectively referred to hereon as the "Interconnect/Collocation
Notice"). The Interconnect/Collocation Notice shall (at a minimum) include: (a)
PSINet's installation date(s); (b) any excess cable storage requirements; (c)
identification of all POP-to- POP Interconnect Facilities and Equipment to be
installed; (d) a diagram of the desired location of the POP-to-POP Interconnect
Facilities and Equipment; (e) the space, power, environmental and other
requirements for the POP-to-POP Interconnect Facilities and Equipment; (f) the
estimated commencement and termination dates for the
interconnection/collocation; (g) all other information reasonably required by
IXC. PSINet's Equipment shall be placed and maintained in accordance with IXC's
requirements and specifications. Within two weeks of receiving the
Interconnection/Collocation Notice, IXC shall respond to PSINet's
Interconnection/Collocation Notice with its acceptance or objections.

- --------

        *       Confidential material has been omitted and filed separately with
                the Securities and Exchange Commission.

                                       -4-

<PAGE>   59



        6. Required Authorizations. PSINet shall obtain, at its sole cost and
expense, from any appropriate public and/or private authority, any required
permission, authorization, permit, license or easement (collectively, the
"Authorizations") to bring fiber to the IXC Premises and, or needed to
construct, install, operate and maintain the POP-to-POP Interconnect Facility
and to use the property over which the POP-to-POP Interconnect Facility will be
operated and maintained. PSINet represents and warrants that such Authorizations
shall be in effect for the entire Term of this Agreement. IXC shall cooperate
with PSINet in its efforts to obtain such authorizations.

        7.     Use of Equipment and POP-to-POP Interconnect Facilities.

               7.1 No Interference. PSINet shall not use its fibers, Equipment
or POP-to- POP Interconnect Facilities, and IXC shall not use its fiber,
equipment or interconnect facilities in any way which interferes with the other
party's use of its fibers or equipment or in any manner which violates any of
the terms or conditions of this Agreement or the Purchase Agreement. PSINet
shall not install any electrical or other equipment that overloads any
electrical paneling, circuitry or wiring.

               7.2 Standards. PSINet shall ensure that its equipment and any
POP-to-POP Interconnect Facilities (as defined) are installed to meet or exceed
any reasonable requirements of IXC, any requirements of IXC's building
management, and any applicable local, state and federal codes and public health
and safety laws and regulations (including fire regulations and the National
Electric Code). In the event IXC's building management or any local, state or
federal body determines the POP-to-POP Interconnect Facility is not in
compliance with the applicable laws and regulations, PSINet shall immediately
make any changes necessary such that the POP-to-POP Interconnect Facility no
longer conflicts with such law or regulations. PSINet further agrees to comply
with the requirements of IXC's or IXC's building management's insurance
underwriter(s).

               7.3 Intervention. If any part of PSINet's fiber, POP-to-POP
Interconnect Facilities or Equipment is not placed and maintained in accordance
with the terms and conditions of this Agreement and PSINet fails to correct the
violation within thirty days from receipt of written notice thereof from IXC,
then IXC may, at its option, without further notice to PSINet, correct the
deficiency at PSINet's expense without liability for damages to the fiber,
POP-to-POP Interconnect Facilities or Equipment or for any interruption of
PSINet's services. As soon as practicable thereafter, IXC shall advise PSINet in
writing of the work performed or the action taken. PSINet shall reimburse IXC
for all expenses incurred by IXC associated with any work or action performed by
IXC pursuant hereto. PSINet shall remit payment to IXC within thirty days from
its receipt of IXC's invoice therefor.

               7.4 Threat to Persons or Property. In the event, and in IXC's
sole determination, if PSINet's fiber, POP-to-POP Interconnect Facilities or
Equipment poses an immediate threat to the safety of IXC employees or the
public, interferes with the performance of IXC's service obligations, or poses
and immediate threat to the physical integrity of IXC's facilities, IXC may
perform such work and/or take such action that it deems necessary without notice
to PSINet and without subjecting itself to any liability for damage to the
fiber, POP-to- POP Interconnect Facilities or the Equipment or for any
interruption of PSINet's services. As soon as practicable thereafter, IXC shall
advise PSINet in writing of the work performed or the action taken. PSINet shall
reimburse IXC for all expenses incurred by IXC associated with any work or
action performed by IXC pursuant hereto. PSINet shall remit payment to IXC
within thirty days from its receipt of IXC's invoice therefor.

        8. Access to IXC Premises.


                                       -5-

<PAGE>   60

               8.1 Notice. Except as specifically set forth in the Purchase
Agreement, the terms in this Section 8 shall govern PSINet's access to the IXC
Premises. In the event PSINet's Equipment or POP-to-POP Interconnect Facilities
are located in the IXC Premises Customer Interface Facility ("CIF"), PSINet may
perform routine preventative maintenance or emergency maintenance and repairs on
its Equipment or POP-to-POP Interconnect Facilities during normal business hours
(7 am - 6 pm local time) without advance notice to IXC. In the event PSINet
desires to: (a) perform routine preventative maintenance or emergency
maintenance and repairs during non-business hours; (b) perform any procedures
other than routine preventative maintenance (such as installation, removal or
relocation of its Equipment or POP-to-POP Interconnect Facilities); (c) perform
any function outside of the CIF or (d) access (on PSINet's side of the
demarcation point) the fibers leading from the IXC electronics which provide the
IRU Capacity, PSINet may do so if: (x) it provides reasonable advance notice to
IXC; and (y) a IXC employee or representative is present on the IXC Premises at
the time. Notice provided as follows shall be deemed "reasonable advance notice"
for the purposes of this section: (i) twenty-four (24) hours for routine
preventative maintenance during non-business hours or outside the CIF; (ii) two
(2) hours for repairs of network malfunction causing loss of service or degraded
conditions (during non-business hours or outside the CIF), provided that such
period shall be reasonably tolled to permit IXC to dispatch personnel to an
un-manned IXC Premise upon receipt of a request for access thereto; (iii) two
(2) weeks notice for removing POP-to-POP Interconnect Facilities and, or
Equipment (regardless of location or time) and (iv) forty-five (45) days (as set
forth in Section 5) for installing Equipment or POP-to-POP Interconnect
Facilities (regardless or location or time). The presence of a IXC employee or
representative shall not relieve PSINet of its responsibility to conduct all of
its work operations in the IXC Premises in a safe and workmanlike manner. Under
no circumstances shall PSINet have access to any fibers on the IXC side of the
demarcation point.

               8.2 Security. PSINet shall abide by IXC's reasonable security
requirements. When deemed appropriate by IXC, PSINet employees or
representatives shall be issued passes or visitor identification cards which
must be presented upon request before entry to the IXC Premises and surrendered
upon demand or upon termination of this Agreement. Such passes or other
identification shall be issued only to persons meeting any reasonable security
criteria applicable at the IXC Premise for such purpose. Notwithstanding any
other provision of this Agreement, IXC shall, without threat of liability, have
the right to immediately terminate the right of access of any PSINet personnel
or representative should it determine in its sole discretion for any lawful
reason that such termination is in its best interest. IXC shall promptly notify
PSINet of any such termination, and PSINet shall have a reasonable opportunity
to demonstrate that the terminated rights of access should be reinstated. Any
termination of access shall remain in effect pending such demonstration and
IXC's final determination as to the advisability of such reinstatement.

        9. Relocation. PSINet shall, at its own expense, relocate its fiber,
POP-to-POP Interconnect Facilities and Equipment upon IXC's written request and
in the reasonable (under the circumstances) time frame required by IXC. Such
relocations could be within the IXC POP or in the event the entire IXC POP is
relocated. In any such event, IXC shall provide the following services at no
cost to PSINet: (i) site make-ready; (ii) the intra-site cabling functionally
equivalent to that which existed in the prior IXC POP; (iii) relocation of IXC's
IRU circuits and equipment used by PSINet; and (iv) re-establishing competitive
access provider and local exchange carrier interconnects common to both IXC and
PSINet.

        10. No Restrictions. Except as specifically set forth in the Purchase
Agreement, nothing contained in this Agreement shall be construed as a
limitation, restriction or prohibition against IXC with respect to any agreement
or arrangement which IXC has heretofore entered into, or may in the future enter
into, with others not parties to this Agreement regarding the IXC Premises.
IXC's



                                       -6-

<PAGE>   61



right to maintain and operate its facilities in such a manner as will best
enable it to fulfill its own service requirements is in no manner limited by
this Agreement.

        11. Inspections. IXC reserves the right to make periodic inspections of
any part of the fiber, POP-to-POP Interconnect Facilities and Equipment located
within or physically attached to the IXC Premises; provided that PSINet shall
have the right to have one or more of its employees or representatives present
during the time of any such inspection. IXC shall give PSINet advance notice of
such inspections, except in those instances where, in the sole judgement of IXC,
safety considerations justify the need for such an inspection without the delay
of providing notice. The making of periodic inspections or the failure to do so
shall not operate to impose upon IXC any liability of any kind whatsoever nor
relieve PSINet of any responsibility, obligation, or liability assumed under
this Agreement.

        12. Emergencies. In the event of an emergency:

               (a) IXC's work shall take precedence over any and all operations
of PSINet in the IXC Premises and IXC may rearrange PSINet's Equipment or
POP-to-POP Interconnect Facilities.

               (b) IXC shall use reasonable efforts to provide PSINet with
advance notice of any such work.

               (c) IXC shall use reasonable care given the circumstances when
handling PSINet Equipment.

        13. Liens and Encumbrances. PSINet shall not have the power, authority
or right to create and shall not permit any lien or encumbrance, including,
without limitation, tax liens, mechanics' liens, or other liens or encumbrances
with respect to work performed, in connection with the installation, repair,
maintenance or operation of its Equipment, POP-to-POP Interconnect Facilities or
other property installed within the IXC Premises.

        14. Term. This Agreement shall become effective as of its execution by
both parties and shall continue in effect until such time as it is terminated on
the earlier of (a) the expiration or termination of the Purchase Agreement or
(b) such time as it is terminated as provided herein or by operation of law.

        15. Subordination. PSINet agrees that its rights under this Agreement
shall be totally subordinate to any mortgages, loans, deeds of trust or any
other borrowing upon the real or personal property which may be incurred by IXC.
PSINet shall sign any such reasonable documents as are necessary to satisfy any
lender, private or institutional, to reflect said subordination.

        16. Release; Indemnification. Each party (each party in such capacity
being referred to as the "Releasing Party") releases, assumes and agrees to
indemnify, defend, protect and save the other party harmless from and against
any claim, damage, loss, liability, cost and expense (including reasonable
attorneys' fees) in connection with any loss or damage to any physical property
or facilities of the Releasing Party or any injury to or death of any person
arising out of or resulting in any way from the negligence or misconduct of the
Releasing Party or its employees, servants, contractors and/or agents.

        17.    Limitation of Liability.

               17.1 Equipment and Facilities. IXC, its employees or
subcontractors shall not be liable for any damages to PSINet's fiber, POP-to-POP
Interconnect Facilities and Equipment collocated on the IXC Premises, except to
the extent that such damages are caused by the gross negligence or intentional
acts of IXC, its agents or employees; provided that the maximum liability of IXC
for any



                                       -7-

<PAGE>   62

damage to PSINet's fiber, POP-to-POP Interconnect Facilities and Equipment shall
not exceed the replacement value of the fiber, POP-to-POP Interconnect
Facilities and Equipment, or in the event that the fiber, POP-to-POP
Interconnect Facilities and the Equipment is repairable, the costs to restore
the fiber, POP-to-POP Interconnect Facilities and the Equipment to its original
condition. IXC shall not be liable for any damages of whatever nature,
including, but not limited to actual or consequential damages, arising from any
interruption or failure in the supply of utilities to the IXC Premises.

               17.2 No Consequential Damages. Except as specifically provided
for in the Purchase Agreement, in no event shall IXC or PSINet be liable for any
special, incidental, direct, indirect, punitive, reliance or consequential
damages, whether foreseeable or not, arising under this Agreement or from any
breach or partial breach of the provisions of this Agreement or occasioned by
any defect in the Bandwidth or other service provided hereunder, delay in
availability of the Bandwidth or any service provided hereunder, failure of the
Bandwidth or other service provided hereunder, interruptions or outages of the
Available System or any other cause whatsoever or arising out of any act or
omission by IXC or PSINet, as applicable, its employees, servants and/or agents,
including but not limited to, damage or loss of property or equipment, loss of
profits or revenue, cost of capital, cost of replacement services, or claims of
customers for service interruptions or transmission problems.

        18. Disclaimer of Warranty. IXC MAKES NO WARRANTY TO PSINET OR ANY OTHER
PERSON OR ENTITY, WHETHER EXPRESS, IMPLIED, OR STATUTORY, AS TO THE DESCRIPTION,
QUALITY, MERCHANTABILITY, COMPLETENESS OR FITNESS FOR ANY PARTICULAR PURPOSE OF
ANY PREMISES, FACILITIES, SERVICES, EQUIPMENT, POWER, CABLE OR FIBERS PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED. NO OTHER WARRANTIES ARE EXPRESSED
OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.

        19. Default/Termination.

               19.1 Default. A party may deliver to the other party a written
"Notice of Default" for: (i) failing to make any payment owed hereunder, when no
bona fide dispute exists (a "Monetary Default"); or (ii) the breaching by either
party or its agents, assigns or affiliates of any Material Provision; or (iii)
the filing or initiating of proceedings by or against a party seeking
liquidation, reorganization or other such relief under any federal or state
bankruptcy or insolvency law (a "Bankruptcy Proceeding"). Such Notice of Default
must prominently contain the following sentences in capital letters: "THIS IS A
FORMAL NOTICE OF A BREACH OF CONTRACT. FAILURE TO CURE SUCH BREACH WILL HAVE
SIGNIFICANT LEGAL CONSEQUENCES." A party that has received a Notice of Default
shall have five (5) business days to cure a Monetary Default, thirty (30) days
to cure the alleged breach of any Material Provision (and, if the defaulting
party shall have commenced actions in good faith to cure such defaults which are
not susceptible of being cured during such 30-day period, such period shall be
extended (but not in excess of 90 additional days) while such party continues
such actions to cure), and shall be given ninety (90) days to remove, have
dismissed or stay any involuntary Bankruptcy Proceeding (each such period, a
"Cure Period"). If such party fails to cure the breach within the Cure Period,
as long as such default shall be continuing, the non-defaulting party shall have
the right to either (a) suspend its performance or payment obligations under
this Agreement, (b) seek an order of specific performance, and/or (c) seek the
award of compensatory damages.

               19.2 Removal Upon Termination. Upon termination of this Agreement
for any reason other than a material default by IXC, PSINet shall remove, at its
sole expense, its fiber, POP-to-POP Interconnect Facilities and Equipment within
ten (10) days following such termination. In the event PSINet fails to remove
its fiber, POP-to-POP Interconnect Facilities and Equipment within such ten (10)
day period, the fiber, POP-to-POP Interconnect Facilities and Equipment shall be



                                       -8-

<PAGE>   63

deemed abandoned and IXC, at its sole discretion and without liability, may
remove the fiber, POP-to-POP Interconnect Facilities and Equipment and be
reimbursed by PSINet for all costs associated with such removal. PSINet shall
make payment to IXC for any such costs within thirty days of its receipt of an
invoice containing such costs. In the event this Agreement terminates due to a
material default by IXC, either PSINet or IXC may remove the PSINet Equipment or
POP-to-POP Interconnect Facilities at its own expense upon fifteen (15) working
days written notice to the other party.

        20. Insurance. PSINet shall, at its expense, obtain and keep in full
force and effect at all times for the duration of this Agreement, with a carrier
or carriers satisfactory to IXC, insurance policies of the following kinds and
in the following amounts:

                (a) Worker's Compensation Insurance in accordance with all
applicable laws;

                (b) Employer's liability insurance with limits for employer's
liability of $500,000 per accident;

               (c) Comprehensive bodily injury and property damage liability
insurance, including automobile insurance and contractual liability insurance,
in at least the following amounts:

<TABLE>
<S>                                                            <C>       
        Bodily injury to any one person                        $1,000,000
        Bodily injury aggregate per occurrence                 $1,000,000
        Property damage in any one accident                    $  500,000
        Property damage aggregate per occurrence               $1,000,000
</TABLE>

Upon request of IXC, PSINet shall furnish IXC certificates of such insurance
and/or copies of the applicable policies, and each policy shall provide that no
change or cancellation shall become effective except upon twenty (20) days prior
written notice to IXC of such change or cancellation. In the event of any change
or cancellation not acceptable to IXC, IXC may demand that PSINet obtain
replacement coverage. If PSINet fails to obtain replacement coverage within
twenty (20) days after such demand by IXC, IXC may obtain replacement coverage
and invoice all premiums therefore to PSINet. PSINet shall make payment to IXC
for any amount of such invoices within thirty days of its receipt thereof.

        21. Assignment. Except as provided below, this Agreement may not be
assigned in whole or in part without the prior written consent of IXC. PSINet
may assign this Agreement in whole, but not in part and only in connection with
a permitted assignment of all of PSINet's rights and obligations under the
Purchase Agreement to an entity that is both a permitted assignee under the
section entitled Binding Effect; Assignment in the Purchase Agreement and a
permitted transferee under the section entitled Restrictions on Resale in the
Purchase Agreement; provided, however, that any such assignment or transfer
shall be subject to IXC's rights under this Agreement and an assignee or
transferee shall continue to perform PSINet's obligations to IXC under the terms
and conditions of this Agreement. This Agreement shall be binding upon and shall
inure to the benefit of the parties hereto and their respective successors and
assigns.

        22. Notices. All notices, claims, demands and other communications under
this Agreement shall be in writing and shall be deemed given when delivered
personally, the next business day after delivered to a nationally recognized
overnight courier for next business day delivery, when transmitted by facsimile
or five (5) days after sent by registered or certified mail, return receipt
requested, to the parties (and to the Persons receiving copies thereof) at the
following addresses or facsimile numbers (or to such other address or facsimile
number as a party may have specified by notice given to the other party pursuant
to this provision):


                                       -9-

<PAGE>   64



               If to IXC to:

                      IXC Internet Services, Inc.
                      5000 Plaza on the Lake, Suite 200
                      Austin, Texas 78746
                      Attention: Chief Financial Officer
                      Facsimile: (512) 328-0239

               With copies to:

                      IXC Communications, Inc.
                      5000 Plaza on the Lake, Suite 200
                      Austin, Texas 78746
                      Attention: General Counsel
                      Facsimile: (512) 328-7902

                      Riordan & McKinzie
                      695 Town Center Drive, Suite 1500
                      Costa Mesa, California 92626
                      Attention: Michael P. Whalen
                      Facsimile: (714) 549-3244

               If to PSINet to:

                      PSINet Inc.
                      510 Huntmar Park Drive
                      Herndon, Virginia 20170
                      Attention: Chairman
                      Facsimile: (703) 904-1608

               With copies to:

                      PSINet Inc.
                      510 Huntmar Park Drive
                      Herndon, Virginia 20170
                      Attention: General Counsel
                      Facsimile: (703) 904-9527

                      Nixon, Hargrave, Devans & Doyle LLP
                      437 Madison Avenue
                      New York, New York 10022
                      Attention: Richard F. Langan, Jr.
                      Facsimile: (212) 940-3111


        23.    General Provisions.

               23.1 Laws and Licenses. This Agreement is subject to all
applicable federal, state and local laws, regulations, rulings and orders of
governmental agencies, including, but not limited to, the Communications Act of
1934 as amended by the Telecommunications Act of 1996, and the rules and
regulations of the FCC. IXC and PSINet agree that, except as otherwise provided
herein, the statute of limitations set forth in the Communications Act of 1934,
47 U.S.C. section 415, as amended, shall govern all actions arising out of this
Agreement, including arbitrations.

               23.2 Confidentiality. This Agreement shall be governed by the
terms of the Confidentiality Agreement entered into between the parties and
dated as of May 14, 1997.



                                      -10-

<PAGE>   65



               23.3 Amendments, Waivers and Consents. For purposes of this
Agreement and the Transaction Documents, except as otherwise specifically set
forth herein or therein, no course of dealing between PSINet and IXC and no
delay on the part of either party hereto in exercising any rights hereunder or
thereunder shall operate as a waiver of the rights hereof and thereof. No
covenant or other provision hereof or thereof may be waived or amended other
than by a written instrument signed by the party so waiving or amending such
covenant or other provision.

               23.4 Section Headings. The table of contents and section headings
in this Agreement have been inserted for reference purposes only and shall not
be deemed to limit or otherwise affect the construction of any provision thereof
or hereof.

               23.5 Governing Law. This Agreement shall be deemed to be a
contract made under, and shall be construed in accordance with, the laws of the
State of Delaware without reference to its principles of conflicts of law.

               23.6 Dispute Resolution. Any controversies, claims or disputes
arising out of or relating to this Agreement shall be resolved in the manner set
forth in the section entitled Dispute Resolution in the Purchase Agreement.

               23.7 Severability. In the event that any one or more of the
clauses, covenants or provisions contained in this Agreement should be held to
be unenforceable under any Federal, State or City law, statute, code,
administrative or regulatory rule, such invalidity or unenforceability shall not
affect the remainder of this Agreement, which shall remain in full force and
effect.

               23.8 Interpretation. This Agreement shall be interpreted in a
manner so as to be consistent with the Purchase Agreement and under the same
rules of construction and interpretation set forth in the Purchase Agreement.

               23.9 Counterparts. This Agreement may be executed simultaneously
in any number of counterparts, each of which when so executed and delivered
shall be taken to be an original, but such counterparts shall together
constitute but one and the same document.

               23.10 Facsimile Delivery. This Agreement may be delivered by
facsimile transmission of an executed counterpart signature page hereof, and
after attachment of such transmitted signature page to a copy of this Agreement,
such copy shall have the same effect and evidentiary value as copies delivered
with original signatures. Any party delivering this Agreement by facsimile
transmission shall deliver to the other party, as soon as practicable after such
delivery, an original executed counterpart signature page of this Agreement.

        IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement
as of the day and year first above written.

                           IXC Internet Services, Inc.

                           By:
                           Name:
                           Title:

                           PSINet Inc.

                           By:
                           Name:
                           Title:



                                      -11-

<PAGE>   66

                                    EXHIBIT D
                                       TO
                                  IRU AND STOCK
                               PURCHASE AGREEMENT


                   Newco Common Stock Percentage Determination


        The exact number of IXC Initial Common Shares to be issued and delivered
by PSINet to IXC at the Closing shall be equal to 19.99999% of the total number
of issued and outstanding shares of Common Stock of PSINet as of the Closing
Date (after giving effect to the issuance of the IXC Initial Common Shares
pursuant to the Agreement), including, for this purpose, shares of Common Stock
of PSINet issuable upon exercise of all warrants issued and outstanding as of
the Closing Date, but without giving effect to any shares of Common Stock
issuable (i) upon exercise of any options issued to current and former
employees, officers, directors and consultants of PSINet and its subsidiaries
which are outstanding as of the Closing Date, and/or (ii) pursuant to such
rights, if any, that Chatterjee (as defined in Section 13.9 of the PSINet
Disclosure Schedule) and/or its designee may have as of the Closing Date under
the Joint Venture Agreement (as defined in Section 13.9 of the PSINet Disclosure
Schedule) (see Section 13.9 of the PSINet Disclosure Schedule); provided,
however, that in addition to any adjustment in the number of IXC Initial Common
Shares pursuant to the second sentence of Section 3.3 of the Agreement, in the
event PSINet, on or prior to the Closing Date, shall issue, or agree between the
date hereof and the Closing Date to issue, to Chatterjee any securities
convertible into or exercisable or exchangeable for shares of Common Stock, upon
issuance thereof, IXC shall be entitled to be issued, or shall receive the same
right to be issued as so agreed to with Chatterjee, such amount of such
securities as is equal to 19.99999% of the total amount of such securities as
then being issued or agreed to be issued to Chatterjee.




<PAGE>   67

                                    EXHIBIT E



                               ASSOCIATED SERVICES


<PAGE>   68

                                    EXHIBIT E
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT


                               ASSOCIATED SERVICES

                  ANCILLARY PRICING SCHEDULE FOR ON-NET SERVICE



<TABLE>
<CAPTION>
NON-RECURRING CHARGES           DS-1             DS-3             OC-3           OC-12
- ---------------------           ----             ----             ----           -----
<S>                          <C>              <C>              <C>               <C>
New Order
    Installation (On-Net)    $       *        $        *       *
New Order
    Installation (Off-Net)           *                 *                *
    *
DS-1 Ramp-Up per DS-O        $       *                 *                *
    *
Order Change
    (less than
    5 business days)         $       *        $        *       $        *        $       *
Order Cancellation
    (less than
    5 business days)         $       *        $        *       $        *        $       *
ASR (new or disconnect)
    (Special Access Only)    $       *        $        *       $        *        $
    *
ASR Supplement               $       *        $        *       $        *        $       *
Order Expedite               $       *        $        *       $        *        $       *
Reconfiguration  ---------- Same as Install ----------

</TABLE>

<TABLE>
<CAPTION>
NON-RECURRING CHARGES          DS-1             DS-3             OC-3           OC-12
- ---------------------          ----             ----             ----           -----
<S>                          <C>              <C>              <C>               <C>
Minimum circuit
    charge (IXC portion)     $       *        $        *

Cross-connect charge         $       *        $        *       $        *        $
    *

    Other Interexchange 
         Carrier to Lessor 
          local access or bypass facility
        (Lessor long haul not involved)

Local bypass charge          $       *        $        *       $        *        $       *

    Lessor POP to Lessor
      POP in same city,
      with no Lessor
      long haul attached
      at either Lessor POP

</TABLE>



                                       -1-

<PAGE>   69


*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                                       -2-

<PAGE>   70


<TABLE>
<CAPTION>
MISCELLANEOUS                                   RECURRING                 NON-RECURRING
- -------------                                   ---------                 -------------
<S>                                             <C>                       <C>
M13     1 yr Term                                  *                            *
        2+ yr Term                                 *                            *
        3+ yr Term                                 *                            *

Echo Canceller (per circuit end)                   *                            *

Second End Loop (Ex: for ADPCM)                    *                            *

Demand Maintenance                                 *

Rack Space                                         *

Shelf Space                                        *                            *

DC Power                                           *

CIF AC/DC Power                                    *

All other services                                 *

</TABLE>

- --------------------

(1)     All of the above charges are subject to change with a 30-day notice.

(2)     Services not described above will be considered special handling and
        charges will be assessed on an individual basis.


*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                       -3-

<PAGE>   71

                              DSO ANCILLARY PRICING

<TABLE>
<CAPTION>
                                                    DSO ANCILLARY PRICING
                                                    ---------------------
<S>                                                <C>                  <C> 
New Order Installation                             $                    *

Order Cancellation Prior to Turn up                $                    *

Order Expedite                                     $                    *

Reconfiguration (City pairs the same)              $                    *

DCS Charge (Switching Only)                        $                    *

DSO DCS Port Charge (Bell access at DCS)           $                    *

DSI DCS Port                                       $                    *

Minimum Charge per DS-0                            $                    *

</TABLE>

- --------------------

(1)     All of the above charges are subject to change with a 30-day notice.

(2)     Services not described above will be considered special handling and
        charges will be assessed on an individual basis.



*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission



                                       -4-

<PAGE>   72


                IXC POLICY OVERVIEW, COLLOCATION RACK SPACE COST


In reference to Rack Space Non Recurring Installation Charges (One time buildout
charges)

The cost for buildout of rack space is $* per rack space. This cost includes the
following:

- -       Rack 19', 23' or 26' Racks. Cabinets will be addressed on a case by case
        basis.

- -       Termination of DC power to rack mounted fuse panels and AC power to a
        dual outlet box. Note: AC power is NOT uninterruptable, generators are
        available at most sites but UPS's are not. Check with IXC representative
        for site specific power capabilities.

- -       Termination of up to 6 DS-3 signal cable pairs (coax) or 56 DS-1
        circuits (ABAM) to DSX panels. Additional terminations will be charged
        at the rate of $* per DS3, and $* per 28 DS1s or a fraction thereof.
        Fiber termination is not included in this price and will be reviewed on
        a case by case basis.

- -       Termination of two POTS lines for remote access to hardware will be
        allowed, where LEC entrance facilities are available. Customer will be
        responsible for ordering and billing of such service and providing
        termination in customer racks.

- -       Only IXC approved materials will be installed, IXC Engineering contact
        can provide details.

- -       IXC will sign off on the install verifying quality and test results.

- -       Customer installation equipment must meet all applicable National
        Electric Code requirements and any other applicable safety/building code
        requirements.

For crossconnect and monthly recurring charges, please refer to the Ancillary
Pricing Schedule as part of the customer Digital Service Agreement.

IXC installation standards are available, and any questions, with regards to
installs, should be addressed with the site technician, prior to installation.

Standard CIF time lines will be maintained for rack installations, contact the
IXC CIF Specialist to review these time frames once site CIF space availability
have been confirmed.




- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                       -5-

<PAGE>   73

                                    EXHIBIT F

                    OC-N SPECIFICATIONS AND TESTING STANDARDS




<PAGE>   74

                                    EXHIBIT F
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT


                    OC-N SPECIFICATIONS AND TESTING STANDARDS

        OC-3: The ANSI SONET (Synchronous Optical Network) transmission standard
for high capacity optical telecommunications whose line rate is 155.52 Mbps. One
OC-3 is comprised of 3 STS-1 Synchronous Transport Signal, Level 1 signals
which, at 51.84 Mbps, is the lowest level SONET signal. The STS-1 is defined at
the electrical level prior to optical conversion. These SONET standards and
elements are further defined in the "Bellcore Synchronous Optical Network
(SONET) Transport Systems: Common Generic Criteria GR-253-CORE, Issue 2,
December, 1995."

        OC-12: The ANSI SONET (Synchronous Optical Network) transmission
standard for high capacity optical telecommunications whose line rate is 622.08
Mbps. One OC-12 is comprised of 12 STS-1 Synchronous Transport Signal, Level 1
signals which, at 51.84 Mbps, is the lowest level SONET signal. The STS-1 is
defined at the electrical level prior to optical conversion. These SONET
standards and elements are further defined in the "Bellcore Synchronous Optical
Network (SONET) Transport Systems: Common Generic Criteria GR-253-CORE, Issue 2,
December, 1995."

        OC-48: The ANSI SONET (Synchronous Optical Network) transmission
standard for high capacity optical telecommunications whose line rate is 2488.32
Mbps. One OC-48 is comprised of 48 STS-1 Synchronous Transport Signal, Level 1
signals which, at 51.84 Mbps, is the lowest level SONET signal. The STS-1 is
defined at the electrical level prior to optical conversion. These SONET
standards and elements are further defined in the "Bellcore Synchronous Optical
Network (SONET) Transport Systems: Common Generic Criteria GR-253-CORE, Issue 2,
December, 1995."

        The optical interface/demarcation for the SONET OC-3, OC-12, and OC-48
tributary signals will occur at the Texas optical interconnect panel. The
optical connector standardized for use at Texas locations is the Ultra Polished
FC/PC connector with a return loss greater than 45 dB. All optical signals at
this demarcation must equal or exceed the applicable Bellcore specifications,
referenced above.

TESTING STANDARDS

        Texas will test and turn-up the OC-3, OC-12, and/or OC-48 circuits to
the applicable demarcation point per this Agreement. The tests will be performed
per the applicable manufacturer's test specifications as it applies to the
specific type of traffic hand- off. The system will also be tested for a
long-term stability test running end-to-end for a period of 24 hours; Bit Error
Rate (BER) performance shall be no greater than 10-(1)(1).

        Five (5) days prior to testing, Texas will notify Virginia verbally and
in writing of Texas' intent to complete testing of the applicable circuit
activation: Virginia will have the right but not the obligation to witness the
activation testing. Copies of test results will be provided to Virginia upon
completion of the activation tests. If Virginia is not present at time of
testing, a copy of the test results will be forwarded to same.

        After Texas delivers circuits to PSINet, PSINet shall test same in
accordance with the following criteria, and accept installation segments of IRU
Capacity only after it meets the following:

        - Optical signal strength and other characteristics are within industry
standards at each termination point as measured with appropriate test equipment.

        - Backup path verified by testing fault switching hardware applicable to
the circuit being provided (test of 1:1 redundancy on the optronics).



                                       -1-

<PAGE>   75

        - Packet data passed with payload contents of 4500 bytes of all zeros
for twelve hours registering frame/code violations or other bit errors at a rate
not to exceed 10-(1)(1).

        - Packet data passed with payload contents of 4500 bytes of pseudo-
random data patterns for twelve hours registering frame/code violations or other
bit errors at a rate not to exceed 10-(1)(1).

        - Live production data passed for twelve hours registering frame/code
violation or other bit errors at a rate not to exceed 10-(1)(1).

        - Each segment, regardless of capacity meets the applicable Bellcore
specification, and equipment manufacturer's specification to the applicable
demarcation point per this Agreement.

        Virginia shall, within 5 business days of delivery either accept or
reject the IRU Capacity for each segment delivered. As soon as Virginia
discovers a problem in testing, Virginia shall notify Texas. If rejected,
Virginia shall specify, in good faith, the defect or failure in each segment
rejected within the applicable 5-business day period. In the event Virginia
rejects, Texas shall promptly, and at no cost to Virginia, commence to remedy
the defect or failure and, following such remedy, deliver the capacity to
Virginia. Virginia, shall provisionally be deemed to have accepted the IRU
Capacity for the applicable segment at the Final Delivery Date (as defined). The
"Final Delivery Date" shall mean the first date that Texas delivered the
relevant segment of the IRU Capacity to Virginia which was followed by either
acceptance by Virginia or a failure by Virginia to reject the IRU Capacity on
such segment within the required time.

        The foregoing procedures shall apply again and successively thereafter
until the defects and/or failures have been remedied, and Virginia accepts the
applicable segment. The date when Virginia accepts the applicable segments shall
be the Acceptance Date.



                                       -2-

<PAGE>   76

                                    EXHIBIT G

                               PSINET'S BANDWIDTH
                                    FORECAST


            NON-BINDING THREE-YEAR FORECAST OF BANDWIDTH REQUIREMENTS

PSINet will order approximately an OC-12 along a route traversing the Available
continental US every six months during the Term. The actual route will depend
upon availability of Bandwidth on the Available System. Every six months during
the Term, PSINet will attempt to add an OC-12 among all needed routes, perhaps
with breaks in the route at different POPs each time, until each route has four
OC-12's. A likely schedule, again depending upon availability of Bandwidth on
the Available System, is as follows:

<TABLE>
<CAPTION>
                  SIX MONTH INTERVAL                         OC-12 MILES ORDERED
                  ------------------                         -------------------
<S>                                                          <C>   
                           1                                            5,000+
                           2                                            6,000
                           3                                            8,000
                           4                                           10,000
                           5                                           10,000
                           6                                           10,000
</TABLE>

During the first interval, PSINet also anticipates ordering a system-wide DS-3,
which is likely to amount to the equivalent of approximately 700 OC-12 route
miles.



<PAGE>   77

                                   EXHIBIT G-1
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT


                           INITIAL ORDER FOR BANDWIDTH


PSINet's initial order for Bandwidth consists of one OC-12 per segment along
each of the following routes, each such segment requested to be delivered by IXC
as of the respective dates provided below:

GROUP 1

               *

GROUP 2

               *

               **

These orders are for express routes with no intermediate drops. The delivery
date for each route will be as set forth below:

Group 1        The later of January 1, 1998, or six (6) months after
               Closing or 60 days after completion of the applicable
               route.

Group 2        The later of June 1, 1998, or 60 days after completion of the
               applicable route.



- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

**      PSINet acknowledges that IXC does not currently plan to complete this
        route by July 1, 1998.


<PAGE>   78


                                    EXHIBIT H

                                MULTIPLEXING FEES



<PAGE>   79

                                    EXHIBIT H
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT

                                MULTIPLEXING FEES

Cost Per On-net NEW Circuit Non-recurring Installation/Provisioning Costs
including Channelization equipment**



<TABLE>
<CAPTION>
CITY A/CITY Z        DS3    OC3 TIER A     OC3 TIER B    OC12 TIER A   OC12 TIER B    OC48
- -------------        ---    ----------     ----------    -----------   -----------    ----
<S>                  <C>     <C>           <C>           <C>           <C>            <C> 
DS3                   *      x              x             x             x              x

OC3 Tier A            x      *              *             x             x              x

OC3 Tier B            x      *              *             x             x              x

OC12 Tier A           x      x              x             *             *              x

OC12 Tier B           x      x              x             *             *              x

OC48                  x      x              x             x             x              *

</TABLE>


TIER A CITIES: WASHDC, PHLAPA, NYCMNY, HDSNOH, CHCGIL, KSCYMO, JPLNMO, DLLSTX,
HSTNTX, PHNXAZ, LSANCA, ATLNGA, and as modified by IXC in future fiber builds.

TIER B CITIES: All On-net cities listed on the Available System other than Tier
A cities.



*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

**      Time and Materials Rates to be determined and applied for new
        interconnection cabling/infrastructure required between PSINet and IXC
        demarcation. Rates/Costs do not include any rates/costs of drops.

        Applies to second channel overbuild on a spur or moving an OC-48.



<PAGE>   80


                                    EXHIBIT I
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT


                              RECONFIGURATION FEES


(See Exhibits E and H)



<PAGE>   81

                                    EXHIBIT J

                       NEWCO CERTIFICATE OF INCORPORATION




<PAGE>   82

                                    EXHIBIT K

                                    POPSPACE




<PAGE>   83

                                    EXHIBIT K
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT


                                    POP SPACE


        "POP" shall mean any of IXC's junction or terminal locations located on
the fiber route that constitutes the completed portion of the Available System,
as selected by written notice from PSINet to IXC, provided that (i) there shall
be no more than * POP's so selected; (ii) a selection, once made, cannot be
changed, provided that if IXC moves a POP, the new location will be considered
the same as the old one for purposes of this clause (ii); and (iii) in no event
will PSINet have the right to select as POPs both a terminal and a junction in
or near the same metropolitan statistical area. Notwithstanding the foregoing,
PSINet and IXC may agree (separately from the Collocation Agreement) that PSINet
may rent cabinet space in other IXC locations and PSINet shall be permitted to
use its IRU fiber and IRU capacity between IXC terminals and junctions on the
Available System in or near the same metropolitan statistical area.



- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

<PAGE>   84

                                    EXHIBIT L

                                PSINET DISCLOSURE
                                    SCHEDULE





<PAGE>   85

                                                                EXHIBIT L TO THE
                                                          IRU AND STOCK PURCHASE
                                                                       AGREEMENT

                           PSINET DISCLOSURE SCHEDULE

13.2           Material Governmental Authority Consents
13.4           Capitalization
13.5           Material Adverse Change
13.6           Other Consents
13.7           Litigation
13.9           Other Agreements

        The following information constitutes the PSINet Disclosure Schedule to
that certain IRU and Stock Purchase Agreement dated as of July 21, 1997 between
PSINet Inc. and IXC Internet Services, Inc. (the "Agreement"). Capitalized terms
used in this PSINet Disclosure Schedule which are not otherwise defined herein
shall have the respective meanings ascribed thereto in the Agreement. All
references herein to Sections are to Sections of the Agreement unless otherwise
noted. The representations and warranties in Section 13 of the Agreement are
made and given subject to the disclosures in this PSINet Disclosure Schedule and
the exceptions set forth herein. This PSINet Disclosure Schedule is incorporated
into the Agreement by reference and made a part thereof. This PSINet Disclosure
Schedule incorporates by reference all applicable information contained in the
PSINet Filings with the Securities and Exchange Commission. Disclosure of
information in any Section of the PSINet Disclosure Schedule, shall be deemed to
be disclosure in each other Section of the PSINet Disclosure Schedule.
Disclosure of any information in the PSINet Disclosure Schedule, whether or not
in response to a requirement contained in the Agreement to schedule material
matters or matters outside the ordinary course of business, shall not be deemed
to be an admission by PSINet that such information is material or outside the
ordinary course of business nor is it or shall it be deemed to be a
representation that such information must be set forth on this PSINet Disclosure
Schedule or otherwise in the Agreement. Nothing in this PSINet Disclosure
schedule shall constitute an admission of any liability or obligation of PSINet
or its affiliates to any third party nor an admission against PSINet or its
Affiliates' interests.



<PAGE>   86

                                                                    SECTION 13.2


                    MATERIAL GOVERNMENTAL AUTHORITY CONSENTS


        1. Filing of a Form D (if elected by PSINet), Form 8-A, Form 8-B, Forms
8- K, Forms S-8, Proxy Statement, registration statement(s) under the Securities
Act, request for confidential treatment and any related documents with the
Commission.

        2. Such filings with the Commission as may be required under the
Registration Rights Agreement contemplated by Section 15.9.

        3. Such consents, approvals, authorizations, designations, declarations
or filings as may be required under state securities laws in connection with the
issuance of any Acquired Shares or under federal or state law in connection with
the Registration Rights Agreement contemplated by Section 15.9 of the Agreement
or in connection with any transfer of Acquired Shares.

        4. Filing with National Association of Securities Dealers, Inc. of one
or more listing applications and of documents filed with the Commission.

        5. Such consents, approvals, authorizations, designations, declarations
or filings as may be required under state corporation and tax laws in connection
with the Reincorporation.

        6. Such filings and notifications as may be required under the
Hart-Scott-Rodino Act.

        7. Such filings as may be required with the U.S. Patent and Trademark
Office and of copyright amendments in connection with the Reincorporation.

        8. Such filings of UCC financing statements and other documents and
instruments as may be required in connection with the Reincorporation.


<PAGE>   87

                                                                    SECTION 13.4

                                 CAPITALIZATION

        1. Upon the Closing Date, after giving effect to the Reincorporation and
assuming that PSINet does not designate any other series of Preferred Stock
prior to completion of the Closing, the authorized capital stock of PSINet will
consist of 200,000,000 shares of Common Stock, $.0001 par value per share,
29,000,000 shares of undesignated Preferred Stock, $.01 par value per share, and
1,000,000 shares of Series A Junior Participating Preferred Stock, $.01 par
value per share.

