ADVANCED FIBRE COMMUNICATIONS INC
424B4, 1997-02-13
TELEPHONE & TELEGRAPH APPARATUS
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<PAGE>
                                                               Filed Pursuant to
                                                                  Rule 424(b)(4)
                                                            (File no. 333-20369)
 PROSPECTUS
                                2,000,000 SHARES
 
                                     [LOGO]
 
                                  COMMON STOCK
                             ---------------------
 
OF  THE 2,000,000  SHARES OF  COMMON STOCK  OFFERED, 1,600,000  SHARES ARE BEING
OFFERED INITIALLY IN THE UNITED STATES AND CANADA BY THE U.S. UNDERWRITERS AND
  400,000 SHARES ARE BEING OFFERED INITIALLY OUTSIDE OF THE UNITED STATES AND
    CANADA BY  THE INTERNATIONAL  UNDERWRITERS. SEE  "UNDERWRITERS." OF  THE
    1,600,000   SHARES  OF   COMMON  STOCK   BEING  OFFERED   BY  THE  U.S.
     UNDERWRITERS, 160,000  SHARES  ARE  BEING  SOLD  BY  THE  COMPANY  AND
     1,440,000  SHARES ARE  BEING SOLD  BY THE  SELLING STOCKHOLDERS. SEE
       "PRINCIPAL AND  SELLING  STOCKHOLDERS."  THE  COMPANY  WILL  NOT
         RECEIVE  ANY OF  THE PROCEEDS FROM  THE SALE OF  SHARES BY THE
         SELLING STOCKHOLDERS. THE COMPANY'S COMMON STOCK IS LISTED ON
          THE NASDAQ  NATIONAL MARKET  UNDER THE  SYMBOL "AFCI."  ON
            FEBRUARY  12, 1997,  THE LAST  SALE PRICE  OF THE COMMON
            STOCK AS REPORTED ON THE  NASDAQ  NATIONAL MARKET  WAS
              $44  3/8  PER  SHARE.  SEE  "PRICE  RANGE  OF COMMON
                                    STOCK."
 
                           --------------------------
 
         THIS OFFERING INVOLVES A HIGH DEGREE OF RISK. SEE ``RISK FACTORS"
                          COMMENCING ON PAGE 4 HEREOF.
                             ---------------------
 
THESE SECURITIES HAVE  NOT BEEN APPROVED  OR DISAPPROVED BY  THE SECURITIES  AND
  EXCHANGE   COMMISSION  OR  ANY  STATE  SECURITIES  COMMISSION  NOR  HAS  THE
    SECURITIES AND EXCHANGE  COMMISSION OR ANY  STATE SECURITIES  COMMISSION
     PASSED   UPON   THE   ACCURACY  OR   ADEQUACY   OF   THIS  PROSPECTUS.
       ANY  REPRESENTATION  TO  THE  CONTRARY  IS  A  CRIMINAL   OFFENSE.
                            ------------------------
 
                             PRICE $44 1/4 A SHARE
                            ------------------------
 
<TABLE>
<CAPTION>
                                                             UNDERWRITING                            PROCEEDS TO
                                           PRICE TO         DISCOUNTS AND        PROCEEDS TO           SELLING
                                            PUBLIC         COMMISSIONS (1)       COMPANY (2)         STOCKHOLDERS
                                      ------------------  ------------------  ------------------  ------------------
<S>                                   <C>                 <C>                 <C>                 <C>
PER SHARE...........................        $44.25              $2.21               $42.04              $42.04
TOTAL (3)...........................     $88,500,000          $4,420,000          $8,408,000         $75,672,000
</TABLE>
 
- ------------
    (1)  THE COMPANY AND  THE SELLING STOCKHOLDERS HAVE  AGREED TO INDEMNIFY THE
       UNDERWRITERS AGAINST CERTAIN LIABILITIES, INCLUDING LIABILITIES UNDER THE
       SECURITIES ACT OF 1933, AS AMENDED.
 
    (2) BEFORE DEDUCTING EXPENSES PAYABLE BY THE COMPANY ESTIMATED AT $450,000.
 
    (3) CERTAIN SELLING STOCKHOLDERS  HAVE GRANTED TO  THE U.S. UNDERWRITERS  AN
       OPTION,  EXERCISABLE WITHIN 30 DAYS OF THE DATE HEREOF, TO PURCHASE UP TO
       AN AGGREGATE OF  300,000 ADDITIONAL SHARES  AT THE PRICE  TO PUBLIC  LESS
       UNDERWRITING  DISCOUNTS  AND  COMMISSIONS  FOR  THE  PURPOSE  OF COVERING
       OVER-ALLOTMENTS, IF ANY. IF THE U.S. UNDERWRITERS EXERCISE SUCH OPTION IN
       FULL, THE TOTAL PRICE TO  PUBLIC, UNDERWRITING DISCOUNTS AND  COMMISSIONS
       AND PROCEEDS TO SELLING STOCKHOLDERS WILL BE $101,775,000, $5,083,000 AND
       $88,284,000, RESPECTIVELY. SEE "UNDERWRITERS."
 
                         ------------------------------
 
    THE  SHARES ARE OFFERED, SUBJECT TO PRIOR  SALE, WHEN, AS AND IF ACCEPTED BY
THE UNDERWRITERS NAMED HEREIN AND SUBJECT  TO APPROVAL OF CERTAIN LEGAL  MATTERS
BY  WILSON SONSINI GOODRICH & ROSATI,  PROFESSIONAL CORPORATION, COUNSEL FOR THE
UNDERWRITERS. IT IS  EXPECTED THAT DELIVERY  OF THE  SHARES WILL BE  MADE ON  OR
ABOUT  FEBRUARY 19, 1997 AT THE OFFICE OF MORGAN STANLEY & CO. INCORPORATED, NEW
YORK, N.Y., AGAINST PAYMENT THEREFOR IN IMMEDIATELY AVAILABLE FUNDS.
 
                           --------------------------
 
MORGAN STANLEY & CO.
            INCORPORATED
 
                MERRILL LYNCH & CO.
 
                                COWEN & COMPANY
 
                                                               HAMBRECHT & QUIST
 
FEBRUARY 12, 1997
<PAGE>
    NO PERSON IS AUTHORIZED IN CONNECTION WITH ANY OFFERING MADE HEREBY TO  GIVE
ANY  INFORMATION OR TO MAKE  ANY REPRESENTATION OTHER THAN  AS CONTAINED IN THIS
PROSPECTUS, AND IF GIVEN OR MADE, SUCH INFORMATION OR REPRESENTATION MUST NOT BE
RELIED UPON AS HAVING BEEN AUTHORIZED BY THE COMPANY OR BY ANY UNDERWRITER. THIS
PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN OFFER TO
BUY BY ANY PERSON IN ANY JURISDICTION IN WHICH IT IS UNLAWFUL FOR SUCH PERSON TO
MAKE SUCH AN OFFERING OR SOLICITATION.  NEITHER THE DELIVERY OF THIS  PROSPECTUS
NOR  ANY  SALE  MADE  HEREUNDER  SHALL UNDER  ANY  CIRCUMSTANCE  IMPLY  THAT THE
INFORMATION CONTAINED HEREIN IS  CORRECT AS OF ANY  DATE SUBSEQUENT TO THE  DATE
HEREOF.
                            ------------------------
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                                                                                       PAGE
                                                                                                                     ---------
<S>                                                                                                                  <C>
Prospectus Summary.................................................................................................          3
Risk Factors.......................................................................................................          4
The Company........................................................................................................         13
Use of Proceeds....................................................................................................         14
Dividend Policy....................................................................................................         14
Price Range of Common Stock........................................................................................         14
Capitalization.....................................................................................................         15
Selected Consolidated Financial Data...............................................................................         16
Management's Discussion and Analysis of Financial Condition and Results of Operations..............................         17
Business...........................................................................................................         24
Management.........................................................................................................         38
Certain Transactions...............................................................................................         48
Principal and Selling Stockholders.................................................................................         51
Description of Capital Stock.......................................................................................         54
Shares Eligible for Future Sale....................................................................................         57
Underwriters.......................................................................................................         59
Legal Matters......................................................................................................         62
Experts............................................................................................................         62
Additional Information.............................................................................................         62
Glossary of Terms..................................................................................................         63
Index to Consolidated Financial Statements.........................................................................        F-l
</TABLE>
 
                            ------------------------
 
    The  Universal Modular Carrier  1000-TM- is a trademark  of the Company. All
other trademarks or trade names referred to in this Prospectus are the  property
of their respective owners.
                            ------------------------
 
    EXCEPT  AS OTHERWISE NOTED HEREIN, INFORMATION IN THIS PROSPECTUS ASSUMES NO
EXERCISE OF THE UNDERWRITERS' OVER-ALLOTMENT  OPTION. THE COMPANY OPERATES ON  A
13-WEEK  FISCAL QUARTER, COMPRISED OF FOUR, FOUR  AND FIVE WEEK MONTHS ENDING ON
THE LAST SATURDAY  OF THE  LAST WEEK OF  THE FIVE-WEEK  MONTH. FOR  PRESENTATION
PURPOSES  ONLY, THE COMPANY HAS SHOWN ITS  FIRST THREE FISCAL QUARTERS AS ENDING
ON MARCH 31, JUNE 30 AND SEPTEMBER  30 AND ITS FOURTH FISCAL QUARTER AND  FISCAL
YEAR AS ENDING ON DECEMBER 31.
                            ------------------------
 
    SEE  "GLOSSARY OF  TERMS" COMMENCING ON  PAGE 63 FOR  DEFINITIONS OF VARIOUS
ACRONYMS AND TECHNICAL TERMS USED IN THIS PROSPECTUS.
                            ------------------------
 
    IN CONNECTION WITH THIS OFFERING, THE UNDERWRITERS MAY OVER-ALLOT OR  EFFECT
TRANSACTIONS WHICH STABILIZE OR MAINTAIN THE MARKET PRICE OF THE COMMON STOCK OF
THE  COMPANY AT  A LEVEL ABOVE  THAT WHICH  MIGHT OTHERWISE PREVAIL  IN THE OPEN
MARKET. SUCH  TRANSACTIONS MAY  BE EFFECTED  ON THE  NASDAQ NATIONAL  MARKET  OR
OTHERWISE. SUCH STABILIZING, IF COMMENCED, MAY BE DISCONTINUED AT ANY TIME.
                            ------------------------
 
    IN CONNECTION WITH THIS OFFERING, CERTAIN UNDERWRITERS MAY ENGAGE IN PASSIVE
MARKET  MAKING TRANSACTIONS  IN THE  COMMON STOCK OF  THE COMPANY  ON THE NASDAQ
NATIONAL MARKET IN ACCORDANCE WITH RULE 10B-6A UNDER THE SECURITIES EXCHANGE ACT
OF 1934. SEE "UNDERWRITERS."
 
                                       2
<PAGE>
                               PROSPECTUS SUMMARY
 
    THE  FOLLOWING SUMMARY  IS QUALIFIED  IN ITS  ENTIRETY BY  THE MORE DETAILED
INFORMATION AND CONSOLIDATED  FINANCIAL STATEMENTS AND  NOTES THERETO  APPEARING
ELSEWHERE IN THIS PROSPECTUS.
 
                                  THE COMPANY
 
    Advanced  Fibre  Communications,  Inc.  ("AFC"  or  the  "Company") designs,
develops, manufactures,  markets  and  supports the  Universal  Modular  Carrier
1000-TM-  (the  "UMC"  system),  a  cost-effective,  multi-feature  digital loop
carrier system developed  to serve  small line-size markets.  The Company's  UMC
system  is designed  to enable  telephone companies,  cable companies  and other
service providers to connect subscribers to the central office switch for  voice
and  data communications over copper wire,  fiber optic cable, coaxial cable and
analog radio networks.  The Company  believes that the  UMC system  is the  only
digital  loop  carrier  that  can  operate  simultaneously  over  a  variety  of
transmission media.  The UMC  system  meets the  service needs  of  subscribers,
including  analog services such as plain  old telephone service, universal voice
grade service and  analog switched data  service, and digital  services such  as
high speed digital data service, ISDN, asynchronous and synchronous data channel
services.
 
    The  UMC  system  has  been  sold to  more  than  450  independent telephone
companies in the  United States, has  been initially deployed  by Ameritech  and
GTE,  and is in  laboratory or field  trials at Pacific  Bell and BellSouth. The
Company has  also sold  the UMC  system  to telephone  companies in  Hong  Kong,
France,  Brazil,  Canada,  China,  Mexico,  the  Netherlands  Antilles  and  the
Dominican Republic. The UMC system is distributed and serviced worldwide through
its direct  sales force  in the  domestic market  and through  its direct  sales
force, distributors and agents in international markets.
 
RECENT DEVELOPMENTS
 
    Revenues  for the  quarter ended December  31, 1996 increased  112% to $41.4
million from $19.5 million  for the quarter ended  December 31, 1995.  Operating
income  in the quarter increased 218% to  $6.2 million from $1.9 million and net
income in the quarter increased  258% to $5.6 million  from $1.6 million in  the
quarter ended December 31, 1995. The Company continued to expand its penetration
of  international markets, completing sales to its first customers in Brazil and
increasing sales in China. The Company  has begun working with Flextronics,  one
of  the Company's  contract manufacturers,  to manufacture  UMC assemblies  at a
Flextronics facility in China.
 
                                  THE OFFERING
 
<TABLE>
<S>                                                   <C>        <C>
U.S. Offering.......................................  1,600,000  Shares
International Offering..............................    400,000  Shares
    Total...........................................  2,000,000  Shares (including 200,000 Shares by the Company and
                                                                 1,800,000 Shares by the Selling Stockholders)
Common Stock to be outstanding after the offering...  33,085,002 Shares (1)
Use of proceeds.....................................  For general corporate purposes, including working capital
Nasdaq National Market symbol.......................  AFCI
</TABLE>
 
                      SUMMARY CONSOLIDATED FINANCIAL DATA
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                       YEAR ENDED DECEMBER 31,
                                                                              ------------------------------------------
                                                                                1993       1994       1995     1996 (2)
                                                                              ---------  ---------  ---------  ---------
<S>                                                                           <C>        <C>        <C>        <C>
CONSOLIDATED STATEMENT OF OPERATIONS DATA:
Revenues....................................................................  $     620  $  18,802  $  54,287  $ 130,193
Gross profit (loss).........................................................     (1,954)     4,678     20,818     56,243
Operating income (loss).....................................................     (7,291)    (7,791)     3,805      1,695
Net income (loss)...........................................................     (7,291)    (7,765)     2,341      7,237
Pro forma net income per share (3)..........................................                        $    0.09  $    0.21
Shares used in per share computations (3)...................................                           27,329     34,282
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                             DECEMBER 31, 1996
                                                                                         --------------------------
                                                                                          ACTUAL    AS ADJUSTED (4)
                                                                                         ---------  ---------------
<S>                                                                                      <C>        <C>
CONSOLIDATED BALANCE SHEET DATA:
Cash and cash equivalents and marketable securities....................................  $ 108,430     $ 116,388
Working capital........................................................................    145,338       153,296
Total assets...........................................................................    175,679       183,637
Total stockholders' equity.............................................................    158,023       165,981
</TABLE>
 
- ------------
(1) Based on the number  of shares outstanding as of  December 31, 1996 and  the
    number  of  shares issuable  upon the  net exercise  of warrants  by certain
    Selling Stockholders in  connection with this  offering. Excludes  7,008,142
    shares  of  Common Stock  reserved for  issuance  under the  Company's stock
    option  plans,  under  which  options  to  purchase  4,313,544  shares  were
    outstanding  as  of December  31, 1996,  and  1,500,000 shares  reserved for
    issuance under the  Company's Employee  Stock Purchase  Plan. Also  excludes
    2,332,686  shares  of Common  Stock reserved  for  issuance pursuant  to the
    exercise of  warrants outstanding  as  of December  31, 1996,  after  giving
    effect  to the net exercise of warrants  to acquire 235,395 shares of Common
    Stock by  certain Selling  Stockholders to  be sold  in this  offering.  See
    "Management  -- Stock Incentive  Plan," " --  Employee Stock Purchase Plan,"
    "Certain   Transactions,"   "Principal   and   Selling   Stockholders"   and
    "Description of Capital Stock."
(2)  Includes  a charge  of $15.8  million to  reflect a  cash payment  of $10.1
    million  and  the  issuance  of  725,787  shares  of  Common  Stock  to  DSC
    Communications  Corporation  in  settlement of  outstanding  litigation. See
    "Business -- Legal Proceedings." Without  this charge, operating income  for
    the year ended December 31, 1996 would have been $17.5 million.
 
(3)  See Note 1 of Notes to Consolidated Financial Statements for an explanation
    of the determination of the number of shares used in computing pro forma net
    income per share.
 
(4) As adjusted to  reflect the sale  of 200,000 shares of  Common Stock by  the
    Company   (after  deducting  underwriting   discounts  and  commissions  and
    estimated offering expenses payable by the Company). See "Use of Proceeds."
 
                                       3
<PAGE>
                                  RISK FACTORS
 
    THIS  PROSPECTUS CONTAINS FORWARD-LOOKING STATEMENTS WHICH INVOLVE RISKS AND
UNCERTAINTIES. THE COMPANY'S ACTUAL RESULTS  COULD DIFFER MATERIALLY FROM  THOSE
ANTICIPATED  IN THESE FORWARD-LOOKING STATEMENTS AS A RESULT OF CERTAIN FACTORS,
INCLUDING THOSE SET FORTH  IN THE FOLLOWING RISK  FACTORS AND ELSEWHERE IN  THIS
PROSPECTUS.  IN EVALUATING THE COMPANY'S  BUSINESS, PROSPECTIVE INVESTORS SHOULD
CAREFULLY CONSIDER THE FOLLOWING  FACTORS IN ADDITION  TO THE OTHER  INFORMATION
PRESENTED IN THIS PROSPECTUS.
 
    LIMITED   HISTORY  OF  OPERATIONS  AND   PROFITABILITY.    The  Company  was
incorporated in May 1992  and was in the  initial startup and development  phase
through  December 1993. The Company began shipping  the UMC in January 1994 and,
accordingly,  has  a  limited  operating  history.  The  Company  has   incurred
substantial  expenditures related to the  development, manufacturing startup and
marketing of the UMC  system. As a result  of these expenditures, combined  with
$25.9  million of  expenses and settlement  amounts recorded  in connection with
certain litigation with DSC Communications Corporation ("DSC") which was settled
in June 1996,  the Company  had an  accumulated deficit  of $6.2  million as  of
December  31, 1996.  Although the Company  achieved profitability  for the years
ended December 31, 1995  and 1996, there  can be no  assurance that the  Company
will  sustain or  increase its  profitability in  the future.  See "Management's
Discussion and Analysis of  Financial Condition and  Results of Operations"  and
"Business -- Legal Proceedings."
 
    POTENTIAL  FLUCTUATIONS  IN  FUTURE  OPERATING  RESULTS;  SEASONALITY.   The
Company's operating results have  been, and will continue  to be, affected by  a
wide  variety of factors,  some of which  are outside of  the Company's control,
that could have a material adverse effect on revenues and results of  operations
during  any particular period.  These factors include:  the mix between domestic
and international sales; the customer mix;  the timing and size of orders  which
are  received and  can be  shipped in  a quarter;  the availability  of adequate
supplies of  key components  and assemblies  and the  adequacy of  manufacturing
capacity;  the Company's ability to introduce new products and technologies on a
timely basis; the timing  of new product introductions  or announcements by  the
Company or its competitors; price competition; and unit volume.
 