        2. As of the date of this Agreement, there are no outstanding
subscriptions, options, warrants, call, rights or other agreements or
commitments to issue, sell, deliver or transfer any shares of Common Stock or
other shares of capital stock of PSINet except options to purchase
[7,557,065.49] shares of Common Stock (subject to adjustment as provided
therein) and warrants to purchase 224,274 shares of Common Stock (subject to
adjustment as provided therein).

        3. See item 2 under Section 13.9 of the PSINet Disclosure Schedule.



<PAGE>   88


                                                                    SECTION 13.5

                             MATERIAL ADVERSE CHANGE


        1. Such changes as may have resulted from general economic or political
matters affecting the industries and markets in which PSINet's business operates
and/or the U.S. economy.

        2. See item 1 under Section 13.9 of the PSINet Disclosure Schedule.



<PAGE>   89

                                                                    SECTION 13.6

                                 OTHER CONSENTS


        1. Such consent as may be required by PSINet's bank lender, Fleet Bank
of Massachusetts, N.A. ("Fleet").

        2. PSINet has a loan facility with Fleet pursuant to which it has
granted Fleet a lien on substantially all of its assets. Such lien would attach
to the IRUs and other rights and property conveyed to PSINet pursuant to the
Agreement.



<PAGE>   90

                                                                    SECTION 13.7

                                   LITIGATION


        1. See item 1 under Section 13.9 of the PSINet Disclosure Schedule.

        2. After the execution of the Joint Venture Agreement referred to in
Section 13.9 of the Disclosure Schedule, Institutional Trading Corporation
("ITC") commenced an action alleging that PSINet owed it an investment banking
finders fee or similar compensation in the amount of $1.5 million in connection
with the transactions contemplated by the Joint Venture Agreement and other
contractual claims. ITC has since withdrawn such action without prejudice. In
the event PSINet completes a transaction with Chatterjee (as defined in Section
13.9 of the PSINet Disclosure Schedule), PSINet believes it is likely that ITC
will commence a new action alleging similar claims with respect to such
transaction.



<PAGE>   91

                                                                    SECTION 13.9

                                OTHER AGREEMENTS


        1. In September 1996, PSINet entered into a Joint Venture Agreement,
dated as of September 19, 1996 (the "Joint Venture Agreement") with Chatterjee
Management Company (doing business as The Chatterjee Group) ("Chatterjee")
pursuant to which PSINet and an investment group led by Chatterjee would
establish a joint venture for the purpose of building an Internet network across
Europe and providing Internet-related services in Europe and such investment
group would invest up to $41 million in the joint venture. A copy of the
original Joint Venture Agreement with Chatterjee has been filed with the
Commission (portions of which are subject to a confidential treatment request
and a complete copy thereof is available for review by IXC). Under certain
circumstances, Chatterjee or its designee would have the right to require PSINet
to issue to Chatterjee or such designee such number of shares of PSINet Common
Stock as shall equal (i) the amount of investments made by Chatterjee or such
designee (none has been made to date) divided by (ii) $11.625, provided,
however, that this right is was not to be exercisable prior to October 1,1997
and under certain other circumstances. No monies have been invested by
Chatterjee or the investment group pursuant to the Joint Venture Agreement nor
were any other actions undertaken to implement it. For several months, PSINet
and Chatterjee have discussed a substantive change to the structure discussed in
the Joint Venture Agreement which, if entered into, would have resulted in a $41
million direct investment in PSINet by Chatterjee consisting of approximately *

        By letter dated July 14, 1997, a copy of which has previously been
furnished to IXC, Chatterjee made certain statements concerning the negotiations
between Chatterjee and PSINet, including, without limitation, (i) Chatterjee's
conclusion that PSINet does not intend to proceed with the Joint Venture
Agreement or the substantive change to the structure discussed in the Joint
Venture Agreement(which Chatterjee claims had been agreed upon by PSINet) and
(ii) Chatterjee's statement that it will proceed based upon that conclusion.
PSINet has not yet responded to that letter. In the event PSINet and Chatterjee
do not complete this transaction (and PSINet presently believes it is likely
that the parties will not reach such an agreement), the Joint Venture Agreement
may be abandoned or Chatterjee may seek to commence arbitration or other
adversarial proceedings against PSINet under the Joint Venture Agreement and
related documents (seeking, among other things, to enforce the Joint Venture
Agreement) or otherwise.

        2. PSINet has issued options and warrants as described in Section 13.4
of the PSINet Disclosure Schedule and has stock option and similar plans, as
described in the PSINet Filings, pursuant to which PSINet may issue additional
options and share underlying such options.


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


<PAGE>   92

                                    EXHIBIT M
                                       TO
                        IRU AND STOCK PURCHASE AGREEMENT

                       IXC INTERNET SERVICES, INC. ("IXC")
                               DISCLOSURE SCHEDULE
                                     TO THE
                        IRU AND STOCK PURCHASE AGREEMENT
                    DATED AS OF JULY 22, 1997 BY AND BETWEEN
                                 PSINET AND IXC
                           (THE "PURCHASE AGREEMENT")


        The representations and warranties in Section 14 of the Purchase
Agreement are made and given subject to the disclosures in this Disclosure
Schedule and the exceptions set forth herein. Unless otherwise defined herein,
the capitalized terms used herein shall have the meanings assigned to such terms
in the Purchase Agreement. Section references herein correspond to section
references in the Purchase Agreement. This Disclosure Schedule incorporates by
reference all applicable information contained in the IXC Communications, Inc.
filings with the Securities and Exchange Commission. The inclusion of any
information on this Disclosure Schedule is not, and shall not be deemed to be, a
representation that such information must be set forth on this Disclosure
Schedule or otherwise in the Purchase Agreement. Nothing in this Disclosure
Schedule shall constitute an admission of any liability or obligation of IXC, or
its affiliates to any third party nor an admission against IXC's or its
affiliates interests.


SECTION 14.2
GOVERNMENTAL AUTHORIZATIONS

A filing by IXC's ultimate parent to the Federal Trade Commission and the United
States Department of Justice under the Hart-Scott-Rodino Antitrust Improvements
Act of 1976.


SECTION 14.3
REQUIRED CONSENTS

Indenture dated as of October 5, 1995 by and among IXC Communications, Inc., the
Guarantors (as defined therein) and IBJ Schroder Bank & Trust Company, as
Trustee with respect to the 12 1/2% Senior Notes due 2005.

SECTION 14.4
PENDING LITIGATION

        1.     TEL CENTRAL COMMUNICATIONS, INC. VS IXC LONG DISTANCE, INC. U.S.
District Court, Western District of Missouri (Central Division) Civil Action No.
97-4095-CV-C

               On April 4, 1997, Tel-Central Communications, Inc.
("Tel-Central") filed a complaint against IXC-LD, one of IXC Communications,
Inc.'s subsidiaries, in the United States District Court in the Western District
of Missouri after IXC Communications, Inc. terminated service to Tel-Central for
failure to pay for services. Tel-Central's complaint makes various state and
federal law claims and seeks damages of over $100 million and asks for punitive
damages of $100 million. On May 23, 1997, Tel Central filed a voluntary Chapter
11 petition in bankruptcy. On May 30, 1997, IXC-LD filed a motion to dismiss the
complaint. The case is currently stayed as a result of the bankruptcy
proceedings.

        2.     TRUMAN BREED, ET AL., VS. IXC ADVANTAGE LONG DISTANCE, INC., IXC 
LONG DISTANCE, INC., IXC COMMUNICATIONS, INC., ET AL. In the District Court of
Travis County, IXC, Cause No. 9705729



<PAGE>   93



               This action, filed May 27, 1997, was brought by a group of
investors in IXC Advantage Long Distance, Inc. ("IXC Advantage") who allege that
IXC Advantage and/or its Chief Executive Officer diverted funds from IXC
Advantage to form a new company named Free Plus Calling, Inc. A subsidiary of
IXC Communications, Inc. had invested in IXC Advantage, owned a 25% interest in
IXC Advantage, and one of such subsidiary's officers served on the board of
directors of IXC Advantage from its formation in mid-1994 until Mach of 1996.
The plaintiffs allege that as a result of the board seat, the defendants either
knew or should have known of the diversion of funds and hence became liable for
the conduct. The defendants currently have an extension of time to answer the
complaint.

        3. DARRYL THOMPSON ET AL., VS. MORGAN COUNTY COMMISSIONERS, ET AL.,
INCLUDING IXC LONG DISTANCE, INC. State of Indiana, Morgan Superior Court No.
55DO2-9701-CP-6

               This action, filed on February 5, 1997, alleges the illegal
construction of fiber across plaintiffs' property. This portion of IXC Carrier,
Inc.'s network consists of an indefeasible right to use ("IRU") fibers from
WorldCom ("WorldCom, Inc."). IXC Carrier, Inc. acquired the IRU from WorldCom
pursuant to an IRU Agreement with WorldCom (the "IRU Agreement"). WorldCom has
accepted defendant's tender of defense and indemnity in this action pursuant to
the IRU Agreement.

        4. IXC LONG DISTANCE, INC. VS. BUILDING FUTURES IN COMMUNICATIONS, INC.

               This arbitration action was filed by IXC-LD on February 10, 1997
seeking $256,393 for past due services, plus additional amounts for accelerated
take-or-pay commitments under the terminated Telecommunications Services
Agreement between the parties dated April 19, 1996. Building Futures in
Communication, Inc. ("BFIC") had been terminated on IXC-LD's network on December
13, 1997 for non-payment. BFIC has counterclaims against IXC-LD for up to $1
million in actual damages plus punitive damages. Discovery is underway and no
arbitration date has yet been set.

        5.     IXC LONG DISTANCE, INC. VS. PRIME TELECOM, INC.

               This arbitration action was filed by IXC-LD on January 14, 1997
seeking $134,187 for past due services, plus additional amounts for accelerated
take-or-pay commitments, under the terminated Telecommunications Services
Agreement between the parties dated May 25, 1995. Prime Telecom, Inc.'s services
had been terminated on IXC-LD's network on December 13, 1997 for non-payment.
Discovery is underway and no arbitration date has been set.


SECTION 14.7
MATERIAL ADVERSE CHANGE

The facts or circumstances set forth in the IXC Communications, Inc.'s News
Release dated July 3, 1997 may cause a Material Adverse Change in IXC.




<PAGE>   94

                                   EXHIBIT N

                         REGISTRATION RIGHTS AGREEMENT


<PAGE>   95

                                                                       EXHIBIT N

                                    EXHIBIT N

                                       TO

                        IRU AND STOCK PURCHASE AGREEMENT


                          REGISTRATION RIGHTS AGREEMENT

        This Registration Rights Agreement (this "Agreement") is made as of the
day of July, 1997 by and between , PSINet Inc., a New York corporation (the
"Company"), and IXC Internet Services, Inc. , a Delaware corporation ("IXC").

                                   WITNESSETH:

        WHEREAS, the Company and IXC have entered into an IRU and Stock Purchase
Agreement dated as of July 21, 1997 (the "IRU Agreement"), pursuant to which the
Company, will issue shares of Common Stock.

        WHEREAS, it is a condition precedent to the consummation of the
transactions under the IRU Agreement that this Agreement be entered into.

        WHEREAS, the Company has previously granted registration rights to
certain other holders of the Company's securities pursuant to the Amended and
Restated Registration Rights Agreement, the 2/8/95 Registration Rights
Agreement, the 6/16/95 Registration Rights Agreement, the 7/11/95 Registration
Rights Agreement and the 9/19/96 Registration Rights Agreement.

        WHEREAS, it is the intention of the parties to this Agreement that the
registration rights granted hereunder shall rank ratably with the registration
rights under the Amended and Restated Registration Rights Agreement, the 2/8/95
Registration Rights Agreement, the 6/16/95 Registration Rights Agreement, the
7/11/95 Registration Rights Agreement and the 9/19/96 Registration Rights
Agreement and with registration rights to be granted under other agreements as
more fully provided in Section 2.6 hereof.

        WHEREAS, certain defined terms are set forth in Article I hereof.

        NOW, THEREFORE, for good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, and in consideration of the mutual
covenants contained herein and for other good and available consideration, the
receipt and adequacy of which are hereby acknowledged, the parties hereto,
intending to be legally bound, agree as follows:



<PAGE>   96

                                    ARTICLE I

                                   DEFINITIONS


SECTION 1.1           CERTAIN DEFINITIONS

        As used in this Agreement, the following terms shall have the meanings
indicated below:

        "Amended and Restated Registration Rights Agreement" shall mean the
Amended and Restated Registration Rights Agreement dated as of January 17, 1995
among the Company and the other parties thereto, as the same has been and
hereafter may be amended from time to time to add additional parties signatory
thereto.

        "Closing" shall mean the closing of the transactions contemplated under
the IRU Agreement as more specifically defined therein.

        "Commission" shall mean the Securities and Exchange Commission or any
other federal agency at the time administering the Securities Act.

        "Common Stock" shall mean the Common Stock, $.01 par value per share, of
the Company.

        "Exchange Act" shall mean the Securities Exchange Act of 1934, as
amended, and the rules and regulations promulgated thereunder.

        "Existing Registration Rights" shall have the meaning set forth in
Section 2.7 hereof.

        "Other Registration Rights" shall have the meaning set forth in Section
2.7 hereof.

        "Person" shall mean any individual, corporation, partnership, firm,
joint venture, association, limited liability company, trust, unincorporated
organization, or other entity.

        "primary offering" shall have the meaning set forth in Section 2.1
hereof.

        "Registrable Securities" shall have the meaning set forth in Section 2.4
hereof.

        "secondary offering" shall have the meaning set forth in Section 2.1
hereof.

        "Securities Act" shall mean the Securities Act of 1933, as amended, and
the rules and regulations promulgated thereunder.

        "2/8/95 Registration Rights Agreement" shall mean the Registration
Rights Agreement dated as of February 8, 1995 among the Company and the other
parties thereto, as the same may be amended from time to time and, to the
extent, if any, the same shall be in effect on the date hereof and remain in
effect from time to time hereafter.

        "6/16/95 Registration Rights Agreement" shall mean the Registration
Rights Agreement dated as of June 16, 1995 among the Company and the other
parties thereto, as the same may be amended from time to time and, to the
extent, if any, the same shall be in effect on the date hereof and remain in
effect from time to time hereafter.

        "7/11/95 Registration Rights Agreement" shall mean the Registration
Rights Agreement dated as of July 11, 1995 among the Company and the other
parties



                                       -2-

<PAGE>   97


thereto, as the same may be amended from time to time and, to the extent, if
any, the same shall be in effect on the date hereof and remain in effect from
time to time hereafter.

        "9/19/96 Registration Rights Agreement" shall mean the Registration
Rights Agreement dated as of September 19, 1996 between the Company and The
Chatterjee Management Company, as the same may be amended from time to time and,
to the extent, if any, the same shall be in effect on the date hereof and remain
in effect from time to time hereafter.



                                       -3-

<PAGE>   98

                                   ARTICLE II

                               REGISTRATION RIGHTS


SECTION 2.1           OPTIONAL REGISTRATIONS

        If at any time or times after the date hereof (so long as IXC shall own
Registrable Securities which are not eligible for sale by IXC under Rule 144(k)
of the Securities Act), the Company shall determine to register any shares of
Common Stock or securities convertible into or exchangeable or exercisable for
shares of the Common Stock under the Securities Act (whether in connection with
a public offering of securities by the Company (a "primary offering"), a public
offering of securities by shareholders (a "secondary offering"), or both, but
not in connection with a registration effected solely to implement an employee
benefit plan or a transaction to which Rule 145 or any other similar rule of the
Commission under the Securities Act is applicable), the Company will promptly
give written notice thereof to IXC. In connection with any such registration, if
within 30 days after receipt of such notice IXC requests the inclusion of some
or all of the Registrable Securities in such registration, the Company, subject
to Section 2.7 hereof, will use its reasonable best efforts to effect the
registration under the Securities Act of all such Registrable Securities;
provided, that such registration is in connection with an underwritten public
offering; and provided, further, that, if the underwriter determines that the
registration of securities in excess of any amount to be registered by the
Company would adversely affect such offering then the Company may (subject to
the allocation priority set forth below) exclude from such registration and
underwriting some or all of the Registrable Securities which would otherwise be
underwritten pursuant to the notice described herein. The Company shall advise
IXC promptly after such determination by the underwriter, and the number of
shares of securities that are entitled to be included in the registration and
underwriting shall be allocated in the following manner: the securities to be
sold by the Company shall be included in such registration and underwriting,
and, subject to Section 2.7 hereof, the number of additional shares that may be
included in the registration and underwriting shall be allocated among IXC and
all holders of other securities having registration rights granted by the
Company requesting that such other securities be included in such registration
and underwriting in proportion, as nearly as practicable, to their respective
holdings of Registrable Securities and such other securities. All expenses of
the registration and offering shall be borne by the Company, except that IXC and
all holders of other securities having registration rights granted by the
Company shall bear underwriting and selling discounts and commissions
attributable to their Registrable Securities or such other securities, as the
case may be, being registered, transfer taxes on shares being sold by IXC or the
other holders, as the case may be, and all fees and expenses of counsel for IXC
and such holders, as the case may be. Without in any way limiting the types of
registrations to which this Section 2.1 shall apply, in the event that the
Company shall effect a "shelf registration" under Rule 415 of the Securities Act
or any other similar rule or regulation, the Company shall take all necessary
action, including, without limitation, the filing of post-effective amendments,
to permit IXC to include its shares in such registration in accordance with the
terms of this Section 2.1.


SECTION 2.2           REQUIRED REGISTRATIONS

        At any time or times after the date hereof (so long as IXC shall own
Registrable Securities which are not eligible for sale by IXC under Rule 144(k)
of the Securities Act), IXC may notify the Company in writing that it (i)
intends to offer or cause to be offered for public sale all or any portion of
its Registrable Securities (such requests shall be in writing and shall state
the number of shares of Registrable Securities to be disposed of and the
intended



                                       -4-

<PAGE>   99



method of disposition of such shares by IXC) and (ii) request that the Company
cause such Registrable Securities to be registered under the Securities Act;
provided, however, that IXC may make only three requests for registration under
this Section 2.2. Upon receipt of such notification, subject to Section 2.7
hereof, the Company will notify all of the Persons who would be entitled to
notice of a proposed registration under Existing Registration Rights or Other
Registration Rights of its receipt of such notification. Upon the written
request of any such Person delivered to the Company within 30 days after receipt
from the Company of such notification, the Company will use its reasonable best
efforts to cause such Registrable Securities as may be requested by IXC or such
securities as may be requested by any such Person to be registered under the
Securities Act within 125 days of the notification by IXC, in accordance with
the terms of this Section 2.2; provided, however, that unless such registration
becomes effective and remains in effect for 60 days, such registration shall not
be counted as one of the three requests for registration that may be made by IXC
under this Section 2.2. IXC shall have the right to select the investment
banker(s) and manager(s) (which shall be of national standing and reputation) to
administer any underwritten public offering under this Section 2.2, subject to
the execution and delivery by such investment banker(s) to the Company of a
confidentiality agreement in form and substance satisfactory to the Company. If
requested in writing by the Company, IXC and the other Persons participating in
a registration under this Section 2.2 shall negotiate in good faith with any
underwriters retained in connection with the underwriting of such registration.
In the case of the registration of Registrable Securities in connection with an
underwritten public offering under this Section 2.2, if the underwriter
determines that the registration of securities in excess of an amount determined
by such underwriter would adversely affect such offering, then the Company may
(subject to the allocation priority set forth below) exclude from such
registration and underwriting some or all of the Registrable Securities and
other securities which would otherwise be underwritten pursuant to this Section
2.2. The Company shall advise IXC and the other Persons who requested to
participate in such registration promptly after such determination by the
underwriter, and the number of securities that are entitled to be included in
the registration and underwriting shall be allocated in the following manner:
subject to Section 2.7 hereof, the number of securities that may be included in
the registration and underwriting shall be allocated among IXC and such other
Persons requesting that Registrable Securities or other securities be included
in such registration and underwriting in proportion, as nearly as practicable,
to their respective holdings of Registrable Securities and other securities;
provided, however, that if the number of Registrable Securities pursuant to such
registration shall be reduced to a number which is less than 80% of the number
of Registrable Securities as to which IXC requested registration pursuant to
this Section 2.2, then such registration shall not be counted as one of the
three requests for registration that may be made by IXC under this Section 2.2.
All expenses of such registration and offering and the reasonable fees and
expenses of one independent counsel for IXC and the other Persons who requested
to participate in such registration shall be borne by the Company; provided,
however, that (i) the Company shall have no liability for such expenses if such
registration does not become effective due solely to the action or failure to
act of IXC and (ii) IXC and other Persons who requested to participate in such
registration shall bear underwriting and selling discounts and commissions
attributable to their Registrable Securities or other securities being
registered and transfer taxes on shares being sold by them. The Company may
postpone the filing of any registration statement required hereunder for a
reasonable period of time, not to exceed 90 days during any 12 month period of
time, if the Company has been advised by legal counsel that such filing would
require the disclosure of a material transaction or other matter and the Company
determines reasonably and in good faith that such disclosure would have a
material adverse effect on the Company. Notwithstanding anything in this Section
2.2 to the contrary, the Company shall not be required to effect a registration
under this Section 2.2 more than 135 days following the end of the Company's
fiscal year, if such registration shall require the preparation of audited
financial statements for



                                       -5-

<PAGE>   100



any interim period not otherwise prepared by the Company. If a demand
registration is requested during such period, subject to the second preceding
sentence, the Company will commence such registration promptly following the end
of the next fiscal year. The Company will enter into customary agreements
(including underwriting agreements) reasonably acceptable to the Company to
facilitate the demand registrations provided for above.


SECTION 2.3           FORM S-3 SHELF REGISTRATION

        IXC shall have the right to request and have effected up to one
registration every six months of Registrable Securities on Form S-3 or any
successor form or, if Form S-3 or any successor form is not available, any
appropriate form under the Act (the "Shelf Registration Statement") for an
offering to be made on a continuous basis covering all the Registrable
Securities (the "Shelf Registration") (such request shall be in writing and
shall state the number of shares of Registrable Securities to be disposed of and
the intended method of disposition of such shares by IXC) provided that the
Registrable Securities for which such registration is requested are not eligible
for sale by IXC under Rule 144(k) of the Securities Act. Subject to the
provisions of applicable law, the Company will use its reasonable best efforts
to (i) file the Shelf Registration Statement to effect the registration of all
shares of Registrable Securities within 30 days of such request and (ii) cause
the Shelf Registration Statement to become effective under the Act on or prior
to the date 45 days from the date of filing and (iii) keep the Shelf
Registration Statement continuously effective for 60 days from the date the
Registration Statement becomes effective under the Act. All expenses in
connection with a registration requested pursuant to this Section 2.3 shall be
borne by the Company; provided, however, that (i) the Company shall have no
liability for such expenses if such registration does not become effective due
solely to the action or failure to act of IXC and (ii) IXC shall bear
underwriting and selling discounts and commissions, if any, attributable to its
Registrable Securities being registered, transfer taxes on shares being sold by
it and all fees and expenses of its counsel. The Company may postpone the filing
of any registration statement required hereunder for a reasonable period of
time, not to exceed 90 days, if the Company has been advised by legal counsel
that such filing would require the disclosure of a material transaction or other
factor which would not otherwise be required to be disclosed at such time and
the Company determines reasonably and in good faith that such disclosure would
have a material adverse effect on the Company with respect to the registration
of the Registrable Securities. The shelf-registration statement may also include
securities held or to be held by other holders of the Company's securities.


SECTION 2.4           REGISTRABLE SECURITIES

        For purposes of this Agreement, the term "Registrable Securities" shall
mean the Common Stock issued or issuable under the IRU Agreement and any Common
Stock issued or issuable with respect thereto by way of a stock dividend or
stock split or in connection with a combination of shares, recapitalization,
merger, consolidation or other reorganization.


SECTION 2.5           FURTHER OBLIGATIONS OF THE COMPANY

        Whenever the Company is required under this Article II to register any
Registrable Securities, it agrees that it shall also do the following:

               (a) Use its reasonable best efforts to diligently prepare and
file with the Commission a registration statement and such amendments and
supplements to said registration statement and the prospectus used in connection
therewith as may be necessary to keep said registration statement effective
(but, in the



                                       -6-

<PAGE>   101



case of a registration under this Agreement, for no more than 60 days after the
initial effective date of the registration statement) and to comply with the
provisions of the Securities Act with respect to the sale of securities covered
by said registration statement for the period necessary to complete the proposed
public offering; provided, however, the Company may suspend the effectiveness of
any registration statement filed hereunder for a reasonable period of time, not
to exceed 90 days, if the Company has been advised by legal counsel that
maintaining such effectiveness would require the disclosure of a material
transaction or other matter and the Company determines reasonably and in good
faith that such disclosure would have a material adverse effect on the Company;
provided, further, that in the event of any such suspension of effectiveness,
the 60 day period of effectiveness required above shall be deemed tolled for the
number of days the effectiveness of such registration statement was suspended
and, if any securities covered by such registration statement remain unsold, the
Company shall thereafter take all necessary actions, including, without
limitation, the filing of post-effective amendments, to cause such registration
statement to become effective for the remainder of such 60 day period;

               (b) Furnish to IXC such copies of each preliminary and final
prospectus and such other documents as IXC may reasonably request to facilitate
the public offering of its Registrable Securities;

               (c) Use its reasonable best efforts to register or qualify the
securities covered by said registration statement at the Company's expense under
the securities or "blue-sky" laws of such jurisdiction as IXC may reasonably
request, provided that the Company shall not be required to register or qualify
the securities in any jurisdictions which require it to qualify to do business
or subject itself to taxation or general service of process therein;

               (d) Immediately notify IXC, at any time when a prospectus
relating to its Registrable Securities is required to be delivered under the
Securities Act, of any stop order issued or threatened by the Commission or of
the happening of any event as a result of which such prospectus contains an
untrue statement of a material fact or omits any material fact necessary to make
the statements therein not misleading, and, at the request of IXC, prepare a
supplement or amendment to such prospectus so that, as thereafter delivered to
the purchasers of such Registrable Securities, such prospectus will not contain
any untrue statement of a material fact or omit to state any material fact
necessary to make the statements therein not misleading;

               (e) Cause all such Registrable Securities to be listed on NASDAQ
or included in each securities exchange or quotation system on which similar
securities issued by the Company are then listed;

               (f) Otherwise use its reasonable best efforts to comply with all
applicable rules and regulations of the Commission and make generally available
to its security holders, in each case as soon as practicable, but not later than
30 days after the close of the period covered thereby, an earnings statement of
the Company which will satisfy the provisions of Section 11(a) of the Securities
Act; and

               (g) Choose the underwriters (except as otherwise provided in
Section 2.2 hereof), auditors, Company legal counsel and financial printer to be
engaged by the Company in any such registration.


SECTION 2.6           NO TRANSFER OF REGISTRATION RIGHTS

        The registration rights of IXC under this Agreement may not be
transferred or assigned except to IXC Communications, Inc. or a controlled
affiliate of IXC Communications, Inc.; provided that such transferee shall have
entered into an



                                       -7-

<PAGE>   102



agreement substantially the same as that set forth in Section 15.8 of the IRU
Agreement.


SECTION 2.7           PRIOR AND OTHER REGISTRATION RIGHTS AGREEMENTS

        Notwithstanding any provision hereof to the contrary, the provisions of
this Article II: (i) shall rank ratably with the registration rights granted
under the Amended and Restated Registration Rights Agreement (the "Amended
Registration Rights") and, to the extent the provisions of this Article II
conflict or are inconsistent with any such Amended Registration Rights, such
conflict or inconsistency shall be resolved in a manner which, to the greatest
extent reasonably feasible, affords IXC and the holders of such Amended
Registration Rights, the ratable benefits of this Article II and such Amended
Registration Rights; (ii) shall rank ratably with the registration rights
granted under the 2/8/95 Registration Rights Agreement (the "2/8/95 Registration
Rights") and, to the extent the provisions of this Article II conflict or are
inconsistent with any such 2/8/95 Registration Rights, such conflict or
inconsistency shall be resolved in a manner which, to the greatest extent
reasonably feasible, affords IXC and the holders of the 2/8/95 Registration
Rights, the ratable benefits of this Article II and such 2/8/95 Registration
Rights; (iii) shall rank ratably with the registration rights granted under the
6/16/95 Registration Rights Agreement (the "6/16/95 Registration Rights") and,
to the extent the provisions of this Article II conflict or are inconsistent
with any such 6/16/95 Registration Rights, such conflict or inconsistency shall
be resolved in a manner which, to the greatest extent reasonably feasible,
affords IXC and the holders of the 6/16/95 Registration Rights, the ratable
benefits of this Article II and such 6/16/95 Registration Rights; (iv) shall
rank ratably with the registration rights granted under the 7/11/95 Registration
Rights Agreement (the "7/11/95 Registration Rights") and, to the extent the
provisions of this Article II conflict or are inconsistent with any such 7/11/95
Registration Rights, such conflict or inconsistency shall be resolved in a
manner which, to the greatest extent reasonably feasible, affords IXC and the
holders of the 7/11/95 Registration Rights, the ratable benefits of this Article
II and such 7/11/95 Registration Rights; (v) shall rank ratably with the
registration rights granted under the 9/19/96 Registration Rights Agreement (the
"9/19/96 Registration Rights") and, to the extent the provisions of this Article
II conflict or are inconsistent with any such 9/19/96 Registration Rights, such
conflict or inconsistency shall be resolved in a manner which, to the greatest
extent reasonably feasible, affords IXC and the holders of the 9/19/96
Registration Rights, the ratable benefits of this Article II and such 9/19/96
Registration Rights; and (vi) shall rank ratably with the registration rights to
be granted under any other agreement in connection with the original issuance of
any other capital stock of the Company (the "Other Registration Rights") and, to
the extent the provisions of this Article II shall conflict with any such Other
Registration Rights, such conflict shall be resolved in a manner which, to the
greatest extent reasonably feasible, affords IXC and the holders of such Other
Registration Rights, the ratable benefits of the provisions of this Article II
and such Other Registration Rights.



                                       -8-

<PAGE>   103


                                   ARTICLE III

                        INDEMNIFICATION AND CONTRIBUTION


SECTION 3.1           INDEMNIFICATION

        Incident to any registration statement referred to in this Agreement,
and subject to applicable law, the Company will indemnify and hold harmless each
underwriter, IXC (including its directors, officers, employees and agents), and
each person who controls any of them within the meaning of Section 15 of the
Securities Act or Section 20 of the Exchange Act, from and against any and all
losses, claims, damages, expenses and liabilities, joint or several (including
any investigation, legal and other expenses incurred in connection with, and any
amount paid in settlement of, any action, suit or proceeding or any claim
asserted), to which they, or any of them, may become subject under the
Securities Act, the Exchange Act or other federal or state statutory law or
regulation, at common law or otherwise, insofar as such losses, claims, damages
or liabilities arise out of or are based on (i) any untrue statement or alleged
untrue statement of a material fact contained in such registration statement
(including any related preliminary or definitive prospectus, or any amendment or
supplement to such registration statement or prospectus), (ii) any omission or
alleged omission to state in such document a material fact required to be stated
in it or necessary to make the statements in it not misleading, or (iii) any
violation by the Company of the Securities Act, any state securities or "blue
sky" laws or any rule or regulation thereunder in connection with such
registration; provided, however, that the Company will not be liable to the
extent that such loss, claim, damage, expense or liability (x) arises from and
is based on an untrue statement or omission or alleged untrue statement or
omission made in reliance on and in conformity with information furnished in
writing to the Company by or on behalf of such underwriter, IXC or controlling
person expressly for use in such registration statement or (y) provided that the
Company has theretofore timely prepared all necessary prospectus supplements or
amendments and provided them to IXC or its representative, arises from the
failure of IXC or any underwriter to comply with such prospectus delivery
requirements as are applicable to it. With respect to losses, claims, damages,
expenses and liabilities arising out of or based upon such untrue statement or
omission or alleged untrue statement or omission in the information furnished in
writing to the Company by or on behalf of IXC expressly for use in such
registration statement or such failure to comply with such prospectus delivery
requirements, IXC will indemnify and hold harmless each underwriter, the Company
(including its directors, officers, employees and agents), and each person who
controls any of them within the meaning of Section 15 of the Securities Act or
Section 20 of the Exchange Act, from and against any and all losses, claims,
damages, expenses and liabilities, joint or several, to which they, or any of
them, may become subject under the Securities Act, the Exchange Act or other
federal or state statutory law or regulation, at common law or otherwise to the
same extent provided in the immediately preceding sentence. In no event,
however, shall the liability of IXC for indemnification under this Section 3.1
exceed the proceeds received by it from its sale of Registrable Securities under
such registration statement.


SECTION 3.2           CONTRIBUTION

        If the indemnification provided for in Section 3.1 above for any reason
is held by a court of competent jurisdiction to be unavailable to an indemnified
party in respect of any losses, claims, damages, expenses or liabilities
referred to therein, then each indemnifying party under this Article III, in
lieu of indemnifying such indemnified party thereunder, shall contribute to the
amount paid or payable by such indemnified party as a result of such losses,
claims, damages, expenses or liabilities in such proportion as is appropriate to
reflect the relative benefits received by the Company, IXC and the underwriters
from the



                                       -9-

<PAGE>   104


offering of the Registrable Securities as well as the relative fault of the
Company, IXC and the underwriters in connection with the statements or omissions
which resulted in such losses, claims, damages, expenses or liabilities, as well
as any other relevant equitable considerations. The relative benefits received
by the Company, IXC and the underwriters shall be deemed to be in the same
respective proportions as the net proceeds from the offering (before deducting
expenses) received by the Company and IXC and the underwriting discount received
by the underwriters, in each case as set forth in the table on the cover page of
the applicable prospectus, bear to the aggregate public offering price of the
Registrable Securities. The relative fault of the Company, IXC and the
underwriters shall be determined by reference to, among other things, whether
the untrue or alleged untrue statement of a material fact or the omission or
alleged omission to state a material fact relates to information supplied by the
Company, IXC or the underwriters and the parties' relative intent, knowledge,
access to information and opportunity to correct or prevent such statement or
omission. The Company and IXC agree that it would not be just and equitable if
contribution pursuant to this Section 3.2 were determined by pro rata or per
capita allocation or by any other method of allocation which does not take
account of the equitable considerations referred to in this paragraph. In no
event, however, shall IXC be required to contribute any amount under this
Section 3.2 in excess of the proceeds received by it from its sale of
Registrable Securities under such registration statement. No person found guilty
of fraudulent misrepresentation (within the meaning of Section 11(f) of the
Securities Act) shall be entitled to contribution from any person who was not
guilty of such fraudulent misrepresentation.


SECTION 3.3           EXPENSES, ETC.

               (a) The amount paid or payable by an indemnified party as a
result of the losses, claims, damages and liabilities referred to in this
Article III shall be deemed to include, subject to the limitations set forth
above, any legal or other expenses reasonably incurred by such indemnified party
in connection with investigating or defending any such action or claim. The
indemnification and contribution provided for in this Article III will remain in
full force and effect regardless of any investigation made by or on behalf of
the indemnified parties or any officer, director, employee, agent or controlling
person of the indemnified parties.

               (b) Notwithstanding the foregoing, to the extent that the
provisions on indemnification and contribution contained in an underwriting
agreement entered into in connection with any registration statement referred to
in this Agreement are in conflict with the foregoing provisions, the provisions
in the underwriting agreement shall control.



                                      -10-

<PAGE>   105


                                   ARTICLE IV

                                    RULE 144


SECTION 4.1           RULE 144 REPORTING

        With a view to making available the benefits of certain rules and
regulations of the Commission which may permit the sale of the Registrable
Securities to the public without registration, the Company agrees to: (i) at all
times make and keep public information available as those terms are understood
and defined in Rule 144 under the Securities Act (and any successor rule to Rule
144); (ii) file with the Commission in a timely manner all reports and other
documents required of the Company under the Securities Act and the Exchange Act;
and (iii) furnish to IXC as promptly as possible upon its request a written
statement by the Company confirming its compliance with the reporting
requirements of Rule 144 and of the Securities Act and the Exchange Act, a copy
of the most recent annual or quarterly report of the Company, and any other
reports and documents so filed as IXC may reasonably request in availing itself
of any rule or regulation of the Commission allowing it to sell any such
securities without registration.


SECTION 4.2           USE OF RULE 144

        IXC shall endeavor to sell its Registrable Securities whenever possible
in transactions pursuant to Rule 144 under the Securities Act (and any successor
rule to Rule 144) rather than pursuant to registrations effected under this
Agreement so long as such sales may be effected in compliance with the
requirements of Rule 144 (or any successor rule to Rule 144).




                                      -11-

<PAGE>   106

                                    ARTICLE V

                                     GENERAL


SECTION 5.1           GRANTING OF RIGHTS AGREEMENTS

        The Company shall not grant any registration rights in respect of any
shares of capital stock of the Company or other securities of the Company if
such rights would be superior to the registration rights granted to IXC under
this Agreement; provided, however, that IXC hereby consents and agrees that the
Company may grant in other agreements to other holders of securities of the
Company registration rights which rank ratably with the registration rights
granted hereunder to IXC.


SECTION 5.2           AMENDMENTS, WAIVERS AND CONSENTS

        For purposes of this Agreement and all agreements, documents and
instruments executed pursuant hereto, except as otherwise specifically set forth
herein or therein, no course of dealing between the Company and IXC and no delay
on the part of any party hereto in exercising any rights hereunder or thereunder
shall operate as a waiver of the rights hereof or thereof. No covenant or other
provision hereof or thereof may be waived or amended other than by a written
instrument signed by the party so waiving or amending such covenant or other
provision. Any waiver or amendment affected in accordance with this Section 5.2
shall be binding upon IXC and the Company at the time such waiver or amendment
is effected.


SECTION 5.3           SURVIVAL OF COVENANTS; ASSIGNABILITY OF RIGHTS

        All covenants and agreements of the Company or IXC made herein shall
survive until fully discharged; provided, however, that notwithstanding any
provision of this Agreement to the contrary, in no event shall IXC be entitled
to any registration rights hereunder to the extent that it could sell pursuant
to Rule 144(k) under the Securities Act Registrable Securities which it desires
to register under the Securities Act pursuant to Sections 2.1, 2.2 or 2.3 hereof
or at any time after one year following the date at which the IRU Agreement is
no longer in effect. This Agreement may not be assigned by IXC except as set
forth in Section 2.6. All covenants and agreements of the Company herein shall
bind the Company's successors and assigns, whether so expressed or not, and,
except as otherwise provided in this Agreement, all such covenants and
agreements shall inure to the benefit of IXC's successors and assigns.


SECTION 5.4           GOVERNING LAW

        This Agreement shall be governed by, and construed and enforced in
accordance with, the laws of the State of New York without reference to its
principles of conflicts of law.


SECTION 5.5           HEADINGS

        The headings used in this Agreement have been inserted for reference
purposes only and shall not control or affect in any manner the meaning or
interpretation of any provision of this Agreement.



                                      -12-

<PAGE>   107



SECTION 5.6           PRONOUNS

        All pronouns and any variation thereof, shall be deemed to refer to the
masculine, feminine or neuter, singular or plural, as the identity of the person
or persons may require.


SECTION 5.7           NOTICES AND DEMANDS

        Any notice or demand which, by any provision of this Agreement or any
agreement, document or instrument executed pursuant hereto or thereto, except as
otherwise provided therein, is required or provided to be given shall be deemed
to have been sufficiently given or served and received for all purposes when
delivered or 5 days after being sent by certified or registered mail, postage
and charges prepaid, return receipt requested, or by express delivery providing
receipt of delivery, to the following addresses: if to the Company, at 510
Huntmar Park Drive, Herndon, Virginia 20170, or at such other address designated
by the Company to IXC in writing; if to IXC, at its mailing address maintained
on the books and records of the Company, or at such other address designated by
IXC to the Company in writing.


SECTION 5.8           SEVERABILITY

        The invalidity or unenforceability of any provision of this Agreement
shall not affect the validity or enforceability of the remaining provisions of
this Agreement, and this Agreement shall be construed in all respects as if such
invalid or unenforceable provision were omitted. All provisions of this
Agreement shall be enforced to the full extent permitted by law.


SECTION 5.9           ENTIRE AGREEMENT

        This Agreement constitutes the entire agreement among the parties
pertaining to the subject matter hereof and supersedes and cancels all other
prior agreements, understandings, negotiations and discussions, whether written
or oral, relating to the subject matter hereof.


SECTION 5.10   COUNTERPARTS

        This Agreement may be executed in one or more counterparts, each of
which shall be deemed to be an original, and all of which together shall be
deemed one and the same instrument.



                                      -13-

<PAGE>   108

        IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                                            PSINET INC.

                                            By:
                                            Name:
                                            Title:

Accepted and Agreed as of the 
date first above written.

IXC INTERNET SERVICES, INC.

By:
Name:
Title:



                                      -14-

<PAGE>   1

                                                                   EXHIBIT 10.20


                     JOINT MARKETING AND SERVICES AGREEMENT


        This JOINT MARKETING AND SERVICES AGREEMENT (this "Agreement") is made
and entered into as of the 22nd day of July 1997 (the "Effective Date"), by and
between IXC Internet Services, Inc., a Delaware corporation ("IXC"), and PSINet
Inc., a New York corporation ("PSINet").

        WHEREAS, IXC and PSINet have entered into an IRU and Stock Purchase
Agreement of even date herewith (the "IRU Agreement"), pursuant to which IXC
will provide to PSINet the right to use certain fibers and capacity on IXC's
fiber optic telecommunications system and PSINet will exchange therefor shares
of its stock;

        WHEREAS, PSINet is in the business of providing, on a dial and dedicated
basis to wholesale and end user customers, Internet connectivity and related
services;

        WHEREAS, IXC desires to create and market various service offerings to
customers incorporating or consisting entirely of an Internet services
component; and

        WHEREAS, PSINet is willing to provide such Internet services, and IXC is
willing to purchase such Internet services, on the terms and subject to the
conditions of this Agreement.

        NOW, THEREFORE, in consideration of the premises and the mutual
covenants of this Agreement, the Parties agree as follows:

1.             DEFINITIONS.

               For purposes of this Agreement, certain terms have been defined
below and elsewhere in this Agreement (including the attached Schedules) to
encompass meanings that may differ from, or be in addition to, the normal
connotation of the defined word. Unless the context clearly indicates otherwise,
any term defined or used in the singular shall include the plural. A defined
word intended to convey its special meaning is capitalized when used.