    The UMC system is sold primarily to telephone companies that install the UMC
system  as part of their access  networks. Additions to those networks represent
complex engineering projects which can require from three to twelve months  from
project  conceptualization to  completion. The  UMC system  typically represents
only a portion of a given project and, therefore, the timing of product shipment
and revenue recognition is often difficult to forecast. In developing countries,
delays and  reductions  in the  planned  project  deployment can  be  caused  by
additional factors, including reductions in capital availability due to declines
in   the  local  economy,   currency  fluctuations,  priority   changes  in  the
government's budget and delays in  receiving government approval for  deployment
of the UMC system in the local loop. The Company's expenditures for research and
development,  marketing and sales, and  general and administrative functions are
based in part on future revenue projections and in the near term are  relatively
fixed.  The  Company may  be unable  to adjust  spending in  a timely  manner in
response to any unanticipated declines in revenues. Accordingly, any significant
decline in demand for  the UMC system  relative to planned  levels could have  a
material  adverse  effect on  the  Company's business,  financial  condition and
results of operations in that quarter  or subsequent quarters. All of the  above
factors  are difficult to forecast, and  these or other factors could materially
adversely affect  the Company's  business, financial  condition and  results  of
operations.  As a result, the Company believes that period-to-period comparisons
are not necessarily meaningful and should  not be relied upon as indications  of
future  performance. Fluctuations in  the Company's operating  results may cause
volatility in the  price of the  Company's Common Stock.  Further, it is  likely
that  in some future quarter the Company's revenues or operating results will be
below the expectations of  public market analysts or  investors. In such  event,
the  market  price of  the  Company's Common  Stock  would likely  be materially
adversely affected.
 
    The Company's customers  normally install  a portion  of the  UMC system  in
outdoor  locations. Shipments of  the UMC system  are subject to  the effects of
seasonality, with fewer installation projects  scheduled for the winter  months.
Accordingly, the Company believes that over time this seasonality will cause its
revenues  in  the  quarter ended  March  31 to  be  lower than  revenues  in the
preceding quarter ended
 
                                       4
<PAGE>
December 31. In particular, the Company currently believes that revenues in  the
quarter  ended March 31,  1997 may be  lower than revenues  in the quarter ended
December 31,  1996.  See  "Management's Discussion  and  Analysis  of  Financial
Condition and Results of Operations -- Quarterly Results of Operations."
 
    DEPENDENCE  ON TELECOMMUNICATIONS INDUSTRY AND  SMALL LINE-SIZE MARKET.  The
Company's customers are  concentrated in the  public carrier  telecommunications
industry.  Accordingly, the  Company's future  success depends  upon the capital
spending patterns of such customers and  the continued demand by such  customers
for  the  UMC  system. The  target  markets for  the  UMC system  are  the small
line-size markets of the United  States and developing countries.  Historically,
these  markets have had little access to  the advanced services that can be made
available through the  UMC system and,  accordingly, there can  be no  assurance
that  potential customers  will consider the  near term value  of these advanced
services to be  sufficient to influence  their purchase decisions.  Furthermore,
there  can be no assurance  that the UMC system  will find widespread acceptance
among the telephone companies and  other potential customers in small  line-size
markets   or  that  such  customers  and  potential  customers  will  not  adopt
alternative architectures or  technologies that  are incompatible  with the  UMC
technology,  which  would  have  a  material  adverse  effect  on  the Company's
business, financial condition and results of operations. In addition, there  can
be no assurance that telephone companies, foreign governments or other customers
will  pursue infrastructure upgrades that will necessitate the implementation of
advanced products such as the UMC system. Infrastructure improvements  requiring
the  Company's or similar technology may be delayed or prevented by a variety of
factors, including cost, regulatory obstacles,  the lack of consumer demand  for
advanced  telecommunications  services  and  alternative  approaches  to service
delivery. See "Management's Discussion and  Analysis of Financial Condition  and
Results    of   Operations,"   "Business   --   Markets   and   Customers"   and
"-- Competition."
 
    CONCENTRATED PRODUCT LINE, NEW PRODUCTS AND RAPID TECHNOLOGICAL CHANGE.  The
Company currently derives substantially all of its revenues from the UMC  system
and  expects that this concentration will continue in the foreseeable future. As
a result, any decrease in the overall level of sales of, or the prices for,  the
UMC  system due to  product enhancements, introductions  or announcements by the
Company's competitors,  a decline  in the  demand for  the UMC  system,  product
obsolescence  or any other  reason could have  a material adverse  effect on the
Company's  business,  financial  condition   and  results  of  operations.   See
"Management's  Discussion  and Analysis  of Financial  Condition and  Results of
Operations."
 
    The telecommunications equipment market is characterized by rapidly changing
technology, evolving industry standards,  changes in end-user requirements,  and
frequent  new  product  introductions  and  enhancements.  The  introduction  of
products embodying new technologies or  the emergence of new industry  standards
can  render existing  products obsolete  or unmarketable.  The Company's success
will depend upon its ability  to enhance the UMC  technology and to develop  and
introduce,  on a timely  basis, new products and  feature enhancements that keep
pace with technological developments and emerging industry standards and address
changing customer  requirements in  a  cost-effective manner.  There can  be  no
assurance  that  the  Company  will be  successful  in  identifying, developing,
manufacturing, and marketing product enhancements  or new products that  respond
to  technological change or  evolving industry standards,  that the Company will
not  experience  difficulties  that  could  delay  or  prevent  the   successful
development,  introduction  and marketing  of these  products,  or that  its new
products and product enhancements will  adequately meet the requirements of  the
marketplace  and achieve market acceptance. Furthermore,  from time to time, the
Company  may  announce  new  products  or  product  enhancements,  services   or
technologies that have the potential to replace or shorten the life cycle of the
UMC  system and  that may  cause customers to  defer purchasing  the UMC system.
There  can  be  no   assurance  that  future   technological  advances  in   the
telecommunications  industry  will not  diminish  market acceptance  of  the UMC
system or  render the  UMC system  obsolete and,  thereby, materially  adversely
affect the Company's business, financial condition and results of operations.
 
    The   Company  has   experienced  delays   in  completing   development  and
introduction of new products, product  variations and feature enhancements,  and
there  can be no  assurance that such delays  will not continue  or recur in the
future. Furthermore, the  UMC system  contains a significant  amount of  complex
hardware  and  software  that may  contain  undetected or  unresolved  errors as
products are introduced or as
 
                                       5
<PAGE>
new versions are  released. The  Company has  in the  past discovered  technical
difficulties  in certain  UMC system  installations. There  can be  no assurance
that, despite significant testing  by the Company,  hardware or software  errors
will  not be found in the UMC  system after commencement of shipments, resulting
in delays in,  or cancellation  of, customer  orders or  in the  loss of  market
acceptance,  any of which could have a  material adverse effect on the Company's
business, financial  condition  and  results of  operations.  See  "Business  --
Competition" and "-- Research and Product Development."
 
    DEPENDENCE  ON SOLE-SOURCE AND OTHER KEY SUPPLIERS.  Certain components used
in the  Company's  products,  including the  Company's  proprietary  application
specific integrated circuits ("ASICs"), codecs, certain surface mount technology
components  and other  components, are  only available  from a  single source or
limited number of  suppliers. Some  of the Company's  sole-source suppliers  are
companies  which  from  time  to  time  allocate  parts  to  telephone equipment
manufacturers due to market demand for telecommunications equipment. Many of the
Company's competitors  are  much larger  and  may  be able  to  obtain  priority
allocations  from these shared suppliers,  thereby limiting or making unreliable
the sources  of supply  for  these components.  The Company  encountered  supply
delays  for  codecs in  the second  quarter  of 1994  which resulted  in delayed
shipments of  the  UMC  system, and  there  can  be no  assurance  that  similar
shortages  will not occur in the future or will not result in the Company having
to pay  a higher  price  for components.  If the  Company  is unable  to  obtain
sufficient  quantities of these or any other components, delays or reductions in
manufacturing or  product shipments  could  occur which  would have  a  material
adverse  effect on  the Company's business,  financial condition  and results of
operations. See "Business -- Manufacturing."
 
    DEPENDENCE ON  LIMITED  NUMBER  OF THIRD  PARTY  MANUFACTURERS  AND  SUPPORT
ORGANIZATIONS.     The  Company  relies  on  a  limited  number  of  independent
contractors that manufacture the  subassemblies to the Company's  specifications
for  use in the  Company's products. In  particular, the Company  relies on: (i)
Flextronics International  Ltd. and  Tanon Manufacturing,  Inc. (a  division  of
Electronic  Associates, Inc.) to manufacture the Company's printed circuit board
assemblies; (ii)  Paragon,  Inc.  to manufacture  backplanes  and  channel  bank
assemblies and (iii) Sonoma Metal Products, Inc. and Cowden Metal San Jose, Inc.
to   manufacture  the  outside  cabinets.  In   the  event  that  the  Company's
subcontractors were to experience financial, operational, production, or quality
assurance difficulties that resulted in a reduction or interruption in supply to
the  Company  or   otherwise  failed   to  meet   the  Company's   manufacturing
requirements,  the  Company's  business,  financial  condition  and  results  of
operations would be adversely affected until the Company established  sufficient
manufacturing  supply from alternative  sources. There can  be no assurance that
the Company's current  or alternative  manufacturers will  be able  to meet  the
Company's  future requirements or that such manufacturing services will continue
to be available to the Company at favorable prices, or at all. See "Business  --
Manufacturing."
 
    The   Company   also   relies   on   Point-to-Point   Communications,   Inc.
("Point-to-Point"), a third-party  support organization,  to provide  first-line
technical  assistance and post-sales  support to AFC customers.  There can be no
assurance that Point-to-Point  will be  able to  provide the  level of  customer
support demanded by the Company's existing or potential customers. See "Business
- -- Sales, Marketing and Customer Support."
 
    COMPETITION.  The market for equipment for local telecommunications networks
is  extremely competitive. The Company's competitors range from small companies,
both domestic  and  international,  to  large  multinational  corporations.  The
Company's  competitors include Alcatel Alsthom Compagnie Generale d'Electricite,
DSC, ECI Telecom, Inc., E/O Networks, Fujitsu America, Inc., Hitron  Technology,
Inc., Lucent Technologies, Inc., NEC America, Inc., Northern Telecom Ltd., Opnet
Technologies  Co. Ltd.,  RELTEC Corporation, Seiscor  Technologies Inc., Siemens
Corporation, Teledata Communications Ltd. and  Vidar-SMS Co. Ltd. Many of  these
competitors  have more  extensive financial,  marketing and  technical resources
than the Company and enjoy superior name recognition in the market. In addition,
the Company has entered into agreements with the Industrial Technology  Research
Institute  ("ITRI") to jointly develop products based on the UMC system. ITRI is
a Taiwanese government-sponsored  research and development  organization in  the
telecommunications  field. Such agreements grant ITRI  and certain of its member
companies certain rights to manufacture and sell the European Telecommunications
Standards Institute ("ETSI") version of the UMC system outside of North America.
Such entities currently compete with the
 
                                       6
<PAGE>
Company  in  international  markets,  primarily  in  China.  In  addition,  upon
termination  of the agreements  with ITRI in  2002, ITRI will  have a worldwide,
non-exclusive, royalty-free, irrevocable license to use the ETSI version of  the
UMC  technology and, consequently, such member companies will be able to compete
with the Company worldwide at such time. There is an ongoing dispute subject  to
litigation  between the Company and ITRI and  such member companies as to, among
other things,  whether  ITRI  possesses  the  right  to  grant  such  rights  to
manufacture  and sell the ETSI version of the UMC system to new member companies
and whether AFC has terminated or may terminate such agreements and the  rights,
if  any, of the  member companies thereunder.  Depending on the  outcome of this
dispute, the Company may face competition from new member companies for the ETSI
version of  the UMC  system. Such  companies may  possess substantially  greater
financial,  marketing and technical resources than  the Company. The Company may
also face competition from new market  entrants. There can be no assurance  that
the Company will be able to compete successfully in the future. See "Business --
Competition," "-- Proprietary Rights and Licenses" and "-- Legal Proceedings."
 
    RISKS ASSOCIATED WITH PENDING LITIGATION.  The Company is a party to certain
legal  proceedings including  the litigation  between the  Company and  ITRI and
certain of its member companies arising primarily out of a dispute regarding the
payment of royalties and  the supply of ASICs  under the agreements between  the
Company  and  ITRI. The  Company is  unable  to determine  the total  expense or
possible loss, if  any, that  may ultimately be  incurred in  the resolution  of
these proceedings. Regardless of the ultimate outcome of these proceedings, they
could result in significant diversion of time by the Company's management. After
consideration  of  the nature  of the  claims  and the  facts relating  to these
proceedings, the Company believes that the resolution of these proceedings  will
not  have  a  material  adverse  effect  on  the  Company's  business, financial
condition and results of operations; however, the results of these  proceedings,
including any potential settlements, are uncertain and there can be no assurance
to that effect. See "Business -- Competition" and "-- Legal Proceedings."
 
    LIMITED  PROTECTION OF PROPRIETARY TECHNOLOGY; RISK OF THIRD-PARTY CLAIMS OF
INFRINGEMENT.   The  Company  attempts  to  protect  its  technology  through  a
combination  of copyrights, trade  secret laws and  contractual obligations. The
Company does not presently hold any patents for its existing products and has no
patent applications  pending.  There can  be  no assurance  that  the  Company's
intellectual   property  protection  measures  will  be  sufficient  to  prevent
misappropriation of the Company's technology  or that the Company's  competitors
will not independently develop technologies that are substantially equivalent or
superior  to the  Company's technology.  In addition,  the laws  of many foreign
countries do not protect the Company's intellectual property rights to the  same
extent  as the laws of the United States.  The failure of the Company to protect
its proprietary  information  could  have  a  material  adverse  effect  on  the
Company's business, financial condition and results of operations.
 
    The  increasing dependence of the telecommunications industry on proprietary
technology has  resulted in  frequent  litigation based  on allegations  of  the
infringement  of  patents and  other intellectual  property.  In June  1996, the
Company settled  litigation with  DSC under  which DSC  had claimed  proprietary
rights to the UMC technology. See "Business -- Legal Proceedings." In the future
the  Company may be  subject to additional litigation  to defend against claimed
infringements of the rights of others or to determine the scope and validity  of
the  proprietary rights  of others. Future  litigation also may  be necessary to
enforce and protect trade secrets  and other intellectual property rights  owned
by  the Company.  Any such  litigation could  be costly  and cause  diversion of
management's attention, either of which could have a material adverse effect  on
the  Company's business, financial condition  and results of operations. Adverse
determinations in such  litigation could  result in  the loss  of the  Company's
proprietary  rights, subject the Company to significant liabilities, require the
Company to  seek  licenses from  third  parties,  or prevent  the  Company  from
manufacturing  or selling its products,  any one of which  could have a material
adverse effect on  the Company's  business, financial condition  and results  of
operations.  Furthermore, there can be no  assurance that any necessary licenses
will be available on reasonable terms.  See "Business -- Proprietary Rights  and
Licenses."
 
    RISK  OF FAILURE TO  MANAGE EXPANDING OPERATIONS.   The Company has recently
experienced a period  of rapid growth,  which has placed  and could continue  to
place,  a significant strain on the Company's management, operational, financial
and  other  resources.  The  members  of  the  Company's  management  team  have
 
                                       7
<PAGE>
limited   experience  in  the  management   of  rapidly  growing  companies.  To
effectively manage the recent growth as  well as any future growth, the  Company
will  need to recruit, train, assimilate, motivate and retain qualified managers
and employees. Management of future growth,  if such growth occurs, may  require
the  Company to implement expanded or  new management and accounting systems. In
connection with the Company's recent growth, management has begun evaluation  of
new  management and  accounting systems and  intends to  begin implementing such
systems in 1997. There can be no  assurance that the Company will complete  such
evaluation or implementation on a timely basis. Information systems expansion or
replacement  can be a complex, costly  and time-consuming process, and there can
be no assurance that any such activities can be accomplished without  disruption
of  the Company's business.  Any business disruption  or other system transition
difficulties could have  a material  adverse effect on  the Company's  business,
financial  condition and  results of operations.  The failure of  the Company to
effectively manage its domestic and  international operations or any current  or
future  growth could have  a material adverse effect  on the Company's business,
financial  condition  and  results  of  operations.  The  Company's  results  of
operations  will be adversely affected if  revenues do not increase sufficiently
to compensate  for  the  increase  in  operating  expenses  resulting  from  any
expansion.  See "Business --  Employees" and "Management  -- Executive Officers,
Key Employees and Directors."
 
    CUSTOMER CONCENTRATION.    Approximately 15.7%  and  8.1% of  the  Company's
revenues  in  1995 and  1996, respectively,  were derived  from sales  to ALLTEL
Supply, Inc. In 1995  and 1996, the Company's  five largest customers  accounted
for  approximately 37% and 28% of revenues, respectively. Although the Company's
largest customers have  varied from  period to period,  the Company  anticipates
that  its results of operations in any given period will continue to depend to a
significant extent  upon sales  to a  small  number of  customers. None  of  the
Company's  customers has  entered into an  agreement requiring it  to purchase a
minimum amount of product from the Company.  There can be no assurance that  the
Company's principal customers will continue to purchase product from the Company
at current levels, if at all. The loss of one or more major customers could have
a  material adverse  effect on the  Company's business,  financial condition and
results of operations.  See "Management's Discussion  and Analysis of  Financial
Condition and Results of Operations" and "Business -- Markets and Customers."
 
    RISKS   ASSOCIATED   WITH  INTERNATIONAL   MARKETS.     International  sales
constituted 13.2% and 20.8%  of the Company's total  revenues in 1995 and  1996,
respectively.  International sales have fluctuated in  absolute dollars and as a
percentage of revenues,  and are  expected to  continue to  fluctuate in  future
periods.  The Company relies on a  number of third-party distributors and agents
to market and  sell the UMC  system outside of  North America. There  can be  no
assurance  that such distributors or agents  will provide the support and effort
necessary to service international markets  effectively. The Company intends  to
expand  its  existing  international  operations  and  enter  new  international
markets, which  will  demand  significant  management  attention  and  financial
commitment.  The Company's  management has  limited experience  in international
operations, and there  can be no  assurance that the  Company will  successfully
expand  its international operations. In addition, a successful expansion by the
Company of its international operations and sales in certain markets may  depend
on  the  Company's  ability  to  establish  and  maintain  productive  strategic
relationships. To date, the  Company has formed three  joint ventures to  pursue
international  markets, two of  which have been  or are in  the process of being
terminated or liquidated  due to  differences with the  joint venture  partners.
There  can be no  assurance that the  Company will be  able to identify suitable
parties for joint ventures or strategic  relationships or, even if such  parties
are  identified, that successful joint  ventures or strategic relationships will
result. Moreover, there can  be no assurance  that the Company  will be able  to
increase  international sales of the  UMC system through strategic relationships
or joint ventures. The failure to do so could significantly limit the  Company's
ability to expand its international operations and could have a material adverse
effect on the Company's business, financial condition and results of operations.
 
    International  telephone  companies  are  in many  cases  owned  or strictly
regulated by  local regulatory  authorities.  Access to  such markets  is  often
difficult  due to  the established relationships  between a  government owned or
controlled  telephone  company  and  its  traditional  indigenous  suppliers  of
telecommunications  equipment. In addition,  the Company's bids  for business in
certain international markets typically will
 
                                       8
<PAGE>
require the Company  to post  bid and performance  bonds and  to incur  contract
penalties should the Company fail to meet production and delivery time schedules
on large orders. The failure of the Company to meet these schedules could result
in  the loss  of collateral  posted for the  bonds or  financial penalties which
could adversely affect the Company's  business, financial condition and  results
of operations.
 
    The   Company's   international   sales   currently   are   primarily   U.S.
dollar-denominated. As a  result, an increase  in the value  of the U.S.  dollar
relative   to  foreign  currencies  could   make  the  Company's  products  less
competitive in international markets. For example, increases in the value of the
U.S. dollar relative to the Mexican peso in late 1994 resulted in a  significant
decrease  in  sales  of  the  UMC  system  to  Telefonos  de  Mexico  for  1995.
Furthermore, operating in international markets subjects the Company to  certain
additional  risks,  including  unexpected  changes  in  regulatory requirements,
political and economic  conditions, tariffs or  other barriers, difficulties  in
staffing  and  managing  international operations,  exchange  rate fluctuations,
potential exchange and  repatriation controls on  foreign earnings,  potentially
negative  tax consequences,  longer sales and  payment cycles  and difficulty in
accounts receivable  collection.  In addition,  any  inability to  obtain  local
regulatory  approval could delay or prevent entrance into international markets,
which could materially  impact the Company's  business, financial condition  and
results of operations. In order to compete in international markets, the Company
will  need to comply  with various regulations  and standards. See "Management's
Discussion and  Analysis  of Financial  Condition  and Results  of  Operations,"
"Business  --  Markets  and Customers"  and  "-- Sales,  Marketing  and Customer
Support."
 