        "Affiliate" has the meaning set forth in Section 19.1 of the IRU
Agreement.

        "Agreement" has the meaning set forth in the preamble.

        *

        "Claim" means any pending or threatened claim, action, proceeding or
suit by any Third Party.

        "Confidential Information" has the meaning set forth in Section 10.1.

        "Cure Period" has the meaning set forth in Section 9.2.1.

        "Damages" means any loss, debt, liability, damage, obligation, claim,
demand, judgment or settlement of any nature or kind, known or unknown,

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                       -1-

<PAGE>   2



liquidated or unliquidated, including without limitation all reasonable costs
and expenses incurred (legal, accounting or otherwise).


        "Documentation" shall mean Reseller Documentation and End User
Documentation.

        "Effective Date" has the meaning set forth in the preamble.

        "End User Documentation" shall mean all documentation provided by PSINet
for use by end users of its services in connection with the use and operation of
the materials describing such services, as such documentation may be amended,
modified or supplemented from time to time.

        "Indemnifying Party" has the meaning set forth in Section 13.1.

        "Infrastructure" has the meaning set forth in Section 6.1.

        "Intellectual Property Rights" shall mean all intangible property rights
protectible by law throughout the world including all copyrights (including,
without limitation, the exclusive right to reproduce, distribute copies of,
display and perform the copyrighted work and to prepare derivative works),
copyright registrations and applications, trademark rights (including trade
dress), trademark registrations and applications, service mark rights, service
mark registrations and applications, patent rights (including the right to apply
therefor), patent applications therefor (including the right to claim priority
under applicable international conventions) and all patents issuing thereon, and
inventions, whether or not patentable, together with all utility and design,
know-how, specifications, trade names, mask-work rights, trade secrets, moral
right, author's rights, algorithms, rights in packaging, goodwill and other
intangible property rights, as may exist now and/or hereafter come into
existence, and all renewals and extensions thereof, regardless of whether any of
such rights arise under the laws of the United States or of any other state,
country or jurisdiction.

        "Internet" has the meaning set forth in Section 19.1 of the IRU
Agreement.

        "IRU Agreement" has the meaning set forth in the recitals of this
Agreement.

        "IXC" has the meaning set forth in the preamble.

        "IXC Customer" means any purchaser of a service offering that includes
Services provided by PSINet under this Agreement. As used in this Agreement, an
"IXC Customer" shall include (i) any party with which IXC enters into an
agreement relating to the sale of services that include Services, (ii) any party
that purchases Services for which billing is provided by IXC, (iii) any party
that purchases Value-Added Services from IXC pursuant to Section 5.1.1, and (iv)
any purchaser of services that include Services from an IXC Reseller. In cases
where IXC uses Services provided by PSINet under this Agreement for its own
internal purposes, IXC shall be deemed an "IXC Customer" for purposes of this
Agreement.

        "IXC Customer Information" shall mean all information relating to each
IXC Customer collected in connection with the provision of Services to such IXC
Customer, including without limitation the name, address, usage, features and
services purchased, locations served, payment history and all other information
identifiable to a particular customer.

        "IXC Documents" has the meaning set forth in Section 5.1.4.


                                       -2-

<PAGE>   3



        "IXC Internet Services" means those Services offered by IXC to IXC
Customers.

        "IXC Resellers" has the meaning set forth in Section 5.1.1.

        "IXC Sales Support Group" has the meaning set forth in Section 3.2.

        "Managed Connectivity Services" or "MCS" has the meaning set forth in
Section 2.1.1.

        "Marks" shall mean trade names, logos, trademarks, trade devices, trade
dress, service marks, symbols, abbreviations or registered marks, or
contractions or simulations thereof, or any other indicia or origin.

        "Material Provision" shall mean any provision of this Agreement
(including, without limitation, payment provisions) the breach of which by one
Party is determined by an arbitration pursuant to Section 15.18 to constitute a
material adverse effect on the use and enjoyment by the other Party of the
benefits of this Agreement.

        "Multiple End-User Restrictions" has the meaning set forth in Section
5.1.2.

        "Opportunity Consulting Services" or "OCS" has the meaning set forth in
Section 2.1.3.

        "Party" means IXC, individually, or PSINet, individually.

        "Parties" means IXC and PSINet, collectively.

        "Person" has the meaning set forth in Section 19.1 of the IRU Agreement.

        "PSINet" has the meaning set forth in the preamble.

        "PSINet Documents" has the meaning set forth in Section 7.4.

        "PSINet Marks" shall mean the PSINet Primary Marks, the PSINet VAS
Marks, such other Marks as are used by PSINet to promote, advertise and market
the Services, and such other Marks as the Parties shall agree upon in writing.

        "PSINet Point of Presence" shall mean one of the points of presence
representing a point of interconnection on the PSINet network. The initial
PSINet Points of Presence are listed in Schedule 6.2 to this Agreement, and
PSINet shall promptly update such schedule during the Term on reasonable notice
to IXC. At any time during the term of this Agreement, PSINet Points of Presence
could be collocated with points of presence on the IXC network pursuant to
Section 6.1.

        "PSINet Primary Marks" shall mean the Marks "PSINet" and "PSINet" and
logo types thereof all as the same may be changed from time to time.

        "PSINet VAS Marks" shall mean such Marks as are used by PSINet to
promote, advertise and market Value Added Services.

        "Releasing Party" has the meaning set forth in Section 12.2.

        "Reseller Documentation" shall mean all documentation made available by
PSINet for use by any reseller or distributor of services of the type comprising
the Services to describe the methods and procedures used by PSINet in the
provisioning and support of users of services of the type comprising any of the
Services provided under this Agreement, as such documentation may be amended,
modified or supplemented from time to time.


                                       -3-

<PAGE>   4



        "Sales Support Services" has the meaning set forth in Section 3.1.

        "Services" means Managed Connectivity Services, Value Added Services and
Opportunity Consulting Services.

        "Term" has the meaning set forth in Section 9.1.

        "Third Party" means an entity other than a Party or any Affiliate of a
Party.

        "Transaction Documents" has the meaning set forth in Section 19.1 of the
IRU Agreement.

        "Value Added Services" or "VAS" has the meaning set forth in Section
2.1.2.

2.             SERVICE DESCRIPTION(S).

        2.1 Initial Description of Services Provided by PSINet. From and after
the Effective Date, on the terms and subject to the conditions set forth in this
Agreement, PSINet shall provide to IXC, and IXC shall have the right to purchase
from PSINet, the following services:

               2.1.1 Managed Connectivity Services ("MCS"), which consist of the
provision of dial-up and dedicated access to the Internet via the PSINet network
to customers and all related products and services now or hereafter offered or
provided by PSINet that deliver or facilitate such access. The initial Managed
Connectivity Services shall comply with the applicable descriptions set forth on
Schedule 2.2, for PSINet's Intranet, LAN-on-Demand, InterMAN, InterFrame,
Wholesale Dial and InterRamp services, including, without limitation, the
functional, technical and performance requirements set forth in such Schedule.
From time to time, the Parties may agree on such modifications to the
functional, technical and performance requirements for MCS as are necessary to
address requirements of IXC Customers. At such times as PSINet provides enhanced
versions of MCS, PSINet shall make such enhanced versions of MCS available to
IXC, and the Parties may agree, for purposes of this Agreement, upon the
functional, technical and performance requirements for such services, which
requirements shall, at a minimum, ensure that such services comply with the
applicable minimum requirements in Section 2.2.

               2.1.2 Value Added Services ("VAS"), consisting of the following
services and products now or hereafter offered by PSINet or a controlled United
States Affiliate: (i) InternetPaper, (ii) Internet Security Services, (iii)
PSIWeb, (iv) any other services or products developed jointly by the Parties,
and (v) any other services or products now or hereafter marketed or offered by
PSINet as a generally available service or product offering other than MCS which
are not subject to exclusive marketing relationships with Third Parties. The
initial Value Added Services shall comply with the applicable descriptions set
forth on Schedule 2.2. From time to time, the Parties may agree on such
modifications to the functional, technical and performance requirements for VAS
as are necessary to address requirements of IXC Customers. At such times as
PSINet provides enhanced versions of VAS, PSINet shall make such enhanced
versions of VAS available to IXC, and the Parties may agree, for purposes of
this Agreement, upon the functional, technical and performance requirements for
such services, which requirements shall, at a minimum, ensure that such services
comply with the applicable minimum requirements in Section 2.2.

               2.1.3 Opportunity Consulting Services ("OCS"), will consist of
pre-sales technical support and post-sales development and/or implementation
support to address specific IXC-identified market opportunities. At such times
as the situation warrants, the Parties may agree, for purposes of this
Agreement, upon the functional, technical and performance requirements for such
services, which requirements shall, at a minimum, ensure that such services
comply with the



                                      -4-
<PAGE>   5


applicable minimum requirements in Section 2.2. Certain joint teaming efforts of
the Parties shall be conducted in accordance with Schedule 2.1.3 hereto.

               2.1.4 IXC shall have the right and option to have any other
PSINet services included under this Agreement on terms and conditions reasonably
consistent herewith. In addition, upon such time that PSINet discontinues a
service generally among its customers, PSINet may remove such service from this
Agreement, but only after providing IXC with at least 30 days' prior written
notice of its intention to do so. If PSINet so removes a service, PSINet will
continue to honor all existing IXC and IXC Reseller service agreements with end
customers by continuing to make such service available to IXC Customers through
the shorter of (i) the end of the term of their respective service agreements,
and (ii) the end of the two-year period commencing on the expiration of PSINet's
30-day notice period.

               2.1.5 Notwithstanding anything to the contrary contained herein,
PSINet reserves the right to modify, alter, improve or change any and all of the
PSINet services comprising the Services covered by this Agreement, and this
Agreement will cover the sales of Services as they may be modified, altered,
improved or changed by PSINet from time to time. Subject to Section 2.1.4, in
all cases where such modification, alteration or change will reduce the
functionality of any PSINet service component comprising the IXC Internet
Services, PSINet will not effect such modifications, alterations or changes
without IXC's specific written approval. Such approval will not be unreasonably
withheld, delayed or conditioned.

        2.2 Minimum Requirements. The MCS, VAS and OCS provided by PSINet under
this Agreement, as described in Schedule 2.2, shall at all times meet the
following minimum requirements:

               2.2.1 The MCS, Internet Security Services and PSIWeb services
provided by PSINet under this Agreement shall be offered and provided with
features and a level of quality that, on average and taken as a whole, equal or
exceed that provided by other leading providers of Internet services offering
comparable services in a substantial portion of the geographic area in which
Services are available pursuant to this Agreement. The Parties agree to work
together on a broader range of service offerings as needed to address market
demand. For purposes of this Agreement, Services shall be deemed to be available
to IXC in any geographic area in which PSINet provides services to customers or,
subject to the last sentence of Section 2.7, in which PSINet has an Affiliate,
strategic partner or other cooperating provider providing services in such area
of the type made available to IXC under this Agreement.

               2.2.2 The MCS and VAS provided by PSINet under this Agreement
shall be offered and provided with features and an overall level of quality that
equals or exceeds that which PSINet offers or provides any other customer.

               2.2.3 The MCS and VAS provided by PSINet under this Agreement
shall comply with all Documentation relating to the MCS and VAS offered or
provided by PSINet as of the Effective Date and as updated from time to time
provided that no such update may operate to have a material adverse impact on
(i) any MCS or VAS (including without limitation the level or quality of service
provided to IXC Customers), taken as a whole, without the prior written consent
of IXC (which shall not be unreasonably withheld, delayed or conditioned),
except to the extent necessary to deal with network emergencies and other
circumstances beyond the control of PSINet, in which case PSINet shall consult
with IXC concerning such change as soon as reasonably practicable, or (ii) any
other Services without providing IXC with advance written notice of such changes
as soon as reasonably practicable.

               2.2.4 PSINet shall not make any changes (i) to any MCS or VAS
that may reasonably be expected to have a material adverse impact on such
Service



                                      -5-
<PAGE>   6

(including without limitation the level or quality of service provided to IXC
Customers), taken as a whole, without the prior written consent of IXC, except
to the extent necessary to deal with network emergencies and other circumstances
beyond the control of PSINet, in which case PSINet shall consult with IXC
concerning such change as soon as reasonably practicable, or (ii) to any OCS
Services provided IXC without providing IXC with advance written notice of such
changes as soon as reasonably practicable.

               2.2.5 The OCS provided to IXC by PSINet shall be performed by
PSINet employees or its subcontractors as deemed by PSINet to be best qualified
and available to perform the task at hand as identified by IXC. Under no
circumstances may PSINet change subcontract relationships in effect at the time
of proposal submission without IXC's specific written approval. Such approval
shall not be unreasonably withheld, delayed or conditioned. PSINet officers
supervising the performance of the services will be empowered to commit the
resources of PSINet to the extent and scope of such officer's authority.

               2.2.6 In the event that Services, as defined herein, or portions
of Services, are provided to IXC by PSINet via a contractual relationship with a
Third Party, PSINet is obligated to maintain such a relationship to the extent
practicable. Should such relationship require that IXC enter into a similar
agreement with the Third Party, PSINet shall use commercially reasonable efforts
to assist IXC in establishing the relationship and securing rates and levels of
service of at least those provided to PSINet by the Third Party.

        2.3 Documentation. PSINet represents that (i) Schedule 2.3 contains a
true and complete list of all Documentation relating to the MCS and VAS offered
or provided by PSINet as of the Effective Date, and (ii) true and complete
copies of all such Documentation have been provided to IXC prior to the
Effective Date. In the event PSINet amends, modifies or supplements any such
Documentation, or creates new Documentation in connection with enhanced versions
of MCS or additional VAS added pursuant to Section 1.1, PSINet shall as soon as
practicable provide IXC with written notice of any such amendments,
modifications, supplements or new Documentation, including copies of the
foregoing.

        2.4    License to Documentation and Other Intellectual Property Rights.

               2.4.1 PSINet grants IXC and IXC Resellers a limited,
non-exclusive, royalty-free, license, in the geographic area in which Services
are available to IXC pursuant to this Agreement, throughout the Term, to (i)
copy, but not modify sales literature and product descriptions (Schedule 2.3
list) in any form, (ii) integrate the Documentation, or any part thereof, into
IXC's catalogs, price lists, brochures and related sales materials, and (iii)
demonstrate, market, distribute and solicit orders for the Services and warrants
that it has such right to grant. The grant of the foregoing license shall not
entitle or in any way be construed to entitle IXC to (a) use PSINet Marks in
connection with IXC's sales, advertisements and promotion of the Services,
except in materials provided (or approved by PSINet prior to IXC's use thereof)
by PSINet; (b) distribute any Services outside the United States of America in
violation of any United States export restrictions; (c) distribute any Services
outside of the geographic areas in which Services are then available to IXC
pursuant to this Agreement; (d) sublicense any of its rights under this
Agreement, except as expressly permitted by this Agreement; or (e) make any
agreement or incur any liability for or on behalf of PSINet except as expressly
contemplated by this Agreement.

               2.4.2 Except for the limited license specifically granted to IXC
in this Agreement, PSINet shall at all times retain full and exclusive right,
title and ownership interest in and to the Services, the PSINet network, all
PSINet Marks and any and all other Intellectual Property Rights or trade secret
rights related thereto. IXC shall notify PSINet of any action by any Third Party
known or suspected by IXC to constitute an infringement of PSINet's proprietary
rights. IXC shall honor all reasonable requests by PSINet, other than engaging
as a party



                                      -6-
<PAGE>   7


in litigation, to perfect and protect, at PSINet's expense, any rights of PSINet
in the Services, the PSINet network or such Intellectual Property Rights or
trade secret rights.

               2.4.3 PSINet represents that no further licenses to Intellectual
Property Rights are needed by IXC to market, offer, provision or use the IXC
Internet Services as contemplated by this Agreement, in the geographic area in
which Services are available to IXC pursuant to this Agreement.

        2.5 PSINet Liability for Affiliate Obligations. To the extent that
PSINet's performance of its obligations hereunder causes PSINet to assign or
delegate all or part of its liabilities, obligations and commitments hereunder
to any of its Affiliates, PSINet covenants and agrees that it shall use its
reasonable efforts to cause any such Affiliate to perform such liabilities,
obligations and commitments in accordance with the terms and provisions hereof.
In the event of such an assignment or delegation, PSINet shall remain liable for
all of its liabilities, obligations and commitments hereunder.

        2.6 Forecasts. The Parties agree to coordinate in estimating the level
and location of demand and traffic for Services during the term of this
Agreement. In that connection, no later than the 15th day of the first month of
each calendar quarter during the term of this Agreement, IXC will provide PSINet
with its projected requirements for each Service, indicating amounts, types and
location during each of the following four calendar months. In the event that
there should be a material change in IXC's proposed requirements as set forth in
the most recent forecast, IXC, as promptly as practicable, shall update such
forecast in order to reflect such change. These forecasts shall be used for the
planning convenience of PSINet and shall not be binding upon IXC, but PSINet
intends to use the forecasts to estimate needed staffing, network provisioning
and product levels for its performance of the terms of this Agreement and shall
only be responsible for using commercially reasonable efforts to satisfy demand
to the extent it materially exceeds such forecasts. IXC shall provide its
initial projected requirements for Services within 15 business days after the
Effective Date. All forecasts provided under this Section 2.6 shall be treated
as Confidential Information of IXC pursuant to Section 10.

        2.7 Geographic Scope. It is the intent of the Parties that IXC be
permitted to provide the IXC Internet Services to the IXC Customers, on the
terms and subject to the conditions of this Agreement, in all of the geographic
areas in which PSINet is now, or at anytime during the Term is then, providing
services to its customers. Notwithstanding the foregoing, IXC acknowledges and
understands that PSINet is not now capable of independently providing certain
services in certain geographic areas outside of the continental United States of
America. To the extent that IXC desires to provide IXC Internet Services to IXC
Customers situated in such geographic areas and PSINet has an Affiliate,
strategic partner or cooperating provider offering services therein, IXC may
request that PSINet obtain a quote from such Affiliate, strategic partner or
cooperating provider for such IXC Internet Services. Within five business days
after such request, PSINet shall contact the appropriate Affiliate, strategic
partner or cooperating provider for purposes of obtaining such quote. The
provision of services under this Section 2.7 by such Affiliate, strategic
partner or cooperating partner to PSINet shall be the subject of negotiation
and, if reached by such parties, agreement.* Notwithstanding anything in this
Agreement to the contrary, PSINet shall not be obligated to provide Services to
an IXC Customer or Third Party in those geographic areas in which PSINet is not
offering services unless (i) it has

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                      -7-
<PAGE>   8

an Affiliate, strategic partner or cooperating provider in a particular
geographic area, and (ii) such Affiliate, strategic partner or cooperating
provider agrees to provide such services on terms and conditions to Texas'
satisfaction.

        2.8 Services Provided by IXC. PSINet shall be presented with the
opportunity to execute IXC's standard reseller agreement for IXC service, on the
terms and subject to the conditions set forth in such agreement.


3.      *

        3.1 * From the Effective Date, PSINet shall offer and provide * as
specified in Schedule 3.1.

        3.2 * PSINet shall create and manage * exclusively for the purpose of *
under Section 3.1. PSINet shall * with knowledgeable, experienced and trained
Internet professionals capable of providing * consistent with Schedule 3.1.

        3.3 * During the Term, PSINet shall staff the * with * full-time
professionals *. Any additional * requested by IXC shall be considered as *. IXC
shall reimburse PSINet * incurred in connection with * requested by IXC,
provided that PSINet shall use good business judgment to minimize such expenses.


4.      CUSTOMER SUPPORT SERVICES.

        4.1 PSINet will provide customer support through its customer support
group or through a Third Party (as determined by PSINet in its sole discretion)
for the Services (other than InterRamp Remote Access services) sold to IXC
Customers as contemplated by this Agreement; provided that PSINet will not be
responsible for providing customer support to any IXC Customer purchasing
Services under a private label which exceeds the level of support which PSINet
is obligated to provide to its customers pursuant to PSINet's service agreements
for the applicable Services, as such agreements may be amended from time to
time. PSINet also may assist IXC with making arrangements for the provision of
customer support with respect to the InterRamp Remote Access services to be sold
to IXC Customers pursuant to this Agreement. IXC acknowledges, however, that IXC
is solely responsible for the provision of such customer support and PSINet
shall have no liability with respect thereto.

        4.2 Notwithstanding the foregoing, IXC shall be responsible for all
pricing and service plans, billing and collections with respect to IXC
Customers.


5. IXC RIGHTS AND RESPONSIBILITIES.

        5.1    IXC Use and Sales of Services.

               5.1.1 IXC may use the Services made available to it pursuant to
this Agreement, on the terms and subject to the conditions hereof, (i) for its
own account, (ii) subject to Section 5.1.2, for resale to IXC Customers, or
(iii) subject to Section 5.1.2, for resale to Third Parties for further resale
or distribution (such Third Parties which, notwithstanding the definition of
"Third Parties" herein, include, without limitation, IXC Customers (including
those

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                      -8-
<PAGE>   9

which are Affiliates of IXC) are referred to herein as "IXC Resellers"), either
alone or in combination with any other products and services. Services offered
by IXC that incorporate MCS and VAS made available to it pursuant to this
Agreement shall, at IXC's discretion, be branded exclusively as IXC services or
otherwise as IXC shall determine. IXC shall specify the design of any user
interface associated with any MCS or VAS, consistent with the preceding
sentence. IXC will have complete discretion to determine the prices to be
charged to IXC Customers for the Services provided under this Agreement and IXC
shall be solely responsible for establishing and collecting customer charges for
services it or its customers offer through the PSINet network and for preparing
and mailing invoices to IXC Customers. In addition, IXC shall be responsible for
payment of the total amounts invoiced it by PSINet (except for any amounts
disputed by IXC in good faith) regardless of whether IXC is paid by its
customers. Subject to the provisions of Section 5.4, IXC shall also have
complete discretion to determine the other terms and conditions on which IXC
makes such Services available to IXC Customers; provided that neither IXC nor
its customers may offer warranties or representations for the Services that
would obligate or otherwise bind PSINet beyond those stated in the applicable
service agreements.

Except as otherwise provided in this Agreement, except as reasonably necessary
for PSINet to assist IXC during the introduction of IXC Internet Services under
this Agreement, IXC shall provide the primary interface to IXC Customers in
connection with the marketing, offering or provision of IXC services that
incorporate the Services, including (a) providing first tier support for non-MCS
and non-VAS IXC services and (b) handling communications to and business
relations with IXC Customers related to contractual agreements, handling
invoicing and payment matters, and handling inquiries and questions from IXC
Customers about Services.

               5.1.2 Subject to Section 2.7, IXC acknowledges and agrees that it
may not offer for sale or distribution to any IXC Customer or IXC Reseller any
Services until such Services are made generally available by PSINet in the
applicable geographic area. Without limiting the generality of the foregoing,
IXC acknowledges and agrees that no Service may be offered for sale or
distribution by IXC to any IXC Customer or IXC Reseller for multiple end-user
use in any particular geographic area until such Service is made generally
available by PSINet for multiple end-user use in such geographic area (the
"Multiple End-User Restrictions"). IXC will use reasonable efforts to cause each
IXC Reseller to include a provision in its agreements with its customers that
such customer will not engage in any conduct that would violate any of the
Multiple End-User Restrictions.

               5.1.3 Notwithstanding anything in Section 5.1.1 to the contrary,
the Parties agree that the determination of customer interfaces, marketing,
provisioning and delivery for jointly developed new product or services
offerings incorporating IXC services or Services as described herein will be
determined by mutual agreement.

               5.1.4 Periodic Audit Rights. PSINet shall have the right, upon
reasonable notice and at a date and time mutually agreed upon by the Parties, to
enter the premises of IXC for the purpose of auditing any of IXC's books of
accounts, documents, records (in any media), papers and files (the "IXC
Documents") relating to its compliance with the provisions of this Agreement.
PSINet shall bear the expense of the audit unless the audit reveals that (i) the
amounts collected by PSINet from IXC hereunder are more than two (2) percent
less than that which should have been paid by IXC to PSINet, or (ii) IXC has not
complied with either or both of the first two sentences of Section 5.1.2, in
which case, the entire cost of the audit shall be borne by IXC. Payment of any
amounts found due and owing PSINet shall be made promptly by IXC upon demand by
PSINet.



                                      -9-
<PAGE>   10

        5.2 Use of Marks. Except as provided herein or by advance written
consent of the other Party, each of IXC and PSINet agrees not to (i) display or
use, in advertising or otherwise, any of the other's Marks, (ii) permit any
Affiliate to display or use any of the other's Marks, or (iii) give permission
to display or use any of the other's Marks to any Third Party. Any use by one
Party of any of the other's Marks shall be subject to such other Party's advance
approval in writing, in its discretion, subject to compliance with guidelines
provided by it. Neither Party shall claim ownership or any other rights in any
of the other's Marks. Upon termination or expiration of this Agreement, any and
all rights or privileges granted by IXC or PSINet to use any Marks shall
immediately expire and each Party shall immediately discontinue the use of such
Marks. Nothing herein shall preclude either Party from making factual references
to the other in government filings, disclosure documents and other public
statements, except as otherwise set forth in the IRU Agreement.

        5.3 Introductory Marketing Campaign. IXC shall have complete discretion
regarding its marketing of the Services provided that neither IXC nor its
customers may offer warranties or representations for the Services that would
obligate or otherwise bind PSINet beyond those stated in the applicable service
agreements or to make any other warranties, promises or representations with
respect to the Services or the PSINet network. In connection with such marketing
activities, IXC shall prominently mention PSINet's role in the provision of such
services in an introductory press release, the content of which shall be
mutually agreed to by the Parties in accordance with Section 19.11 of the IRU
Agreement.

        5.4 Provisions Applicable to End Users.

               5.4.1 IXC's Use of Services. IXC's use of Services in IXC's
capacity as end user of Services for its own account shall be governed by
Schedule 5.4.1 and the terms and conditions of this Agreement generally.

               5.4.2 Agreements with IXC Customers Other than IXC. IXC's
agreements with IXC Customers (other than IXC) to provision Services shall
comply with Schedule 5.4.2.

6.      INFRASTRUCTURE.

        6.1 Use of IXC Equipment and Facilities. Except as otherwise agreed to
by the Parties, in providing the Services to IXC under this Agreement, PSINet
may, in its sole discretion, purchase infrastructure, equipment, facilities and
services necessary for the transmission of data (collectively, "Infrastructure")
from IXC provided (i) PSINet is not restricted from purchasing such
Infrastructure from IXC under contractual obligations binding on PSINet at the
time the purchase decision is being considered, (ii) such Infrastructure meets
PSINet's reasonable functional, technical and performance requirements, and
(iii) IXC offers such Infrastructure to PSINet at a price and on terms and
conditions that, on average or taken as a whole, are competitive as compared to
those offered to PSINet in good faith by other leading providers of
infrastructure, equipment, facilities and services similar to the Infrastructure
at the time IXC makes its offer.

        6.2 Provisioning of Customers. In connection with the provision of MCS
hereunder, it is the intention of the Parties that IXC shall assume
responsibility for providing, at IXC's expense or the expense of the IXC
Customer, connectivity between the IXC Customer's premises and any PSINet Point
of Presence listed in Schedule 6.2 (as such schedule may be modified or
supplemented from time to time) that is selected by IXC, subject to Section 6.3.
PSINet shall assume responsibility for providing and conditioning Customer
premises equipment, consistent with Section 2 herein. Notwithstanding the
foregoing, the Parties acknowledge that the articulation of procedures to
accomplish coordinated provisioning of Services involving a dedicated access
component by the Parties may not be in place for a period after the Effective



                                      -10-
<PAGE>   11

Date. During this period, PSINet shall assume this responsibility and shall be
paid at the rates as indicated in Schedule 7.1. IXC shall notify PSINet of its
readiness to transition this responsibility.

        6.3 Interconnection with PSINet Facilities. IXC and PSINet shall
coordinate with respect to (i) the definition of the interfaces between the IXC
network and the PSINet network at the PSINet Points of Presence, (ii) the
management of traffic routed by PSINet from the premises of IXC Customers to
PSINet Points of Presence, and (iii) access by PSINet to the IXC network for the
purposes of providing Services under this Agreement. PSINet shall be responsible
for the day-to-day management of the PSINet network relating to the provision of
Services, including monitoring and taking actions necessary to remedy problems
with, or disruption of, the Services, establishment and maintenance of routing
tables and routing policies at Points of Presence, and establishment and
maintenance of peering points with the global Internet.

        6.4 Customer Transfers. At any time, IXC shall have the right to migrate
IXC Customers to such services as provided by IXC or on IXC's behalf by a Third
Party. PSINet shall provide all reasonable cooperation in support, to the extent
practicable, of a seamless, minimally disruptive migration of such IXC Customers
in connection with such services (including without limitation all IXC Customer
Information and, to the extent practicable, any necessary transfer of customer
addresses).

        6.5 Interfaces. The Parties shall develop methods, procedures and
associated interfaces for cooperating on a "seamless" basis in all areas
relating to the marketing and provision of the Services, including without
limitation order processing, customer care, network monitoring and maintenance,
and problem escalation and resolution; provided, however, that PSINet shall in
no event be obligated to provide services or support of any kind to IXC or IXC
Customers which exceeds that which it is required to provide to its own
customers pursuant to PSINet's service agreements for the applicable comparable
services, as such agreements may be amended from time to time. The Parties shall
use commercially reasonable efforts to agree on an initial plan to accomplish
the foregoing, including appropriate training of each other's employees, by no
later than 30 days after the Effective Date. At any time during the Term, PSINet
will cooperate in good faith with IXC in connection with inquiries concerning
potential problems affecting any aspect of the provision of Services.

7.      PRICING AND PAYMENT.

        7.1 * PSINet shall at all times make sure that all fees and other
charges charged to IXC for each of the individual service components comprising
the Services, as represented in Schedule 2.2, *.

        7.2 Independent End-Customer Pricing. Each of the Parties will have
complete discretion regarding the prices that it charges to its customers for
its services.

        7.3    *

               7.3.1 *. The term * is defined as * for any individual service
components comprising the Services. The initial * are set forth in Appendix 1 to
Schedule 7.1. PSINet represents and warrants to IXC that the *. At such times as
enhancements to existing Services or additional Services are added by

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.



                                      -11-
<PAGE>   12

agreement of the Parties pursuant to Section 2.1, * be applicable to IXC's
purchase of such services.

               7.3.2 *. At all times during the Term, in the event PSINet or any
of its Affiliates enters into a new or renewal agreement or understanding
pursuant to which * for any of the individual service components comprising the
Services * under this Agreement (i) PSINet shall notify IXC promptly of such
event, and (ii) Appendix 1 to Schedule 7.1 shall automatically * shall be in
effect only for so long as that * and, subject to Section 7.3.1, * shall return
to its immediately * upon termination of such period. Notwithstanding anything
in this Agreement to the contrary, in the event that there should be * shall not
be effective against IXC until PSINet has provided IXC with at least 60 days'
prior written notice of *.

               7.3.3 Modifications At Request. At any time during the Term, IXC
or PSINet may initiate negotiations in the Benchmark Prices as necessary to
ensure that requirements imposed on PSINet under this Agreement * for any
individual service component comprising the Service *.

               7.3.4 Consideration Exclusions. For the purposes of determining *
pursuant to this Section 7 as of any determination date with respect to any
Service, the Parties shall disregard (i) services offered free-of-charge to
employees, employee families, prior * for any individual service component
comprising the Services *.

               7.3.5 Promotional Pricing. In addition to the * specified under
this Section 7, the parties shall also agree from time to time on promotional
and other pricing as may be appropriate to take maximum advantage of market
opportunities.

               7.3.6 Dispute Resolution. Any dispute relating to the * or any
adjustments thereof, applicable under this Section 7.1 shall be resolved
pursuant to Section 15.18 of this Agreement.

        7.4. *. IXC shall have the right, upon reasonable notice and at a date
and time mutually agreed upon by the Parties, *, including, without limitation,
*. IXC shall bear the expense * hereunder are * service or product, in which
event, * shall be borne by PSINet.*

        7.5 Invoicing and Payment. During the Term, PSINet shall invoice IXC for
Services delivered to each IXC Customer. Such invoices shall be delivered by
PSINet to IXC in both paper and electronic form with content and formats as
agreed to by the Parties. IXC shall pay PSINet for the Services according to the
schedule set forth in Schedule 7.1. IXC agrees to pay PSINet, in advance, as
invoiced by PSINet, each month during the term, all fees and other charges with
respect to MCS and VAS, and in arrears for OCS, payable under this Agreement for
such month. All such fees for MCS and VAS for the initial month of service for
any IXC Customer shall be prorated for the portion of the month beginning on the
date on which the IXC Customer service commences and ending on the last calendar
day of such initial month and the amount invoiced by PSINet, with respect to
each such IXC Customer shall include such prorated fees and the fees and charges
payable for the following full month.

        7.6 Credits/Adjustments. All IXC Customers shall be granted service
disruption credits and adjustments, quality of service commitment credits and
adjustments, and the like as may be established by PSINet with respect to PSINet
customers, and as modified from time to time, by PSINet, at its sole discretion.

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                                      -12-
<PAGE>   13

In the event that IXC, as promptly as practicable, notifies PSINet after
learning of the failure of PSINet to deliver any of the Services to any IXC
Customer, IXC will be entitled to a credit representing any reasonable
adjustment requested by IXC and approved in advance by PSINet as a result of
such failure to meet customer service expectations.

        7.7 Late Payment. PSINet invoices for amounts payable under this
Agreement shall be due within 30 days of the date of invoice. If a dispute
arises as to any portion of an invoice, IXC shall pay the undisputed amount of
such invoice when due and shall notify PSINet in writing of the disputed amount
no later than 30 days from the date of invoice.

        7.8 Payment Dispute Resolution. In the event of payment dispute, the
PSINet Authorized Representative and the IXC Authorized Representative (as such
capitalized terms are defined in the IRU Agreement) will first attempt in good
faith to promptly resolve the dispute. If the dispute has not been resolved by
the Authorized Representatives within 14 days after IXC's notice, or if either
Party will not agree to meet within such 14-day period, the matter will be
referred to the Chief Executive Officer of PSINet and the Chief Executive
Officer of IXC who will in good faith attempt to resolve the dispute. If the
dispute remains unresolved within an additional 14-day period, the dispute shall
be submitted to arbitration as per the IRU Agreement.

        In the event that any amount remains unpaid after its due date, such
amount shall be subject to an interest charge equal to the lesser of one and
one-half percent of the unpaid balance per month or the maximum rate allowed
under applicable state law and, if such amount shall not have been paid in full
within five business days of the applicable due date when no bona fide dispute
exists, PSINet may, without any liability to IXC, at its option, suspend the
provision of services under this Agreement until such amount is paid in full.

8.      NO RESTRICTIONS.

        Notwithstanding any other provision of this Agreement, except as
provided in Section 2.7, nothing in this Agreement shall limit or in any way
affect (i) the performance of any Party's obligations under a binding agreement
in effect as of the Effective Date (and each Party shall disclose to the other
such agreements that, to such Party's knowledge, are in effect as of such date
to the extent possible consistent with any obligations of confidentiality owing
to Third Parties), (ii) PSINet's right to provide Internet services for its own
account directly to any end user or wholesale customer (subject to section 10)
or otherwise to engage in services involving packet, frame relay, asynchronous
transfer mode or other Internet services, (iii) IXC's right to build, operate
and maintain its own global network, and (iv) either Party's right in any way to
market, offer or provide any products and services that are not, generally,
marketed principally as Internet services.


9.      TERM AND TERMINATION.

        9.1 Term. The term of this Agreement shall commence on the Effective
Date and shall end on the earlier of (i) the termination of the IRU Agreement,
and (ii) such earlier date as of which this Agreement expires or is terminated
pursuant to Section 9.2.

        9.2 Termination.

            9.2.1 A Party may deliver to the other Party a written "Notice of
Default" in the event that the other Party has breached any Material Provision
hereunder. Such Notice of Default must prominently contain the following
sentences in capital letters: "THIS IS A FORMAL NOTICE OF A BREACH OF CONTRACT.
FAILURE TO CURE SUCH BREACH WILL HAVE SIGNIFICANT LEGAL CONSEQUENCES." A Party




                                      -13-
<PAGE>   14

that has received a Notice of Default shall have thirty (30) days to cure the
alleged breach (and, if the defaulting Party shall have commenced actions in
good faith to cure such defaults which are not susceptible of being cured during
such 30-day period, such period shall be extended (but not in excess of 90
additional days) while such Party continues such actions to cure (the "Cure
Period"). If such Party fails to cure the breach within the Cure Period, as long
as such default shall be continuing, the non-defaulting Party shall have the
right to either (i) suspend its performance or payment obligations under this
Agreement and/or any of the Transaction Documents (other than obligations under
Section 15.8(a) of the IRU Agreement and the Standstill Agreement (as defined in
the IRU Agreement)), (ii) seek an order of specific performance, and/or (iii)
seek the award of compensatory damages.

               9.2.2 PSINet shall terminate, or use commercially reasonable
efforts to terminate, the access rights of any IXC Customer as soon as is
reasonably practicable upon written notice from IXC or any IXC Customer to do so
or upon mutually agreed upon electronic process with receipt confirmed, but
shall have no liability in connection therewith.

               9.2.3 PSINet shall have the right to terminate any IXC Customer
on written notice to IXC (or sooner, if required by law, provided, however that
PSINet should thereafter provide written notice to IXC) in the event of any use
or alleged use by such IXC Customer of the Services or the PSINet network which
is in violation of any law, regulation or treaty, any of the Multiple End-User
Restrictions, PSINet's Net Abuse Policy (available at PSINet's web site at
'http:\\www.psi.net'), any community standard or accepted Internet policy or
which results in the receipt by PSINet of any formal or informal complaint.


10.     CONFIDENTIAL INFORMATION.

        10.1 Nondisclosure. If either Party acquires Confidential Information of
the other, such receiving Party shall maintain the confidentiality of the
disclosing Party's Confidential Information, shall use such Confidential
Information only for the purposes for which it is furnished and shall not
reproduce or copy it in whole or in part except for use as authorized in this
Agreement. Without limiting the generality of the foregoing, neither Party shall
use the Confidential Information of the other Party to solicit the other Party's
customers or to otherwise compete unfairly with the other Party. Confidential
Information shall mean all information of the disclosing Party which it treats
as confidential or proprietary including, without limitation, all of the
following: (i) information concerning customers and the contractual terms under
which services are being provided to such customer by a Party; and (ii) all
customer lists and other information regarding the customers of a Party.
Confidential Information shall not include information which is or hereafter
becomes generally available to others without restriction or which is obtained
by the receiving Party without violating the disclosing Party's rights under
this Article 10 or any other obligation of confidentiality. The terms and
conditions of this Agreement shall constitute Confidential Information. PSINet
and IXC shall cooperate to request confidential treatment as may be mutually
agreed by them with respect to certain terms of this Agreement and the
transactions contemplated hereby in any filing with the Securities and Exchange
Commission, any other government authority or any securities exchange or stock
market.

        10.2 Duration. With respect to all Confidential Information, the
Parties' rights and obligations under this Article shall remain in full force
and effect following the termination of this Agreement.


        10.3 Ownership. All materials and records which constitute Confidential
Information, other than service orders and copies of this Agreement, shall be
and remain the property of, and belong exclusively to, the disclosing Party, and
the



                                      -14-
<PAGE>   15

receiving Party agrees either to surrender possession of and turn over or to
destroy and certify to the other Party the destruction of all such Confidential
Information which it may possess or control upon request of the disclosing Party
or upon the termination of this Agreement.

        10.4 Injunctive Relief. The Parties acknowledge and agree that, in the
event of a breach or threatened breach by any Party of any provision of this
Article, the other Party will have no adequate remedy in money or damages and,
accordingly, shall be entitled to an injunction against such breach. However, no
specification in this Section of a specific legal or equitable remedy shall be
construed as a waiver or prohibition against any other legal or equitable
remedies in the event of a breach of this Section of this Agreement.

        10.5 Legal Obligation to Disclose. Each Party shall be released from its
obligations under this Section 10 with respect to information which such Party
is required to disclose to others pursuant to obligations imposed by law, rule
or regulation or securities exchange or stock market rule; provided, however,
that prior to any such required disclosure, such Party shall, to the extent
practicable, provide written notice and consult with the other Party.

11.     REPRESENTATIONS AND WARRANTIES.

        11.1 By PSINet. PSINet represents and warrants to IXC that (i) it is a
corporation duly organized, validly existing and in good standing in the State
of New York; (ii) it has full corporate power and authority to own and operate
the Services and the PSINet network and to carry on its business as presently
conducted; (iii) it has, or has licensed, sufficient right, title and interest
in and to the Services, the PSINet Marks (within the United States) and the
PSINet network; (iv) it has all requisite authority to execute and deliver this
Agreement and to carry out the transactions contemplated hereby; (v) this
Agreement is a valid and binding obligation of PSINet, enforceable against
PSINet in accordance with its terms except as such enforceability may be limited
by laws relating to creditors' rights generally and the exercise of judicial
discretion in accordance with general equitable principles; and (vi) the
licenses granted and obligations owed to IXC hereunder do not conflict with the
rights granted or obligations owed by PSINet to any Third Party.

        EXCEPT FOR THE REPRESENTATIONS AND WARRANTIES SPECIFICALLY SET FORTH IN
THIS SECTION 11.1, PSINET MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND
WHATSOEVER, WHETHER EXPRESS, IMPLIED OR STATUTORY, AND PSINET EXPRESSLY
DISCLAIMS AND EXCLUDES ALL OTHER REPRESENTATIONS AND WARRANTIES OF ANY KIND.
WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, PSINET MAKES NO WARRANTY TO
IXC OR ANY OTHER PERSON OR ENTITY, WHETHER EXPRESS, IMPLIED OR STATUTORY, AS TO
THE DESCRIPTION, QUALITY, COMPLETENESS, MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE OF ANY INTERNET SERVICE OR ANY OTHER SERVICE PROVIDED
HEREUNDER OR DESCRIBED HEREIN, OR AS TO ANY OTHER MATTER, ALL OF WHICH
WARRANTIES ARE HEREBY EXCLUDED AND DISCLAIMED.