    DEPENDENCE ON KEY PERSONNEL.  The Company's success depends to a significant
extent upon a number of key  technical and management employees. In  particular,
the  Company's success  depends in  large part  on the  knowledge, expertise and
services of  its co-founders:  Donald Green,  Chairman of  the Board  and  Chief
Executive  Officer; James  T. Hoeck,  Vice President,  Advanced Development; and
John W. Webley, Vice President, Advanced  Development. The loss of the  services
of  any of  these persons  or other key  employees of  the Company  could have a
material adverse  effect  on the  Company's  business, financial  condition  and
results  of operations. The Company does not have employment agreements with, or
key person life  insurance for,  any of  its employees.  Competition for  highly
qualified  employees is  intense and the  process of locating  key technical and
management personnel with the combination  of skills and attributes required  to
execute  the Company's strategy is often lengthy. There can be no assurance that
the Company will  be successful in  retaining its existing  key personnel or  in
attracting   and  retaining  the  additional   employees  it  may  require.  See
"Management."
 
    COMPLIANCE WITH  REGULATIONS AND  INDUSTRY  STANDARDS.   The UMC  system  is
required  to  comply with  a  large number  of  voice and  data  regulations and
standards, which vary between domestic  and international markets, and may  vary
by  the specific international market into which the Company sells its products.
Standards  setting  and  compliance  verification  in  the  United  States   are
determined  by the  Federal Communications  Commission ("FCC"),  by Underwriters
Laboratories,  by  independent  telephone  companies,  by  Bell   Communications
Research   ("Bellcore")   and   by   other   independent   third-party   testing
organizations. In international markets, the Company's products must comply with
recommendations issued by the Consultative Committee on International  Telegraph
and  Telephony  and with  requirements  established by  the  individual regional
carriers which specify how equipment that  is connected to their local  networks
must  operate. In  addition, the Company's  products must  comply with standards
issued by the European  Telecommunications Standards Institute. These  standards
are  implemented and enforced by  the Telecommunications Regulatory Authority of
each European nation.  Standards for new  services continue to  evolve, and  the
Company  will be  required to  modify its  products or  develop and  support new
versions of its products to meet  these standards. The failure of the  Company's
products to comply, or delays in meeting compliance, with the evolving standards
both  in its  domestic and international  markets could have  a material adverse
affect on the Company's business, financial condition and results of operations.
 
    In addition, the Company  will need to ensure  that its products are  easily
integrated  with  the carriers'  network management  systems. The  Regional Bell
Operating Companies  ("RBOCs"), which  represent  a large  segment of  the  U.S.
telecommunications  market, in many cases require that equipment integrated into
their  networks  be  tested  by  Bellcore,  indicating  that  the  products  are
interoperable  with the operations, administration, maintenance and provisioning
systems used by the RBOCs to manage their networks.
 
                                       9
<PAGE>
Bellcore testing  requires  significant  investments  in  resources  to  achieve
compliance. The UMC system completed a Bellcore technical audit and was found to
meet  applicable requirements.  The failure  to maintain  such compliance  or to
obtain it on new features released in  the future could have a material  adverse
affect on the Company's business, financial condition and results of operations.
 
    The  Company has not received ISO certification, which certifies that design
and manufacturing  processes  adhere  to  certain  established  standards.  Many
telecommunications  service  providers, particularly  in  international markets,
will  not  purchase  products  from   suppliers  that  have  not  received   ISO
certification.  Accordingly, until it  is able to  obtain ISO certification, the
Company may be precluded  from selling its products  to these service  providers
and  its ability to compete with other suppliers of communications equipment may
be adversely affected. The Company has initiated the formal process of  applying
for  ISO-9001 certification  and expects  to complete  the audit  process during
1997. ISO-9001 addresses quality  assurance in design, development,  production,
installation and service. There can be no assurance as to when or if the Company
will  receive such certification.  The failure to  obtain such certification may
preclude the Company from selling the UMC system in certain markets.
 
    The  U.S.   Congress   recently   passed   new   regulations   that   affect
telecommunications services, including changes to pricing, access by competitive
suppliers  and  many  other broad  changes  to the  data  and telecommunications
networks and services. These changes will have a major impact on the pricing  of
existing  services,  and may  affect the  deployment  of future  services. These
changes could cause  greater consolidation in  the telecommunications  industry,
which  in turn could disrupt existing customer relationships and have a material
adverse effect on  the Company's  business, financial condition  and results  of
operations.  There can be no assurance that any regulatory changes will not have
a material  adverse  effect  on  the demand  for  the  UMC  system.  Uncertainty
regarding future policies combined with emerging new competition may also affect
the demand for telecommunications products such as the UMC system. See "Business
- -- Compliance with Regulatory and Industry Standards."
 
    RISKS  ASSOCIATED WITH POTENTIAL ACQUISITIONS.   An important element of the
Company's strategy is to review acquisition prospects that would complement  its
existing   product  offerings,  augment  its  market  coverage  or  enhance  its
technological capabilities  or that  may otherwise  offer growth  opportunities.
While  the  Company  has no  current  agreements or  negotiations  underway with
respect to  any such  acquisitions, the  Company recently  acquired a  partner's
interest  in one of its  joint ventures and may  make additional acquisitions of
businesses, products or technologies in  the future. Future acquisitions by  the
Company could result in potentially dilutive issuances of equity securities, the
incurrence  of debt and contingent liabilities and amortization expenses related
to goodwill and other intangible assets, any of which could materially adversely
affect the Company's  business, financial  condition and  results of  operations
and/or  the price  of the Company's  Common Stock.  Acquisitions entail numerous
risks, including  difficulties  in  the  assimilation  of  acquired  operations,
technologies and products, diversion of management's attention to other business
concerns, risks of entering markets in which the Company has no or limited prior
experience  and potential loss  of key employees  of acquired organizations. The
Company's management has no  experience in assimilating acquired  organizations.
No  assurance can  be given  as to  the ability  of the  Company to successfully
integrate any  businesses, products,  technologies or  personnel that  might  be
acquired  in the future,  and the failure of  the Company to do  so could have a
material adverse  effect  on the  Company's  business, financial  condition  and
results of operations. See "Use of Proceeds."
 
    MANAGEMENT'S  DISCRETION AS TO USE OF UNALLOCATED NET PROCEEDS.  The Company
expects to  use the  net proceeds  to be  received by  the Company  for  general
corporate  purposes,  including  working  capital.  Consequently,  the  Board of
Directors and management of the Company will have broad discretion in allocating
a significant portion of such net proceeds. See "Use of Proceeds."
 
    CONTROL OF  THE  COMPANY; ANTI-TAKEOVER  EFFECTS.   Immediately  after  this
offering,  officers,  directors  and  their  affiliates  will  beneficially  own
approximately 29.2%  of the  Company's  outstanding Common  Stock. Due  to  this
ownership  position, these stockholders will  be able to significantly influence
the affairs  and policies  of the  Company, the  election of  directors and  the
approval  or  disapproval  of  matters  submitted  to  a  vote  of stockholders.
Furthermore, these  stockholders  may  have conflicts  of  interest  with  other
stockholders
 
                                       10
<PAGE>
with  respect to the  affairs and policies  of the Company.  The Company is also
subject to certain  provisions of Delaware  law which could  have the effect  of
delaying,  deterring or preventing a change in control of the Company, including
Section 203 of the Delaware General Corporation Law, which prohibits a  Delaware
corporation  from  engaging  in  any business  combination  with  any interested
stockholder for a  period of  three years  from the  date the  person became  an
interested  stockholder  unless certain  conditions  are met.  In  addition, the
Company's certificate  of incorporation  and bylaws  contain certain  provisions
that  could  discourage  potential  takeover attempts  and  make  more difficult
attempts by stockholders to change management. The Company's Board of  Directors
is  classified  into three  classes of  directors serving  staggered, three-year
terms and has the  authority, without action by  the Company's stockholders,  to
fix  the rights and preferences and issue  shares of the Preferred Stock, and to
impose various  procedural  and  other  requirements that  could  make  it  more
difficult  for stockholders to  effect certain corporate  actions. The Company's
certificate of incorporation provides that directors may be removed only by  the
affirmative  vote of the  holders of two-thirds  of the shares  of capital stock
entitled to vote. Any vacancy  on the board of directors  may be filled only  by
vote  of  the  majority of  directors  then  in office.  Further,  the Company's
certificate of  incorporation  provides  that  any  "Business  Combination"  (as
therein  defined)  requires the  affirmative vote  of  two-thirds of  the shares
entitled to  vote, voting  together as  a single  class. These  provisions,  and
certain  other provisions of the certificate of incorporation which may have the
effect of delaying proposed stockholder actions until the next annual meeting of
stockholders, together with  the ownership position  of the officers,  directors
and  their affiliates, could have the effect  of delaying or preventing a tender
offer for the Company's Common Stock  or other changes of control or  management
of  the Company, which could adversely affect  the market price of the Company's
Common Stock. See "Description of Capital Stock."
 
    POSSIBLE VOLATILITY OF STOCK PRICE.   The trading price of the Common  Stock
has  fluctuated  significantly since  the Company's  initial public  offering in
October 1996 and could be subject  to significant fluctuations in the future  in
response  to  variations in  quarterly operating  results, changes  in analysts'
earnings estimates, announcements of new products and innovations by the Company
or its  competitors,  general  conditions in  the  telecommunications  equipment
industry  and other factors. In  addition, the stock market  in recent years has
experienced extreme price and volume fluctuations that often have been unrelated
or disproportionate  to  the operating  performance  of companies.  These  broad
fluctuations may adversely affect the market price of the Common Stock.
 