        11.2 By IXC. IXC represents and warrants to PSINet that (i) it is a
corporation duly organized, validly existing and in good standing in the State
of Delaware; (ii) it has full corporate power and authority to carry on its
business as presently conducted; (iii) it has sufficient right, title and
interest in and to the IXC Marks, (iv) it has all requisite authority to execute
and deliver this Agreement and to carry out the transactions contemplated
hereby; (v) this Agreement is a valid and binding obligation of IXC, enforceable
against IXC in accordance with its terms except as such enforceability may be
limited by laws relating to creditors' rights generally and the exercise of
judicial discretion in accordance with general equitable principles and (vi) the
obligations owed to PSINet hereunder do not conflict with the rights granted or
obligations owed by IXC to any Third Party.



                                      -15-
<PAGE>   16

        EXCEPT FOR THE REPRESENTATIONS AND WARRANTIES SPECIFICALLY SET FORTH IN
THIS SECTION 11.2, IXC MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND
WHATSOEVER, WHETHER EXPRESS, IMPLIED OR STATUTORY, AND IXC EXPRESSLY DISCLAIMS
AND EXCLUDES ALL OTHER REPRESENTATIONS AND WARRANTIES OF ANY KIND.

12.     LIMITATION OF LIABILITY.

        12.1 Limitation of Liability. Except for direct damages otherwise
specifically provided for in this Agreement, in no event shall IXC or PSINet be
liable for any special, incidental, direct, indirect, punitive, reliance or
consequential damages, whether foreseeable or not, arising under this Agreement
or from any breach or partial breach of the provisions of this Agreement or
occasioned by any defect in the Services or other service provided hereunder,
delay in availability of the Services or any service provided hereunder, failure
of the Services or other service provided hereunder, interruptions or outages of
the PSINet network or any other cause whatsoever or arising out of any act or
omission by IXC or PSINet, as applicable, its employees, servants and/or agents,
including but not limited to, damage or loss of data, property or equipment,
loss of profits or revenue, cost of capital, cost of replacement services, or
claims of customers for service interruptions or transmission problems.

        12.2 Release; Indemnification. Each Party (each Party in such capacity
being referred to as the "Releasing Party") releases, assumes and agrees to
indemnify, defend, protect and save the other Party harmless from and against
any claim, damage, loss, liability, cost and expense (including reasonable
attorneys' fees) in connection with any loss or damage to any physical property
or facilities of the Releasing Party or any injury to or death of any Person
arising out of or resulting in any way from the negligence or misconduct of the
Releasing Party or its employees, servants, contractors and/or agents.

13.     INDEMNIFICATION.

        13.1 Indemnification Obligations. IXC and PSINet (hereinafter where
either has undertaken the action or inaction to be indemnified against shall be
known as the "Indemnifying Party") agree to assume all liability for and
indemnify, defend and hold harmless the other Party or any third Party claiming
through the other Party, from and against all liability, loss, cost, damage,
expense or cause of action, of whatsoever character, or injury or death of any
Person and damage to or destruction of any property, including, without
limitation, third Parties and all related expenses, including, but not limited
to, reasonable attorneys' fees, investigators' fees and litigation expenses and
costs of enforcing this Section 13 arising out of or relating to, in whole or in
part, any of the following:

               (i)    claims for libel, slander, infringement of copyright or
                      unauthorized use of a trade secret, trade name or service
                      mark that results from the transmission of material over
                      the PSINet network by the Indemnifying Party, authorized
                      representatives of the Indemnifying Party or other Persons
                      not associated with, or related to, either IXC or PSINet;
                      or

               (ii)   claims of any Third Party arising out of the negligent or
                      willful act or omission of the Indemnifying Party or its
                      agents, servants, employees, contractors or
                      representatives (other than IXC, if PSINet is the
                      Indemnifying Party, or PSINet, if IXC is the Indemnifying
                      Party); or

               (iii)  claims for patent infringement arising out of the use of
                      the PSINet network by the Indemnifying Party or any Person
                      authorized by the Indemnifying Party or resulting from the
                      acts of the Indemnifying Party or the Indemnifying Party's
                      representatives in combining the PSINet network with the



                                      -16-
<PAGE>   17

                      facilities of the Indemnifying Party or others, or using
                      the PSINet network either alone or in connection with that
                      of the Indemnifying Party or others; or

               (iv)   claims, except as otherwise set forth herein, for the
                      material breach of or failure to comply, in any material
                      respect, with any term or condition of this Agreement by
                      the Indemnifying Party or its officers, employees or
                      invitees; or

               (v)    claims resulting from patent or trade secret infringement
                      or infringement or unauthorized use of trade secrets or
                      trade name by the Indemnifying Party in connection with
                      this Agreement.

        In addition, PSINet will defend, indemnify and hold IXC harmless from
and against any claim or threat of claim by an IXC Customer or an IXC Reseller
which is based on any warranty, promise or representation made by IXC as part of
a service agreement and for which PSINet is responsible in accordance with the
terms of this Agreement. Similarly, IXC will defend, indemnify and hold PSINet
harmless from and against any claim or threat of claim which is based on any
warranty, promise or representation made by IXC to a Third Party for which
PSINet is not responsible in accordance with the terms of this Agreement.

        PROVIDED, HOWEVER, NOTWITHSTANDING ANY PROVISION OF THIS AGREEMENT TO
THE CONTRARY, IN NO EVENT SHALL EITHER PARTY BE LIABLE TO THE OTHER (OR TO ANY
THIRD PARTY CLAIMING THROUGH SUCH OTHER PARTY) FOR CONSEQUENTIAL, INCIDENTAL,
EXEMPLARY OR PUNITIVE DAMAGES, AND THE FOREGOING INDEMNITIES SHALL NOT APPLY
WITH RESPECT TO SUCH DAMAGES.

        13.2 Notices and Defense. The Indemnifying Party shall provide the other
Party with notice of any such claim by a Third Party, and assure the defense of
such claim, on the terms and subject to Sections 9.2 and 9.3 of the IRU
Agreement.

14.     NON-SOLICITATION.

               a. From the date hereof until three years after the Closing Date,
neither IXC nor any of its Affiliates will, directly or indirectly, either alone
or in association with others in any part of the world induce, request,
encourage or assist any employee of PSINet or its Affiliates to terminate his or
her employment with PSINet, or to join with or become employed by, render
services to or otherwise be engaged by IXC or any of its Affiliates in any
direct or indirect capacity.

               b. From the date hereof until three years after the Closing Date,
neither PSINet nor any of its Affiliates will, directly or indirectly, either
alone or in association with others in any part of the world induce, request,
encourage or assist any employee of IXC or its Affiliates to terminate his or
her employment with IXC, or to join with or become employed by, render services
to or otherwise be engaged by PSINet or any of its Affiliates in any direct or
indirect capacity.

               c. If, at the time of enforcement of Section 14, a court shall
hold that the duration, scope, geographic area or other restrictions stated
herein are unreasonable under circumstances then existing, the Parties agree
that the maximum duration, scope, geographic area or other restrictions deemed
reasonable under such circumstances by such court shall be substituted for the
stated duration, scope, geographic area or other restrictions.

15.     MISCELLANEOUS.



                                      -17-
<PAGE>   18

        15.1 Independent Contractors. The Parties are acting as independent
contractors and under no circumstances shall any of the employees of one Party
be deemed the employees of the other for any purpose. Except as otherwise
expressly provided in this Agreement, this Agreement does not constitute either
Party as the agent or legal representative of the other Party and does not
create a partnership or joint venture between the Parties. Except as otherwise
expressly provided in this Agreement, neither Party shall have any authority to
act for the other Party in any agency or other capacity, to make commitments of
any kind for the account of, or on behalf of, the other Party or to contract for
or bind the other Party in any manner whatsoever. This Agreement confers no
rights of any kind upon any Third Party.

        15.2 Force Majeure. Notwithstanding any provision in this Agreement to
the contrary, neither Party shall be liable for failure to fulfill its
obligations hereunder (except with respect to payment or other monetary
obligation or as otherwise specifically set forth herein) if such failure is due
to causes beyond its reasonable control, including, without limitation, actions
or failures to act of the other Party or, acts of God, flood, fire, storm,
catastrophe, governmental prohibitions or regulations, viruses which did not
result from the acts or omissions of such Party, its employees or agents,
national emergencies, acts of public enemies, national emergency, insurrections,
riots or wars, breakdown of or damage to plants or equipment or facilities
(other than arising out of the neglect of or mishandling by such Party), the
relevant portion of the Internet is down due to a technology failure (other than
arising out of the neglect of or mishandling by such Party), failure of a
supplier to supply necessary materials or equipment in a timely manner,
destruction of property, embargoes, boycotts, governmental legislation or
regulations, orders or acts of civil or military authorities, governmental acts
or orders of courts or administrative agencies, or strikes, lockouts, work
stoppages or other labor difficulties. The time for any performance required
hereunder shall be extended by the delay incurred as a result of such act of
force majeure, and each Party shall act with diligence to correct such force
majeure.

        15.3 Delays or Omissions. No delay or omission to exercise any right,
power or remedy accruing to a Party under this Agreement shall impair any such
right, power or remedy of such Party nor shall it be construed to be a waiver of
any such breach or default, or an acquiescence therein, or of any similar breach
or default thereafter occurring; nor shall any waiver of any single breach or
default be deemed a waiver of any other breach or default theretofore or
thereafter occurring. Any waiver, permit, consent or approval of any kind or
character on the part of either Party of any breach or default under this
Agreement, or any waiver on the part of either Party of any provisions or
conditions of this Agreement must be made in writing and shall be effective only
to the extent specifically set forth in such writing. All remedies, either under
this Agreement or by law or otherwise afforded to a Party, shall be cumulative
and not alternative.

        15.4 Binding Agreement. This Agreement shall be binding upon and shall
inure to the benefit of the Parties hereto and their respective successors and
permitted assigns. No Person or entity other than the Parties hereto (and their
respective successors and permitted assigns) is or shall be entitled to bring
any action to enforce any provision of this Agreement against either of the
Parties, and the covenants and agreements set forth in this Agreement shall be
solely for the benefit of, and shall be enforceable only by, the Parties or
their respective successors and assigns as permitted hereunder.

        15.5 Additional Actions, Documents and Information. Each of the Parties
agrees that it will, at any time, prior to, at or after the date hereof, take or
cause to be taken such further actions, and execute, deliver and file or cause
to be executed, delivered and filed such further documents and instruments and
obtain such consents, as may be reasonably requested in order to fully
effectuate the purposes, terms and conditions of this Agreement.



                                      -18-
<PAGE>   19


        15.6 Notices. (a) All notices and other communications required or
permitted hereunder shall be in writing and shall be mailed by certified or
registered mail (return receipt requested), express air courier, charges
prepaid, or facsimile addressed as follows:

        To IXC:                             with a copy to:

        IXC Internet Services, Inc.         IXC Communications, Inc.
        500 Plaza on the Lake, Suite 200    5000 Plaza on the Lake,
        Austin, TX 78746-1050               Suite 200, Austin,
        Attn: Chairman                      TX 78746
        Facsimile: (512) 328-0239           Attention: General Counsel
                                            Facsimile: (512) 328-7902

                                            Riordan & McKinzie
                                            695 Town Center Drive,
                                            Suite 1500
                                            Costa Mesa, California 92626
                                            Attn: Michael P. Whalen
                                            Facsimile: (714) 549-3244

        To PSINet:                          with copy to:

        PSINet Inc.                         PSINet Inc.
        510 Huntmar Park Drive              510 Huntmar Park Drive
        Herndon, Virginia 20170             Herndon, Virginia 20170
        Facsimile: 703.397.5318             Facsimile: 703.904.9527
        Attn:  Vice President and           Attn: General Counsel
               General Manager,
               Wholesale Group


or to such other address as either Party shall have furnished to the other in
writing.

               (b) If a notice is given by either Party by certified or
registered mail, it will be deemed received by the other Party on the fifth
business day following the date on which it is deposited for mailing. If a
notice is given by either Party by air express courier, it will be deemed
received by the other Party on the next business day following the date on which
it is provided to the air express courier. If a notice is given by facsimile, it
will be deemed received by the other Party after confirmation of receipt.
Notwithstanding the foregoing, any payments made under this Agreement shall be
deemed received only when actually received.

        15.7 Attorneys' Fees. If any arbitration is commenced between the
Parties regarding the performance of this Agreement, the prevailing Party shall
be entitled, in addition to such other relief as may be granted, to a reasonable
sum for its attorneys' fees in such proceeding and for the expenses and costs of
such proceeding as the arbitrator may determine.

        15.8 Assignment. No assignment of this Agreement or of any rights or
obligations hereunder may be made by either Party without the prior written
consent of the other Party hereto and any attempted assignment without the
required consent shall be void; provided, however, that notwithstanding the
foregoing, (i) each Party shall have the right to pledge, assign or otherwise
transfer this Agreement and its rights hereunder, in whole or in part, as
collateral security to any lender, and (ii) each Party shall have the right to
assign or transfer this Agreement and its rights hereunder, in whole or in part,
to any direct or indirect wholly-owned subsidiary of that Party or to any Person
into which that Party may be merged or consolidated or which purchases all or
substantially all of the assets of that Party; provided, however, that (a) such



                                      -19-
<PAGE>   20

subsidiary or Person agrees to be bound by the terms of this Agreement and (b)
any such assignment or transfer shall not relieve that Party from any liability
or obligation under this Agreement.

        15.9 No Third Party Beneficiaries. No provision to this Agreement is
intended, nor shall any be interpreted, to provide or create any Third Party
beneficiary rights or any other rights of any kind in any client, customer,
affiliate, shareholder, partner of any Party or any other Third Party; unless
specifically provided otherwise herein, and except as so provided, all
provisions hereof, shall be personal solely between the Parties to this
Agreement.

        15.10 Export Controls. IXC agrees and acknowledges that any export of
the Services and the subsequent use thereof is subject to U.S. export control
laws and regulations. IXC shall not directly or indirectly transfer the
Services, or the documentation relating thereto, to any country or location
outside of the United States without obtaining the prior written consent of
PSINet.

        15.11 Severability. In case any provision of this Agreement shall be
invalid, illegal or unenforceable, such provision shall be construed so as to
render it enforceable and effective to the maximum extent possible in order to
effectuate the intention of this Agreement; and the validity, legality and
enforceability of the remaining provisions hereof shall not in any way be
affected or impaired thereby.

        15.12 Public Announcements. Each Party shall have the right to review,
comment upon and approve any publicity materials, press releases or other public
statements by the other that refer to, or that describe any aspect of, this
Agreement made prior to, or within 90 days after, the Effective Date; provided,
however, that with respect to disclosure documents required under the Securities
Exchange Act of 1934, as amended, subject to the last sentence of this Section
15.12, each Party shall only have the right to prior review and to comment upon
the other Party's disclosure documents. Each Party agrees that it will not issue
any such publicity materials, press releases or public statements without the
prior written approval of the other Party. The provisions of this section shall
survive termination of this Agreement for a period of two years, except for the
last sentence hereof which shall survive as may be mutually agreed by them for
the Term.

        15.13 Expenses. Each Party shall pay its own legal and other costs
incurred in connection with this Agreement and in the preparation for and
consummation of the transactions provided for herein.

        15.14 Taxes. IXC shall be liable for and shall reimburse PSINet for all
taxes and related charges, however designated, resulting from the provision of
Services as contemplated hereby, including federal, state, provincial or local
sales, use or value-added taxes (VAT) and excise taxes, imposed in connection
with or arising from the provision of Services. In no event shall IXC be
obligated to pay income taxes levied upon PSINet's net income or any real or
personal property taxes assessed against PSINet or PSINet's property, including
any gross receipts taxes assessed in lieu of net income or property taxes,
provided that, if the terms of the relevant statute or ordinance imposes such
gross receipts tax upon IXC, then IXC shall be liable for such tax.

        15.15 Survival of Obligations. The Parties' rights and obligations that,
by their nature, would continue beyond the termination, cancellation, or
expiration of this Agreement, shall survive such termination, cancellation or
termination.

        15.16 Titles and Subtitles. The titles of the Articles and Sections of
this Agreement are for convenience of reference only and are not to be
considered in construing this Agreement.



                                      -20-
<PAGE>   21

        15.17 Governing Law. This Agreement shall be governed in all respects by
the laws of the State of Delaware without reference to its principles of
conflicts of laws.

        15.18 Dispute Resolution. Any controversy or claim arising out of or
relating to this Agreement or with respect to an alleged breach of the terms
hereof, subject to Section 7.8, above, shall be resolved in accordance with the
provisions of Section 19.14 of the IRU Agreement.

        15.19 Entire Agreement/Amendments. This Agreement and the Reciprocal
Confidentiality Agreement constitutes the full and entire understanding and
agreement between the Parties with regard to the subjects hereof and supersedes
all prior oral and written agreements, commitments and understandings with
respect to such matters. Neither this Agreement nor any term hereof may be
amended, waived, discharged or terminated, except by a written instrument signed
by the Parties hereto.

        15.20 Counterparts. This Agreement may be executed simultaneously in two
or more counterparts, each counterpart shall be deemed to be an original, and
all counterparts individually or together shall constitute one and the same
instrument.

        15.21 Schedules. The information set forth in the following Schedules to
this Agreement is intended to supplement the information contained in this
Agreement. In the event of any conflict between the terms of this Agreement and
the information contained in the Schedules hereto, the terms of this Agreement
shall prevail and control.

BOTH Parties represent and warrant that the Person whose signature appears below
is duly authorized to enter into this Agreement on behalf of the Party.

IN WITNESS WHEREOF, THE PARTIES HAVE ENTERED INTO THIS AGREEMENT AS OF THE
EFFECTIVE DATE:

IXC Internet Services, Inc.                 PSINet Inc.

By: /s/ RALPH J. SWETT                      By: /s/ WILLIAM L. SCHRADER
Name:   RALPH J. SWETT                      Name:   WILLIAM L. SCHRADER
Title:  Chairman, President and CEO         Title:  Chairman, President and CEO
Date:   7/22/97                             Date:   7/22/97



                                      -21-
<PAGE>   22


                                 SCHEDULE 2.1.3

                            MASTER TEAMING AGREEMENT


DEFINITIONS:

        "Client" refers to a major domestic or worldwide corporation which
either issues a request for Proposal or would be receptive to an unsolicited
Proposal for procurement of products and/or services of the types provided by
the Parties.

        "Project" refers to a certain procurement of services by and delivery to
Client.

        "Proposal" refers to the documentation of the plan, approach,
methodology, deliverables, costs, etc. submitted to a Client.

        "Team Leader" shall mean the Party submitting the proposal to Client and
fulfilling the leadership role in Project management.

        "Team Member" shall mean the Party who is not the Team Leader.

        All other capitalized terms used herein but which are not otherwise
defined shall have the meanings given to them in the Joint Marketing and
Services Agreement to which this Schedule 2.1.3 is attached (the "Marketing
Agreement").


ARTICLE I - INTRODUCTION AND SCOPE.

1.1     With respect to IXC, this Agreement applies only to the Internet
        Services and Broadband Services divisions of IXC and to teaming efforts
        regarding the products and services of such divisions. In addition, this
        Agreement shall apply only to teaming efforts regarding products and
        services to be sold and/or provided in the Territory, except as stated
        below. The Parties acknowledge that Projects may be performed outside
        the Territory either directly or indirectly through local subsidiaries
        or subcontractors and may be under this Agreement or under separate
        agreements of their respective local subsidiaries, all as the Parties
        may agree from time-to-time. The Parties will endeavor to ensure that
        the provisions of any such separate agreement, to the extent reasonably
        possible, will be the same as those of this Agreement. However, because
        of the various legal and business requirements of such subsidiaries or
        imposed on such subsidiaries, certain modifications of the provisions of
        this Agreement may be required for its adoption for use in such
        instances.

1.2     This Agreement applies only to the preparation and submission of
        Proposals and other related activities and performance of the Parties in
        order to obtain a contract from the applicable Client. The provision of
        products and/or services by a Party hereto as subcontractor to the other
        Party hereto as prime contractor will be under a separate agreement, as
        stated in Section 2.3 of this Agreement.

1.3     Either Party may request the other Party's participation in the
        development of a Proposal. Such request will be in writing in the form
        of a Statement of Intent To Develop A Proposal (the "Statement of
        Intent") substantially in the form of Exhibit A hereto, signed by a
        requesting Party. Such Statement of Intent may contain a brief
        preliminary description of the products and services each Party would
        provide, with the full description of the products and services to be
        provided by a Party as subcontractor to the other Party as prime
        contractor, and the applicable fees and charges, to be agreed upon and
        completed at a later


                                 Schedule 2.1.3

                                  Page 1 of 12

<PAGE>   23



        date and incorporated in a subcontract to be negotiated and executed by
        the Parties with respect to the applicable Project. The Party receiving
        such a request to participate will respond in writing as to whether or
        not it will participate in the Proposal and Project by the earlier of
        (i) ten (10) business days after its receipt of the request, or (ii)
        thirty (30) days prior to the due date of the Proposal. A Party's
        election to participate shall be effected by executing and returning the
        Statement of Intent. An election to decline the offer to participate
        shall be effected by sending written notice of this decision to the
        offering Party. In the event of an election to decline participation,
        the following provisions of this Agreement will not apply to the
        applicable Proposal and Project:
        Articles III, IV and V, and Section 2.3.


ARTICLE II - RELATIONSHIP OF THE PARTIES.

2.1     The Parties shall act as independent contractors in the performance of
        this Agreement. Neither Party shall act as agent for or partner of the
        other Party for any purpose whatsoever, and the employees of one Party
        shall not be deemed the employees of the other Party.

2.2     Nothing in this Agreement shall be construed to grant either the Team
        Leader or the Team Member the right to make commitments of any kind for
        or on behalf of the other Party without the prior written consent of the
        other Party.

2.3     It is understood and agreed that, in the event a contract is awarded to
        the Team Leader by the Client, the Team Leader will be the prime
        contractor. In such event, the Team Leader agrees, subject to the
        Client's approval, promptly upon receipt of the contract award, to
        negotiate in good faith a subcontract with the Team Member for
        performance of its proposed portions of the Project. The Parties agree
        to use reasonable efforts to negotiate and agree upon model form
        subcontract agreements which shall be used as standard form agreements,
        to the extent reasonably possible, between Team Leader and Team Member
        for Team Member's provision of products and or services with respect to
        Projects.


ARTICLE III - PROPOSAL PREPARATION AND SUBMISSION TO CLIENT.

3.1     Each Party shall use reasonable commercial efforts to prepare its
        portions of the Proposal for a Project and to obtain the award to the
        applicable prime contractor hereunder of a contract for the Project.

3.2     The Team Member shall submit to the Team Leader all necessary technical
        and business data and information concerning its proposed portion of the
        Project, including pricing data, required for use in preparation of the
        Proposal. The Team Member shall make available appropriate and
        high-quality personnel to provide reasonable assistance to the Team
        Leader in the preparation of the Proposal as directed by the Team
        Leader.

3.3     The Team Leader shall prepare the Proposal, integrate the information
        provided by the Team Member and submit the Proposal to the Client. The
        Team Leader agrees to consult with the Team Member on all matters
        concerning the portion of the Project to be performed by the Team Member
        prior to submission of the Proposal to the Client.

3.4     The Team Leader shall identify the Team Member as a proposed
        subcontractor and describe the Team Member's Project responsibilities in
        the Proposal.

                                 Schedule 2.1.3

                                  Page 2 of 12

<PAGE>   24



3.5     The Team Leader shall handle contract negotiations with the Client and,
        subject to Client approval, the Team Member will have the opportunity to
        be present at meetings with the Client related to its proposed portion
        of the Project.

3.6     The Team Leader agrees to consult with and obtain the concurrence of the
        Team Member prior to making any Proposal change relating to the Team
        Member's proposed portion of the Project.

3.7     The Team Leader agrees to keep the Team Member advised of all changes in
        the Client's requirements affecting the Team Member's proposed portion
        of the Project and as to the probability of contract award to the team.

3.8     The Team Leader shall use its best efforts to obtain the contract award,
        including participation in oral presentations and preparation of best
        and final offers, and the Team Member agrees to assist in such efforts
        as the Team Leader may reasonably require.

3.9     All contacts with the Client with respect to the Project Proposal shall
        be the responsibility of the Team Leader. Any contacts made by the Team
        Member with the Client shall be only with the full knowledge, prior
        concurrence and participation of the Team Leader.


ARTICLE IV - PROJECT SUBCONTRACT.

4.1     In the event of a contract award to the Team Leader, the Parties shall
        immediately commence good faith negotiations of a subcontract consistent
        with the terms of this Agreement, the applicable Proposal, and the
        applicable prime contract, as may be appropriate, encompassing the Team
        Member's proposed portion of the Project. The Team Leader agrees to use
        its best efforts to secure approval of such subcontract by the Client in
        the event such approval is necessary. Team Leader, with Team Member's
        agreement, may authorize Team Member to begin work, at the direction of
        the Team Leader, prior to execution of the subcontract, for the specific
        Project, subject to the terms of the model form subcontract agreement
        referred to in Section 2.3, above.

4.2     The specific work to be performed by the Team Member will be described
        in the applicable subcontract and/or in orders issued thereunder by Team
        Leader from time to time. Article V below describes generally the
        products and services to be provided by the Parties with respect to
        Projects.

4.3     The subcontract with the Team Member shall include, among other
        appropriate provisions, those provisions for the prime contract between
        the Team Leader and the Client which the prime contract requires are to
        be flowed down to a subcontractor, provided that Team Member either was
        aware of such flow-down requirement before preparation of Team Member's
        portion of the Proposal or subsequently agrees to such provisions. Team
        Member will advise Team Leader, prior to submission of the Proposal, of
        any such flow-down provisions of the proposed Client prime contract as
        to which Team Member takes exception; any such provisions, of which Team
        Member was aware, to which exception is not taken will be included in
        the subcontract.


ARTICLE V - GENERAL RESPONSIBILITIES FOR PRODUCTS AND SERVICES.

5.1     IXC generally will provide products and services of the following types
        for Projects:

                                 Schedule 2.1.3

                                  Page 3 of 12

<PAGE>   25



                                   [TO FOLLOW]

5.2     "Corporation" generally will provide products and services of the
        following types for Projects:

                                   [TO FOLLOW]


ARTICLE VI - COST AND EXPENSES.


6.1     Each Party will bear all of its own costs and expenses relating to the
        preparation of Proposals and to the performance of its other obligations
        and activities under this Agreement. Neither Party will charge the other
        Party for any services unless specifically agreed otherwise in writing
        by the Parties.


ARTICLE VII - PROPRIETARY INFORMATION.


7.1     Each Party anticipates that it may be necessary to provide access to
        information of a confidential or proprietary nature (hereinafter
        referred to as "Proprietary Information") to the other Party in the
        performance of this Agreement. To the extent possible, Proprietary
        Information shall be clearly identified or labeled as such by the
        disclosing Party at the time of disclosure. Where concurrent
        identification of such information is not feasible, the disclosing Party
        shall provide such identification as promptly thereafter as possible.
        However, whether or not so designated, each Party's client lists,
        business plans, and the pricing of its products and services will be
        deemed the confidential information of such Party.

7.2     Each Party agrees that it will hold such Proprietary Information
        confidential in the same manner as it holds its own Proprietary
        Information of like kind, but in any case, by the use of at least
        reasonable care. Disclosures of Proprietary Information shall be
        restricted to those individuals who are participating in preparation of
        the Proposal and other work related to the Project. Each Party shall
        return all such Proprietary Information of the other upon termination of
        the Agreement and completion of all pending Projects.

7.3     Neither Party shall reproduce, disclose or use Proprietary Information
        of the other except as follows:

(a)     Proprietary Information furnished by the Team Leader may be used by the
        Team Member in performing its obligations under this Agreement and any
        resulting subcontract.

(b)     Proprietary Information furnished by the Team Member may be used by the
        Team Leader in performing its obligations under this Agreement,
        including preparation of the Proposal for submission to the Client, and
        in performance of a resulting subcontract between the Parties for a
        Project.

(c)     Proprietary Information furnished by either Party may be used in
        accordance with written authorization received from the disclosing
        Party.

7.4     The limitations on reproduction, disclosure, and use of Proprietary
        Information shall not apply to, and neither Party shall be liable for,
        reproduction, disclosure or use of Proprietary Information of the other
        to the extent such information: (1) becomes known to the public from a
        source other than the receiving Party; (2) was or becomes known to the
        receiving 

                                 Schedule 2.1.3

                                  Page 4 of 12

<PAGE>   26



        Party from a Third Party having the right to disclose it and having no
        obligation of confidentiality to the disclosing Party with respect to
        the applicable information; (3) is furnished to others by its owner
        without restriction on disclosure; (4) is independently developed by
        personnel of the receiving Party who have not had access to such
        information; or (5) is disclosed pursuant to governmental or judicial
        requirement.

7.5     Neither the signing of this Agreement nor the furnishing of any
        Proprietary Information by either Party to the other shall be construed
        as granting the other Party expressly, by implication, by estoppel or
        otherwise, any license under any invention, patent, trademark, copyright
        or other proprietary right now or hereafter owned or controlled by the
        Party disclosing and furnishing same.

7.6     Each Party admits for all purposes that any violation or threatened
        violation of this Article VII shall constitute an irreparable injury to
        the disclosing Party for which monetary damages provide an inadequate
        remedy, and agrees that, in addition to all other rights provided by law
        to which the disclosing Party shall hereby be entitled, it shall have
        the right to seek to have an injunction or equivalent remedy issued
        against the receiving Party to prevent said Party from violations or
        further violations of this Article VII.

7.7     The provisions of this Article VII shall survive termination of this
        Agreement and any Proposal effort.


ARTICLE VIII - INTELLECTUAL PROPERTY RIGHTS.


8.1     All rights in and to inventions conceived and/or reduced to practice,
        and in and to works of authorship created in the performance of this
        Agreement (and any resulting subcontracts signed by the Parties for a
        Project, except as the Parties agree otherwise in any such subcontracts)
        shall be the sole and entire property of the originating Party,
        including full ownership and title to related patents, copyrights and
        other intellectual property. In the event of joint inventions or joint
        works or authorship, the Parties shall engage in good faith negotiations
        to establish respective ownership rights therein. Failing agreement
        within thirty (30) days from initiation of good faith negotiations by
        either Party, [the Parties shall be deemed to have joint ownership,
        without right of account, of the intellectual property rights embodied
        in such new inventions and/or works of authorship.]

8.2     Notwithstanding the foregoing, with respect to any Proposal effort by
        the Parties, it is understood and agreed that Team Member shall grant a
        license or transfer rights to Team Leader and/or the Client in
        inventions, works of authorship, data and information as required by the
        terms of the applicable request for Proposal for a Project, provided
        that Team Member was aware of such terms at the time Team Member
        prepared its portion of the Proposal, and except to the extent
        exceptions are taken to the applicable provisions of the request for
        Proposal. Such license or transfer of rights shall not exceed the
        requirements of the prime contract for such Project. Intellectual
        property rights embodied in preexisting equipment or computer software
        shall remain the sole property of its then owner, provided, however,
        such owner hereby agrees to license such software for use by the Client
        to the extent required by the prime contract.


                                 Schedule 2.1.3

                                  Page 5 of 12

<PAGE>   27




ARTICLE IX - NON-EXCLUSIVITY/EXCLUSIVITY OF RELATIONSHIP.

9.1     Except as stated below, the participation of the Parties in a Project
        under this Agreement shall be on a non-exclusive basis, and each Party
        shall retain complete freedom to work alone or with other Third Parties
        in bidding or performing work on any such Project. However, on a
        case-by-case basis, the Parties may agree, with respect to any
        particular Project, to participate with each other on an exclusive
        teaming basis, and, in the event of such an agreement to team
        exclusively, it shall be under the following terms.

(a)     [Neither Party may enter into or participate in a teaming agreement or
        effort with another Third Party for the purpose of proposing to provide
        products or services for a Project subject to this Agreement of the
        types for which it is responsible under this Agreement.]

(b)     [Neither Party may quote, offer to provide, provide, offer to sell, or
        sell to the applicable Client or to any prime or subcontractor to the
        applicable Client any products or services relating to the applicable
        Project of the types for which it is responsible under this Agreement,
        other than pursuant to a Proposal under this Agreement or a subcontract
        between the Parties.]

(c)     [With respect to IXC, the exclusive teaming obligations and restrictions
        stated above shall apply only to its IXC Internet Services division, and
        the other divisions and business units of IXC Communications, Inc. are
        free of any such obligations and restrictions.]

(d)     Notwithstanding the foregoing, in the event that any other division of
        IXC invites IXC Internet Services division to participate with it in any
        Proposal for any Project or to provide any products or services with
        respect to a Project, IXC Internet Services division may do so, provided
        that such other division of IXC became aware of such Project other than
        through a violation of the rights of "Corporation" regarding protection
        of its Proprietary Information under this Agreement. In the event the
        IXC Internet Services division participates or provides any products or
        services as described above in this Section 9.1(d), both Parties to this
        Agreement will be relieved of and discharged from the exclusive teaming
        obligations and restrictions stated above with respect to the applicable
        Proposal and Project.

9.2     The Parties will be relieved of and discharged from the above exclusive
        teaming obligations and restrictions to the extent that either Party's
        participation in the applicable Project with any other Third Party is
        pursuant to any agreement executed prior to its agreement to team
        exclusively hereunder. Each Party will exert best efforts to advise the
        other Party of any such previously existing agreement as soon as
        possible. In the event that a Party participates in a Project with a
        Third Party under the circumstances described above in this Section 9.2
        and that such Party is relieved of and discharged from the said
        exclusive teaming obligations and restrictions under this Section 9.2,
        the other Party may, at its option, terminate the applicable Proposal
        under this Agreement and/or participate in the Project itself,
        independently of the other Party, or with any other Third Party, and
        will be deemed relieved of and discharged from the above-referenced
        exclusive teaming obligations and restrictions.

9.3     The Parties will be relieved of and discharged from the above exclusive
        teaming obligations and restrictions to the extent provided under
        Section 15.4, below, regarding termination of a Proposal effort.

                                 Schedule 2.1.3

                                  Page 6 of 12

<PAGE>   28



ARTICLE X - LIMITATION OF LIABILITY.

10.1    NEITHER PARTY WILL BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE,
        INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND (INCLUDING, BUT NOT
        LIMITED TO, LOST PROFITS) INCURRED OR ARISING OUT OF THE PERFORMANCE OF
        THIS AGREEMENT EVEN IF THAT PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
        SUCH DAMAGES.


ARTICLE XI - NON-SOLICITATION.

11.1    Neither Party shall actively solicit for employment any of each other's
        personnel during the period of such employees' assignment to or work on
        any Proposal and for the period of six (6) months following termination
        of assignment of each such employee to the Proposal effort. Publicizing
        available employment positions in newspapers or other media of mass
        communication shall not be deemed active solicitation for employment
        under this provision.


ARTICLE XII - FORCE MAJEURE.

12.1    Neither Party shall be liable for any failure to perform or for any
        delay in performance of this Agreement where the failure or delay is due
        to acts of God or public enemy, war, riot, embargo, fire, explosion,
        sabotage, flood, accident, strikes, lockouts or other labor disturbances
        or to enactment, promulgation or issuance of any laws, regulations,
        orders or decrees of any competent governmental, regulatory or judicial
        authority, or, without limiting the foregoing, to any circumstances
        beyond such Party's reasonable control. During such period of
        disability, each Party's obligations will be suspended and
        commensurately extended until such time as performance is no longer
        prevented or hindered, provided that if such period extends for the
        shorter of (I) thirty (30) days, or (ii) a period of such duration that
        either Party consequently reasonably determines that affected Proposal
        efforts are jeopardized, either Party thereafter may terminate this
        Agreement as it applies to any adversely affected Proposal, if such
        right is exercised before the disability is remedied and performance is
        resumed.


ARTICLE XIII - PUBLIC ANNOUNCEMENT.

13.1    Any news release, public announcement, advertisement or publicity
        released by either Party concerning this Agreement, any Proposal, or any
        contract award related thereto, will be subject to the prior review,
        comment and approval of the other Party, except that this Agreement and
        its terms may be disclosed by either Party as required by any law,
        regulation or court order. Any such publicity shall give due credit to
        the contribution of each Party.


ARTICLE XIV - GOVERNING LAW.

14.1    This Agreement shall be construed in accordance with the local law of
        the State of Texas.

                                 Schedule 2.1.3

                                  Page 7 of 12

<PAGE>   29


ARTICLE XV - TERM AND TERMINATION OF AGREEMENT AND PROPOSAL EFFORTS.

15.1    This Agreement is effective upon execution by both Parties and will
        continue in effect thereafter for an initial term of one (1) year.
        Thereafter, the term of this Agreement will be deemed renewed
        automatically, subject to termination as set forth below or as
        other-wise provided in this Agreement.

15.2    Either Party may terminate this Agreement, for its convenience, with or
        without cause, upon at least thirty (30) days advance written notice to
        the other Party, effective as of the end of the initial term or at any
        time thereafter. With respect to the performance of obligations
        regarding any Proposal which would extend beyond the termination of this
        Agreement, the provisions of this Agreement applicable to such
        performance and the corresponding rights and obligations of the Parties
        will be deemed to survive the termination of this Agreement and continue
        in effect as required for the completion of such performance.

15.3    With respect to a Proposal, the rights and obligations of the Parties
        under this Agreement, except any obligations relating to the protection
        of a Party's confidential information, shall terminate upon the first to
        occur of any of the following events:

(a)     cancellation of the applicable request for Proposal or modification of
        the said request for Proposal resulting in the deletion of the
        requirement of the Team Member's products or services or a substantial
        portion thereof;

(b)     elimination by the Client of the Team Leader from consideration as prime
        contractor or award of the prime contract to a company other than the
        Team Leader);

(c)     award of a prime contract to the Team Leader which does not include the
        Team Member's products or services or a substantial portion thereof;

(d)     notification by the Client that the Team Member is unacceptable as a
        subcontractor, or a direction by the Client to utilize a subcontractor
        other than the Team Member, or a determination by either, the Client or
        the Team Leader that the Team Member's offerings do not fully comply
        with the mandatory requirements of the request for Proposal;

(e)     notification of termination by either Party in the event the Parties are
        unable to agree, negotiating in good faith, on the terms and conditions
        of the SUBCONTRACT, within sixty (60) days (or such longer period as the
        Parties may agree) from the award of a prime contract to Team Leader.

(f)     execution of the applicable subcontract between the Parties;

(g)     filing by or against either Party of a petition or a resolution made or
        passed by either Party for the bankruptcy, winding-up, liquidation or
        dissolution of such Party, or the appointment of a receiver or trustee
        in respect of such Party or of its assets, or the acknowledgment by such
        Party of its inability to meet its debts as they fall due, or a general
        assignment of the assets of such Party for the benefit of its creditors;

(h)     termination by either Party under Article XII of this Agreement;

(i)     determination, made reasonably and in good faith, by Team Leader to
        withdraw a Proposal for the reason that it has no reasonable prospect of
        being awarded the prime contract, making continuation of the Proposal
        effort uneconomical or impractical.

                                 Schedule 2.1.3

                                  Page 8 of 12

<PAGE>   30


(j)     notification of termination, effective thirty (30) days after such
        notification, by a Party to the other Party as a result of a material
        breach or default of this Agreement by the other Party which is not
        cured, corrected or remedied by the expiration of such thirty-day
        period;

15.4    In the event any Proposal effort is terminated under Sections 15.3(a)
        through (i), above, both Parties will be deemed relieved of and
        discharged from any exclusive teaming obligations and restrictions under
        Article IX or any other exclusive teaming provision with respect to the
        applicable terminated Proposal effort. In the event a Party terminates
        any Proposal effort as a result of the other Party's breach under
        Section 15.3(j), above, such terminating (non-breaching) Party will be
        deemed relieved of and discharged from any exclusive teaming obligations
        and restrictions as stated above in this Section 15.4. Except as
        otherwise stated in this Section 15.4 or elsewhere in this Agreement,
        the said exclusive teaming obligations and restrictions will survive
        such termination.


ARTICLE XVI - CONDUCT OF THE PARTIES.

16.1    Neither Party, in the performance of this Agreement, shall take any
        action that would be illegal under any applicable rule, regulation or
        law. The Parties and their respective business associates shall avoid
        any practices that are unlawful, improper or unethical and shall conduct
        themselves at all times in a manner that will avoid any appearance of
        impropriety on the part of either Party in the event of public
        disclosure.


ARTICLE XVII - SURVIVAL.

17.1    In addition to those provisions hereof expressly stated to survive this
        Agreement, any provisions of this Agreement and the related rights and
        obligations of the parties which, by their nature, should survive
        termination of this Agreement, will so survive and continue in effect as
        appropriate.


ARTICLE XVIII - GENERAL.

18.1    All notices, requests, consents and other communications hereunder shall
        be deemed to have been duly given if delivered in accordance with
        Section 15.6 of the Marketing Agreement.

18.2    Except as otherwise stated in this Agreement or the Marketing Agreement,
        this Agreement may not be assigned or otherwise transferred by either
        Party, in whole or in part, without the express prior written consent of
        the other Party. No provision of this Agreement may be waived except by
        a writing by the Party to be charged, nor may this Agreement be amended
        except by a writing executed by an authorized representative of each
        Party.

18.3    The foregoing represents the complete and exclusive statement of the
        agreement between the Parties and supersedes any prior oral or written
        agreements, Proposal, commitments, understandings, or communications
        with respect to the subject matter of this Agreement.

                                 Schedule 2.1.3

                                  Page 9 of 12

<PAGE>   31


        IN WITNESS WHEREOF, the Parties have caused this Agreement to be
executed by their duly authorized representatives, with the intention of being
legally bound hereby.

[IXC INTERNET SERVICES]                            ("CORPORATION" NAME)

By:                                                By:
        (Signature)                                       (Signature)
Name:                                              Name:
Title:                                             Title:
Date:                                              Date:


Master Teaming Agreement

Between IXC INTERNET SERVICES and ______________ dated___________________.