    BENEFITS  OF THE  OFFERING TO  SELLING STOCKHOLDERS.   Existing stockholders
will be selling 1,800,000 shares of  the Common Stock offered hereby  (2,100,000
shares  if the Underwriter's over-allotment option  is exercised). The price per
share paid by the  Selling Stockholders for  their shares is  a fraction of  the
proposed public offering price for the Common Stock offered hereby. See "Certain
Transactions."
 
    SHARES ELIGIBLE FOR FUTURE SALE.  Sales of a substantial number of shares of
Common Stock in the public market following this offering could adversely affect
the  market price for the Company's Common Stock. The number of shares of Common
Stock available for sale in the  public market is limited by restrictions  under
the  Securities  Act of  1933, as  amended  (the "Securities  Act"), and  by the
following lock-up agreements  (collectively, the "Lock-Up  Agreements"): (i)  in
connection  with the Company's initial  public offering, the Company's officers,
directors and certain stockholders agreed  (the "IPO Lock-Up Agreement") not  to
sell or otherwise dispose of any of their shares for 180 days following the date
of  the Company's  initial public offering  without the prior  consent of Morgan
Stanley &  Co. Incorporated;  and (ii)  in connection  with this  offering,  the
Company's  executive  officers,  directors  and  the  Selling  Stockholders have
entered into agreements with Morgan  Stanley & Co. Incorporated (the  "Follow-On
Lock-Up  Agreements")  pursuant to  which  such holders  agreed  not to  sell or
otherwise dispose of  any of their  shares for 90  days following completion  of
this  offering.  Morgan Stanley  & Co.  Incorporated may,  however, in  its sole
discretion at any time  and without notice,  release all or  any portion of  the
securities  subject to Lock-Up Agreements. Upon completion of this offering, the
Company will  have  outstanding 33,085,002  shares  of Common  Stock.  Of  these
shares:  7,193,750 shares (including the 5,175,000  shares sold in the Company's
initial public offering and the 2,000,000 shares sold in this offering) will  be
available for immediate sale; 10,412,264 shares will become eligible for sale on
March  30, 1997 upon expiration  of the IPO Lock-Up  Agreements pursuant to Rule
701  or  Rule  144  under  the  Securities  Act  ("Rule  701"  and  "Rule  144,"
respectively) (subject in certain
 
                                       11
<PAGE>
cases to the volume limitations of Rule 144); 13,237 shares will become eligible
for  sale pursuant to Rule  701 at various dates between  March 30, 1997 and the
expiration date  of the  Follow-On Lock-Up  Agreements; 11,862,058  shares  will
become  eligible for  sale 90  days after the  completion of  this offering upon
expiration of the Follow-On Lock-Up Agreements pursuant to Rule 701 or Rule  144
(subject  in  certain cases  to the  volume  limitations of  Rule 144);  and the
remaining 3,603,693 shares will  become eligible for sale  pursuant to Rule  144
(subject  in certain  cases to  the applicable  Rule 144  volume limitations) at
various dates  following  expiration of  the  Follow-On Lock-Up  Agreements.  In
addition,  as  of December  31, 1996,  the Company  had outstanding  warrants to
purchase an aggregate of 2,332,686 shares  of Common Stock (after giving  effect
to  the net exercise of  warrants to purchase 235,395  shares in connection with
this offering). These warrants contain net exercise provisions. Accordingly, any
shares issued  upon net  exercise will  be eligible  for sale  immediately  upon
expiration  of any lock-up agreements to  which such shares are subject pursuant
to Rule 144. In addition, the Company has filed a registration statement on Form
S-8 with the Securities and  Exchange Commission (the "Commission")  registering
8,675,676  shares  of Common  Stock reserved  for  issuance under  the Company's
Employee Stock Purchase  Plan and  1996 Stock  Incentive Plan.  Of such  shares,
4,313,544  shares  subject to  stock options  outstanding  under the  1996 Stock
Incentive Plan are subject to lock-up  agreements and will be eligible for  sale
upon expiration of such lock-up agreements as follows: 3,289,508 shares on March
30,  1997  and the  remaining 1,024,036  shares 90  days from  the date  of this
Prospectus. The 1,500,000 shares reserved under the Employee Stock Purchase Plan
will  be  eligible  for  sale  upon  issuance.  In  addition,  the  holders   of
approximately  19,869,482 shares  of Common  Stock outstanding  or issuable upon
exercise of outstanding warrants have certain  rights to require the Company  to
register  those shares under the Securities  Act. If such holders, by exercising
their demand  registration  rights,  cause  a  large  number  of  shares  to  be
registered  and sold  in the  public market,  such sales  could have  a material
adverse effect  on the  market price  for  the Company's  Common Stock.  If  the
Company were required to include in a Company-initiated registration shares held
by such holders pursuant to the exercise of their piggyback registration rights,
such  sales may have an adverse effect  on the Company's ability to raise needed
capital. See "Description of Capital  Stock," "Shares Eligible for Future  Sale"
and "Underwriters."
 
                                       12
<PAGE>
                                  THE COMPANY
 
    Advanced  Fibre  Communications,  Inc.  ("AFC"  or  the  "Company") designs,
develops, manufactures,  markets  and  supports the  Universal  Modular  Carrier
1000-TM-  (the  "UMC"  system),  a  cost-effective,  multi-feature  digital loop
carrier system developed  to serve  small line-size markets.  The Company's  UMC
system  is designed  to enable  telephone companies,  cable companies  and other
service providers to connect subscribers to the central office switch for  voice
and  data communications over copper wire,  fiber optic cable, coaxial cable and
analog radio networks.  The Company  believes that the  UMC system  is the  only
digital  loop  carrier  that  can  operate  simultaneously  over  a  variety  of
transmission media.  The UMC  system meets  the service  needs of  domestic  and
international subscribers, including analog services such as plain old telephone
service ("POTS"), universal voice grade service ("UVG") and analog switched data
service,  and digital  services such as  high speed digital  data service, ISDN,
asynchronous and synchronous data channel ("ADU" and "SDU") services. Through  a
relationship  with Tellabs Operations,  Inc. ("Tellabs"), AFC  has developed the
capability to deliver many of these same services over cable TV networks.
 
    Although urban  markets have  experienced the  greatest initial  demand  for
additional   lines  and  high-speed  telecommunications  services,  the  Company
believes that demand  for these  services is  increasing in  rural and  suburban
markets  as well.  The Company  also believes,  however, that telecommunications
service providers  in suburban  and  rural markets  generally  do not  have  the
resources  to  completely replace  existing copper  networks and  therefore must
upgrade to fiber in incremental steps. These incremental infrastructure upgrades
result in hybrid networks containing  both copper and fiber transmission  lines.
In  addition, worldwide  demand for  POTS and,  to a  lesser extent,  high speed
telecommunications services, is creating the need for significant infrastructure
investments to  increase  the effective  capacity  of existing  copper,  replace
deteriorating  copper and provide  services in new  areas. As telecommunications
service providers upgrade to fiber technology, deploy new networks and plan  for
future  subscriber  services,  they must  determine  how to  ensure  a seamless,
cost-effective connection between copper and  fiber facilities within the  local
loop.
 
    The UMC system is easily scalable from six to 672 lines through the addition
of  plug-in components. Utilizing a single platform  and a variety of line cards
supporting specific services, the UMC system is capable of providing a range  of
voice  and data  services. In  addition, the  UMC system  can be  installed in a
variety of network configurations to support the varying geographic distribution
of subscriber  bases. The  Company has  designed  the UMC  system to  require  a
minimum number of common control units to support transmission over a variety of
media  and  the delivery  of more  advanced services  and features  by telephone
companies. Thus, the UMC  system offers a cost-effective  solution to the  small
line-size market with a wide variety of features and advanced services.
 
    The  UMC  system  has  been  sold to  more  than  450  independent telephone
companies in the  United States, has  been initially deployed  by Ameritech  and
GTE,  and is in  laboratory or field  trials at Pacific  Bell and BellSouth. The
Company has  also sold  the UMC  system  to telephone  companies in  Hong  Kong,
France,  Brazil,  Canada,  China,  Mexico,  the  Netherlands  Antilles  and  the
Dominican Republic. The UMC system is distributed and serviced worldwide through
its direct  sales force  in the  domestic market  and through  its direct  sales
force, distributors and agents in international markets.
 
    The Company was incorporated in California in May 1992 and reincorporated in
Delaware  in  September  1995.  The Company's  principal  executive  offices are
located at 1445 McDowell  Boulevard North, Petaluma,  California 94954, and  the
telephone number at that address is (707) 794-7700.
 
RECENT DEVELOPMENTS
 
    Revenues  for the  quarter ended December  31, 1996 increased  112% to $41.4
million from $19.5 million  for the quarter ended  December 31, 1995.  Operating
income  in the quarter increased 218% to  $6.2 million from $1.9 million and net
income in the quarter increased  258% to $5.6 million  from $1.6 million in  the
quarter ended December 31, 1995. The Company continued to expand its penetration
of  international markets, completing sales to its first customers in Brazil and
increasing sales  in  China. The  Company  has begun  working  with  Flextronics
International,   Ltd.   ("Flextronics"),   one   of   the   Company's   contract
manufacturers, to manufacture UMC assemblies at a Flextronics facility in China.
 
                                       13
<PAGE>
                                USE OF PROCEEDS
 
    The net proceeds  to the  Company from  the sale  of the  200,000 shares  of
Common  Stock offered by the Company  hereby will be approximately $8.0 million,
after deducting underwriting  discounts and commissions  and estimated  offering
expenses  payable by the Company. The Company will not receive any proceeds from
the sale of Shares by the Selling  Stockholders. The Company expects to use  the
net  proceeds received  by it from  the Shares sold  by it in  this offering for
general  corporate   purposes,  including   the  funding   of  working   capital
requirements.  Pending  such  uses, the  Company  will invest  the  net proceeds
received  by  it   in  this  offering   in  investment-grade,   interest-bearing
securities.
 
    From  time to time, the Company may evaluate opportunities to enter into new
strategic relationships, joint ventures, potential acquisitions or other similar
transactions and  may  use  a  portion  of  the  proceeds  to  enter  into  such
transactions.  There are no present understandings or agreements with respect to
any such transaction, and there can be no assurance that the Company will  enter
into any such arrangements.
 
                                DIVIDEND POLICY
 
    The  Company has never declared or paid cash dividends on its capital stock.
The Company currently intends to retain all of its earnings, if any, for use  in
its  business  and  does  not  anticipate  paying  any  cash  dividends  in  the
foreseeable  future.  In  addition,  the  Company's  revolving  line  of  credit
agreement  requires the prior consent of the bank before payment of dividends by
the Company.
 
                          PRICE RANGE OF COMMON STOCK
 
    The Company's Common Stock  has traded on the  Nasdaq National Market  under
the  symbol "AFCI" since October 1,  1996. The Company's initial public offering
price was  $25  per share.  The  following table  sets  forth, for  the  periods
indicated,  the high and low closing sale  prices for the Company's Common Stock
as reported by the Nasdaq National Market:
 
<TABLE>
<CAPTION>
                                                                                 HIGH        LOW
                                                                               ---------  ---------
<S>                                                                            <C>        <C>
Year Ending December 31, 1997:
  First Quarter (through February 12, 1997)..................................  $  55 5/8  $  44 3/8
Year Ending December 31, 1996:
  Fourth Quarter (beginning October 1, 1996).................................     61 1/4     44 1/2
</TABLE>
 
    On February 12, 1997, the  last reported sale price  of the Common Stock  on
the  Nasdaq National Market was $44 3/8 per share. As of December 31, 1996 there
were approximately 211 holders of record of the Company's Common Stock.
 
                                       14
<PAGE>
                                 CAPITALIZATION
 
    The  following table  sets forth  the capitalization  of the  Company (i) at
December 31,  1996, and  (ii) as  adjusted to  give effect  to the  sale by  the
Company  of  200,000  shares  of  Common  Stock  (after  deducting  underwriting
discounts and  commissions  and  estimated  offering  expenses  payable  by  the
Company).
 
<TABLE>
<CAPTION>
                                                                                              DECEMBER 31, 1996
                                                                                           -----------------------
                                                                                             ACTUAL    AS ADJUSTED
                                                                                           ----------  -----------
                                                                                            (IN THOUSANDS, EXCEPT
                                                                                                 SHARE DATA)
<S>                                                                                        <C>         <C>
Stockholders' equity (deficit):
  Preferred Stock, $.01 par value; 5,000,000 shares authorized, no shares issued and
   outstanding...........................................................................  $   --       $  --
  Common Stock, $.01 par value; 100,000,000 shares authorized, 32,649,607 shares issued
   and outstanding, actual; 33,085,002 shares issued and outstanding, as adjusted (1)....         326         331
Additional paid-in capital...............................................................     164,002     171,955
Notes receivable from stockholders.......................................................        (151)       (151)
Accumulated deficit......................................................................      (6,154)     (6,154)
                                                                                           ----------  -----------
  Total stockholders' equity.............................................................     158,023     165,981
                                                                                           ----------  -----------
      Total capitalization...............................................................  $  158,023   $ 165,981
                                                                                           ----------  -----------
                                                                                           ----------  -----------
</TABLE>
 
- ---------
(1)  Excludes 7,008,142 shares  of Common Stock reserved  for issuance under the
    Company's stock  option plans,  under which  options to  purchase  4,313,544
    shares  were  outstanding  as of  December  31, 1996,  and  1,500,000 shares
    reserved for issuance under the Company's Employee Stock Purchase Plan. Also
    excludes 2,332,686 shares of Common Stock reserved for issuance pursuant  to
    the  exercise of warrants  outstanding as of December  31, 1996 after giving
    effect to  the issuance  of 235,395  shares  of Common  Stock upon  the  net
    exercise of warrants by certain Selling Stockholders in connection with this
    offering.  See ``Management --  Stock Incentive Plan,"  `` -- Employee Stock
    Purchase Plan," ``Certain Transactions" and ``Description of Capital Stock."
 
                                       15
<PAGE>
                      SELECTED CONSOLIDATED FINANCIAL DATA
 
    The following  selected  consolidated  financial  data  should  be  read  in
conjunction  with  the  Company's consolidated  financial  statements  and notes
thereto and  the  discussion under  ``Management's  Discussion and  Analysis  of
Financial  Condition  and  Results  of Operations"  included  elsewhere  in this
Prospectus. The consolidated statement  of operations data  for the years  ended
December  31, 1994,  1995 and  1996 and  consolidated balance  sheet data  as of
December 31, 1995  and 1996 are  derived from financial  statements, which  have
been  audited by KPMG Peat Marwick LLP, independent auditors, included elsewhere
in this Prospectus. The consolidated statement  of operations data for the  year
ended  December 31, 1993 and the consolidated  balance sheet data as of December
31, 1993  and 1994  have  been derived  from  audited financial  statements  not
included  in this Prospectus. The consolidated  statement of operations data for
the period from May 29, 1992 to December  31, 1992 and balance sheet data as  of
December 31, 1992 have been derived from unaudited financial statements that are
not   contained  herein  but   which  reflect,  in   management's  opinion,  all
adjustments, consisting of  normal recurring adjustments,  necessary for a  fair
presentation thereof. These historical results are not necessarily indicative of
the results to be expected in the future.
 
<TABLE>
<CAPTION>
                                                                  INCEPTION (MAY
                                                                   29, 1992) TO
                                                                   DECEMBER 31,             YEAR ENDED DECEMBER 31,
                                                                  ---------------  ------------------------------------------
                                                                       1992          1993       1994       1995     1996 (1)
                                                                  ---------------  ---------  ---------  ---------  ---------
                                                                             (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                                               <C>              <C>        <C>        <C>        <C>
CONSOLIDATED STATEMENT OF OPERATIONS DATA:
Revenues........................................................     $     275     $     620  $  18,802  $  54,287  $ 130,193
Cost of revenues................................................            38         2,574     14,124     33,469     73,950
                                                                         -----     ---------  ---------  ---------  ---------
  Gross profit (loss)...........................................           237        (1,954)     4,678     20,818     56,243
                                                                         -----     ---------  ---------  ---------  ---------
Operating expenses:
  Research and development......................................           622         2,044      2,867      5,730     14,413
  Selling, general and administrative...........................           266         2,509      5,051      9,660     21,188
  DSC litigation costs..........................................        --               784      4,551      1,623     18,947
                                                                         -----     ---------  ---------  ---------  ---------
    Total operating expenses....................................           888         5,337     12,469     17,013     54,548
                                                                         -----     ---------  ---------  ---------  ---------
Operating income (loss).........................................          (651)       (7,291)    (7,791)     3,805      1,695
Gain on dissolution (equity in loss) of joint venture, net......        --            --         --         (1,516)     1,516
Other income (expense), net.....................................           (25)       --             26        149        872
                                                                         -----     ---------  ---------  ---------  ---------
Income (loss) before income taxes...............................          (676)       (7,291)    (7,765)     2,438      4,083
Income taxes (benefit)..........................................        --            --         --             97     (3,154)
                                                                         -----     ---------  ---------  ---------  ---------
Net income (loss)...............................................     $    (676)    $  (7,291) $  (7,765) $   2,341  $   7,237
                                                                         -----     ---------  ---------  ---------  ---------
                                                                         -----     ---------  ---------  ---------  ---------
Pro forma net income per share (2)..............................                                         $    0.09  $    0.21
                                                                                                         ---------  ---------
                                                                                                         ---------  ---------
Shares used in per share computations (2).......................                                            27,329     34,282
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                         DECEMBER 31,
                                                                  -----------------------------------------------------------
                                                                       1992          1993       1994       1995       1996
                                                                  ---------------  ---------  ---------  ---------  ---------
                                                                                        (IN THOUSANDS)
<S>                                                               <C>              <C>        <C>        <C>        <C>
CONSOLIDATED BALANCE SHEET DATA:
Cash and cash equivalents and marketable securities.............     $  --         $     450  $   3,858  $  11,118  $ 108,430
Working capital.................................................            77           466      6,809     18,770    145,338
Total assets....................................................           458         3,787     14,884     36,680    175,679
Redeemable convertible preferred stock..........................        --             9,152     23,546     37,777     --
Total stockholders' equity (deficit)............................          (661)       (7,952)   (15,706)   (15,765)   158,023
</TABLE>
 
- ------------
(1)  Includes  a charge  of $15.8  million to  reflect a  cash payment  of $10.1
    million and  the  issuance of  725,787  shares of  Common  Stock to  DSC  in
    settlement  of outstanding litigation. See ``Business -- Legal Proceedings."
    Without this charge, operating income for  the year ended December 31,  1996
    would have been $17.5 million.
 
(2)  See Note 1 of Notes to Consolidated Financial Statements for an explanation
    of the determination of the number of shares used in computing pro forma net
    income per share.
 
                                       16
<PAGE>
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
OVERVIEW
 
    AFC  designs develops, manufactures, markets and  supports the UMC system, a
cost-effective multi-feature  digital loop  carrier  system developed  to  serve
small  line-size  markets.  The  Company's  UMC  system  is  designed  to enable
telephone companies,  cable companies  and other  service providers  to  connect
subscribers  to the central office switch for voice and data communications over
copper, fiber,  coaxial  cable  and  analog  radio  networks.  The  Company  was
incorporated  in May 1992 and  was in the initial  startup and development phase
through December 1993. The Company began  shipping the UMC in January 1994  and,
accordingly, has a limited operating history.
 
    The   Company  has   incurred  substantial   expenditures  related   to  the
development, manufacturing startup and marketing of the UMC system. As a  result
of  these expenditures, combined  with $25.9 million  of expenses and settlement
amounts recorded  in  connection with  certain  litigation with  DSC  which  was
settled  in June 1996, the Company had an accumulated deficit of $6.2 million as
of December 31, 1996. Although the Company achieved profitability for the  years
ended  December 31, 1995  and 1996, there  can be no  assurance that the Company
will sustain or increase its profitability in the future.
 
    The Company currently derives substantially all of its revenues from the UMC
system and  expects that  this concentration  will continue  in the  foreseeable
future.  As a  result, any  decrease in the  overall level  of sales  of, or the
prices for,  the  UMC  system  due to  product  enhancements,  introductions  or
announcements  by the Company's competitors, a decline in the demand for the UMC
system, product obsolescence or any other  reason would have a material  adverse
effect on the Company's business, financial condition and results of operations.
The  Company derives a minor amount of revenue from royalties generated from the
Company's various strategic relationships. Support revenues have been negligible
since most systems shipped to date  remain under the Company's initial  two-year
product warranty period.
 