                                 Schedule 2.1.3

                                  Page 10 of 12

<PAGE>   32


                                    EXHIBIT A

                FORM OF STATEMENT OF INTENT TO DEVELOP A PROPOSAL


Client:____________________________________________________________

Team Leader:_______________________________________________________

Team Member:_______________________________________________________

Request For Proposal Title/number (if applicable)__________________

Proposal Due Date (if applicable)__________________________________

Development of Proposal. The parties agree to jointly develop a client proposal
under which each party would provide the respective products and services
generally and briefly described as follows:

- -------------------------------------------------------------------

- -------------------------------------------------------------------

- -------------------------------------------------------------------

- -------------------------------------------------------------------

- -------------------------------------------------------------------


                                 Schedule 2.1.3

                                  Page 11 of 12



<PAGE>   33



ACKNOWLEDGEMENT: This Statement of Intent To Develop A Proposal is issued
pursuant to the Master Teaming Agreement identified above. All of the terms and
conditions of the said Master Teaming Agreement are incorporated in and made a
part of this document as if expressly set forth herein.

IXC Internet Services                       ("Corporation" name)

By:                                         By:
Name:                                       Name:
Title:                                      Title:



                                 Schedule 2.1.3

                                  Page 12 of 12



<PAGE>   34



                                  SCHEDULE 2.2

                             PSI SERVICE COMMITMENTS


1.      In providing Managed Connectivity Services under this Agreement, PSI
        will, at a minimum, comply with the following performance requirements:

        (a)     Service Availability. 24 x 7 (subject to scheduled downtime for
                network maintenance during low traffic periods, upon not less
                than one week notice, when possible, to IXC and affected IXC
                Customers).

        (b)     Service Reliability. 99.5%, excluding network problems (i)
                occurring between the customer's premise and the PSI
                Points-of-Presence, and (ii) occurring beyond the point where
                information exits the PSI backbone.

        (c)     Installations. Including acceptance and compliance with the
                minimum performance capabilities, PSI will complete as soon as
                practical but to occur no later than (i) 45 days after receipt
                of order by PSI and (ii) three business days following IXC or
                LEC provisioning of circuits pursuant to an assignment of
                customer addresses by InterNIC (which assignment will be
                requested promptly by PSI following receipt of order). In cases
                in which new circuits do not need to be provisioned in
                connection with a new installation, new customers may be given a
                shorter committed date for completion of installations.

        (d)     Problem Responsiveness. The Parties will develop a mutually
                agreeable interface to the PSI trouble ticket system and
                appropriate problem escalation procedures to address the needs
                of IXC and IXC Customers.

*


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                                  Schedule 2.2

                                   Page 1 of 2


<PAGE>   35



        (a)     Class B Allocation and Transfer. Immediately upon execution of
                the Joint Marketing and Services Agreement to which this
                Schedule is attached (the "Marketing Agreement"), PSI will
                allocate a class B-sized block of address space, transfer all
                existing IXC (the PSI customer) addresses to it, and grant IXC
                all of PSI's right, title and interest in and to such class B
                address block. PSI will assist IXC in obtaining a class B from
                the InterNic (or other authority). At such time as such class B
                is allocated, IXC will transfer all of IXC's right, title and
                interest in and to such class B address block to PSI.

        (b)     Infrastructure Engineering. PSI will, at all times, treat the
                IXC class B as it would one of its own class B's for the
                purposes of routing, peering, and network throughput
                optimization.

3.      Announcement. The services specified by IXC will be provided as a
        feature or function of the new PSI product/price plan for the ISP
        business market. Such plan is not completed. Upon completion, PSI will
        provide Internet routing for IXC and IXC customer networks via a
        separate AS number(s) assigned by appropriate Internet authorities. PSI
        will assist IXC in obtaining the necessary AS number(s), ownership of
        which is to be transferred and assigned to IXC. Notwithstanding the
        foregoing, PSI will obtain and implement updates to its ISP peering
        relationships and router configurations to allow full Internet routing
        for the IXC AS number(s) and associated networks at such time as PSI is
        able to do so.

4.      Peering. PSI acknowledges that IXC reserves the right to establish its
        own peering relationships with other ISPs. PSI will work jointly with
        IXC to ensure appropriate routing for IXC between PSI and IXC borders.

5.      Hardware. PSI will make the equipment in Appendix 1 to this Schedule 2.2
        available for resale by IXC unless PSI is prevented from doing so by its
        contracts with the equipment suppliers. Should such supplier agreements
        prevent such resale, PSI will assist IXC in acquiring its own licenses
        to do so. The prices on Appendix 1 to this Schedule 2.2 may be changed
        to reflect the then PSI acquisition cost for such. Prices charged to IXC
        by PSI shall, however, be subject to the most favored pricing provisions
        of the Marketing Agreement.

6.      Terms. PSI's obligations with respect to delivery of Services under the
        Marketing Agreement to an IXC Customer is, for all Services, subject to
        compliance by such IXC Customer, with the terms and conditions set forth
        in PSI's standard service agreements relating to the comparable services
        offered by PSI to PSI customers.

7.      Cooperation. The Parties shall cooperate with each other to ensure that
        the product service descriptions, whether contained in the Documents,
        service agreements, world-wide web site pages or elsewhere, at all times
        fairly and accurately describe the features and functions of the
        Services.




                                  Schedule 2.2

                                   Page 2 of 2

<PAGE>   36



                           APPENDIX 1 TO SCHEDULE 2.2

PSINET
INTRANET WAREHOUSE - HARDWARE LIST

<TABLE>
<CAPTION>
PRODUCT NUMBER                      DESCRIPTION                                 PRICES
- --------------                      -----------                                 ------
<S>                       <C>                                                   <C>
ROUTERS:
ascend-50                 Ascend Pipeline 50 Router (with integrated NT1)            $
                          *
                          Compatible with LAN-ISDN

ascend-P130               Ascend Pipeline 130 Router (with integrated NT1       * 
                          and T1 CSU/DSU) Compatible with LAN-ISDN and 
                          interFrame 128K-T1 Services

cisco-2504     Cisco 2504 Router (TokenRing, v. 35, IP Only)                    *
                          Compatible with interFrame, InterPPP, and
                          LAN-ISDN (18 Channel)

cisco-2514     Cisco 2514 Dual Ethernet Router                                  *
                          Compatible with InterFrame and InterPPP Services

comp-sys-900i             Compatible Systems MicroRouter 900i Single            *
                          Ethernet Router 
                          Compatible with LAN-DIAL, LAN-ISDN (18
                          Channel), InterPPP and InterFrame 56K Services

comp-sys-1220i            Compatible Systems MicroRouter 1220i Dual Ethernet    *
                          Router Compatible with LAN-DIAL, LAN-ISDN (18
                          Channel), InterPPP and InterFrame 56K-T1 Services

comp-sys-1220iV35         Compatible Systems MicroRouter 1220i Dual Ethenet     *
                          Router (with v.35 cable)
                          Compatible with LAN-DIAL LAN-ISDN (18 Channel),
                          InterPPP and InterFrame 56K bps-T1 Services

comp-sys-1270i            Compatible Systems MicroRouter 1270i Dual             *
                          Ethernet Router (with integrated T1 CSU/DSU)
                          Compatible with LAN-Dial, LAN-ISDN (18
                          Channel), and InterFrame 56K-T1 services

farallon-netop            Farallon Netopia 640 ISDN Router (with                *
640                       integrated NT1)
                          PC version for unlimited users. Compatible with
                          LAN-ISDN Service

farallon-netop            Farallon Netopia 440 ISDN Router (with                *
440                       integrated NT1)
                          Macintosh version for unlimited users.
                          Compatible with LAN-ISDN Service
</TABLE>

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Appendix 1 to Schedule 2.2

                                   Page 1 of 3

<PAGE>   37


<TABLE>
<CAPTION>
PRODUCT NUMBER                      DESCRIPTION                               PRICES
- --------------                      -----------                               ------

<S>                       <C>                                                   <C>
livingston-irx            Livingston IRX-211 Firewall Router (with              *
221                       v.35 cable)
                          Compatible with Interframe and InterPPP Services

protean-                  Protean Globetrotter 60 (with v.35 cable)             *
globetrot 60              Compatible with Interframe Service

rockwell-nh-bri           Rockwell NetHopper NH-BRI 616 (with                   *

                          integrated NT1)
                          Includes internal analog modem. Compatible with
                          LAN-ISDN and LAN-DIAL Services.

MODEMS & CSU/DSUS:                                                              *
astro-nx1                 Astrocom NX1 T1 CSU/DSU (Including sub-rate
                          T1)
                          Compatible with Interframe 128K-T1 Services

astro-2364                Astrocom 2364 56K CSU/DSU                             *
                          Compatible with Interframe 56K and
                          InterPPP Services

usr-sportPC               US Robotics Sportster 33.6 Kbps Modem                 *

                          PC version compatible with InterRamp and
                          LAN-DIAL Services

usr-sportMAC              US Robotics Sportster 33.6 Kbps Modem                 *
                          Macintosh version compatible with InterRamp
                          and LAN-DIAL Services

MISCELLANEOUS:
3com-ImpactPC             3Com Impact (with external TA/NT1)                    *
                          PC version compatible with InnerRamp Service
                          via ISDN

3com-ImpactMAC            3Com Impact (with external TA/NT1)                    *
                          Macintosh version compatible with
                          InterRamp Service via ISDN

motorola-                 Motorola Bitsurfer Pro (with external TA/NT1          *
                          and two bitsurfPC analog ports) PC version compatible
                          with LAN-ISDN and InterRamp Service via ISDN.

motorola-                 Motorola Bitsurfer PRO (with external TA/NT1          *
                          and bitsur MAC two analog ports) Macintosh version
                          compatible with LAN-ISDN and InterRamp Service via
                          ISDN.

nt-nt1                    Northern TelecomTM Standalone NT1 Model A
Includes 2 watt power supply. Compatible with                                   *
</TABLE>

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                           Appendix 1 to Schedule 2.2

                                   Page 2 of 3

<PAGE>   38



                        InterRamp and LAN-ISDN Services.

Note:          Continental U.S. Shipping:

Orders in Virginia must includes a 4.5% sales tax.

                          Hardware: There is a [*] shipping fee for all
                          hardware purchased through PSINet.

Terms: Net 30 days.


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                           Appendix 1 to Schedule 2.2

                                   Page 3 of 3

<PAGE>   39


                           ATTACHMENTS TO SCHEDULE 2.2


                                  REQUIREMENTS

                                       FOR

                          MANAGED CONNECTIVITY SERVICES

                                       AND

                              VALUE-ADDED SERVICES



<PAGE>   40

              DEDICATED INTERNET ACCESS SERVICE SERVICE REQUIREMENTS VERSION 1.1

1.      Overview

PSI's Dedicated Internet Access services provide full-time dedicated Internet
access via point-to-point 56K and T1 leased lines or SMDS metropolitan area
network T1 and T3 connections.

The PSI Dedicated Internet Access services include:

               - PSINet InterFrame
               - PSINet InterMAN

The PSI Dedicated Internet Access service specifications are included in
Schedule 2.3.

2.      Wholesale Service Branding

PSI is to deliver the Dedicated Internet Access service to IXC and IXC Customers
on a branded basis, such that the service is delivered to the end customer as an
IXC or IXC Reseller branded service. Service branding is to be present in the
following areas:

               -  Sales collateral
               -  Service manuals and other service-related material.
               -  All PSI contact with the end customer, such as during order
                  verification, service provisioning, and customer support
               -  Email addresses and web site domain names for customer
                  support, service status, service information.
               -  Service usage reports

Where additional investment and resources are required, PSI will state estimated
costs in advance for which IXC or the IXC Reseller is responsible.

3.      Delivery Processes

Documented delivery processes are to be developed by PSI. PSI will work to
integrate internal processes with IXC's service processes, specifically in the
areas of:

               -  Sales support
               -  Order processing
               -  Service provisioning
               -  Customer support
               -  Network operation procedures and escalation
               -  Trouble ticketing and tracking
               -  Billing

PSI must create and maintain delivery process documentation specific to the
items listed above.

4.      Service Implementation

IXC is responsible for:

               -  Submitting accurate and correct service order information
                  to PSI

PSI is responsible for:


                           Attachments to Schedule 2.2

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<PAGE>   41


               -  Via IXC, ordering, installing, and configuring the
                  customer's communications circuit
               -  Internet service provisioning and configuration (IP
                  addresses, DNS, routing, etc.) for the customer's network
               -  Registration and assignment of IP address numbers
               -  Registration of the customer's domain name
               -  Implementation of routing information as required for the
                  customer's environment.

PSI's installation technicians are responsible for remotely assisting the
customer's technical liaison in the physical installation of the customer
premise equipment (CPE).

Service implementation details are described below.

4.1.           Site Planning and Preparation Coordination

Site planning coordination will be provided by PSI to the customer's designated
point of contact. This helps customers to prepare for installation of the
Dedicated Internet Access service. Customers need to provide space and power for
the CPE equipment, an attachment to the customer's internal network, and at
least one computer with TCP/IP support.

4.2.           Communications Circuit Ordering

PSI is responsible for ordering (from IXC, on behalf of the customer) and
maintaining the communications circuit necessary for delivery of service. IXC
will either provide the circuit itself or order one from another
telecommunications vendor and at IXC's cost.

4.2.1.  Inside Wiring

PSI arranges for IXC to terminate the circuit in proximity to the planned
location of the premises equipment. Any cost associated with extending the
circuit to this location (inside wiring) is passed on to the customer.

4.3.           Customer Premise Equipment

The customer premises equipment package consists of a TCP/IP router with
appropriate LAN and WAN interfaces, a CSU/DSU corresponding to the connection
type, and associated cables.

4.3.1.  Supported Customer Premise Equipment

PSI will only support CPE that has been tested by PSI and certified for
compatibility with PSI services. PSI will maintain a current WWW list of
certified and supported CPE.

4.3.2.  Customer Premise Equipment Provisioning

Managed services (e.g., InterMAN, InterFrame with RouteWaller) require that the
CPE be owned and operated by PSI. When the customer prefers to own and operate
their own equipment, CPE may be purchased through PSI. When purchased through
PSI, the package of service equipment utilized by each customer is to be
pre-assembled by PSI and subjected to a hardware quality acceptance test by PSI
before delivery to the customer site. Equipment not purchased through PSI is
subject to verification of suitability by PSI. PSI will consider non-certified
routers on a case-by-case basis.


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<PAGE>   42



Customers providing their own premises equipment must maintain the premises
equipment to current hardware and software revision levels for compatibility
with the PSI service.

4.4.           Customer Premise Equipment Staging and Configuration

To ease installation, equipment is to be either pre-configured by PSI before
delivery to the IXC customer site or PSI assists in remotely configuring after
it is connected to the network.

For customer premise equipment supplied by PSI, PSI is responsible for
pre-configuring the customer premise equipment with its initial configuration
information prior to shipping to the IXC customer site.

When the IXC customer supplies the premise equipment, PSI is responsible for
providing to the customer initial configuration information for the customer
premise equipment sufficient to enable IP connectivity to the customer's
network.

4.5.           Customer Premise Equipment Installation

PSI's installation technicians are responsible for remotely assisting the IXC
customer's technical liaison in the installation of the premises equipment. The
customer's technical liaison performs the physical installation of the premises
equipment. On-site CPE installation by a PSI field technician or agent is to be
provided by PSI on an optional basis (InterFrame) unless otherwise specified in
the service specification (InterMAN). Please see attached price sheet.

4.6.           Ipaddress Allocation

*


*

4.7.IP Routing Service

4.7.1.  IP Routing for IXC Customers

PSI must perform any IP routing configuration changes to its network routers
necessary to enable Internet routing for IP traffic destined to or received from
the IXC customer's network.

*

4.8.           Domain Name Service (DNS)

PSI is to provide IXC Dedicated Internet Access customers with primary and/or
secondary domain name service as necessary for successful presence on the
Internet.

4.8.1.  Domain Name Registration

On behalf of IXC customers, PSI is to perform registration of the customers'
domains with the InterNIC and/or its successors. PSI is to submit domain name
registrations to the InterNIC using registration and billing information
provided

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                           Attachments to Schedule 2.2

                                  Page 3 of 34

<PAGE>   43



to PSI by IXC or the IXC Reseller as part of the customer order. InterNIC or its
successor(s) will invoice the IXC customer directly for the domain name
registered.

For existing customer domains, PSI is responsible for assisting IXC customers
with the transfer of existing domain name service to the PSI nameservers, using
processes designed to minimize any discontinuity of Domain Name Service for the
customer's domains.

4.8.2.   Domain Name Service Operation

DNS service provided to IXC customers by PSI must be maintained on multiple
nameservers which are physically diverse and connected to the PSI backbone at
different points.

IXC customers may elect to run and administer their own primary and/or secondary
nameservers. For customers running their own primary nameserver, PSI is to offer
secondary nameservice for the customer's domains on at least two PSI
nameservers.

Nameservice for one domain per customer connection is part of the basic service.
Nameservice for additional domains is available as an option. Please see
attached fee schedule.

4.8.3.  DNS Updates

For IXC customer domains for which PSI provides primary nameservice, PSI must
perform updates to the customer domain zone information as reasonably requested
by the customer. Zone update procedures are to be documented by PSI and provided
to IXC. PSI is to provide a web interface as soon as possible that allows IXC
customers to make changes to their domain information interactively.

Turnaround time for updated IXC customer DNS information to be available on the
Internet via Internet accessible PSI nameservers must be no more than 24 hours.

4.9.           Acceptance Testing

PSI is to conduct ping test to the customer's site to ensure that the customer
premise router can successfully communicate over the IXC Dedicated Internet
Access service and service billing by PSI to IXC may be initiated. Additional
tests will be performed thereafter to verify the proper operation of the on-site
equipment package, the local access facility, and the PSI Internet
infrastructure, including IP routing, DNS, Usenet news, and other services.

4.10.          Acceptance Criteria.

PSI implementation of service for IXC Dedicated Internet Access service
customers is considered complete when the following criteria have been met:

4.10.1. A circuit has been installed and configured to give the customer the
amount of bandwidth contracted for between the customer location and the PSI
Point-of-Presence (POP). If a Frame Relay connection, PVCs have been configured
with appropriate CIR and burst values as contracted for by the customer.

4.10.2. The Dedicated Internet Access router and associated premises equipment
is installed at the customer site, and IP connectivity between the customer
network and the Internet (including routing outside PSI networks) exists.

PSI must verify IP connectivity through a test which:


                           Attachments to Schedule 2.2

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<PAGE>   44



               -  sends repeated pings through the Internet to the
                  customer site and verifies that the pings were
                  received.

               -  in cases when the premises equipment configuration
                  supports it, PSI must verify IP routing through a
                  trace route test.

4.10.3. IP addresses have been allocated from IXC's address space to the
customer for use on their network.

4.10.4. Any necessary routing changes have been made in PSI's network routers so
that routes to the customers IP networks and addresses are announced to the
Internet.

4.10.5. For customers with their own domain, the domain is registered with the
InterNIC and any PSI-supplied primary and secondary DNS servers are operational
for it.

4.10.6. Any initial customer requested packet-filtering option has been
installed in the customer premise Dedicated Internet Access router.

4.10.7. The customer has been informed that the Internet service is available
for implementation of Internet application such as, Telnet, FTP, E-Mail or WWW,
and has acknowledged that they plan to configure these applications within the
installation phase or that they do not intend to at this time. Billing will
commence upon a successful ping test and not acceptance of working Internet
application.

4.10.8. The customer has been informed of the operational status of the
customer's Internet connection and been provided with documentation of (i) the
Internet service configuration, and (ii) the acceptance test results.

4.10.9. IXC has been informed of the operational status of the customer's
Internet connection and been provided with documentation of (i) the Internet
service configuration, and (ii) the acceptance test results.

4.10.10.The IXC customer has been given an information package designed for new
Dedicated Internet Access customers.

5.             SERVICE OPTIONS

5.1.           Usenet News Service

IXC offers NNTP news feeds and/or NNRP news server access to its Dedicated
Access Internet Service customers. PSI is responsible for working with the IXC
customer to determine whether the size of the customer's Internet access line is
sufficient to meet the customer's network news requirements. PSI is to provide
the IXC customer with Usenet News access via an NNTP news feed from PSI's news
servers to the customer's news server, or alternately by allowing the IXC
customer to directly access PSI's news server with client software using the
NNRP protocol.

Please see fee schedule for pricing.

 5.1.1. NNTP News Feed

As a prerequisite to receiving a Usenet News Feed, the IXC customer must install
a news server. PSI is responsible for assisting the IXC customer in determining
the news feed parameters.

Once the server is in place and the service is established, PSI is to maintain
the news feeds for all IXC customers receiving NNTP news feeds.



                           Attachments to Schedule 2.2

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<PAGE>   45



PSI's news servers are to accept news postings from the customer's news server
and propagate these postings on to other Usenet news servers on the Internet.

IXC customers may request changes to the list of news groups fed from PSI's news
servers, during normal business hours and at a frequency averaging up to one
change request per week. PSI is responsible for implementing the required
changes on the PSI news servers within 24 hours.

Please see fee schedule for pricing.

5.1.2.  NNRP News Access

The IXC Dedicated Access Internet Service customer may chose not to run a news
server on their network and instead request NNRP access to PSI's news servers as
a client. PSI must provide NNRP access to the IXC Dedicated Access Internet
Service customer for up to 25 newsreader clients. PSI's news servers are to
accept Usenet news postings from the customer's NNRP clients and propagate these
postings on to other Usenet news servers on the Internet.

Please see fee schedule for pricing.

5.2.           Network Usage Statistics Reporting

PSI is responsible for providing Network Usage Statistics Reporting to IXC
Dedicated Internet Access service customers. Network Usage Statistics Reports
are to be traffic summary reports that allow customers to track access line
utilization and peak activity periods. The usage report must be produced on a
regular basis (daily, weekly, and monthly) and is to be provided to the customer
and to IXC via email and the Web.

The usage information is to be collected from the customer premises and other
network equipment using SNMP and other measurement tools.

Please see fee schedule for pricing.

5.3.           Emergency Backup Service

In the event of a failure in connectivity between the customer's location and
the PSI Point-of-Presence (POP) due to POP equipment failure or failure of the
circuit connecting the customer location to the PSI POP, PSI must provide to the
customer a PSI dial-up packet access point within four hours after disruption of
service (except as provided in Section 15.2 of the Marketing Agreement). This
service option must be requested and set up in advance of an event.

6.             Network Operations Support

PSI's is responsible for network operations support for network services
provided to IXC Dedicated Internet Access service as described in this section.

6.1.           PSI Infrastructure Operations Support

PSI must monitor the PSI network 24 hours a day, 365 days a year. PSI is to
provide proactive operations support and troubleshooting of all network and
service infrastructure components providing service to IXC customers, including
IXC-provided circuits (such as circuits from the PSI POP to the customer
premise).

PSI will use SNMP and other software tools to monitor the network. This software
must be supplemented with additional tools to monitor non- SNMP equipment,
domain name servers, NNTP news servers and feeds, and other network services.

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<PAGE>   46



All network services (routing, DNS, email servers, Usenet news, NTP, security,
etc.) must be monitored for availability and performance. The monitoring
software must report the status of the network to a display which is monitored
throughout the day.

Service outages are to be automatically detected. Troubleshooting procedures and
customer notification will occur within * of an outage.

IXC and PSI will work jointly on resolution procedures.

6.1.1          Network Reports

PSI is to provide IXC with network status logs on a regular basis to provide IXC
with the ability to evaluate staff responsiveness and network availability. All
changes in the PSI network status must be logged.

PSI is to provide IXC with regular reports on the status of the PSI network.
Report information is to be defined by IXC, and will include but not be limited
to:

*

6.2            Customer Connectivity Support

PSI must monitor IXC customers' connectivity to ensure continuous Internet
connectivity is provided to the customer network. IXC Dedicated Internet Access
customer connectivity outages must be detected by PSI and acted upon by PSI
within *.

PSI must follow up on loss of connectivity using documented trouble resolution
procedures as jointly developed by IXC and PSI.

6.3            Communications Link Maintenance

PSI is responsible for monitoring and maintaining the communications link
between the Customer and PSI. This includes problem diagnosis and any necessary
vendor interaction for dispatch and repair. PSI's staff is to escalate
communications circuit problems using documented trouble resolution procedures
as jointly developed by IXC and PSI.

6.4            Customer Premises Equipment Maintenance for Interman

If the customer has contracted for customer premise Internet router and CSU/DSU
maintenance, PSI is responsible for maintaining the customer premise equipment.
PSI must diagnose failures, usually with the assistance of the technical liaison
designated by the customer at the site, and shall determine whether equipment
replacement is required.

6.4.1          On-Site CPE Repair / Replacement for Interman

PSI is responsible for performing the actual equipment replacement with
telephone assistance (as necessary).

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


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<PAGE>   47



Response time for performing customer premise equipment replacement must meet
the schedule described within the PSI customer maintenance contract.

7.             Technical Services and Customer Support

IXC is to provide first level customer support for all IXC Dedicated Access
Internet customers.

7.1            Standard Service Customer Support Helpline

PSI must staff an IXC Customer Support helpline with trained and qualified PSI
customer support representatives from 8am-8pm EST/EDT Monday through Friday.
Customer support staff must be trained in supporting Dedicated Internet Access
service customers. Additionally, an outage support hotline (Netwatch) shall be
staffed 24 hours per day, 7 days per week, 365 days per year for network access
emergency reporting to IXC and its customers.

7.1.1          Customer Support Helpline Response Time

Calls to the PSI-provided IXC customer support hotline must be answered within *
rings., 8am-8pm EST/EDT Monday through Friday. For similar response times
off-hours, optional support may be available (at additional cost).

7.2            Customer Support Email Mailbox See Section 7.4.

7.3            Fault Isolation and Problem Resolution

PSI is to perform fault isolation for problems related to the PSI provided
service. Fault isolation may involve coordination among network operators and
technicians, staff at the affected site, telecommunications carriers, and other
vendors. Depending on the specific technologies used, the process may involve
testing equipment, reconfiguring routers, or diagnosing communications link
problems. PSI is responsible for diagnosing service problems and tracking repair
progress. PSI is to use documented trouble resolution procedures as jointly
developed and agreed upon by PSI and IXC.

7.4            Trouble Ticketing System

PSI must use a Trouble Ticketing System to track problems from initial report
through satisfactory resolution. As PSI staff works to resolve problems, the
current status must be maintained in the Trouble Ticketing System.

7.4.1          IXC Customer Access to Trouble Ticketing System

IXC customers will be provided access by PSI to any trouble tickets related to
their service, as soon as the technology is available to PSI. If additional
programming is required to deliver this functionality, it will be costed out and
provided to IXC in advance. The trouble ticketing system should provide
designated customer contacts with automatic access to the trouble tickets via
web interfaces.

PSI Backbone status information should also be made available to IXC Customer
contacts requesting same via the same interfaces.


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 8 of 34

<PAGE>   48



7.4.2          IXC Reseller Access to Trouble Ticketing System

IXC resellers will be provided access by PSI to any trouble tickets related to
the service, as soon as the technology is available to PSI. If additional
programming is required to deliver this functionality, it will be costed out and
provided to IXC in advance. The trouble ticketing system should provide
designated IXC Reseller contacts with automatic access to the trouble tickets
via web interfaces.

PSI Backbone status information should also be made available to IXC Reseller
contacts requesting same via the same interfaces.

7.4.3          IXC Access to Trouble Ticketing System

IXC will be provided access by PSI to any trouble tickets related to the service
provided to IXC, IXC Resellers and their end customers, as soon as the
technology is available to PSI. If additional programming is required to deliver
this functionality, it will be costed out and provided to IXC in advance. The
trouble ticketing system should provide designated IXC contacts with automatic
access to the trouble tickets via web interfaces.

PSI Backbone status information should also be made available to IXC Reseller
contacts requesting same via the same interfaces.

PSI is to work with IXC to integrate trouble ticketing systems and processes as
much as reasonably possible.

7.5            PROBLEM NOTIFICATION

7.5.1          IXC Customer Problem Notification

The PSI operations staff must inform the technical contact of IXC Dedicated
Internet Access service customers of any outages affecting their service. The
operations staff must also keep Dedicated Internet Access customers informed of
any widespread outages on connecting networks.

7.5.2          IXC Reseller Problem Notification

The PSI operations staff must inform the technical contact of IXC Resellers of
any outages affecting service to their end customers. The operations staff must
also keep IXC Resellers informed of any widespread outages on connecting
networks.

7.5.3          IXC Problem Notification

The PSI operations staff must inform the IXC technical contacts of any outages
affecting service to IXC, IXC Resellers, or IXC end customers. The operations
staff must also keep IXC informed of any widespread outages on connecting
networks.

7.6            Software and Configuration Support for Interman

PSI is responsible for coordinating software updates and configuration changes
on the customer premise router and CSU/DSU equipment of IXC customers as
required to provide Internet service. Notice of software changes is to be made
to the customer technical contacts, and every effort must be made to perform
maintenance during off-hours.

7.7            Escalation Procedures


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<PAGE>   49



Documented customer support processes are to be developed jointly by PSI and
IXC. Specific process documentation is required for the following:

               - customer support procedures
               - trouble escalation procedures
               - trouble ticketing, tracking, and resolution

PSI must provide information to the IXC customer describing customer support,
problem resolution, and trouble escalation procedures, customer contact
information, and trouble reporting methods.

8.             Security Procedures

The following services provide security procedures: RouteWaller (InterFrame),
SecureEnterprise (InterFrame and InterMAN), and PSI IntraNet.

Additionally, PSI's Net Abuse policy shall apply to all IXC customers.



                           Attachments to Schedule 2.2

                                  Page 10 of 34

<PAGE>   50


      SWITCHED LAN INTERNET ACCESS SERVICE SERVICE REQUIREMENTS VERSION 1.1

1.             Overview

PSI's Switched LAN Internet Access services provide on-demand switched
connectivity to the Internet via an analog modem (9.6 - 33.6 Kbps) or an ISDN
NT1 (64 - 128 Kbps) and a customer premise router. Connectivity is provided to
the customer's LAN rather than a single system, via the customer premise router.
Connections are established between the customer premise and an PSI
Point-of-Presence (POP) using the Point-to-Point Protocol (PPP).

The PSI Switched LAN Internet Access services include:

               - PSINet LAN-On-Demand (LAN-Dial and LAN-ISDN)

The PSI Switched LAN Internet Access service specification is included in
Schedule 2.3.

2.             Wholesale Service Branding

PSI is to deliver the Switched LAN Internet Access service to IXC and IXC
Customers on a branded basis, such that the service is delivered to the end
customer as an IXC or IXC Reseller branded service. Service branding is to be
present in the following areas:

               - Sales collateral
               - Service manuals and other service-related material.
               - All PSI contact with the end customer, such as during order
                 verification, service provisioning, and customer support
               - Email addresses and web site domain names for customer
                 support, service status, service information. o Service
                 usage reports

Where additional investment and resources are required, PSI will state estimated
costs in advance for which IXC or the IXC reseller is responsible.

3.             Delivery Processes

Documented delivery processes are to be developed by PSI. PSI must work to
integrate internal processes with IXC's service processes, specifically in the
areas of:

               -  sales support
               -  order processing
               -  service provisioning
               -  customer support
               -  network operation procedures and escalation
               -  trouble ticketing and tracking
               -  billing

PSI must create and maintain delivery process documentation specific to the
items listed above.

4.             Service Implementation

PSI is responsible for providing and maintaining dial-up Points-of-Presence
(POPs) with analog modem and ISDN access capability that allow local switched

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<PAGE>   51



access from the customer location. PSI will provide modem ports via dial-up
access numbers for IXC Switched LAN Internet Access Service customers.

IXC is responsible for:

               - Submitting accurate and correct service order information
                 to PSI

PSI is responsible for:

               - Internet service provisioning and configuration ( * , DNS,
                 routing, etc.) for the customer's network

*

               - Registration of the customer's domain name

               - Implementation of routing information as required for the
                 customer's environment.

PSI is responsible for remotely assisting the customer's technical liaison in
the physical installation of the customer premise equipment (CPE).

Implementation support details are described below.

4.1.           Site Planning and Preparation Coordination

Site planning coordination must be provided by PSI to the customer's designated
point of contact. This helps customers to prepare for installation of the
Switched LAN Internet Access service. Customers need to provide space and power
for the CPE equipment, an attachment to the customer's internal network, and at
least one computer with TCP/IP support.

4.2.           Communications Circuit Ordering

The customer is responsible for ordering and having installed an analog phone
line or an ISDN line to support the service at its sole cost.

The customer should arrange for the circuit to terminate in proximity to the
planned location of the premises equipment. Any cost associated with extending
the circuit to the planned location of the premises equipment (inside wiring) is
the responsibility of customer.

4.3.           Customer Premise Equipment

The customer premise equipment package consists of a TCP/IP router with
appropriate LAN and WAN interfaces, an analog modem or ISDN NT1 device, and
associated cables.

4.3.1.  Supported Customer Premise Equipment

PSI will only support CPE that has been tested by PSI and certified for
compatibility with PSI services. PSI will maintain a current WWW list of
certified and supported CPE.

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

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<PAGE>   52



4.3.2.  Customer Premise Equipment Provisioning

The customer premise equipment may be purchased through PSI. When purchased
through PSI, the package of service equipment utilized by each customer is to be
pre-assembled by PSI and subjected to a hardware quality acceptance test by PSI
before delivery to the customer site. Equipment not purchased through PSI is
subject to verification of suitability by PSI.

Customers providing their own premises equipment must maintain the premises
equipment to current hardware and software revision levels for compatibility
with the PSI service.

4.4.           Equipment Staging and Configuration

For customer premise equipment supplied by PSI, PSI is responsible for
pre-configuring the customer premise equipment with its initial configuration
information prior to shipping to the IXC customer site.

When the IXC customer supplies the premise equipment, PSI is responsible for
providing to the customer initial configuration information for the customer
premise equipment sufficient to enable IP connectivity to the customer's
network.

4.5.           Customer Premise Equipment Installation - Not Applicable

4.6.           Customer Premise Equipment

PSI is responsible for remotely assisting the IXC customer's technical liaison
in the installation of the premises equipment. The customer's technical liaison
performs the physical installation of the premises equipment.

*

PSI is responsible for maintaining a record of all IP address allocations for
each IXC customer. PSI is to provide this information to IXC on a regular basis.

4.8.           IP Routing Service

PSI must perform any IP routing configuration changes to its network routers
necessary to enable Internet routing for IP traffic destined to or received from
the IXC customer's network.

4.8.1.  Routing Service for Multiple Connected Networks

BGP routing is not available to IXC Switched LAN Internet Access customers.

4.9.            Domain Name Service (DNS)

PSI is to provide IXC Switched LAN Internet Access customers with primary and/or
secondary domain name service as necessary for successful presence on the
Internet.

4.9.1.  Domain Name Registration

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 13 of 34

<PAGE>   53



On behalf of IXC customers, PSI is to perform registration of the customers'
domains with the InterNIC and/or its successors. PSI is to submit domain name
registrations to the InterNIC using registration and billing information
provided to PSI by IXC or the IXC Reseller as part of the customer order.

For existing customer domains, PSI is responsible for assisting IXC customers
with the transfer of existing domain name service to the PSI nameservers, using
processes designed to minimize any discontinuity of Domain Name Service for the
customer's domains. InterNIC or its successor(s) will invoice the IXC customer
directly for the domain name registered.

For IXC customer domains for which PSI is to operate the primary nameserver, PSI
is to register with the InterNIC only the secondary nameservers. This is to
ensure that DNS lookups are not affected during rebooting of the primary
nameserver.

4.9.2.   Domain Name Service Operation.

DNS service provided to IXC customers by PSI must be maintained on multiple
nameservers which are physically diverse and connected to the PSI backbone at
different points.

IXC customers may elect to run and administer their own primary and/or secondary
nameservers. For customers running their own primary nameserver, PSI is to offer
secondary nameservice for the customer's domains on at least two PSI
nameservers. Nameservice for one domain per customer connection is part of the
basic service. Nameservice for additional domains is available as an option.
Please see attached fee schedule.

4.9.3.  DNS Updates

For IXC customer domains for which PSI provides primary nameservice, PSI must
perform updates to the customer domain zone information as reasonably requested
by the customer. Zone update procedures are to be documented by PSI and provided
to IXC. PSI is to provide a web interface as soon as possible that allows IXC
customers to make changes to their domain information interactively.

Turnaround time for updated IXC customer DNS information to be available on the
Internet via Internet accessible PSI nameservers must be no more than 24 hours.

4.10.          Acceptance Testing

PSI is to conduct tests to the customer's site to ensure that the customer
premise router can successfully communicate over the IXC Switched LAN Internet
Access service. Service billing will commence seven business days after account
creation by PSI. Additional tests will be performed thereafter to verify the
proper operation of the on-site equipment package, the local access facility,
and the PSI Internet infrastructure, including IP routing, DNS, Usenet news, and
other services.

4.11.           Acceptance Criteria

PSI implementation of service for IXC Switched LAN Internet Access service
customers is considered complete when the following criteria have been met:

4.11.1. A dial-in port matching the customer's contract port type and speed is
available to the customer at the local IXC Point-of-Presence (POP).

4.11.2. The customer is able to successfully establish a PPP connection


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<PAGE>   54



4.11.3. The Switched LAN Internet Access router and associated premises
equipment is installed at the customer site, and IP connectivity between the
customer network and the Internet (including routing outside PSI networks)
exists. PSI must verify IP connectivity through a test which:

(a) sends repeated pings through the Internet to the customer site and verifies
that the pings were received.

(b) in cases when the premises equipment configuration supports it, PSI must
verify IP routing through a traceroute test.

*

(d) Any necessary routing changes have been made in PSI's network routers so
that routes to the customers IP networks and addresses are announced to the
Internet.

(e) For customers with their own domain, the domain is registered with the
InterNIC and any PSI-supplied primary and secondary DNS servers are operational
for it.

(f) Any initial customer requested packet-filtering has been installed in the
customer premise Switched LAN Internet Access router.

(g) The customer has been informed that the Internet service is available from
implementation of Internet application such as, Telnet, FTP, E-Mail or WWW, and
has acknowledged that they plan to configure these applications within the
installation phase or that they do not intend to at this time. Billing will
commence upon a successful ping test and not acceptance of working Internet
application.

(h) The customer has been informed of the operational status of the customer's
Internet connection and been provided with documentation of (i) the Internet
service configuration, and (ii) the acceptance test results.

(i) IXC has been informed of the operational status of the customer's Internet
connection and been provided with documentation of (i) the Internet service
configuration, and (ii) the acceptance test results.

(j) The IXC customer has been given an information package designed for new
Switched LAN Internet Access customers.

5.             Service Options

5.1.           Usenet News Service

5.2.           Usenet News

IXC offers NNRP news server access to its Switched LAN Internet Access Service
customers. PSI is responsible for working with the IXC customer to determine
whether the size of the customer's Internet access line is sufficient to meet
the customer's network news requirements. PSI is to provide the IXC customer
with Usenet News access by allowing the IXC customer to directly access PSI's
news server with client software using the NNRP protocol.

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 15 of 34

<PAGE>   55



Please see fee schedule for pricing.

5.2.1.  NNTP News Feed

NNTP news feeds are not available to Switched LAN Internet Access service
customers.

5.2.2.  NNRP News Access

NNRP access is be provided by PSI to IXC's Switched LAN Internet Access service
customers. PSI must provide NNRP access to the IXC Dedicated Access Internet
Service customer for up to 25 newsreader clients. PSI's news servers are to
accept Usenet news postings from the customer's NNRP clients and propagate these
postings on to other Usenet news servers on the Internet

Please see fee schedule for pricing.

5.2            Network Usage Statistics Reporting

PSI is responsible for providing Network Usage Statistics Reporting to IXC
Switched LAN Internet Access service customers. Network Usage Statistics Reports
are to be traffic summary reports that allow customers to track access line
utilization and peak activity periods.

The usage report must be produced on a regular basis (daily, weekly, and
monthly) and is to be provided to the customer and to IXC via email and the Web.

The usage information is to be collected from the customer premises and other
network equipment using SNMP and other measurement tools.

Please see fee schedule for pricing.

5.3.           Emergency Backup Service

In the event of a failure in connectivity between the customer's location and
the PSI Point-of-Presence (POP) due to POP equipment failure ) then the customer
may use a different dialup POP.

6.             Network Operations Support

PSI is responsible for network operations support for network services provided
to IXC Switched LAN Internet Access service as described in this section.

6.1.           PSI Infrastructure Operations Support

PSI must monitor the PSI network 24 hours a day, 365 days a year. PSI is to
provide proactive operations support and troubleshooting of all network and
service infrastructure components providing service to IXC customers, including
IXC-provided circuits (such as circuits from the PSI POP to the customer
premise).

PSI is to use SNMP and other software to monitor the network. This software must
be supplemented with additional tools to monitor non-SNMP equipment, domain name
servers, NNTP news servers and feeds, and other network services.

All network services (routing, DNS, email servers, Usenet news, NTP, security,
etc.) must be monitored for availability and performance. The monitoring
software must report the status of the network to a display which is monitored
throughout the day.


                           Attachments to Schedule 2.2

                                  Page 16 of 34

<PAGE>   56



Service outages are to be automatically detected within * and acted upon using
trouble resolution procedures agreed upon by PSI and IXC.

6.1.1.         Network Reports

PSI is to provide IXC with network status logs on a regular basis to provide IXC
with the ability to evaluate staff responsiveness and network availability. All
changes in the PSI network status must be logged.

PSI is to provide IXC with regular reports on the status of the PSI network.
Report information is to be defined by IXC, and will include but not be limited
to:

*

 Please see example attached.

6.2.           Customer Connectivity Support

PSI must monitor PSI's connectivity to ensure continuous Internet connectivity
is available to the customer network. Outages affecting IXC Switched LAN
Internet Access customer connectivity outages must be detected by PSI and acted
upon by PSI within ** .

PSI staff must follow up on loss of connectivity using documented trouble
resolution procedures as jointly developed by IXC and PSI.

6.3.           Communications Link Maintenance

PSI is responsible for monitoring the backbone and POP equipment. This includes
problem diagnosis and any necessary vendor interaction for dispatch and repair.
PSI's staff is to escalate communications circuit problems using documented
trouble resolution procedures as jointly developed by IXC and PSI.

7.             Technical Services and Customer Support

IXC is to provide first level customer support for all IXC Switched LAN Internet
Access customers.

7.1.            24-Hour Customer Support Helpline

PSI must staff an IXC Customer Support helpline with trained and qualified PSI
customer support representatives from 8am-8pm EST/EDT Monday through Friday.
Customer support staff must be trained in supporting Dedicated Internet Access
service customers. Additionally, an outage support hotline (Netwatch) shall be
staffed 24 hours per day, 7 days per week, 365 days per year for network access
emergency reporting to IXC and its customers.

7.1.1.  Customer Support Helpline Response Time

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

**      Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

                           Attachments to Schedule 2.2

                                  Page 17 of 34

<PAGE>   57



Calls to the PSI-provided IXC customer support hotline must be answered within *
rings., 8am-8pm EST/EDT Monday through Friday. For similar response times
off-hours, optional support may be available (at additional cost).

7.2.           Customer Support Email Mailbox

See section 7.4.

7.3.           Fault Isolation and Problem Resolution

PSI is to perform fault isolation for problems related to the PSI provided
service. Fault isolation may involve coordination among network operators and
technicians, staff at the affected site, telecommunications carriers, and other
vendors. Depending on the specific technologies used, the process may involve
testing equipment, reconfiguring routers, or diagnosing communications link
problems. The PSI operations staff is responsible for diagnosing service
problems and tracking repair progress. PSI is to use documented trouble
resolution procedures as jointly developed and agreed upon by PSI and IXC.

7.4.           Trouble Ticketing System

PSI must use a Trouble Ticketing System to track problems from initial report
through satisfactory resolution. As PSI staff works to resolve problems, the
current status must be maintained in the Trouble Ticketing System.

7.4.1.   IXC Customer Access to Trouble Ticketing System

IXC customers must be provided access by PSI to any trouble tickets related to
their service, as soon as the technology is available to PSI. If additional
programming is required to deliver this functionality, it will be costed out and
provided to IXC in advance. The trouble ticketing system should provide
designated customer contacts with automatic access to the trouble tickets via
web interfaces.

PSI Backbone status information must also be made available to IXC customer
contacts requesting same via the same interfaces.

7.4.2.  IXC Reseller Access to Trouble Ticketing System

IXC resellers must be provided access by PSI to any trouble tickets related to
the service provide to their end customers, as soon as the technology is
available to PSI. If additional programming is required to deliver this
functionality, it will be costed out and provided to IXC in advance.. The
trouble ticketing system should provide designated IXC Reseller contacts with
automatic access to the trouble tickets via web interfaces.

PSI Backbone status information must also be made available to IXC Reseller
contacts requesting same via the same interfaces.

7.4.3.  IXC Access to Trouble Ticketing System

IXC must be provided access by PSI to any trouble tickets related to the service
provide to IXC, IXC Resellers and their end customers, as soon as the technology
is available to PSI. If additional programming is required to deliver this
functionality, it will be costed out and provided to IXC in advance. The trouble
ticketing system should provide designated IXC contacts with automatic access to
the trouble tickets via web interfaces.

PSI Backbone status information must also be made available to IXC Reseller
contacts requesting same via the same interfaces.

                           Attachments to Schedule 2.2

                                  Page 18 of 34

<PAGE>   58



PSI is to work with IXC to integrate trouble ticketing systems and processes as
much as reasonably possible.

7.5.           Problem Notification

7.5.1.  IXC Customer Problem Notification

PSI must inform the technical contact of IXC Switched LAN Internet Access
service customers of any outages affecting their service. The operations staff
must also keep Switched LAN Internet Access customers informed of any widespread
outages on connecting networks.

7.5.2.  IXC Reseller Problem Notification

The PSI operations staff must inform the technical contact of IXC Resellers of
any outages affecting service to their end customers. The operations staff must
also keep IXC Resellers informed of any widespread outages on connecting
networks.

7.5.3.  IXC Problem Notification

The PSI operations staff must inform the IXC technical contacts of any outages
affecting service to IXC, IXC Resellers, or IXC end customers. The operations
staff must also keep IXC informed of any widespread outages on connecting
networks.

7.6.           Software and Configuration Support

PSI is responsible for coordinating software updates and configuration changes
on the customer premise router and CSU/DSU equipment of IXC customers as
required to provide Internet service. Notice of software changes is to be made
to the customer technical contacts, and every effort must be made to perform
maintenance during off-hours.

7.7.           Escalation Procedures

Documented customer support processes are to be developed by PSI. Specific
process documentation is required for the following:

               - customer support procedures
               - trouble escalation procedures
               - trouble ticketing, tracking, and resolution

PSI must provide information to the IXC customer describing customer support,
problem resolution, and trouble escalation procedures, customer contact
information, and trouble reporting methods.

8.              Security Procedures

The following services provide security procedures: RouteWaller (InterFrame),
SecureEnterprise (InterFrame and InterMAN), and PSI IntraNet.

Additionally, PSI's Net Abuse policy shall apply to all IXC customers.


                           Attachments to Schedule 2.2

                                  Page 19 of 34

<PAGE>   59

          MANAGED INTRANET WAN SERVICE SERVICE REQUIREMENTS VERSION 1.1

1.             Overview

PSI's Managed Intranet WAN services provide private IP networking with mediated
Internet access for a single organizations with multiple site. Private internal
IP traffic is logically isolated from the public Internet through integration of
Frame Relay PVCs and managed private routing. Exchange traffic between the
customer's private intranet and the public Internet is mediated through a
centrally specified security policy which is implemented globally at all
intranet sites. External traffic never intermingles with internal traffic. The
service is a fully managed turnkey solution that includes all necessary CPE
required to deliver the service.

The PSI Managed Intranet services include:

o PSI IntraNet

The PSI Managed Intranet service specification is included in Schedule 2.2.

2.             Wholesale Service Branding

PSI is to deliver the Managed Intranet WAN service to IXC and IXC Customers on a
branded basis, such that the service is delivered to the end customer as an IXC
or IXC Reseller branded service. Service branding is to be present in the
following areas:

               -  Sales collateral
               -  Service manuals and other service-related material
               -  All PSI contact with the end customer, such as during order
                  verification, service provisioning, and customer support
               -  Email addresses and web site domain names for customer
                  support, service status, service information
               -  Service usage reports

Where additional investment and resources are required, PSI will state estimated
costs in advance for which IXC or the IXC Reseller is responsible.

3.             Delivery Processes

Documented delivery processes are to be developed by PSI. PSI will work to
integrate internal processes with IXC's service processes, specifically in the
areas of:

               - Sales support
               - Order processing
               - Service provisioning
               - Customer support
               - Network operation procedures and escalation
               - Trouble ticketing and tracking
               - Billing

PSI must create and maintain delivery process documentation specific to the
items listed above.


                           Attachments to Schedule 2.2

                                  Page 20 of 34

<PAGE>   60



4.             Service Implementation

PSI's Managed Intranet WAN Service is to provide to IXC and IXC resellers:

               -  Full service provisioning, through IXC, of all
                  communications circuits and hardware, including ordering,
                  installation, and configuration
               -  Provisioning and maintenance of customer premise equipment
                  - CSU/DSUs and IP routers
               -  Internet service provisioning and configuration ( *
                  where appropriate, DNS, routing, etc) for the
                  customer's network
               -  Registration of customer's domain name
               -  Configuration and management of the Intranet WAN CPE
                  routers
               -  24 x 7 proactive network monitoring, fault isolation, and
                  management
               -  Single point of contact for trouble reporting and problem
                  resolution
               -  Security policy planning and management services for
                  Internet access control

PSI's installation technicians are responsible for remotely assisting the
customer's technical liaison in the physical installation of the customer
premise equipment (CPE).

Service implementation details are described below.

4.1.           Site Planning and Preparation Coordination

Site planning coordination is to be provided by PSI to the customer's designated
point of contact. This helps customers to prepare for installation of the
Intranet WAN service. Customers need to provide space and power for the CPE
equipment, an attachment to the customer's internal network, and at least one
computer with TCP/IP support.

4.2.            Communications Circuit Ordering

PSI is responsible for ordering (from IXC, on behalf of the customer) and
maintaining the communications circuits necessary for delivery of service. IXC
will either provide the circuits itself or order them from another
telecommunications vendor at IXC's expense.

4.2.1          Inside Wiring

PSI will coordinate with the customer on inside wiring. The customer should
arrange for the circuit to terminate in proximity to the planned location of the
premises equipment. Any cost associated with extending the circuit to the
planned location of the premises equipment (inside wiring) is the responsibility
of customer.

4.3.       24 X 7 Proactive Network Monitoring, Fault Isolation, and Management

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 21 of 34

<PAGE>   61



PSI is to provide 24 x 7 monitoring of the Intranet WAN service. Any detected
faults are acted upon immediately, isolated to their cause, and proactively
managed through resolution.

4.4.           Single Point of Contact

PSI is to provide the IXC customer with a single point of contact for trouble
reporting and resolution for any problems related to the Intranet WAN service.
PSI is responsible for interacting with all communications circuit and hardware
equipment vendors as needed to maintain the Intranet WAN.

4.5.           Network Usage Statistics Reporting

PSI is responsible for producing Network Usage Statistics Reports as part of the
Managed Intranet WAN service. Reports are to include a traffic summary that
allows customers to track WAN line utilization and peak activity periods. The
usage report is to be produced on a regular basis (daily, weekly, and monthly)
and is to be provided to the customer via email and/or the Web. The usage
information is to be collected from the customer premises equipment using SNMP
tools, among other methods.

4.6.           Customer Premise Equipment

The customer premises equipment package consists of a TCP/IP router with
appropriate LAN and WAN interfaces, a CSU/DSU corresponding to the connection
type, and associated cables.

PSI provides all necessary CPE required for the Managed Intranet WAN service.

4.6.1.  Customer Premise Equipment Staging and Configuration

PSI is responsible for pre-configuring the CPE before delivery to the customer
sites and remotely configuring the CPE after it is connected to the network. PSI
remotely assists the customer's technical liaison in the installation of the
premises equipment at each Intranet WAN site. The customer's technical liaison
performs the physical installation of the premises equipment. On-site CPE
installation by an PSI field technician or agent is to be made available by PSI
to the IXC Customer on an optional basis.

4.6.2.  CPE Router Management

As a part of the Managed Intranet WAN service, PSI is responsible for managing
the CPE routers at each site on the Intranet WAN on an ongoing basis. Management
is to include:

               -  Router software upgrades
               -  Router access control list changes as requested by IXC or
                  the IXC customer
               -  Router configuration changes as new sites are added to the
                  Intranet WAN
               -  24 x 7 monitoring of the Intranet WAN for inter-site
                  connectivity
               -  24 x 7 monitoring of the Intranet WAN routers for correct
                  operation
               -  24 x 7 monitoring of Intranet WAN line utilization
               -  Generation of usage statistics reports on a daily, weekly,
                  and monthly basis

4.7.           Acceptance Testing


                           Attachments to Schedule 2.2

                                  Page 22 of 34

<PAGE>   62



PSI is to conduct ping test to the customer's site to ensure that the customer
premise router can successfully communicate over the IXC Managed Intranet WAN
service and service billing by PSI to IXC may be initiated. Additional tests
will be performed thereafter to verify the proper operation of the on-site
equipment package, the local access facility, and the PSI infrastructure.

4.8.           Acceptance Criteria

PSI implementation of service for IXC Managed Intranet WAN service customers is
considered complete when the following criteria have been met:

4.8.1 Circuits and PVCs have been installed at each site and configured to give
the customer the amount of bandwidth contracted for between the customer
location and the PSI Point-of-Presence (POP).

4.8.2 The Managed Intranet WAN router and associated premises equipment is
installed at the customer site, and IP connectivity exists between the customer
networks at each site and the Internet (including routing outside PSI networks).
PSI must verify IP connectivity through a test which:

               (i) sends repeated pings through the Internet to the customer
site and verifies that the pings were received.

               (ii) in cases when the premises equipment configuration supports
it, PSI must verify IP routing through a traceroute test.

*

               (iv) Any necessary routing changes have been made in PSI's
network routers so that routes to the customers IP networks and addresses are
announced to the Internet.

               (v) For customers with their own domain, the domain is registered
with the InterNIC and any PSI-supplied primary and secondary DNS servers are
operational for it.

               (vi) Any initial customer requested packet-filtering option has
been installed in the customer premise Managed Intranet WAN router.

               (vii) The customer has been informed that the Internet service is
available from implementation of Internet application such as, Telnet, FTP,
E-Mail or WWW, and has acknowledged that they plan to configure these
applications within the installation phase or that they do not intend to at this
time. Billing will commence upon a successful ping test and not acceptance of
working Internet application.

               (viii) The customer has been informed of the operational status
of the customer's Intranet WAN connection and been provided with documentation
of (i) the Intranet WAN service configuration, and (ii) the acceptance test
results.

               (ix) IXC has been informed of the operational status of the
customer's Intranet WAN connection and been provided with documentation of (i)
the Intranet WAN service configuration, and (ii) the acceptance test results.

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 23 of 34

<PAGE>   63



               (x) The IXC customer has been given an information package
designed for new Managed Intranet WAN customers.

5.             Service Options

There are currently no service options available with the Managed Intranet WAN
service.

6.             Network Operations Support

PSI is responsible for network operations support for network services provided
to IXC Managed Intranet WAN service as described in this section.

6.1.           PSI Infrastructure Operations Support

PSI must monitor the PSI network 24 hours a day, 365 days a year. PSI is to
provide proactive operations support and troubleshooting of all network and
service infrastructure components providing service to IXC customers, including
IXC-provided circuits (such as circuits from the PSI POP to the customer
premise).

PSI will use SNMP and other software tools to monitor the network. This software
must be supplemented with additional tools to monitor non- SNMP equipment,
domain name servers, NNTP news servers and feeds, and other network services.

All network services (routing, DNS, email servers, NTP, security, etc.) must be
monitored for availability and performance. The monitoring software must report
the status of the network to a display which is monitored throughout the day.

Service outages are to be automatically detected. Troubleshooting procedures and
customer notification will occur within * of an outage.

IXC and PSI will work jointly on resolution procedures.

6.1.1.  Network Reports.

PSI is to provide IXC with network status logs on a regular basis to provide IXC
with the ability to evaluate staff responsiveness and network availability. All
changes in the PSI network status must be logged.

PSI is to provide IXC with regular reports on the status of the PSI network.
Report information is to be defined by IXC, and will include but not be limited
to:

*

Please see example attached.

6.2.           Customer Connectivity Support

PSI must monitor IXC Intranet WAN customers' connectivity to ensure continuous
IP connectivity among the Intranet WAN sites. IXC customer's Intranet WAN
connectivity outages must be detected by PSI and acted upon by PSI within * .

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 24 of 34

<PAGE>   64



PSI must follow up on loss of connectivity using documented trouble resolution
procedures as jointly developed by IXC and PSI.

6.3.           Communications Lik Maintenance

PSI is responsible for monitoring and maintaining the communications link
between the customer and PSI. This includes problem diagnosis and any necessary
vendor interaction for dispatch and repair. PSI's staff is to escalate
communications circuit problems using documented trouble resolution procedures
as jointly developed by IXC and PSI.

6.4.           Customer Premises Equipment  Maintenance for Interman

If the customer has contracted for customer premise Internet router and CSU/DSU
maintenance, PSI is responsible for maintaining the customer premise equipment.
PSI must diagnose failures, usually with the assistance of the technical liaison
designated by the customer at the site, and shall determine whether equipment
replacement is required.

6.4.1.  On-site CPE Repair / Replacement for InterMAN

PSI is responsible for performing the actual equipment replacement with
telephone assistance (as necessary).

Response time for performing customer premise equipment replacement must meet
the schedule described within the PSI customer maintenance contract.

7.             Technical Services and Customer Support

IXC is to provide first level customer support for all IXC Managed Intranet WAN
customers.

7.1.           Standard Service Customer Support Helpline

PSI must staff an IXC Customer Support line with trained and qualified PSI
customer support representatives from 8am-8pm EST/EDT Monday through Friday.
Customer support staff must be trained in supporting Managed Intranet WAN
service customers. Additionally, an outage support hotline (Netwatch) shall be
staffed 24 hours per day, 7 days per week, 365 days per year for network access
emergency reporting to IXC and its customers.

7.1.1.  Customer Support Helpline Response Time

Calls to the PSI-provided IXC customer support hotline must be answered within
seven rings., 8am-8pm EST/EDT Monday through Friday. For similar response times
off-hours, optional support may be available (at additional cost).

7.2.           Customer Support Email Mailbox

               See section 7.4

7.3.           Fault Isolation and Problem Resolution

PSI is to perform fault isolation for problems related to the PSI provided
service. Fault isolation may involve coordination among network operators and
technicians, staff at the affected site, telecommunications carriers, and other
vendors. Depending on the specific technologies used, the process may involve
testing equipment, reconfiguring routers, or diagnosing communications link
problems. PSI is responsible for diagnosing service problems and tracking repair
progress. PSI is to use documented trouble resolution procedures as jointly
developed and agreed upon by PSI and IXC.

                           Attachments to Schedule 2.2

                                  Page 25 of 34

<PAGE>   65


7.4.           Trouble Ticketing System

PSI must use a Trouble Ticketing System to track problems from initial report
through satisfactory resolution. As PSI works to resolve problems, the current
status must be maintained in the Trouble Ticketing System.

7.4.1.  IXC Customer Access to Trouble Ticketing System

IXC customers will be provided access by PSI to any trouble tickets related to
their service, as soon as the technology is available to PSI. If additional
programming is required to deliver this functionality, it will be costed out and
provided to IXC in advance. The trouble ticketing system should provide
designated customer contacts with automatic access to the trouble tickets via
web interfaces

PSI Backbone status information should also be made available to customer
contacts requesting same via the same interfaces.

7.4.2.  IXC Reseller Access to Trouble Ticketing System

IXC resellers will be provided access by PSI to any trouble tickets related to
the service, as soon as the technology is available to PSI. If additional
programming is required to deliver this functionality, it will be costed out and
provided to IXC in advance. The trouble ticketing system should provide
designated IXC Reseller contacts with automatic access to the trouble tickets
via web interfaces.

PSI Backbone status information should also be made available to IXC Reseller
contacts requesting same via the same interfaces.

7.4.3.  IXC Access to Trouble Ticketing System

IXC will be provided access by PSI to any trouble tickets related to the service
provided to IXC, IXC Resellers and their end customers, as soon as the
technology is available to PSI. If additional programming is required to deliver
this functionality, it will be costed out and provided to IXC in advance. The
trouble ticketing system should provide designated IXC contacts with automatic
access to the trouble tickets via web interfaces

PSI Backbone status information should also be made available to IXC Reseller
contacts requesting same via the same interfaces

PSI is to work with IXC to integrate trouble ticketing systems and processes as
much as reasonably possible

7.5.           Problem Notification.

                          7.5.1.    IXC Customer Problem Notification. PSI must
inform the technical contact of IXC Managed Intranet WAN service customers of
any outages affecting their service. The operations staff must also keep Managed
Intranet WAN customers informed of any widespread outages on connecting networks

                          7.5.2.    IXC Reseller Problem Notification. PSI must
inform the technical contact of IXC Resellers of any outages affecting service
to their end customers. The operations staff must also keep IXC Resellers
informed of any widespread outages on connecting networks

                          7.5.3.    IXC Problem Notification. PSI must inform
the IXC technical contacts of any outages affecting service to IXC, IXC
Resellers, or IXC end customers. The operations staff must also keep IXC
informed of any widespread outages on connecting networks


                           Attachments to Schedule 2.2

                                  Page 26 of 34

<PAGE>   66


7.6. Software and Configuration Support for InterMAN. PSI is responsible for
coordinating software updates and configuration changes on the customer premise
router and CSU/DSU equipment of IXC customers as required to provide Internet
service. Notice of software changes is to be made to the customer technical
contacts, and every effort must be made to perform maintenance during off-hours

7.7 Escalation Procedures. Documented customer support processes are to be
developed jointly by PSI and IXC. Specific process documentation is required for
the following:

               -  customer support procedures

               -  trouble escalation procedures

               -  trouble ticketing, tracking, and resolution

PSI must provide information to the IXC customer describing customer support,
problem resolution, and trouble escalation procedures, customer contact
information, and trouble reporting methods.

8.             Security Procedures

PSI's security procedures include a default Interim Security Policy for new
intranet sites, security policy planning before the sites are integrated into an
intranet, verification of identity of the customer technical contact before
requests for changes are accepted, and sign-off by the customer technical
contact of implementation plans before changes are implemented

Additionally, PSI's Net Abuse policy shall apply to all IXC customers.


                           Attachments to Schedule 2.2

                                  Page 27 of 34

<PAGE>   67


               INTERNET REMOTE ACCESS SERVICE SERVICE REQUIREMENTS VERSION 1.1

1.             Overview

The PSI Internet Remote Access service provides on-demand switched connectivity
to the Internet for corporate user groups of telecommuters and mobile workers
via analog modems (9.6 - 33.6 Kbps) or ISDN NT1s (64 - 128 Kbps), and
centralized account management by the customer technical administrator through a
web-based Account Management System. Connectivity is provided for client access
for single systems. Connections are established between the users and a PSI
Point-of-Presence (POP) using the Point-to-Point Protocol (PPP).

The PSI Internet Remote Access services include:

               -          InterRamp Remote Access for Business

The PSI Remote Access service specification is included in Schedule 2.3.

Additional service requirements to be decided.


                           Attachments to Schedule 2.2

                                  Page 28 of 34

<PAGE>   68


       MANAGED INTERNET SECURITY SERVICES SERVICE REQUIREMENTS VERSION 1.1


1.             OVERVIEW

PSI's Managed Internet Security services provide security policy planning and
implementation for Internet access control and remote user authentication
services. Security services are provided to the customer as a value-added option
to a PSI Dedicated Internet Access service, and include all necessary CPE
required to deliver the service.

The PSI Managed Internet Security services include:

               - RouteWaller (for InterFrame)

               - SecureEnterprise (for InterFrame and InterMAN)

The PSI Managed Internet Security service specifications are included in
Schedule 2.3.

Additional service requirements to be decided.


                           Attachments to Schedule 2.2

                                  Page 29 of 34

<PAGE>   69


                    INTERNET FAX SERVICE SERVICE REQUIREMENTS VERSION 1.1


1.             OVERVIEW

PSI's Internet Fax service provides global hardcopy delivery of documents
through the Internet to any fax machine in the world. Traffic is routed from the
fax client on the customer user desktop to a server where the best price can be
attained for the final dial-out connection.

The PSI Internet Fax services include:

               - PSInet InternetPaper

The PSI Internet Fax service specification is included in Schedule 2.3.

Additional service requirements to be decided.


                           Attachments to Schedule 2.2

                                  Page 30 of 34

<PAGE>   70


       WHOLESALE DIAL-UP INTERNET ACCESS SERVICE REQUIREMENTS VERSION 1.0



1.             OVERVIEW

PSI's Wholesale Dial-up Internet Access services provide, on a wholesale basis,
on-demand switched connectivity to the Internet via an analog modem (9.6 - 33.6
Kbps) or an ISDN NT1 (64 - 128 Kbps). The PSI Wholesale Dial-up Internet Access
services include:

               - PSINet Consumer Wholesale

The PSInet Consumer Wholesale service descriptions are included in Schedule 2.3.

2.             WHOLESALE SERVICE BRANDING

PSI is to deliver the Dial-up Internet Access service on a branded basis, such
that the service is delivered to the end customer as an IXC / IXC reseller
branded service. Service branding is to be present in the following areas:

               -  Sales collateral
               -  End user software diskettes
               -  User manuals and other service-related material.
               -  All PSI contact with the end customer, such as during order
                  verification, service provisioning, and customer support
               -  Email addresses and web site domain names for customer
                  support, service status, service information.
               -  Domain names used for end user account, as reflected in
                  user email addresses and user web page location
                  identifiers.
               -  Service usage reports

PSI will provide service branding pricing under separate cover.

3.             DELIVERY PROCESSES

Documented delivery processes are to be developed by PSI and are subject to
approval by IXC. PSI will work to integrate internal processes with IXC's
service processes, specifically in the areas of:

               -  order processing
               -  service provisioning
               -  customer support
               -  network operation procedures and escalation
               -  trouble ticketing and tracking
               -  billing

PSI must create and maintain delivery process documentation specific to the
items listed above.

PSI has created the processes above and have incorporated them into the Consumer
Wholesale Users Guide, previously supplied to IXC.

4.             SERVICE IMPLEMENTATION

PSI is to provide IXC with a dial-up Internet access product. RADIUS
authentication shall be performed by PSI. PSI provides modem ports, traffic
propagation, authentication and second level support. Customer support, software
fulfillment and billing may be outsourced.

                           Attachments to Schedule 2.2

                                  Page 31 of 34

<PAGE>   71


Implementation details are described below.

4.1.           Dial-Up Pop Infrastructure

PSI is responsible for installing and maintaining the network infrastructure for
providing analog and ISDN dial-up Internet access at multiple dial-up
Points-of-Presence (dial-up POPs) across the U.S. as well as 800 number Internet
access.

4.1.1.  Port Availability

PSI is responsible for maintaining an adequate number of modem and ISDN ports
for the dial-up service at each dial-up POP, based on the ratio of user accounts
to modem ports (user:modem ratio). User:Port ratios are to be maintained at no
more than approximately * at each PSI dial- up POP. PSI is to monitor the
user:port ratios of user accounts to available modem ports at each dial-up POP.
PSI will use best efforts to ensure the network is maintained at a level which
meet reasonable commercial standards and shall maintain its network in good
condition and repair. User:Port ratios are to be calculated for each separate
dial-up POP, with analog and ISDN ratios calculated separately.

PSI will provide IXC with real-time, 24hr/day access to its POPs for IXC's
analysis and debugging.

4.2.           Radius Authentication

PSI is to install and maintain distributed RADIUS authentication servers to be
used for verifying user authentication. PSI's distributed RADIUS servers must be
configured to communicate with a central RADIUS server that contains the IXC
customer's authorized user database.

4.3.           Optional End User Software

PSI is to provide, for a fee, IXC or IXC Reseller branded, pre-configured
Internet access software on appropriate media (3.5" floppy or CD- ROM), and
appropriate operating system (Windows 3.1, Win 95, NT, MacOS).

4.3.1.  Internet Connectivity Software Suite

The end user dial-up access software is to include:

               - An IP connectivity software suite of
               - Dial-up communications
               - TCP/IP stack
               - PPP software
               - Netscape or Internet Explorer web browser
               - E-mail reader
               - News reader
               - Service Initiation Screens

- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                           Attachments to Schedule 2.2

                                  Page 32 of 34

<PAGE>   72



4.3.2.  Software Customizing and Branding

The Internet access software media is to be available as private-label, branded
software. Branding is to include the following:

               -  Custom diskette packaging that reflects the IXC Customer
                  dial-up service brand
               -  Customized Service Initiation and Welcome screen
               -  Custom screen logo
               -  Custom initial default home page for the web browser
                  included with the software.
               -  Custom user manuals that reflects the IXC Customer
                  dial-up service brand.

4.3.3.  Software Fulfillment

PSI is to arrange for the Internet access software to be delivered to the end
user upon receiving an account activation order for a new customer of the IXC
Reseller. The software shipment can be contracted by PSI to a fulfillment house
company that specializes in software diskette distribution. PSI is responsible
for the end user receiving the software no more than ten days following the
account activation order being received by PSI. PSI will provide a fee schedule
to IXC based on IXC sales projections given to the fulfillment house by PSI.

4.4.           Optional End User Help Desk

First tier end user help desk support is to be coordinated by PSI, or an agreed
upon subcontractor, for a fee. Help desk support is to include

               - help regarding the installation and use of supported
                 desktop connectivity software, including web browser and
                 email
               - trouble reporting regarding use of the wholesale dial-up
                 service
               - general use of the dial-up service

Dial-up customer support is provided on a branded basis, with PSI customer
support representatives answering the phone in the name of the IXC Reseller.
Fees for this service are directly proportional with the amount of users the IXC
Reseller has using the network and are priced out separately for each
participating IXC Reseller. Call answering is to be customized in accordance
with the IXC Reseller's policies and procedures and may add additional cost to
each IXC Reseller.

4.5.           Optional Email Services

End user email services are to be offered by PSI, or its subcontractor, for an
added fee. Wholesale dial-up user mailboxes are to be hosted by PSI on a
managed, industry standard SMTP/POP3 e-mail server. Each user is to be provided
with their own email address and storage for up to 5 MB or 35 days of unread
mail, whichever is less. The mailserver is to be configured using a domain name
specific to the IXC Customer's branded dial-up service, which is the domain name
that is to appear in the end-users' email addresses.

PSI, or its subcontractor, is to host and manage the mail service with the same
robustness and operational care as is considered best practice within the
industry. PSI, or its subcontractor, is responsible for providing to IXC and the
IXC Reseller Web-based email administration tools for managing the email
service.



                           Attachments to Schedule 2.2

                                  Page 33 of 34

<PAGE>   73


4.6            Optional Usenet News Services

End user Usenet News services are offered by PSI to IXC Wholesale Dial-up
customers. An additional fee may apply.

4.7            Account Usage Call Records

PSI, or its subcontractor, is responsible for reporting detailed account call
record information to the IXC on a regular basis (daily, weekly, monthly).
Separate call record information must be provided to IXC for each IXC reseller
customer, as well as total aggregate call record information. Call records are
to be provided via electronic files as well as via a secure Web server
accessible to the IXC. PSI will provide a fee schedule based on these criteria.


                           Attachments to Schedule 2.2

                                  Page 34 of 34

<PAGE>   74

                                  SCHEDULE 2.3

                                  DOCUMENTATION



1.      Service Descriptions - As per the Attachments to Schedule 2.2

2.      Standard Contract - PSI Standard Customer Agreement and all Addenda

3.      *

        Other Marketing Materials/Collateral


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                                  Schedule 2.3

                                   Page 1 of 1

<PAGE>   75


                                  SCHEDULE 3.1

                                  SALES SUPPORT


3.1     PSI will produce * for IXC. A program outline shall be provided by
        August 1, 1997 and the initial drafts of the program shall be provided
        by PSI to IXC no later than August 15, 1997. The program package will
        include * provided by PSI to IXC within 48 hours of the execution date.

3.2     PSI will * for IXC by no later than January 1, 1998. * shall be agreed
        upon by IXC and PSI. IXC will pay * for PSI employees related to the * .
        PSI will pay all expenses associated with *. IXC will bear the costs of
        *.

3.3      * by PSI sufficiently to meet the needs of IXC.  *.

3.4     PSI will establish * email list by August 15, 1997 to help *. This is a
        general * will be monitored by experienced *.

3.5     PSI will create or cause to be created * by no later than the end of
        3Q97. * other appropriate information which will enhance and supplement
        * .

3.6     At additional cost where noted, PSI will do each of the following:

        (a)     PSI will provide additional * at prices to be agreed by IXC,
                with IXC responsible for reasonable * of PSI personnel * .

        (b)     PSI will provide IXC * basis at no charge.

        (c)     To the extent permitted by applicable law, PSI will provide IXC
                with * basis at no charge.

        (d)     PSI will entertain * at IXC's request.




- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.


                                  Schedule 3.1

                                   Page 1 of 1

<PAGE>   76


                                 SCHEDULE 5.4.1

                     PROVISION GOVERNING IXC USE OF SERVICES

The following provisions shall apply to IXC's use of Services in IXC's capacity
as an end user of Services for its own account (provided that such provisions
shall be modified automatically to the extent PSI waives such provisions, or
imposes less restrictive provisions, on its customers under its standard terms
and conditions and normal business practices (including where exceptions are
routinely granted to customers), or for any other reseller or distributor of
services of the type comprising the Services):

(A)     IXC shall be solely responsible for the content of any transmissions
        over the Internet by IXC and any person or Third Party utilizing IXC's
        facilities with IXC's consent. IXC agrees that it and any such person or
        Third Party utilizing IXC's facilities shall not knowingly disrupt other
        network users, network services or network equipment. Disruptions
        include, but are not limited to, distribution of unsolicited advertising
        or chain letters, propagation of computer worms and viruses, and using
        the network to make unauthorized entry to any other machine accessible
        via the network.

(B)     Except as expressly set forth in or contemplated by the Joint Marketing
        and Services Agreement to which this Schedule is attached (the
        "Marketing Agreement"), PSI DISCLAIMS ALL EXPRESS AND IMPLIED
        WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
        PARTICULAR PURPOSE. PSI shall not be liable for any damages that IXC may
        suffer arising out of use, or inability to use, the Services or products
        provided hereunder unless such damage is caused by a negligent, reckless
        or intentional act of PSI. PSI shall not be liable for unauthorized
        access by Third Parties to IXC's transmission facilities or premise
        equipment or for unauthorized access to or alteration, theft, loss or
        destruction of IXC's data files, programs, procedures or information
        through accident, fraudulent means or devices or any other method
        provided that the foregoing shall not relieve PSI from responsibility
        for any of the foregoing to the extent it results from PSI's actions (or
        inactions) while responsible for security and system administration
        within the IXC network. Except as expressly set forth in or contemplated
        by the Marketing Agreement, in any instance involving performance or
        nonperformance by PSI with respect to Services or products provided
        hereunder, (a) the price paid for Services which were not provided, or
        (b) in the case of products, the products shall be repaired or replaced
        by the manufacturer, subject to applicable warranty. Except as expressly
        set forth in or contemplated by the Marketing Agreement, in the case of
        refund for lost Services, credit will be issued only for periods of lost
        Service greater than twenty-four (24) hours.

(C)     IXC agrees to comply with U.S. law with regard to the transmission of
        technical data which is exported from the United States using the
        Services.

(D)     The following additional provisions shall apply to the following types
        of Services (as indicated): Dedicated Internet Access Service (PSINet
        InterFrame), Dedicated Internet Access Service (PSINet InterMAN),
        Switched LAN Internet Access Service, Managed Intranet WAN Service,
        Internet Remote Access Service, Managed Internet Security Services,
        PSINet InternetPaper Service and PSINet Consumer Wholesale Service:

                                 Schedule 5.4.1

                                  Page 1 of 26

<PAGE>   77



         DEDICATED INTERNET ACCESS SERVICE CUSTOMER CONTRACT PROVISIONS

                                PSINET INTERFRAME

PSINET NETWORK USAGE.

        A. COMPLIANCE WITH LAW AND POLICY. Customer has read and agrees to
        comply with PSINet's Net-Abuse Policy ("Policy") as currently set forth
        on PSINet's Web site (http://www.psi.net) and as the Policy may be
        modified by PSINet in its sole discretion from time to time. Any
        content, material, message or data made available or transmitted through
        the Service, wherever it is sent from, viewed, received, or retrieved,
        that is in violation of (i) any local, state, federal or international
        law, regulation or treaty; (ii) the Policy; or (iii) any community
        standard or accepted Internet policy is prohibited. Any such violation
        may be deemed a material breach of this Agreement and PSINet may, in its
        sole discretion, disable or terminate the Service with written notice to
        Customer, but without any cure period.

        B. CUSTOMER-ONLY TRAFFIC. The right to use the Service is strictly
        limited to Customer only and does not extend to any other person,
        corporation or entity except for wholly-owned affiliates of Customer and
        those members of Customer's staff and consultants in the course of
        performing work for Customer.

        C. THIRD-PARTY TRAFFIC. Customer may host world-wide web sites on behalf
        of third parties. In addition, Customer may feed USENET News to a third
        party, but may not send any posting from that third party, including,
        but not limited to, electronic mail, back to PSINet's wide-area network
        system (the "Network") or the Internet through the Service. Any other
        third party traffic, including packet access and electronic mail,
        whether sent or received through Customer's facilities by or on behalf
        of a third party through the Service, is expressly prohibited.

CUSTOMER NETWORK SECURITY. PSINet provides no user access security with respect
to any of Customer's facilities or facilities of others. Customer shall be
responsible for user/access security as well as access to its network or to the
Network. PSINet will assist in network security breach detection or
identification, but shall not be liable for any inability, failure or mistake in
doing so.

SERVICE ASSURANCE. If Customer notifies PSINet immediately upon its failure to
access the Network through Customer's standard means or the backup mechanisms
provided with the Service, and PSINet determines in its reasonable commercial
judgment that the Network is therefore unavailable to Customer ("Unavailable"),
one of the following will apply:

        1. If PSINet determines that the Network is Unavailable for one (1) or
        more consecutive hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) day's Service fee; or

        2. If PSINet determines that the Network is Unavailable for an aggregate
        of four (4) or more hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) week's Service fee.

These two options are not cumulative. For purposes of this section, scheduled
maintenance will not be considered to be Unavailability. PSINet shall not be
responsible for any toll charges incurred by Customer's use of any telephone
company ("Telco") or other telecommunications services as a result of this


                                 Schedule 5.4.1

                                  Page 2 of 26



<PAGE>   78



section. THE FOREGOING TWO OPTIONS STATE PSINET'S SOLE OBLIGATION, AND
CUSTOMER'S SOLE REMEDY, FOR NETWORK UNAVAILABILITY.

SPECIAL TERMS FOR THE "ON-SITE SERVICE" OPTION.

        "ON-SITE SERVICE" OPTION SPECIFICS.

        (1) EQUIPMENT ACCESS AND CONNECTION. The Equipment shall be installed
        and maintained by PSINet or its subcontractors as PSINet shall designate
        in writing. Customer shall provide 24 hour per day, 7 days per week
        access to the Equipment (with appropriate escort if required by
        Customer) by PSINet-designated individuals. If Customer cannot provide
        this access, any Service Assurance remedy provided above is suspended
        during such time. Customer shall not allow its personnel or others on
        its premises to tamper with the Equipment. PSINet will verbally
        authorize on an event-by-event basis individuals at Customer's location
        to open Equipment cabinets for appropriate routine and emergency
        reasons. Customer shall retain the right to disconnect the Equipment
        from its LAN at any time. PSINet reserves the right to shut down the
        Equipment at Customer's location in accordance with PSINet's emergency
        operating procedures with notification to Customer. Relocation of the
        Equipment may only be performed by PSINet or its subcontractors at
        Customer's expense. PSINet is not responsible for Service disruptions
        caused by Customer's Equipment relocation requirements.

        (2) SECURITY FILTERING SUB-OPTION. If initialed on Customer's Order
        Form, PSINet shall provide the Security Filtering Sub-Option along with
        the On-Site Service Option. PSINet shall provide packet filtering based
        on network number and protocol for non-Customer networks, and on an
        individual host basis for Customer host computers.

               (a) Customer will delegate two security contacts, a primary and a
               secondary. Contact names, phone numbers, fax numbers, and
               electronic mail addresses must be provided to PSINet on the Order
               Form. PSINet will take direction ONLY from these contacts.

               (b) Customer security contacts must participate in an initial
               phone consultation with PSINet's Security Coordinator.

               (c) Customer requests must be made by electronic mail or fax to
               the designated PSINet address to facilitate an audit trail.

               (d) PSINet Network Operations can be instructed by other Customer
               contacts to disable non-PSINet access (for instance, MAE-East and
               CIX access).

LIMITED WARRANTIES.

        A. SERVICE. PSINET WARRANTS THAT THE SERVICE WILL OPERATE SUBSTANTIALLY
        IN CONFORMANCE WITH THE SPECIFICATIONS. PSINET MAKES NO OTHER WARRANTIES
        OF ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, INCLUDING, BUT NOT
        LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS OF THE
        SERVICE FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY
        RIGHTS. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND
        TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM.
        USE OF ANY INFORMATION OBTAINED THROUGH THE SERVICE IS AT CUSTOMER'S
        RISK. PSINET SPECIFICALLY DENIES ANY RESPONSIBILITY FOR THE ACCURACY OR
        QUALITY OF INFORMATION OBTAINED THROUGH THE SERVICE.

        B. EQUIPMENT. PSINET REPRESENTS AND WARRANTS THAT DURING THE TERM OF
        THIS AGREEMENT IT WILL MAKE REASONABLE EFFORTS TO ENSURE THE EQUIPMENT
        OPERATES 


                                 Schedule 5.4.1

                                  Page 3 of 26


<PAGE>   79



        SUBSTANTIALLY IN CONFORMANCE WITH THE SPECIFICATIONS. ANY UNAUTHORIZED
        CHANGES TO OR INAPPROPRIATE USAGE OF THE EQUIPMENT, HOWEVER, WILL VOID
        THE FOREGOING WARRANTY. PSINET DOES NOT WARRANT THAT THE EQUIPMENT WILL
        BE ENTIRELY FREE FROM DEFECTS OR THAT ITS OPERATION WILL BE ERROR FREE.
        FURTHERMORE, CUSTOMER ACKNOWLEDGES THAT PSINET HAS MADE NO OTHER
        REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH RESPECT
        TO THE CONDITION OR PERFORMANCE OF THE EQUIPMENT, OR ITS MERCHANTABILITY
        OR FITNESS FOR A PARTICULAR PURPOSE. C. GENERAL. EACH PARTY ACKNOWLEDGES
        THAT IT HAS READ AND UNDERSTANDS THIS AGREEMENT AND AGREES TO BE BOUND
        BY ITS TERMS. EACH PARTY FURTHER WARRANTS THAT IT HAS FULL CORPORATE
        POWER AND AUTHORITY TO ENTER INTO AND DELIVER THIS AGREEMENT AND TO
        PERFORM ITS OBLIGATIONS HEREUNDER, AND THAT THE PERSON WHOSE SIGNATURE
        APPEARS BELOW IS DULY AUTHORIZED TO ENTER INTO THIS AGREEMENT ON BEHALF
        OF THAT PARTY.

LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS HEREUNDER,
NEITHER PARTY SHALL BE LIABLE FOR DIRECT DAMAGES GREATER THAN THE SUM TOTAL OF
PAYMENTS MADE BY CUSTOMER TO PSINET DURING THE SIX (6) MONTHS IMMEDIATELY
PRECEDING THE EVENT FOR WHICH DAMAGES ARE CLAIMED. EXCEPT FOR THE FOREGOING,
PSINET SHALL HAVE NO LIABILITY TO CUSTOMER WITH RESPECT TO (I) ANY CLAIM, LOSS
OR DAMAGE OF ANY KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR PASSIVE
NEGLIGENCE OR STRICT LIABILITY OF PSINET FOR CLAIMS ARISING OUT OF OR IN
CONNECTION WITH THE SERVICE OR THE EQUIPMENT, WHETHER OR NOT KNOWN OR DISCLOSED
TO PSINET; (II) ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, PUNITIVE OR
CONSEQUENTIAL LOSSES OR DAMAGES RESULTING FROM THE DELIVERY, INSTALLATION,
MAINTENANCE, OPERATION OR USE OF THE SERVICE OR THE EQUIPMENT; (III) ANY ACT OR
OMISSION OF ANY OTHER ENTITY FURNISHING EQUIPMENT, PRODUCTS OR SERVICES TO
CUSTOMER; (IV) ANY PERSONAL OR PROPERTY DAMAGES DUE TO THE LOSS OF STORED,
TRANSMITTED OR RECORDED DATA RESULTING FROM THE SERVICE OR THE EQUIPMENT, EVEN
IF PSINET HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES; AND (V) ANY LOSS
OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF CUSTOMER OR ITS EMPLOYEES, AGENTS
OR REPRESENTATIVES.

IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS AGREEMENT EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
SERVICE COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR OTHER SIMILAR TERMS
WITHOUT A SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO ASSUME A GREATER DEGREE
OF LIABILITY TO CUSTOMER.



                                 Schedule 5.4.1

                                  Page 4 of 26


<PAGE>   80

                        DEDICATED INTERNET ACCESS SERVICE
                          CUSTOMER CONTRACT PROVISIONS


                                 PSINET INTERMAN


PSINET NETWORK USAGE.

        A. COMPLIANCE WITH LAW AND POLICY. Customer has read and agrees to
        comply with PSINet's Net-Abuse Policy ("Policy") as currently set forth
        on PSINet's Web site (http://www.psi.net) and as the Policy may be
        modified by PSINet in its sole discretion from time to time. Any
        content, material, message or data made available or transmitted through
        the Service, wherever it is sent from, viewed, received, or retrieved,
        that is in violation of (i) any local, state, federal or international
        law, regulation or treaty; (ii) the Policy; or (iii) any community
        standard or accepted Internet policy is prohibited. Any such violation
        may be deemed a material breach of this Agreement and PSINet may, in its
        sole discretion, disable or terminate the Service with written notice to
        Customer, but without any cure period.

        B. CUSTOMER-ONLY TRAFFIC. The right to use the Service is strictly
        limited to Customer only and does not extend to any other person,
        corporation or entity except for wholly-owned affiliates of Customer and
        those members of Customer's staff and consultants in the course of
        performing work for Customer.

        C. THIRD-PARTY TRAFFIC. Customer may host world-wide web sites on behalf
        of third parties. In addition, Customer may feed USENET News to a third
        party, but may not send any posting from that third party, including,
        but not limited to, electronic mail, back to PSINet's wide-area network
        system (the "Network") or the Internet through the Service. Any other
        third party traffic, including packet access and electronic mail,
        whether sent or received through Customer's facilities by or on behalf
        of a third party through the Service, is expressly prohibited.

CUSTOMER NETWORK SECURITY. PSINet provides no user access security with respect
to any of Customer's facilities or facilities of others. Customer shall be
responsible for user/access security as well as access to its network or to the
Network. PSINet will assist in network security breach detection or
identification, but shall not be liable for any inability, failure or mistake in
doing so.

        PSINET-PROVIDED EQUIPMENT.

        (1) EQUIPMENT SPACE. Customer shall provide and maintain suitable
        Equipment Space meeting or exceeding the requirements set forth in the
        Specifications.

        (2) EQUIPMENT. The Equipment Space will house Equipment owned by PSINet
        required for the Service. PSINet shall retain all right, title, and
        interest in the Equipment at all times. PSINet will provide Equipment in
        order to facilitate the connection between Customer's network and the
        Telco circuit leading to the Network. The particular make and model of
        Equipment shall be selected for Customer by PSINet in its sole
        discretion. If PSINet determines in its sole reasonable judgment that
        the Equipment is defective, PSINet shall replace the defective Equipment
        at no cost to Customer. THE FOREGOING STATES PSINET'S SOLE OBLIGATION,
        AND CUSTOMER'S SOLE REMEDY, FOR ANY DEFECTIVE EQUIPMENT.


                                 Schedule 5.4.1

                                  Page 5 of 26


<PAGE>   81



        (3) EQUIPMENT ACCESS AND CONNECTION. The Equipment shall be installed
        and maintained by PSINet, or its subcontractors as PSINet shall
        designate in writing. Customer shall provide 24 hour per day, 7 days per
        week access to the Equipment (with appropriate escort if required by
        Customer) by PSINet-designated individuals. If Customer cannot provide
        this access, any Service Assurance remedy provided below is suspended
        during such time. Customer shall not allow its personnel or others on
        its premises to open the Equipment cabinets. PSINet will verbally
        authorize on an event-by-event basis individuals at Customer's location
        to open Equipment cabinets for appropriate routine and emergency
        reasons. Customer shall retain the right to disconnect the Equipment
        from its LAN at any time. PSINet reserves the right to shut down the
        Equipment at Customer's location in accordance with PSINet's emergency
        operating procedures with notification to Customer.

        (4) EQUIPMENT RELOCATION. Relocation of the Equipment may only be
        performed by PSINet or its subcontractors at Customer's expense. PSINet
        is not responsible for Service disruptions caused by Customer's
        Equipment relocation requirements.

        (5) EQUIPMENT RETURN. Upon termination of the Service for any reason,
        Customer agrees immediately to allow the return of the Equipment to
        PSINet. PSINet retains all rights to recover possession of the Equipment
        from Customer.

SECURITY FILTERING OPTION. If initialed on Customer's Order Form, PSINet shall
provide the Security Filtering Option. PSINet shall provide packet filtering
based on network number and protocol for non-Customer networks, and on an
individual host basis for Customer host computers.

        (1) Customer will delegate two security contacts, a primary and a
        secondary. Contact names, phone numbers, fax numbers, and electronic
        mail addresses must be provided to PSINet on the Order Form. PSINet will
        take direction ONLY from these contacts.

        (2) Customer security contact points must participate in an initial
        phone consultation with PSINet's Security Coordinator.

        (3) Customer requests must be made by electronic mail or fax to the
        designated PSINet address to facilitate an audit trail. (4) PSINet
        Network Operations can be instructed by other Customer contacts to
        disable non-PSINet access (for instance, MAE-East and CIX access).

SERVICE ASSURANCE. If Customer notifies PSINet immediately upon its failure to
access the Network through Customer's standard means or the backup mechanisms
provided with the Service, and PSINet determines in its reasonable commercial
judgment that the Network is therefore unavailable to Customer ("Unavailable"),
one of the following will apply:

        1. If PSINet determines that the Network is Unavailable for one (1) or
        more consecutive hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) day's Service fee; or

        2. If PSINet determines that the Network is Unavailable for an aggregate
        of four (4) or more hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) week's Service fee.

These two options are not cumulative. For purposes of this section, scheduled
maintenance will not be considered to be Unavailability. PSINet shall not be


                                 Schedule 5.4.1

                                  Page 6 of 26


<PAGE>   82



responsible for any toll charges incurred by Customer's use of any telephone
company ("Telco") or other telecommunications services as a result of this
section. THE FOREGOING TWO OPTIONS STATE PSINET'S SOLE OBLIGATION, AND
CUSTOMER'S SOLE REMEDY, FOR NETWORK UNAVAILABILITY.

LIMITED WARRANTIES.

        A. SERVICE. PSINET WARRANTS THAT THE SERVICE WILL OPERATE SUBSTANTIALLY
        IN CONFORMANCE WITH THE SPECIFICATIONS. PSINET MAKES NO OTHER WARRANTIES
        OF ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, INCLUDING, BUT NOT
        LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS OF THE
        SERVICE FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY
        RIGHTS. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND
        TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM.
        USE OF ANY INFORMATION OBTAINED THROUGH THE SERVICE IS AT CUSTOMER'S
        RISK. PSINET SPECIFICALLY DENIES ANY RESPONSIBILITY FOR THE ACCURACY OR
        QUALITY OF INFORMATION OBTAINED THROUGH THE SERVICE.

        B. EQUIPMENT. PSINET REPRESENTS AND WARRANTS THAT DURING THE TERM OF
        THIS AGREEMENT IT WILL MAKE REASONABLE EFFORTS TO ENSURE THE EQUIPMENT
        OPERATES SUBSTANTIALLY IN CONFORMANCE WITH THE SPECIFICATIONS. ANY
        UNAUTHORIZED CHANGES TO OR INAPPROPRIATE USAGE OF THE EQUIPMENT,
        HOWEVER, WILL VOID THE FOREGOING WARRANTY. PSINET DOES NOT WARRANT THAT
        THE EQUIPMENT WILL BE ENTIRELY FREE FROM DEFECTS OR THAT ITS OPERATION
        WILL BE ERROR FREE. FURTHERMORE, CUSTOMER ACKNOWLEDGES THAT PSINET HAS
        MADE NO OTHER REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR
        IMPLIED, WITH RESPECT TO THE CONDITION OR PERFORMANCE OF THE EQUIPMENT,
        OR ITS MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

        C. GENERAL. EACH PARTY ACKNOWLEDGES THAT IT HAS READ AND UNDERSTANDS
        THIS AGREEMENT AND AGREES TO BE BOUND BY ITS TERMS. EACH PARTY FURTHER
        WARRANTS THAT IT HAS FULL CORPORATE POWER AND AUTHORITY TO ENTER INTO
        AND DELIVER THIS AGREEMENT AND TO PERFORM ITS OBLIGATIONS HEREUNDER, AND
        THAT THE PERSON WHOSE SIGNATURE APPEARS BELOW IS DULY AUTHORIZED TO
        ENTER INTO THIS AGREEMENT ON BEHALF OF THAT PARTY.

LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS HEREUNDER,
NEITHER PARTY SHALL BE LIABLE FOR DIRECT DAMAGES GREATER THAN THE SUM TOTAL OF
PAYMENTS MADE BY CUSTOMER TO PSINET DURING THE SIX (6) MONTHS IMMEDIATELY
PRECEDING THE EVENT FOR WHICH DAMAGES ARE CLAIMED. EXCEPT FOR THE FOREGOING,
PSINET SHALL HAVE NO LIABILITY TO CUSTOMER WITH RESPECT TO (I) ANY CLAIM, LOSS
OR DAMAGE OF ANY KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR PASSIVE
NEGLIGENCE OR STRICT LIABILITY OF PSINET FOR CLAIMS ARISING OUT OF OR IN
CONNECTION WITH THE SERVICE OR THE EQUIPMENT, WHETHER OR NOT KNOWN OR DISCLOSED
TO PSINET; II) ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, PUNITIVE OR
CONSEQUENTIAL LOSSES OR DAMAGES RESULTING FROM THE DELIVERY, INSTALLATION,
MAINTENANCE, OPERATION OR USE OF THE SERVICE OR THE EQUIPMENT; (III) ANY ACT OR
OMISSION OF ANY OTHER ENTITY FURNISHING EQUIPMENT, PRODUCTS OR SERVICES TO
CUSTOMER; (IV) ANY PERSONAL OR PROPERTY DAMAGES DUE TO THE LOSS OF STORED,
TRANSMITTED OR RECORDED DATA RESULTING FROM THE SERVICE OR THE EQUIPMENT, EVEN
IF PSINET HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES; AND (V) ANY LOSS
OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF CUSTOMER OR ITS EMPLOYEES, AGENTS
OR REPRESENTATIVES.

IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS AGREEMENT EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
SERVICE COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR OTHER SIMILAR TERMS
WITHOUT A

                                 Schedule 5.4.1

                                  Page 7 of 26

<PAGE>   83



SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO ASSUME A GREATER DEGREE OF
LIABILITY TO CUSTOMER.



                                 Schedule 5.4.1

                                  Page 8 of 26

<PAGE>   84



                      SWITCHED LAN INTERNET ACCESS SERVICE
                          CUSTOMER CONTRACT PROVISIONS


PSINET NETWORK USAGE.

        A. COMPLIANCE WITH LAW AND POLICY. Customer has read and agrees to
        comply with PSINet's Net-Abuse Policy ("Policy") as currently set forth
        on PSINet's Web site (http://www.psi.net) and as the Policy may be
        modified by PSINet in its sole discretion from time to time. Any
        content, material, message or data made available or transmitted through
        the Service, wherever it is sent from, viewed, received, or retrieved,
        that is in violation of (i) any local, state, federal or international
        law, regulation or treaty; (ii) the Policy; or (iii) any community
        standard or accepted Internet policy is prohibited. Any such violation
        may be deemed a material breach of this Agreement and PSINet may, in its
        sole discretion, disable or terminate the Service with written notice to
        Customer, but without any cure period.

        B. CUSTOMER-ONLY TRAFFIC. The right to use the Service is strictly
        limited to Customer only and does not extend to any other person,
        corporation or entity except for wholly-owned affiliates of Customer and
        those members of Customer's staff and consultants in the course of
        performing work for Customer.

        C. THIRD-PARTY TRAFFIC. Customer may host world-wide web sites on behalf
        of third parties. In addition, Customer may feed USENET News to a third
        party, but may not send any posting from that third party, including,
        but not limited to, electronic mail, back to PSINet's wide-area network
        system (the "Network") or the Internet through the Service. Any other
        third party traffic, including packet access and electronic mail,
        whether sent or received through Customer's facilities by or on behalf
        of a third party through the Service, is expressly prohibited.

SERVICE USAGE. No more than one connection can be used at any time with a
Service as paid for by Customer and assigned by PSINet. If two individuals or
groups need to simultaneously access PSINet through separate phone lines, then
they would have to acquire two Services, and so on. Service use is defined as a
connection with a PSINet modem or access device using the public switched
telephone system (e.g. POTS lines or ISDN circuits). This single phone line
connection does allow for multiple individual user sessions.

CUSTOMER NETWORK SECURITY. PSINet provides no user access security with respect
to any of Customer's facilities or facilities of others. Customer shall be
responsible for user/access security as well as access to its network or to the
Network. PSINet will assist in network security breach detection or
identification, but shall not be liable for any inability, failure or mistake in
doing so.

SERVICE ASSURANCE. If Customer notifies PSINet immediately upon its failure to
access the Network through Customer's standard means, including multiple
alternative dialup POPs, provided with the Service, and PSINet determines in its
reasonable commercial judgment that the Network is therefore unavailable to
Customer ("Unavailable"), one of the following will apply:

        1. If PSINet determines that the Network is Unavailable for one (1) or
        more consecutive hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) day's Service fee; or


                                 Schedule 5.4.1

                                  Page 9 of 26

<PAGE>   85



        2. If PSINet determines that the Network is Unavailable for an aggregate
        of four (4) or more hours during any calendar month, PSINet, upon
        Customer's request, will credit Customer's monthly invoice the pro-rated
        charges for one (1) week's Service fee.

These two options are not cumulative. For purposes of this section, scheduled
maintenance will not be considered to be Unavailability. PSINet shall not be
responsible for any toll charges incurred by Customer's use of any telephone
company ("Telco") or other telecommunications services as a result of this
section. THE FOREGOING TWO OPTIONS STATE PSINET'S SOLE OBLIGATION, AND
CUSTOMER'S SOLE REMEDY, FOR NETWORK UNAVAILABILITY.

LIMITED WARRANTIES.

        A. SERVICE. PSINET WARRANTS THAT THE SERVICE WILL OPERATE SUBSTANTIALLY
        IN CONFORMANCE WITH THIS AGREEMENT. PSINET MAKES NO OTHER WARRANTIES OF
        ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, INCLUDING, BUT NOT
        LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS OF THE
        SERVICE FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY
        RIGHTS. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND
        TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM.
        USE OF ANY INFORMATION OBTAINED THROUGH THE SERVICE IS AT CUSTOMER'S
        RISK. PSINET SPECIFICALLY DENIES ANY RESPONSIBILITY FOR THE ACCURACY OR
        QUALITY OF INFORMATION OBTAINED THROUGH THE SERVICE.

        B. EQUIPMENT. PSINET REPRESENTS AND WARRANTS THAT DURING THE TERM OF
        THIS AGREEMENT IT WILL MAKE REASONABLE EFFORTS TO ENSURE THE EQUIPMENT
        OPERATES SUBSTANTIALLY IN CONFORMANCE WITH THIS AGREEMENT. ANY
        UNAUTHORIZED CHANGES TO OR INAPPROPRIATE USAGE OF THE EQUIPMENT,
        HOWEVER, WILL VOID THE FOREGOING WARRANTY. PSINET DOES NOT WARRANT THAT
        THE EQUIPMENT WILL BE ENTIRELY FREE FROM DEFECTS OR THAT ITS OPERATION
        WILL BE ERROR FREE. FURTHERMORE, CUSTOMER ACKNOWLEDGES THAT PSINET HAS
        MADE NO OTHER REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR
        IMPLIED, WITH RESPECT TO THE CONDITION OR PERFORMANCE OF THE EQUIPMENT,
        OR ITS MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

        C. GENERAL. EACH PARTY ACKNOWLEDGES THAT IT HAS READ AND UNDERSTANDS
        THIS AGREEMENT AND AGREES TO BE BOUND BY ITS TERMS. EACH PARTY FURTHER
        WARRANTS THAT IT HAS FULL CORPORATE POWER AND AUTHORITY TO ENTER INTO
        AND DELIVER THIS AGREEMENT AND TO PERFORM ITS OBLIGATIONS HEREUNDER, AND
        THAT THE PERSON WHOSE SIGNATURE APPEARS BELOW IS DULY AUTHORIZED TO
        ENTER INTO THIS AGREEMENT ON BEHALF OF THAT PARTY.

LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS HEREUNDER,
NEITHER PARTY SHALL BE LIABLE FOR DIRECT DAMAGES GREATER THAN THE SUM TOTAL OF
PAYMENTS MADE BY CUSTOMER TO PSINET DURING THE SIX (6) MONTHS IMMEDIATELY
PRECEDING THE EVENT FOR WHICH DAMAGES ARE CLAIMED. EXCEPT FOR THE FOREGOING,
PSINET SHALL HAVE NO LIABILITY TO CUSTOMER WITH RESPECT TO (I) ANY CLAIM, LOSS
OR DAMAGE OF ANY KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR PASSIVE
NEGLIGENCE OR STRICT LIABILITY OF PSINET FOR CLAIMS ARISING OUT OF OR IN
CONNECTION WITH THE SERVICE OR THE EQUIPMENT, WHETHER OR NOT KNOWN OR DISCLOSED
TO PSINET; (II) ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, PUNITIVE OR
CONSEQUENTIAL LOSSES OR DAMAGES RESULTING FROM THE DELIVERY, INSTALLATION,
MAINTENANCE, OPERATION OR USE OF THE SERVICE OR THE EQUIPMENT; (III) ANY ACT OR
OMISSION OF ANY OTHER ENTITY FURNISHING EQUIPMENT, PRODUCTS OR SERVICES TO
CUSTOMER; (IV) ANY PERSONAL OR PROPERTY DAMAGES DUE TO THE LOSS OF STORED,
TRANSMITTED OR RECORDED DATA RESULTING FROM THE SERVICE OR THE EQUIPMENT, EVEN
IF PSINET HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES; AND (V) ANY LOSS
OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF CUSTOMER OR ITS EMPLOYEES, AGENTS
OR REPRESENTATIVES.

                                 Schedule 5.4.1

                                  Page 10 of 26

<PAGE>   86



IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS AGREEMENT EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
SERVICE COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR OTHER SIMILAR TERMS
WITHOUT A SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO ASSUME A GREATER DEGREE
OF LIABILITY TO CUSTOMER.







                                 Schedule 5.4.1

                                  Page 11 of 26

<PAGE>   87



                          MANAGED INTRANET WAN SERVICE
                          CUSTOMER CONTRACT PROVISIONS


PSINET NETWORK USAGE.

        A. COMPLIANCE WITH LAW AND POLICY. Customer has read and agrees to
        comply with PSINet's Net-Abuse Policy ("Policy") as currently set forth
        on PSINet's Web site (http://www.psi.net) and as the Policy may be
        modified by PSINet in its sole discretion from time to time. Any
        content, material, message or data made available or transmitted through
        the Service, wherever it is sent from, viewed, received, or retrieved,
        that is in violation of (i) any local, state, federal or international
        law, regulation or treaty; (ii) the Policy; or (iii) any community
        standard or accepted Internet policy is prohibited. Any such violation
        may be deemed a material breach of this Agreement and PSINet may, in its
        sole discretion, disable or terminate the Service with written notice to
        Customer, but without any cure period.

        B. CUSTOMER-ONLY TRAFFIC. The right to use the Service is strictly
        limited to Customer only and does not extend to any other person,
        corporation or entity except for wholly-owned affiliates of Customer and
        those members of Customer's staff and consultants in the course of
        performing work for Customer.

        C. THIRD-PARTY TRAFFIC. Customer may host world-wide web sites on behalf
        of third parties. In addition, Customer may feed USENET News to a third
        party, but may not send any posting from that third party, including,
        but not limited to, electronic mail, back to PSINet's wide-area network
        system (the "Network") or the Internet through the Service. Any other
        third party traffic, including packet access and electronic mail,
        whether sent or received through Customer's facilities by or on behalf
        of a third party through the Service, is expressly prohibited.

CUSTOMER EQUIPMENT AND NETWORK. PSINet provides no user access security with
respect to any of Customer's facilities or facilities of others. PSINet will
assist in enforcing a customer-specified access policy as provided in the
Specifications subject to the limits of the implementing equipment and the level
of subscribed service. PSINet is not liable for any inability, failure or
mistake in implementing, enforcing, or monitoring the enforcement of the
specified policy.

PSINET-PROVIDED EQUIPMENT.

        (1) Equipment Space. Customer shall provide and maintain suitable
        Equipment Space meeting or exceeding the requirements set forth in the
        Specifications.

        (2) Equipment. The Equipment Space at each site specified by Customer
        will house Equipment owned by PSINet required for the Service. PSINet
        shall retain all right, title, and interest in the Equipment at all
        times. PSINet will provide Equipment at each site to provide the
        connection between Customer's network and the Telco circuit leading to
        the Network. The particular make and model of Equipment shall be
        selected for Customer by PSINet in its sole discretion. If PSINet
        determines in its sole reasonable judgment that the Equipment is
        defective, PSINet shall replace the defective Equipment at no cost to
        Customer. THE FOREGOING STATES PSINET'S SOLE OBLIGATION, AND CUSTOMER'S
        SOLE REMEDY, FOR ANY DEFECTIVE EQUIPMENT.


                                 Schedule 5.4.1

                                  Page 12 of 26

<PAGE>   88



        (3) Equipment Access and Connection. The Equipment shall be maintained
        by PSINet or its subcontractors. Customer shall not allow its personnel
        or others on its premises to open the Equipment cabinets. PSINet will
        verbally authorize on an event-by-event basis individuals at Customer's
        location to open Equipment cabinets for appropriate routine and
        emergency reasons. Customer shall retain the right to disconnect the
        Equipment from its LAN at any time. PSINet reserves the right to shut
        down the Equipment at Customer's location in accordance with PSINet's
        emergency operating procedures with notification to Customer.

        (4) Equipment Relocation. PSINet is not responsible for Service
        disruptions caused by Customer's Equipment relocation requirements.

        (5) Equipment Return. Upon termination of the Service for any reason,
        Customer agrees immediately to allow the return of the Equipment to
        PSINet. PSINet retains all rights to recover possession of the Equipment
        from Customer.

LIMITED WARRANTIES.

        A. SERVICE. PSINET WARRANTS THAT THE SERVICE WILL OPERATE SUBSTANTIALLY
        IN CONFORMANCE WITH THE SPECIFICATIONS. PSINET MAKES NO OTHER WARRANTIES
        OF ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, INCLUDING, BUT NOT
        LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS OF THE
        SERVICE FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY
        RIGHTS. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND
        TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM.
        USE OF ANY INFORMATION OBTAINED THROUGH THE SERVICE IS AT CUSTOMER'S
        RISK. PSINET SPECIFICALLY DENIES ANY RESPONSIBILITY FOR THE ACCURACY OR
        QUALITY OF INFORMATION OBTAINED THROUGH THE SERVICE.

        B. EQUIPMENT. PSINET REPRESENTS AND WARRANTS THAT DURING THE TERM OF
        THIS AGREEMENT IT WILL MAKE REASONABLE EFFORTS TO ENSURE THE EQUIPMENT
        OPERATES SUBSTANTIALLY IN CONFORMANCE WITH THE SPECIFICATIONS. ANY
        UNAUTHORIZED CHANGES TO OR INAPPROPRIATE USAGE OF THE EQUIPMENT,
        HOWEVER, WILL VOID THE FOREGOING WARRANTY. PSINET DOES NOT WARRANT THAT
        THE EQUIPMENT WILL BE ENTIRELY FREE FROM DEFECTS OR THAT ITS OPERATION
        WILL BE ERROR FREE. FURTHERMORE, CUSTOMER ACKNOWLEDGES THAT PSINET HAS
        MADE NO OTHER REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR
        IMPLIED, WITH RESPECT TO THE CONDITION OR PERFORMANCE OF THE EQUIPMENT,
        OR ITS MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

        C. GENERAL. EACH PARTY ACKNOWLEDGES THAT IT HAS READ AND UNDERSTANDS
        THIS AGREEMENT AND AGREES TO BE BOUND BY ITS TERMS. EACH PARTY FURTHER
        WARRANTS THAT IT HAS FULL CORPORATE POWER AND AUTHORITY TO ENTER INTO
        AND DELIVER THIS AGREEMENT AND TO PERFORM ITS OBLIGATIONS HEREUNDER, AND
        THAT THE PERSON WHOSE SIGNATURE APPEARS BELOW IS DULY AUTHORIZED TO
        ENTER INTO THIS AGREEMENT ON BEHALF OF THAT PARTY.

LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS HEREUNDER,
NEITHER PARTY SHALL BE LIABLE FOR DIRECT DAMAGES GREATER THAN THE SUM TOTAL OF
PAYMENTS MADE BY CUSTOMER TO PSINET DURING THE SIX (6) MONTHS IMMEDIATELY
PRECEDING THE EVENT FOR WHICH DAMAGES ARE CLAIMED. EXCEPT FOR THE FOREGOING,
PSINET SHALL HAVE NO LIABILITY TO CUSTOMER WITH RESPECT TO (I) ANY CLAIM, LOSS
OR DAMAGE OF ANY KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR PASSIVE
NEGLIGENCE OR STRICT LIABILITY OF PSINET FOR CLAIMS ARISING OUT OF OR IN
CONNECTION WITH THE SERVICE OR THE EQUIPMENT, WHETHER OR NOT KNOWN OR DISCLOSED
TO PSINET; (II) ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, PUNITIVE OR
CONSEQUENTIAL LOSSES OR DAMAGES RESULTING FROM THE DELIVERY, INSTALLATION,
MAINTENANCE, OPERATION OR USE OF THE SERVICE OR THE EQUIPMENT; (III) ANY ACT OR
OMISSION OF ANY OTHER ENTITY FURNISHING EQUIPMENT, PRODUCTS OR SERVICES TO

                                 Schedule 5.4.1

                                  Page 13 of 26

<PAGE>   89



CUSTOMER; (IV) ANY PERSONAL OR PROPERTY DAMAGES DUE TO THE LOSS OF STORED,
TRANSMITTED OR RECORDED DATA RESULTING FROM THE SERVICE OR THE EQUIPMENT, EVEN
IF PSINET HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES; AND (V) ANY LOSS
OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF CUSTOMER OR ITS EMPLOYEES, AGENTS
OR REPRESENTATIVES.

IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS AGREEMENT EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
SERVICE COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR OTHER SIMILAR TERMS
WITHOUT A SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO ASSUME A GREATER DEGREE
OF LIABILITY TO CUSTOMER.



                                 Schedule 5.4.1

                                  Page 14 of 26

<PAGE>   90



                     INTERNET REMOTE ACCESS SERVICE CUSTOMER
                               CONTRACT PROVISIONS


PSINET NETWORK USAGE.

        A. COMPLIANCE WITH LAW AND POLICY. Customer along with each End-User,
        has read and agrees to comply with PSINet's Net-Abuse Policy ("Policy")
        as currently set forth on PSINet's Web site (http://www.psi.net) and as
        the Policy may be modified by PSINet in its sole discretion from time to
        time. Any content, material, message or data made available or
        transmitted through an Account wherever it is sent from, viewed,
        received, or retrieved, that is in violation of (i) any local, state,
        federal or international law, regulation or treaty; (ii) the Policy; or
        (iii) any community standard or accepted Internet policy is prohibited.
        Any such violation may be deemed a material breach of this Agreement and
        PSINet may, in its sole discretion, disable or terminate an Account or
        the Service with written notice to Customer, but without any cure
        period.

        B. CUSTOMER-ONLY TRAFFIC. The right to use an Account is strictly
        limited to Customer only and does not extend to any other person,
        corporation or entity except for wholly-owned affiliates of Customer and
        those members of Customer's staff and consultants in the course of
        performing work for Customer.

        C. THIRD-PARTY TRAFFIC. Customer's End-Users may feed USENET News to a
        third party, but may not send any posting from that third party,
        including, but not limited to, electronic mail, back to the Network or
        the Internet through an Account. Any other third party traffic,
        including packet access and electronic mail, whether sent or received
        through Customer's facilities by or on behalf of a third party through
        the Service, is expressly prohibited.

CUSTOMER NETWORK AND FACILITIES. Customer shall remain responsible for
user/access security as well as access to its network or to the Network. PSINet
provides no user access security with respect to any of Customer or its
End-Users' facilities or facilities of others. PSINet will assist in network
security breach detection or identification, but shall not be liable for any
inability, failure or mistake in doing so.

"FIRST-LINE" SERVICE SUPPORT. Customer's MIS/Technical administrator or contact
is solely responsible for all first line customer support for End-Users. If
End-Users require additional support, only Customer's designated Help Desk or
MIS/Technical contact may request support directly from PSINet's Customer
Support Group (CSG).

10. NO WARRANTIES. NEITHER PSINET, ITS AFFILIATES, DIRECTORS, EMPLOYEES AND
SUBCONTRACTORS WARRANT ANY CONNECTION TO, TRANSMISSION OVER, NOR RESULTS OR USE
OF, ANY NETWORK CONNECTION OR FACILITIES PROVIDED (OR FAILED TO BE PROVIDED)
UNDER THIS AGREEMENT. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND
TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM. USE OF ANY
INFORMATION OBTAINED VIA AN ACCOUNT IS AT CUSTOMER AND THEIR END-USER'S RISK.
PSINET SPECIFICALLY DENIES ANY RESPONSIBILITY FOR THE ACCURACY OR QUALITY OF
INFORMATION OBTAINED THROUGH THE ACCOUNTS. PSINET MAKES NO WARRANTIES OF ANY
KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO,
ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS OF THE SERVICE FOR A PARTICULAR
PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY RIGHTS.

PSINET MAKES NO WARRANTY WITH RESPECT TO ANY SOFTWARE OR HARDWARE USED OR
PROVIDED BY PSINET IN CONNECTION WITH AN ACCOUNT. ANY PATENT, TRADEMARK, TRADE
SECRET OR WARRANTY INFRINGEMENTS, WHETHER ACTUAL OR ALLEGED, ARE THE DIRECT

                                 Schedule 5.4.1

                                  Page 15 of 26

<PAGE>   91



RESPONSIBILITY OF THE MANUFACTURER OF SAID HARDWARE OR SOFTWARE PRODUCT. PSINET
ASSUMES NO RESPONSIBILITY FOR ANY ACTIONS OR LIABILITIES ARISING FROM THE
POSSESSION OR USE OF THESE SOFTWARE OR HARDWARE PRODUCTS.

11. LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS
HEREUNDER, NEITHER PARTY SHALL BE LIABLE FOR DIRECT DAMAGES GREATER THAN THE SUM
TOTAL OF PAYMENTS MADE BY CUSTOMER TO PSINET DURING THE SIX (6) MONTHS
IMMEDIATELY PRECEDING THE EVENT FOR WHICH DAMAGES ARE CLAIMED. EXCEPT FOR THE
FOREGOING AND WITHOUT LIMITING ITS GENERALITY, PSINET SHALL HAVE NO LIABILITY TO
CUSTOMER OR ANY THIRD PARTY WITH RESPECT TO (I) ANY CLAIM, LOSS OR DAMAGE OF ANY
KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR PASSIVE NEGLIGENCE OR STRICT
LIABILITY OF PSINET FOR CLAIMS ARISING OUT OF OR IN CONNECTION WITH THE
INDIVIDUAL ACCOUNTS OR SERVICE OR RELATED HARDWARE OR SOFTWARE WHETHER OR NOT
KNOWN OR DISCLOSED TO PSINET; (II) ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
PUNITIVE OR CONSEQUENTIAL LOSSES OR DAMAGES RESULTING FROM THE DELIVERY,
INSTALLATION, MAINTENANCE, OPERATION OR USE OF THE INDIVIDUAL ACCOUNTS OR
SERVICE OR RELATED HARDWARE OR SOFTWARE; (III) ANY ACT OR OMISSION OF ANY OTHER
ENTITY FURNISHING HARDWARE, SOFTWARE OR SERVICES TO CUSTOMER; (IV) ANY PERSONAL
OR PROPERTY DAMAGES DUE TO THE LOSS OF STORED, TRANSMITTED OR RECORDED DATA
RESULTING FROM ANY INDIVIDUAL ACCOUNT, THE SERVICE OR RELATED HARDWARE OR
SOFTWARE, EVEN IF PSINET HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES;
AND (V) ANY LOSS OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF CUSTOMER OR ITS
EMPLOYEES, AGENTS OR REPRESENTATIVES.

IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS AGREEMENT EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
INDIVIDUAL ACCOUNTS AND SERVICE COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR
OTHER SIMILAR TERMS WITHOUT A SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO
ASSUME A GREATER DEGREE OF LIABILITY TO CUSTOMER OR OTHER THIRD PARTIES.



                                 Schedule 5.4.1

                                  Page 16 of 26

<PAGE>   92



                       MANAGED INTERNET SECURITY SERVICES
                          CUSTOMER CONTRACT PROVISIONS


        SECURITY SERVICES DEFINED. Customer desires certain additional security
        services offered by PSS (the "Security Services") as specified in the
        "RouteWalle(SM) Managed Perimeter Security Service Specifications," and
        the "SecureEnterpriseTM Enterprise-Wide Managed Security Service
        Specifications" which are collectively called the "Specifications" and
        are incorporated herein by reference. The Security Services are designed
        to provide certain access control techniques or information to Customer
        regarding its computer or computer network(s)' connection to the Network
        and the Internet. The addition of the Security Services for Customer as
        contemplated in this Agreement requires Customer to possess or acquire a
        Dedicated Internet Access Service (InterFrame, for the RouteWaller
        Security Service, and InterFrame or InterMAN, for the SecureEnterprise
        Security Service) from PSINet Inc. which connects Customer's host
        computer or local area network (LAN) to the PSINet wide-area network
        system (the "Network") and the Internet.

3.      SECURITY SERVICES POLICY CREATION AND IMPLEMENTATION.

        A. LIMITED SCOPE. WHILE PSS WILL ENDEAVOR TO PROVIDE AND/OR INSTALL
        EQUIPMENT OR CONSULTING AND IMPLEMENTATION EXPERTISE, AS APPLICABLE IN
        CONJUNCTION WITH THE SELECTED SECURITY SERVICE, CUSTOMER ACKNOWLEDGES
        THAT IT IS FAMILIAR WITH AND HAS HAD ADEQUATE OPPORTUNITY TO EVALUATE
        THE SECURITY SERVICE SELECTED AND THAT PSS WILL ONLY ULTIMATELY ACT UPON
        THE POLICY AND PROCEDURES ESTABLISHED AND COMMUNICATED IN WRITING BY
        CUSTOMER THROUGH ITS AUTHORIZED REPRESENTATIVES (SPECIFICALLY, THE
        "SECURITY OFFICERS" IDENTIFIED BY CUSTOMER IN THE SECURITY SERVICES
        ORDER FORM ("ORDER FORM") WHICH IS INCORPORATED HEREIN BY REFERENCE).
        ANY AND ALL SUCH WRITTEN COMMUNICATIONS SHALL BE APPENDED TO THIS
        AGREEMENT TO THE EXTENT AGREED UPON BY PSS.

        B. PROCEDURE.

        (1)    Customer shall delegate two Security Officers, a primary and a
               secondary. Security Officer names, phone numbers, fax numbers,
               and electronic mail addresses must be provided to PSS on the
               order form. PSS will take direction ONLY from these Security
               Officers for Security Service.

        (2)    Customer Security Officers must participate in an initial phone
               consultation with PSS's Security Coordinator.

        (3)    Customer requests for security provisions shall be made by
               electronic mail or fax to the designated PSS address to
               facilitate an audit trail.

        (4)    PSS Network Operations can be instructed by other Customer
               contacts to disable non-PSS access (for instance, MAE-East,
               MAE-West or CIX access).

        (5)    The Security Service can only be facilitated using PSS provided
               equipment at Customer's site and with Customer's employees. (6)
               PSS will ship PSS-owned equipment only to Customer's Security
               Officers for Customer either to install or have PSS personnel
               install.

4.      PSS-OWNED EQUIPMENT:


                                 Schedule 5.4.1

                                  Page 17 of 26

<PAGE>   93



        A. PSS-OWNED EQUIPMENT USAGE GRANTS. PSS hereby grants Customer a
        non-exclusive license to use the PSS-owned Equipment associated with the
        selected Security Service, along with any related user documentation,
        subject to the terms provided herein. Customer agrees and acknowledges
        that it has no right, title or interest in or to any of the PSS-owned
        Equipment, including, but not limited to, any related patents,
        trademarks, copyrights or other proprietary rights, except as
        specifically set forth herein.

        (1)    CUSTOMER MAY

                (a)     make copies of the software portions of the PSS-owned
                        Equipment for backup and archival purposes only,
                        provided that the software and all proprietary notices
                        remain intact.

                (b)     make copies of the PSS-owned Equipment's documentation,
                        provided that such documentation is copied in its
                        entirety and all proprietary notices remain intact.

        (2)    CUSTOMER MAY NOT

                (a)     rent, lend, sublicense or lease the PSS-owned Equipment
                        to another party.

                (b)     modify, disassemble, decompile or reverse engineer any
                        portion of the PSS-owned Equipment.

        B. PSS-OWNED EQUIPMENT SPACE. In order to allow for the Security
        Service, Customer shall, during the term of this Agreement, provide and
        maintain suitable Equipment Space. The Equipment Space will house the
        PSS-owned Equipment required for the Security Service. Customer shall
        retain the right to disconnect the PSS-owned Equipment from its LAN at
        any time; however such action will suspend the Security Service and any
        associated warranties provided by PSS.

        C. RELOCATION OF PSS-OWNED EQUIPMENT. Should Customer deem it necessary
        to have the PSS-owned Equipment relocated, Customer shall be responsible
        for moving the PSS-owned Equipment under PSS supervision. PSS shall not
        be responsible for any Security Service disruptions caused by the
        PSS-owned Equipment's relocation.

        D. USAGE OF PSS-OWNED EQUIPMENT. Should PSS provide PSS-owned Equipment
        to Customer (as will be labeled by PSS) for its use as part of this
        Agreement, title to the Equipment shall be and remain in PSS at all
        times, and Customer shall have no interest therein except as expressly
        provided under this Agreement. Customer assumes full responsibility for,
        and, in the event of lost or damaged PSS-owned Equipment, shall pay the
        replacement cost plus 5% to the nearest $10.00, plus any applicable
        shipping and handling charges. Upon termination of this Agreement,
        Customer shall immediately return all PSS-owned Equipment to PSS.

        E. REPROGRAMMING/REPAIRING PSS-OWNED ACCESS CONTROL CARDS. In the event
        Customer requires PSS to reprogram or repair an individual Access
        Control Card owned by PSS and already in use by Customer, Customer shall
        be responsible for all shipping fees to and from PSS and will incur a
        one-time handling fee of $25.00 per PSS-owned Access Control Card.

7.      CONFIDENTIAL INFORMATION.


                                 Schedule 5.4.1

                                  Page 18 of 26

<PAGE>   94



        A. ACKNOWLEDGMENT OF CONFIDENTIALITY. Each Party hereby acknowledges
        that it may be exposed to confidential and proprietary information
        belonging to the other party or relating to its affairs, including
        materials expressly designated or marked as confidential. Confidential
        Information does not include (i) information already known or
        independently developed by the recipient; (ii) information in the public
        domain through no wrongful act of the recipient, or (iii) information
        received by recipient from a third party who was free to disclose it.

        B. COVENANT NOT TO DISCLOSE. Each party hereby agrees that it shall not
        use, commercialize or disclose the other party's Confidential
        Information to any person or entity, except to its own employees or
        agents having a "need to know" such information in connection with the
        performance of this Agreement, and to such other recipients as the other
        party may approve in a signed, written document. Neither party shall
        alter or remove from any software, documentation or other Confidential
        Information of the other party (or any third party) any proprietary,
        copyright, trademark or trade secret legend. The parties' obligations of
        confidentiality under this Agreement shall survive termination of this
        Agreement for any reason.

8. NON CIRCUMVENTION. During the term of this Agreement and for a period of
eighteen (18) months thereafter, Customer agrees not to hire, solicit, nor
attempt to solicit the services, of any employee or subcontractor of PSS, its
parent or affiliate companies, without PSS' prior written consent; provided,
however, that Customer is not prevented from employing such person who contacts
Customer on his or her own initiative and without any direct or indirect
solicitation by Customer. Violation of this provision shall, in addition to
other relief, entitle PSS or its parent company to assert liquidated damages
against Customer equal to one hundred fifty (150) percent of the solicited
person's annual compensation.

9. CUSTOMER EQUIPMENT AND NETWORK. PSS IS NOT RESPONSIBLE TO CUSTOMER FOR THE
COST OR EXPENSE OF ADMINISTRATIVE, TECHNICAL, EMERGENCY AND SUPPORT PERSONNEL AT
CUSTOMER'S LOCATION NECESSARY FOR DEALING WITH PSS OR FOR PROVIDING AND
MAINTAINING CUSTOMER'S OWN COMPUTER EQUIPMENT AND NETWORK OR INTERNET ACCESS.
CUSTOMER SHALL CONTINUE TO BE RESPONSIBLE FOR USER/ACCESS SECURITY AND NETWORK
ACCESS TO ITS COMPUTER OR COMPUTER NETWORK(S). PSS WILL ASSIST IN NETWORK
SECURITY BREACH DETECTION OR IDENTIFICATION IN ACCORDANCE WITH THE SECURITY
SERVICE SELECTED AND INDUSTRY STANDARDS, BUT DOES NOT GUARANTEE A SECURE
COMPUTER OR COMPUTER NETWORK(S) OR ASSUME RESPONSIBILITY FOR ANY INABILITY,
FAILURE OR MISTAKE BY PSS IN PROVIDING SUCH ASSISTANCE.

10. LIMITED PERFORMANCE WARRANTY ON PSS-OWNED EQUIPMENT. PSS REPRESENTS AND
WARRANTS THAT DURING THE TERM OF THIS AGREEMENT IT WILL MAKE REASONABLE EFFORTS
TO ENSURE THE PSS-OWNED EQUIPMENT USED IN CONNECTION WITH THE SECURITY SERVICE
OPERATES SUBSTANTIALLY IN CONFORMANCE WITH THE RELEVANT SPECIFICATIONS. ANY
UNAUTHORIZED CHANGES TO OR INAPPROPRIATE USAGE OF THE PSS-OWNED EQUIPMENT;
HOWEVER, WILL VOID ANY WARRANTY PROVIDED HEREUNDER.

PSS DOES NOT WARRANT THAT THE EQUIPMENT WILL BE ENTIRELY FREE FROM DEFECTS OR
THAT ITS OPERATION WILL BE ERROR FREE. FURTHERMORE, CUSTOMER ACKNOWLEDGES THAT
PSS HAS MADE NO OTHER REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, WITH RESPECT TO THE CONDITION OR PERFORMANCE OF THE EQUIPMENT, OR ITS
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. EXCEPT AS EXPRESSLY
PROVIDED ABOVE, PSS SHALL HAVE NO LIABILITY TO CUSTOMER WITH RESPECT TO (I) ANY
CLAIM, LOSS OR DAMAGE OF ANY KIND OR NATURE WHATSOEVER INCLUDING THE ACTIVE OR
PASSIVE NEGLIGENCE OR STRICT LIABILITY OF PSS FOR CLAIMS ARISING OUT OF OR IN
CONNECTION WITH THE EQUIPMENT, WHETHER OR NOT KNOWN OR DISCLOSED TO PSS; (II)
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, PUNITIVE OR CONSEQUENTIAL LOSSES OR
DAMAGES RESULTING FROM THE DELIVERY, INSTALLATION, MAINTENANCE, OPERATION,
SERVICE OR USE OF THE EQUIPMENT EXCEPT AS SPECIFIED ABOVE; (III) ANY ACT OR
OMISSION OF ANY

                                 Schedule 5.4.1

                                  Page 19 of 26

<PAGE>   95



OTHER ENTITY FURNISHING EQUIPMENT, PRODUCTS OR SERVICES TO CUSTOMER; (IV) ANY
PERSONAL OR PROPERTY DAMAGES OR FOR LOSS OF STORED, TRANSMITTED OR RECORDED DATA
RESULTING FROM THE EQUIPMENT, EVEN IF PSS HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES; AND (V) ANY LOSS OR DAMAGES DUE TO THE FAULT OR NEGLIGENCE OF
CUSTOMER OR ITS EMPLOYEES, AGENTS OR REPRESENTATIVES.

EXCEPT AS EXPRESSLY SET FORTH ABOVE, PSS MAKE NO WARRANTIES WITH RESPECT TO:

        A. NON-PSS-OWNED EQUIPMENT. WITH RESPECT TO EQUIPMENT NOT OWNED BY PSS,
        PSS ASSIGNS TO CUSTOMER AND CUSTOMER MAY HAVE THE BENEFIT OF ANY
        MANUFACTURER'S WARRANTIES AND THE EQUIPMENT'S SERVICE AGREEMENTS (THE
        PERFORMANCE AND CHARACTER OF WHICH SHALL IN ALL CASES BE GOVERNED BY THE
        APPLICABLE THIRD PARTY LICENSE AGREEMENTS) TO THE EXTENT AVAILABLE AND
        ASSIGNABLE BY PSS; PROVIDED, HOWEVER, THAT CUSTOMER'S SOLE REMEDY FOR
        THE BREACH OF ANY SUCH WARRANTY, INDEMNIFICATION OR SERVICE AGREEMENT
        SHALL BE ACTIONS OR CLAIMS AGAINST THE MANUFACTURER, AND NOT AGAINST
        PSS, ITS PARENT COMPANY, THEIR DIRECTORS, EMPLOYEES AND AGENTS, NOR
        SHALL ANY SUCH BREACH HAVE ANY EFFECT WHATSOEVER ON THE RIGHTS AND
        OBLIGATIONS OF EITHER PARTY WITH RESPECT TO THIS AGREEMENT.

        B. SECURITY SERVICES. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN
        COMPUTER AND TRANSMISSION NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED
        THEREFROM. EXCEPT AS SPECIFICALLY PROVIDED IN THE SECTION ABOVE IN
        CONNECTION WITH THE RELATED PSS-OWNED EQUIPMENT, PSS MAKES NO WARRANTIES
        OF ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY, WITH RESPECT TO
        THE SECURITY SERVICES, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED
        WARRANTY OF MERCHANTABILITY OR FITNESS OF THE SECURITY SERVICE FOR A
        PARTICULAR PURPOSE. PSS MAKES NO WARRANTY TO ANY THIRD PARTY WHO MAY
        RELY UPON THE SECURITY OF CUSTOMER'S COMPUTER OR COMPUTER NETWORK. C.
        BREACHES IN SECURITY. CUSTOMER AGREES THAT IN NO EVENT SHALL PSS, ITS
        PARENT COMPANY, THEIR AFFILIATES, DIRECTORS, EMPLOYEES AND AGENTS BE
        HELD LIABLE FOR ANY SECURITY BREACH EXPERIENCED BY CUSTOMER, ITS USERS
        OR OTHERS RELYING ON CUSTOMER'S COMPUTER OR COMPUTER NETWORK, WHETHER OR
        NOT RELATED TO OR ARISING FROM THE SECURITY SERVICE, OR FOR ANY FAILURE
        OF THE SECURITY SERVICE TO PERFORM IN ANY RESPECT.

11.    LIMITATION OF REMEDIES AND LIABILITIES. CUSTOMER AND PSS ACKNOWLEDGE THAT
THE FOLLOWING PROVISIONS REFLECT A FAIR ALLOCATION OF RISK:

        A. REMEDIES. CUSTOMER'S SOLE AND EXCLUSIVE REMEDIES FOR PSS'S DEFAULT
        HEREUNDER SHALL BE (I) TO OBTAIN THE REPAIR, REPLACEMENT OR CORRECTION
        OF THE DEFECTIVE EQUIPMENT TO THE EXTENT WARRANTED ABOVE OR, IF PSS
        REASONABLY DETERMINES THAT SUCH REMEDY IS NOT ECONOMICALLY OR
        TECHNICALLY FEASIBLE, (II) TO OBTAIN AN EQUITABLE PARTIAL OR FULL REFUND
        OF AMOUNTS PAID WITH RESPECT TO THE DEFECTIVE SECURITY SERVICE. CUSTOMER
        MAY TERMINATE THIS AGREEMENT AND RECOVER AMOUNTS PAID HEREUNDER WITH
        RESPECT TO THE INFRINGING SECURITY SERVICE, IN WHICH CASE, SUCH
        TERMINATION AND RECOVERY SHALL BE CUSTOMER'S SOLE AND EXCLUSIVE REMEDY
        IN RESPECT THEREOF.

        B. LIABILITIES. PSS SHALL NOT BE LIABLE FOR ANY AMOUNT EXCEEDING THE SUM
        OF FEES PAID FOR THE SECURITY SERVICE AT ISSUE DURING THE TWELVE (12)
        MONTHS PRECEDING SUCH CLAIM. IN NO EVENT SHALL EITHER PARTY BE LIABLE,
        WHETHER IN CONTRACT, TORT (INCLUDING NEGLIGENCE) OR OTHERWISE, FOR ANY
        PUNITIVE, SPECIAL, INDIRECT, INCIDENTAL OR OTHER CONSEQUENTIAL DAMAGES
        (INCLUDING LOST SAVINGS, PROFIT OR BUSINESS INTERRUPTION, LOSS OR
        MISAPPROPRIATION OF DATA, OR LOSS OR MISAPPROPRIATION OF CONFIDENTIAL OR
        PROPRIETARY INFORMATION, EVEN IF THE PARTY IS ADVISED IN ADVANCE OF SUCH
        POSSIBILITY) OF THE OTHER PARTY OR ANY THIRD PARTIES ARISING OUT OF OR
        IN RELATION TO THIS AGREEMENT. THE PARTIES AGREE TO WORK IN GOOD FAITH
        TO IMPLEMENT THE PURPOSES OF THIS AGREEMENT, BUT RECOGNIZE THAT THE
        SECURITY SERVICE TO BE PROVIDED BY PSS COULD NOT BE MADE AVAILABLE UNDER
        THESE

                                 Schedule 5.4.1

                                  Page 20 of 26

<PAGE>   96



        TERMS OR OTHER SIMILAR TERMS WITHOUT A SUBSTANTIAL INCREASE IN COST IF
        PSS WERE TO ASSUME A GREATER DEGREE OF LIABILITY TO CUSTOMER.

12. INSURANCE. Each party shall maintain adequate insurance protection covering
its respective activities hereunder, including coverage for statutory worker's
compensation, comprehensive general liability for bodily injury and tangible
property damage, as well as adequate coverage for vehicles, and for losses
attributable to fraudulent modification, damage or destruction of electronic
data.

13. EXPORT CONTROLS. Customer agrees and acknowledges that any export of the
Equipment used for the Security Services is subject to U.S. export control laws
and regulations. Customer shall not directly or indirectly transfer the
Equipment, or the documentation relating thereto, to any country or location
outside of the United States without obtaining the prior written consent of PSS.

FORCE MAJEURE. Neither party shall be responsible for, and will not be
considered in breach or default of this Agreement on account of, any failure to
perform or delay in performance of any obligations hereunder caused by acts of
God, flood, fire, storm, war, public enemy, labor disturbances, including
strikes and lockouts, Equipment malfunction, failure of the Equipment
manufacturer to deliver Equipment, governmental regulations or interferences or
any other event not within the reasonable control of the responsible party and
which that party is unable to overcome by the exercise of reasonable diligence,
provided that such party will use its best efforts to resume normal performance.



                                 Schedule 5.4.1

                                  Page 21 of 26

<PAGE>   97



                          PSINET INTERNETPAPER SERVICE
                          CUSTOMER CONTRACT PROVISIONS


SERVICE SUPPORT. Only Customer's MIS/Technical contact, designated below, may
request technical support assistance for the Option directly from PSINet's
Customer Support Group (CSG).

NO WARRANTY. PSINET PROVIDES THE OPTION ON AN "AS IS" BASIS. PSINET MAKES NO
OTHER WARRANTIES OF ANY KIND, WHETHER EXPRESSED, IMPLIED OR STATUTORY,
INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS
OF THE OPTION FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF ANY THIRD PARTY
RIGHTS. CUSTOMER IS RESPONSIBLE FOR ASSESSING ITS OWN COMPUTER AND TRANSMISSION
NETWORK NEEDS, AND THE RESULTS TO BE OBTAINED THEREFROM. USE OF ANY INFORMATION
OBTAINED THROUGH THE OPTION IS AT CUSTOMER'S RISK. PSINET SPECIFICALLY DENIES
ANY RESPONSIBILITY FOR THE ACCURACY OR QUALITY OF INFORMATION OBTAINED THROUGH
THE OPTION.

LIMITATION OF LIABILITY. EXCEPT FOR CUSTOMER'S PAYMENT OBLIGATIONS HEREUNDER, IN
NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
EXEMPLARY, PUNITIVE OR OTHER CONSEQUENTIAL DAMAGES WHETHER OR NOT FORESEEABLE,
INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR THE LOSS OF DATA, GOODWILL OR
PROFITS, ARISING OUT OF OR IN RELATION TO THIS ADDENDUM EVEN IF ADVISED
BEFOREHAND OF THE POSSIBILITY OF SUCH LIABILITY. THE PARTIES AGREE TO WORK IN
GOOD FAITH TO IMPLEMENT THE PURPOSES OF THIS ADDENDUM, BUT RECOGNIZE THAT THE
OPTION COULD NOT BE MADE AVAILABLE UNDER THESE TERMS OR OTHER SIMILAR TERMS
WITHOUT A SUBSTANTIAL INCREASE IN COST IF PSINET WERE TO ASSUME A GREATER DEGREE
OF LIABILITY TO CUSTOMER.




                                 Schedule 5.4.1

                                  Page 22 of 26

<PAGE>   98



                        PSINET CONSUMER WHOLESALE SERVICE
                         SUBSCRIBER CONTRACT PROVISIONS


TERMINATION OF ACCESS. Subscribers are required to comply with PSINet's
Net-Abuse Policy ("Policy") as currently set forth on PSINet's Web site
(HTTP://WWW.PSI.NET) and as the Policy may be modified by PSINet in its sole
discretion from time to time. Any content, material, message, or data made
available or transmitted through the Network, wherever it is sent from, viewed,
received, or retrieved, that is in violation of (i) any local, state, federal or
international law, regulation or treaty; (ii) the Policy; or (iii) any community
standard or accepted Internet policy is prohibited. In the event of violation of
the foregoing by any Subscriber, PSINet will advise Retailer accordingly, and
PSINet reserves the right, in its sole discretion, to terminate such
Subscriber's Access immediately with written notice to Retailer.

INDEMNIFICATION OF PSINET. SUBSCRIBER SHALL INDEMNIFY AND HOLD HARMLESS PSINET
AND PSINET'S DIRECTORS, OFFICERS, EMPLOYEES, AGENTS AND ADVISORS FROM AND
AGAINST ANY AND ALL CLAIMS OF OTHER PERSONS OR ENTITIES ARISING OUT OF ANY
MATERIAL, MESSAGE, DATA, INFORMATION OR OTHER CONTENT TRANSMITTED OR MADE
AVAILABLE BY SUBSCRIBER OR ARISING OUT OF OTHER ACTS OR OMISSIONS OF SUBSCRIBER.



                                 Schedule 5.4.1

                                  Page 23 of 26

<PAGE>   99



                                 SCHEDULE 5.4.2

                   PROVISIONS IN AGREEMENTS WITH IXC CUSTOMERS


Except as otherwise contemplated under Section 5.1 of the Joint Marketing and
Services Agreement to which this Schedule is attached (the "Marketing
Agreement"), IXC shall require that any IXC Customer to which Services are
provided enter into an agreement that provides, among other things, terms and
conditions reasonably consistent with the provisions of Schedule 5.4.1 to the
Marketing Agreement; provided, however, that with respect to any IXC Customer
for which IXC is not in privity of contract with, IXC shall use reasonable best
efforts to cause the IXC Reseller to require that such IXC Customer enter into
an agreement that provides, among other things, terms and conditions reasonably
consistent with the provisions of Schedule 5.4.1 to the Marketing Agreement. The
parties shall be permitted to make appropriate substitutions to reflect the
identity and uniqueness of the providing party so long as the contract
provisions set forth on Schedule 5.4.1 remain in substantially the form attached
thereto and do not impose any greater liability, obligation or commitment on the
part of PSI. Such agreement shall also provide that, except to the extent caused
by PSI's gross negligence, recklessness or willful misconduct, (i) such IXC
Customer shall defend, indemnify and hold harmless PSI and its respective
directors, officers, employees and agents from any claim asserted by any IXC
Customer or any Third Party to or arising out of use by the IXC Customer or
Third Party of the Services or products provided hereunder, (ii) that PSI shall
not be liable to IXC Customer for indirect, consequential, incidental or special
damages even if advised of the possibility in advance, and (iii) that PSI's
liability for damages to any IXC Customer for any cause whatsoever, regardless
of form of action, shall be limited to the greater of (A) $25,000 for each site
provisioned for Services under this Agreement or (B) the amounts paid by such
IXC Customer for Services during the twelve (12) month period preceding the
incident giving rise to the claim for damages. The foregoing requirements may be
waived or modified with the consent of PSI and shall be modified automatically
to the extent PSI waives such provisions, or imposes less restrictive
provisions, on its customers under its standard terms and conditions and normal
business practices (including where exceptions are routinely granted to
customers), or for any other reseller or distributor. Each Party agrees to
consider such modifications to the foregoing requirements as are reasonably
required in light of market conditions. In situations in which PSI enters into
an agreement directly with the IXC Customer for the provision of the Services,
as contemplated under Section 5.4.2 of the Marketing Agreement, PSI agrees to
include corresponding provisions in its agreements with IXC Customers for the
benefit of IXC.



                                 Schedule 5.4.2

                                   Page 1 of 1

<PAGE>   100



                                  SCHEDULE 6.2

                             PSI POINTS OF PRESENCE

                              PSINet Access Numbers


<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Birmingham              AL                  205-942-9890     Yes          Yes
Birmingham              AL                  205-942-5809                  Yes         Yes
Huntsville              AL                  205-536-5920     Yes          Yes
Mobile                  AL                  334-660-0271     Yes          Yes
Little Rock             AR                  501-340-6400     Yes          Yes
Little Rock             AR                  501-372-2888                  Yes         Yes
Phoenix                 AZ                  602-640-6096     Yes          Yes
Phoenix                 AZ                  602-640-1072                  Yes         Yes
Tucson                  AZ                  520-620-6152     Yes          Yes
Bakersfield             CA                  805-322-2100     Yes          Yes
Barstow                 CA                  619-255-4044     Yes
Berkeley                CA                  510-848-1596                  Yes         Yes
Berkeley                CA                  510-848-1398     Yes          Yes
Burbank                 CA                  818-526-7749     Yes          Yes
Burbank                 CA                  818-526-7791                  Yes         Yes
Chico                   CA                  916-891-1055     Yes          Yes
Concord                 CA                  510-688-2363     Yes          Yes
Concord                 CA                  510-688-2367                  Yes         Yes
Fresno                  CA                  209-497-0200     Yes          Yes
Irvine                  CA                  714-450-0955     Yes          Yes
Irvine                  CA                  714-450-0255                  Yes         Yes
Los Angeles             CA                  213-625-8300     Yes          Yes
Los Angeles             CA                  213-622-3499                  Yes         Yes
Malibu                  CA                  310-317-8300     Yes
Malibu                  CA                  310-456-6171                  Yes         Yes
Mission Viejo           CA                  714-461-7915     Yes          Yes
Mission Viejo           CA                  714-461-7247                  Yes         Yes
Modesto                 CA                  209-524-0197     Yes          Yes
Mountain View           CA                  415-390-0900     Yes          Yes
Mountain View           CA                  415-428-0704                  Yes         Yes
Orinda                  CA                  510-254-7549     Yes          Yes
Orinda                  CA                  510-254-9675                  Yes         Yes
Pasadena                CA                  818-449-2859     Yes          Yes
Pasadena                CA                  818-449-1706     Yes          Yes
Pasadena                CA                  818-449-9750                  Yes         Yes

</TABLE>

                                  Schedule 6.2

                                   Page 1 of 9

<PAGE>   101


<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Sacramento              CA                  916-537-2901     Yes          Yes
Sacramento              CA                  916-536-3800     Yes
San Bernardino          CA                  909-824-9223     Yes          Yes
San Diego               CA                  619-230-1221     Yes          Yes
San Diego               CA                  619-232-1613                  Yes         Yes
San Francisco           CA                  415-442-4600     Yes          Yes
San Francisco           CA                  415-538-7866                  Yes         Yes
San Francisco           CA                  415-538-1594                  Yes         Yes
San Luis Obispo         CA                  805-545-5827     Yes          Yes
San Ramon               CA                  510-866-1791                  Yes         Yes
San Ramon               CA                  510-866-1879     Yes          Yes
Santa Ana               CA                  714-547-9231     Yes          Yes
Santa Ana               CA                  714-558-8232                  Yes         Yes
Santa Clara             CA                  408-980-8120     Yes          Yes
Santa Clara             CA                  408-727-1796                  Yes         Yes
Stockton                CA                  209-464-0899     Yes          Yes
Torrance                CA                  310-781-9329     Yes          Yes
Torrance                CA                  310-781-9216                  Yes         Yes
Van Nuys                CA                  818-781-1827     Yes          Yes
Van Nuys                CA                  818-781-2158                  Yes         Yes
Colorado Springs        CO                  719-594-2090     Yes          Yes
Colorado Springs        CO                  719-536-6900                  Yes         Yes
Denver                  CO                  303-713-4580     Yes          Yes
Denver                  CO                  303-713-6980                  Yes         Yes
Hartford                CT                  860-947-7656     Yes          Yes
Hartford                CT                  860-947-1200                  Yes         Yes
New Haven               CT                  203-497-8727     Yes          Yes
Stamford                CT                  203-316-2947     Yes          Yes
Wilton                  CT                  203-834-6730     Yes
Washington              DC                  202-296-1127     Yes          Yes
Washington              DC                  202-296-1388                  Yes         Yes
Wilmington              DE                  302-576-0500     Yes          Yes
Ft Lauderdale           FL                  954-971-5720     Yes          Yes
Ft Myers                FL                  941-477-5000     Yes          Yes
Jacksonville            FL                  904-355-1523     Yes          Yes
Miami                   FL                  305-471-6819     Yes          Yes
Miami                   FL                  305-471-8102                  Yes         Yes
Miami                   FL                  305-471-8978                  Yes         Yes
Orlando                 FL                  407-648-9426     Yes          Yes

</TABLE>

                                  Schedule 6.2

                                   Page 2 of 9

<PAGE>   102



<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Orlando                 FL                  407-648-9826                  Yes         Yes
Sarasota                FL                  941-362-0764     Yes          Yes
Sarasota                FL                  941-362-0864                  Yes         Yes
St Petersburg           FL                  813-826-0052     Yes          Yes
St Petersburg           FL                  813-826-3010                  Yes         Yes
Tallahassee             FL                  904-222-5078     Yes          Yes
Tampa                   FL                  813-276-9824     Yes          Yes
Tampa                   FL                  813-273-0923                  Yes         Yes
Winter Park             FL                  407-975-4600     Yes          Yes
Albany                  GA                  912-430-1000     Yes          Yes
Atlanta                 GA                  404-527-0300                  Yes         Yes
Atlanta                 GA                  770-577-1666                  Yes         Yes
Atlanta                 GA                  404-865-0110     Yes          Yes
Atlanta                 GA                  770-421-1576                  Yes         Yes
Atlanta                 GA                  770-421-0546     Yes          Yes
Augusta                 GA                  706-849-2280     Yes          Yes
College Park            GA                  404-762-5160     Yes          Yes
Des Moines              IA                  515-222-2140     Yes          Yes
Chicago                 IL                  312-565-9446                  Yes         Yes
Chicago                 IL                  312-565-4310                  Yes         Yes
Chicago                 IL                  312-240-3396     Yes          Yes
Schiller Park           IL                  847-671-4033     Yes          Yes
Urbana                  IL                  217-373-2680     Yes          Yes
Fort Wayne              IN                  219-452-1004     Yes          Yes
Indianapolis            IN                  317-842-7547     Yes          Yes
Indianapolis            IN                  317-576-0308                  Yes         Yes
South Bend              IN                  219-271-0326     Yes          Yes
Hutchinson              KS                  316-694-0036     Yes          Yes
Wichita                 KS                  316-337-0198     Yes          Yes
Wichita                 KS                  316-337-0095                  Yes         Yes
Louisville              KY                  502-584-1710     Yes          Yes
Louisville              KY                  502-588-9091                  Yes         Yes
Baton Rouge             LA                  504-928-2660     Yes          Yes
Baton Rouge             LA                  504-231-9963     Yes
New Orleans             LA                  504-366-0091     Yes          Yes
New Orleans             LA                  504-366-6003                  Yes         Yes
Lafayette               LA                  318-262-0039     Yes
Shreveport              LA                  318-686-2577     Yes          Yes
Boston                  MA                  617-927-3600     Yes          Yes

</TABLE>

                                  Schedule 6.2

                                   Page 3 of 9

<PAGE>   103

<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Boston                  MA                  617-450-6800                  Yes         Yes
Boston                  MA                  617-927-3800                  Yes         Yes
Springfield             MA                  413-846-0300     Yes          Yes
Billerica               MA                  508-439-6000     Yes          Yes
Billerica               MA                  508-262-9400                  Yes         Yes
Concord                 MA                  508-371-5300     Yes          Yes
Annapolis               MD                  410-268-0669     Yes
Baltimore               MD                  410-244-0719     Yes          Yes
Baltimore               MD                  410-244-0935                  Yes         Yes
Bel Air                 MD                  410-638-0219     Yes          Yes
Frederick               MD                  301-663-8153     Yes          Yes
Hagerstown              MD                  301-665-1216     Yes          Yes
Salisbury               MD                  410-341-0278     Yes          Yes
Portland                ME                  207-791-8300     Yes          Yes
Ann Arbor               MI                  313-998-2601     Yes          Yes
Bay City                MI                  517-667-6121     Yes          Yes
Centerline              MI                  810-574-0259     Yes
Detroit                 MI                  313-225-4099     Yes          Yes
Detroit                 MI                  313-259-0680     Yes          Yes
Flint                   MI                  810-768-7980     Yes
Grand Rapids            MI                  616-235-9246     Yes          Yes
Grand Rapids            MI                  616-235-1190                  Yes         Yes
Jackson                 MI                  517-783-0809     Yes          Yes
Kalamazoo               MI                  616-226-8593     Yes
Kalamazoo               MI                  616-226-8589     Yes          Yes
Lansing                 MI                  517-336-8936     Yes          Yes
Lansing                 MI                  517-267-9846     Yes          Yes
Midland                 MI                  517-837-1394     Yes          Yes
Pontiac                 MI                  810-475-4425     Yes
Royal Oak               MI                  810-614-3580     Yes          Yes
Royal Oak               MI                  810-435-2388     Yes          Yes
Royal Oak               MI                  810-435-5440     Yes          Yes
Saginaw                 MI                  517-771-0053     Yes
Duluth                  MN                  218-720-5960     Yes
St Paul                 MN                  612-223-7560     Yes
Minneapolis             MN                  612-317-9260     Yes          Yes
Minneapolis             MN                  612-317-9280                  Yes         Yes
Kansas City             MO                  816-235-7000     Yes          Yes
Kansas City             MO                  816-235-7300                  Yes         Yes
</TABLE>


                                  Schedule 6.2

                                   Page 4 of 9

<PAGE>   104


<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
St Louis                MO                  314-516-0000     Yes          Yes
St Louis                MO                  314-622-0026                  Yes         Yes
Jackson                 MS                  601-956-2325     Yes          Yes
Jackson                 MS                  601-956-3883     Yes
Pascagoula              MS                  601-934-2180     Yes          Yes
Billings                MT                  406-247-3000     Yes
Asheville               NC                  704-253-0221     Yes
Charlotte               NC                  704-554-5680     Yes          Yes
Charlotte               NC                  704-554-5907                  Yes         Yes
Durham                  NC                  919-572-9895     Yes          Yes
Durham                  NC                  919-572-9891                  Yes         Yes
Fayetteville            NC                  910-323-9401     Yes          Yes
Greensboro              NC                  910-333-2366     Yes
Greensboro              NC                  910-574-0105                  Yes         Yes
Raleigh                 NC                  919-876-7279                  Yes         Yes
Raleigh                 NC                  919-876-8141     Yes          Yes
Rocky Mount             NC                  919-407-8042     Yes          Yes
Southern Pines          NC                  910-692-5130     Yes
Triangle Park           NC                  919-558-2121     Yes
Winston Salem           NC                  910-721-1212     Yes          Yes
Fargo                   ND                  701-271-6300     Yes          Yes
Lincoln                 NE                  402-458-2800     Yes
Manchester              NH                  603-644-0500     Yes
Atlantic City           NJ                  609-484-3516     Yes          Yes
Ewing                   NJ                  609-278-3268     Yes          Yes
Fairlawn                NJ                  201-794-1795     Yes          Yes
Hackensack              NJ                  201-343-8210     Yes          Yes
Moorestown              NJ                  609-667-0496     Yes          Yes
Morristown              NJ                  201-898-6758     Yes          Yes
Morristown              NJ                  201-898-6511                  Yes         Yes
Mt Holly                NJ                  609-265-8511     Yes          Yes
Newark                  NJ                  201-622-6100     Yes          Yes
Newark                  NJ                  201-645-0874     Yes          Yes
Perth Amboy             NJ                  908-442-6182     Yes          Yes
Princeton               NJ                  609-252-0301     Yes          Yes
Riverton                NJ                  609-786-1079     Yes          Yes
Trenton                 NJ                  609-631-0494     Yes          Yes
Vineland                NJ                  609-205-0040     Yes          Yes
Waverly                 NJ                  201-923-3113                  Yes         Yes
</TABLE>


                                  Schedule 6.2

                                   Page 5 of 9


<PAGE>   105

<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Albuquerque             NM                  505-246-9088     Yes          Yes
Las Vegas               NV                  702-382-6667     Yes          Yes
Reno                    NV                  702-322-9191     Yes          Yes
Albany                  NY                  518-436-3200     Yes
Buffalo                 NY                  716-888-1000     Yes          Yes
Buffalo                 NY                  716.843.0480     Yes          Yes
Buffalo                 NY                  716-843-0500                  Yes         Yes
Elmsford                NY                  914-789-8000     Yes          Yes
Garden City             NY                  516-227-5600     Yes          Yes
Garden City             NY                  516-357-2800     Yes
Islip                   NY                  516-468-5100     Yes          Yes
Islip                   NY                  516-468-2100                  Yes         Yes
Ithaca                  NY                  607-266-4600     Yes          Yes
Ithaca                  NY                  607-266-4500                  Yes         Yes
New York                NY                  212-328-4487     Yes          Yes
New York                NY                  212-709-3940                              Yes
New York                NY                  212-709-3960                  Yes         Yes
New York                NY                  212-709-3980                  Yes         Yes
New York                NY                  212-440-8180                  Yes         Yes
Poughkeepsie            NY                  914-451-7800     Yes          Yes
Rochester               NY                  716-428-3700     Yes          Yes
Rochester               NY                  716-324-1000     Yes
Syracuse                NY                  315-448-4000     Yes          Yes
Troy                    NY                  518-270-7020     Yes                       No
White Plains            NY                  914-993-6000     Yes          Yes
White Plains            NY                  914-286-3520                  Yes         Yes
Akron                   OH                  330-374-6990     Yes          Yes
Akron                   OH                  330-253-9993                  Yes         Yes
Cincinnati              OH                  513-792-9299     Yes          Yes
Cincinnati              OH                  513-361-4100                  Yes         Yes
Cleveland               OH                  216-696-8236                  Yes         Yes
Cleveland               OH                  216-696-6331     Yes          Yes
Cleveland               OH                  216-622-7300     Yes          Yes
Columbus                OH                  614-442-9500     Yes          Yes
Columbus                OH                  614-222-0825                              Yes
Dayton                  OH                  937-640-5321     Yes          Yes
Dayton                  OH                  937-220-6211                  Yes         Yes
Dublin                  OH                  614-228-7452     Yes          Yes
Dublin                  OH                  614-766-9196     Yes          Yes
</TABLE>

                                  Schedule 6.2

                                   Page 6 of 9


<PAGE>   106

<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Toledo                  OH                  419-246-2020     Yes          Yes
Youngstown              OH                  330-747-7070     Yes          Yes
Oklahoma City           OK                  405-270-0534     Yes
Tulsa                   OK                  918-445-2622     Yes          Yes
Medford                 OR                  541-776-4510     Yes          Yes
Portland                OR                  503-972-1495     Yes
Portland                OR                  503-972-1493                  Yes         Yes
Allentown               PA                  610-774-9866     Yes          Yes
Altoona                 PA                  814-949-7045     Yes          Yes
Altoona                 PA                  814-949-7046                  Yes         Yes
Carlisle                PA                  717-258-4462     Yes          Yes
Lancaster               PA                  717-871-6380     Yes
Harrisburg              PA                  717-770-2100     Yes          Yes
Harrisburg              PA                  717-770-1194                  Yes         Yes
Philadelphia            PA                  215-440-4205     Yes          Yes
Philadelphia            PA                  215-440-1274                  Yes         Yes
Pittsburgh              PA                  412-562-1103     Yes          Yes
Reading                 PA                  610-670-4650     Yes          Yes
Scranton                PA                  717-941-0113     Yes          Yes
State College           PA                  814-235-7670     Yes          Yes
York                    PA                  717-846-0086     Yes          Yes
Providence              RI                  401-276-2000     Yes
Charleston              SC                  803-853-4001     Yes          Yes
Columbia                SC                  803-254-2220     Yes          Yes
Greenville              SC                  864-288-1702     Yes          Yes
Greenville              SC                  864-288-4525                  Yes         Yes
Jackson                 TN                  901-661-9025     Yes          Yes
Knoxville               TN                  423-558-8400     Yes          Yes
Knoxville               TN                  423-588-0804                  Yes         Yes
Memphis                 TN                  901-371-2030     Yes          Yes
Memphis                 TN                  901-387-1793                  Yes         Yes
Nashville               TN                  615-385-4004     Yes          Yes
Nashville               TN                  615-385-7148                  Yes         Yes
Abilene                 TX                  915-738-3100     Yes          Yes
Amarillo                TX                  806-345-1500     Yes
Austin                  TX                  512-464-0011     Yes
Austin                  TX                  512-464-0008                  Yes         Yes
Dallas                  TX                  214-953-3199     Yes          Yes
Dallas                  TX                  214-979-2059                  Yes         Yes

</TABLE>

                                  Schedule 6.2

                                   Page 7 of 9


<PAGE>   107

<TABLE>
<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Dallas                  TX                  214-860-1902                  Yes         Yes
El Paso                 TX                  915-545-7300     Yes          Yes
Ft Worth                TX                  817-258-9700     Yes
Houston                 TX                  713-767-1503     Yes          Yes
Houston                 TX                  713-567-0497                  Yes         Yes
Lubbock                 TX                  806-741-4400     Yes          Yes
Midland                 TX                  915-699-9500     Yes
San Angelo              TX                  915-481-8100     Yes
San Antonio             TX                  210-244-1900     Yes
Waco                    TX                  817-745-2000     Yes          Yes
Salt Lake City          UT                  801-264-7940     Yes
Salt Lake City          UT                  801-284-0480                  Yes         Yes
Danville                VA                  804-791-4306     Yes          Yes
Fredericksburg          VA                  540-374-0571     Yes          Yes
Herndon                 VA                  703-904-0600     Yes
Herndon                 VA                  703-904-7088                  Yes         Yes
Herndon                 VA                  703-904-9050                  Yes         Yes
Herndon                 VA                  703-742-0706                  Yes         Yes
Herndon                 VA                  703-742-5488                  Yes         Yes
Leesburg                VA                  703-779-1868     Yes          Yes
Lynchburg               VA                  804-528-0448     Yes          Yes
Norfolk                 VA                  804-455-8178     Yes          Yes
Richmond                VA                  804-755-7018     Yes          Yes
Richmond                VA                  804-672-0730                  Yes         Yes
Roanoke                 VA                  540-857-4320     Yes          Yes
Burlington              VT                  802-651-6600     Yes          Yes
Rutland                 VT                  802-786-7300     Yes          Yes
Seattle                 WA                  206-441-2203                  Yes         Yes
Seattle                 WA                  206-812-1155     Yes          Yes
Seattle                 WA                  206-443-0224     Yes          Yes
Seattle                 WA                  206-812-0396                  Yes         Yes
Tacoma                  WA                  206-552-2134     Yes          Yes
Green Bay               WI                  414-983-2080     Yes          Yes
Janesville              WI                  608-755-9420     Yes          Yes
Milwaukee               WI                  414-223-0220     Yes
Milwaukee               WI                  414-223-0222                  Yes         Yes
Charleston              WV                  304-353-7886     Yes          Yes
Morgantown              WV                  304-291-3256     Yes          Yes
</TABLE>

                                  Schedule 6.2

                                   Page 8 of 9


<PAGE>   108

<TABLE>

<CAPTION>
    CITY               STATE                   PHONE #       V.34         ISDN        2B
    ----               -----                   -------       ----         ----        --
<S>                    <C>                  <C>              <C>          <C>         <C>
Wheeling                WV                  304-233-1840     Yes          Yes
</TABLE>

                                  SCHEDULE 7.1


                          PRICES FOR OPTIONAL SERVICES

        The following are Optional Prices by Service, not including taxes and
postage, etc.:

WHOLESALE DIAL-UP INTERNET ACCESS                          $$$$

        1.     Fulfillment (mailer, labeling,
               inserts, etc.)                       1.00/unit
        2.     Software, Netscape software          15.00/seat based upon an
                                                    initial order of 250,000 or
                                                    more, orders below this are
                                                    priced at $30.00/seat

We have a special situation that allows us to sell Netscape to you during July
for lower prices.

Please call for more details, Delivery to be required prior to July 31, 1997.

        3.     Diskette Duplication                  3.50/set
        4.     CD Duplication                        2.00/set
        5.     Printing                              1.75/set
        6.     Customer Support for individuals      5.00/month/subscriber
        7.     Email services                        Prices available on July
                                                     15th
        8.     Usenet news                           10.00/each reader/month


DEDICATED INTERNET ACCESS SERVICE

        1.     Welcome Letters (setup and
               print merged)                          6.50/each, plus a one time
                                                      setup fee per Reseller of
                                                      2,000/one time

        2.     Materials                              1.00/unit
        3.     Printing                               1.75/set
        4.     Fulfillment (mailer, labeling,
               insert, etc.)                          1.00/unit
        5.     Usenet news                            10.00/reader/month
        6.     News Feeds                             195.00/month
        7.     RouteWaller Internet Security
               (w/5 free cards) plus a monthly charge 195.00/initial
                                                      250.00/MRC
        8.     Cold spare router                      100.00/month
        9.     SecureEnterprise                       4,000.00/Initial
               (w/5 free access control cards)        1,600.00/month
               Cold spare redundancy option           665.00/month
        10.    Additional Access Cards &
               authentication service                 15.00/month


                                  Schedule 6.2

                                   Page 1 of 3

<PAGE>   109

LAN ON DEMAND

        1.     Welcome Letters (setup and print
               merged)                                6.50/each, plus a one time
                                                      setup fee per if Reseller
                                                      or 2.00/one time
        2.     Materials                              1.00/unit
        3.     Printing                               1.75/set
        4.     Fulfillment (mailer, labeling,
               insert, etc.)                          1.00/unit


INTERMAN                                              10.00/reader

        1.     Security Filtering                     195.00/setup plus
                                                      50.00/month MRC


WEB BUSINESS SERVICES

        1.     Web Start base site templates used     795.00/psi web setup


FIELD SERVICES, AVAILABLE ONLY IN IMAN CITIES

        1.     On-site Field Service visits           $1,000.00/day (billable in
                                                      1/2 day increments)

DNS SERVICES

        1.     Additional Domain Name                 $100.00/each
        2.     Additional 1 IP network number         $100.00/each


VALUE ADDED RESELLER

        1.     PSI Master VAR agreement commissions   18%
               on Services
               (Not including any circuit charges or
               installation fees)
               Subject to an agreement on activity to be
               performed by both Parties


Network Monthly usage reports                         TBD

Off-hours Helpline Support (other than 8am to 8pm)    TBD



                                  Schedule 7.1

                                   Page 2 of 3

<PAGE>   110




                                  APPENDIX 1 TO
                                  SCHEDULE 7.1

                                        *

                 (CONFIDENTIAL AND PROPRIETARY TO PSINET, INC.)

<TABLE>
<CAPTION>
                                 RETAIL PRICE     IXC COST         MARGIN         MARGIN
                                 ------------    -----------     ----------      ----------
                                 NRC     MRC     NRC     MRC     NRC    MRC      NRC    MRC
                                 ---     ---     ---     ---     ---    ---      ---    ---
<S>                            <C>      <C>     <C>     <C>      <C>    <C>     <C>   <C>   
LAN-DIAL                       $  145   $ 145   $  145  $  90    $ 0    $  55   $ 0%  $  61%

LAN-ISDN                          295     295      295    135      0      160     0%    119%

InterFrame 56                     295     395      295    175      0      220     0%    126%

InterFrame 128                    995     895      995    795      0      100     0%     13%

InterFrame 256                    995     995      995    895      0      100     0%     11%

InterFrame 512                    995   1,595      995  1,095      0      500     0%     46%

InterFrame T1                     995   1,995      995  1,395      0      600     0%     43%

InterMAN T1                     3,000   1,200    3,000    800      0      400     0%     50%

InterMAN 4M                     5,000   3,000    5,000  2,100      0      900     0%     43%

InterMAN 10M                    5,000   4,000    5,000  2,900      0    1,100     0%     38%

InterMAN 16M                    5,000   8,000    5,000  5,750      0    2,250     0%     39%

InterMAN 25M                    5,000  10,000    5,000  7,225      0    2,775     0%     38%

InterMAN T3 (SMDS)              5,000  12,000    5,000  8,395      0    3,605     0%     43%

InterMAN T3 (ATM)              15,000  12,000   15,000  8,395      0    3,605     0%     43%

PSIWebt T1                        250     100      250     80      0       20     0%     25%

PSIWebt 10M                       250     500      250    400      0      100     0%     25%

PSIWebt T3                        250   3,000      250  2,500      0      500     0%     20%

InterRamp Remote
Access**                         0.00   19.95     0.00   9.00      0    10.95     0%    122%

</TABLE>


- --------

*       Confidential material has been omitted and filed separately with the
        Securities and Exchange Commission.

**      Price is per unit.

                                  Schedule 7.1

                                   Page 3 of 3



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