    The Company sells its products worldwide, primarily through its direct sales
force  in the domestic market, and  through its direct sales force, distributors
and agents in  international markets.  In April 1994,  the Company  and a  third
party  entered  into  a  joint  venture, pursuant  to  which  a  Hong Kong-based
subsidiary was formed, 49% of which was  owned by the Company and the  remaining
51%  of which was owned by the third  party. In April 1996, the Company acquired
the third party's interest in the  subsidiary. As a result of this  acquisition,
the  Company began consolidating  the results of  the Hong Kong-based subsidiary
and of a China-based joint venture, 60% of which was owned by the subsidiary and
40% of which was owned  by the joint venture  partner. The change in  accounting
from  the equity method to  consolidation did not have  a material impact on the
Company's financial condition and results of operations in 1996. In August 1996,
the Company and the  China-based joint venture partner  agreed to liquidate  the
joint  venture. A charge for  liquidation costs of $383,000  was recorded in the
second half of  1996. The  liquidation is expected  to be  completed during  the
first  quarter of  1997 and  is not expected  to have  a material  impact on the
Company's financial condition and results of operations. See Note 2 of Notes  to
Consolidated Financial Statements.
 
    The  Company's customers  normally install  a portion  of the  UMC system in
outdoor locations. Shipments  of the UMC  system are subject  to the effects  of
seasonality,  with fewer installation projects  scheduled for the winter months.
Accordingly, the Company believes that over time this seasonality will cause its
revenues in  the  quarter ended  March  31 to  be  lower than  revenues  in  the
preceding  quarter  ended  December  31. In  particular,  the  Company currently
believes that revenues in  the quarter ended  March 31, 1997  may be lower  than
revenues  in the quarter  ended December 31,  1996. See "Management's Discussion
and Analysis  of Financial  Condition  and Results  of Operations  --  Quarterly
Results of Operations."
 
                                       17
<PAGE>
RESULTS OF OPERATIONS
 
    The following table sets forth, for the periods indicated, the percentage of
revenues  represented by certain  items reflected in  the Company's consolidated
statements of operations:
 
<TABLE>
<CAPTION>
                                                                                          YEAR ENDED DECEMBER 31,
                                                                                     ---------------------------------
                                                                                       1994       1995       1996(1)
                                                                                     ---------  ---------  -----------
 
<S>                                                                                  <C>        <C>        <C>
Revenues...........................................................................      100.0%     100.0%      100.0%
Cost of revenues...................................................................       75.1       61.7        56.8
                                                                                     ---------  ---------       -----
  Gross profit.....................................................................       24.9       38.3        43.2
                                                                                     ---------  ---------       -----
Operating expenses:
  Research and development.........................................................       15.2       10.6        11.1
  Selling, general and administrative..............................................       26.9       17.8        16.3
  DSC litigation costs.............................................................       24.2        3.0        14.5
                                                                                     ---------  ---------       -----
    Total operating expenses.......................................................       66.3       31.3        41.9
                                                                                     ---------  ---------       -----
Operating income (loss)............................................................      (41.4)       7.0         1.3
Gain on dissolution (equity in loss) of joint venture, net.........................     --           (2.8)        1.2
Other income, net..................................................................        0.1        0.3         0.6
                                                                                     ---------  ---------       -----
Income (loss) before income taxes..................................................      (41.3)       4.5         3.1
Income taxes (benefit).............................................................     --            0.2        (2.4)
                                                                                     ---------  ---------       -----
Net income (loss)..................................................................      (41.3)%       4.3%        5.5%
                                                                                     ---------  ---------       -----
                                                                                     ---------  ---------       -----
</TABLE>
 
- ------------
(1) Includes  a charge  of $15.8  million to  reflect a  cash payment  of  $10.1
    million  and  the issuance  of  725,787 shares  of  Common Stock  to  DSC in
    settlement of  outstanding litigation.  See  Note 10  of  the Notes  to  the
    Consolidated  Financial Statements. Without this charge, operating income as
    a percentage of  revenues for the  year ended December  31, 1996 would  have
    been 13.4%.
 
1996 COMPARED WITH 1995
 
    REVENUES.   Revenues increased  139.8% from $54.3 million  in 1995 to $130.2
million for 1996. International revenues  increased 276.7% from $7.2 million  in
1995  to $27.1 million in 1996 and represented 13.2% and 20.8% of total revenues
in 1995 and 1996, respectively. No single customer accounted for 10% or more  of
revenues  in 1996.  ALLTEL Supply, Inc.  an affiliate of  ALLTEL, an independent
domestic telephone company, accounted  for 15.7% of total  revenues in 1995.  No
other  single customer accounted for  10% or more of  revenues in 1995. Although
the Company's largest customers have varied  from period to period, the  Company
anticipates  that its results of operations in any given period will continue to
depend to a significant extent upon sales to a small number of customers.  There
can  be no  assurance that  the Company's  principal customers  will continue to
purchase product from the Company at current levels, if at all. The loss of  one
or  more major customers could  have a material adverse  effect on the Company's
business, financial condition and results of operations.
 
    International and domestic revenues  increased as a  result of expansion  of
the  Company's customer  base and  the introduction of  new features  in the UMC
system. The increase in international revenues was partially due to higher sales
levels in China resulting from  the acquisition in April  1996 of the shares  of
the  Company's Hong  Kong-based subsidiary not  previously owned  by the Company
(which resulted in  the consolidation  for financial reporting  purposes of  the
Company's  China-based operations) as well as increased levels of sales activity
in China. The increase in international revenues was also attributable to  sales
to France Telecom, Hong Kong Telecom and Promon Electronics (Brazil).
 
    GROSS  PROFIT.    Gross  profit is  comprised  of  revenues  less materials,
manufacturing and  warranty  costs. Gross  profit  increased 170.2%  from  $20.8
million  in  1995 to  $56.2 million  in 1996.  As a  percent of  revenues, gross
profits were 38.3% in 1995 and 43.2%  in 1996. The improvement in gross  margins
was  attributable  to  greater  efficiencies  in  purchasing  and  manufacturing
activities resulting from higher unit volumes. Also, the Company realized  lower
product costs as a result of engineering design improvements. Gross margins were
negatively  impacted in  1996 by  the increased  level of  sales in  China which
generally have a lower gross margin due  to the higher cost of distribution  and
price sensitivity as compared with other markets. In the
 
                                       18
<PAGE>
future, gross margins may fluctuate due to a wide variety of factors, including:
the  mix between domestic and international  sales; the customer mix; the timing
and size of  orders which  are received  and can be  shipped in  a quarter;  the
availability  of  adequate supplies  of key  components  and assemblies  and the
adequacy of  manufacturing  capacity; the  Company's  ability to  introduce  new
products  and  technologies  on  a  timely  basis;  the  timing  of  new product
introductions  or  announcements  by  the  Company  or  its  competitors;  price
competition; and unit volume.
 
    RESEARCH  AND DEVELOPMENT.   Expenses  relating to  research and development
activities increased 151.5% from $5.7 million in 1995 to $14.4 million in  1996.
As  a percentage of  revenues, research and  development expenses increased from
10.6% for 1995 to 11.1% in 1996. The increase resulted primarily from the hiring
of additional personnel and  the increased use of  outside services for  certain
development  efforts  during  1996.  The number  of  employees  in  research and
development increased from 63 at December 31, 1995 to 124 at December 31,  1996.
The  increase  in research  and development  expenses  was also  attributable to
higher costs  for material  and test  equipment  used to  develop and  test  new
products  and  features.  The  Company  expects  that  research  and development
expenditures generally will continue to increase in absolute dollars to  support
the  continued development of  new features and  product cost reduction efforts.
All research and development costs have been expensed as incurred.
 
    SELLING, GENERAL AND  ADMINISTRATIVE.  Selling,  general and  administrative
expenses increased 119.3% from $9.7 million in 1995 to $21.2 million in 1996. As
a percentage of revenues, selling, general and administrative expenses decreased
from  17.8% in  1995 to  16.3% in 1996.  Costs in  the sales  and marketing area
increased significantly  from period  to  period reflecting  the hiring  of  new
employees,  and  commissions earned  by the  Company's  sales force  and outside
international sales representatives as  a result of  higher revenue levels.  The
Company  also increased  its advertising and  trade show  participation in 1996.
General and administrative expenses  increased as a result  of the expansion  of
the  administrative  staff  in  1996,  the legal  costs  incurred  for  the ITRI
litigation and the additional costs associated with being a public company.
 
    DSC LITIGATION COSTS.  Litigation  expenses incurred in connection with  the
DSC  litigation increased from $1.6 million for  1995 to $18.9 million for 1996.
The increase is primarily attributable to  the $15.8 million charge recorded  in
the  second quarter of 1996  in connection with the  final settlement of the DSC
litigation. See Note 10 of Notes to the Consolidated Financial Statements.
 
    GAIN ON DISSOLUTION (EQUITY  IN LOSS) OF  JOINT VENTURE, NET.   In 1996  and
1995,  the Company made advances  to a joint venture in  which the Company had a
50% ownership interest. In April 1995, the  Company made a loan of $1.0  million
to  the joint venture.  During 1995 and  the first quarter  of 1996, the Company
recorded its proportionate share of the joint venture's losses to the extent  of
the  loan and advances. As a result,  the loan and intercompany receivables were
reduced to zero  on the  Company's balance  sheet as  of December  31, 1995.  On
December  23, 1996  the Company  and the joint  venture partner  entered into an
agreement to terminate the  joint venture. In  connection with the  dissolution,
the  joint venture partner  reimbursed the Company $1,683,000  for all loans and
advances made by the Company to date.  The reimbursement was recorded as a  gain
in the fourth quarter of 1996 and is reflected in gain on dissolution (equity in
loss) of joint venture, net.
 
    OTHER  INCOME, NET.   Net  other income increased  from $149,000  in 1995 to
$872,000 in 1996 and consisted primarily  of interest income from the  Company's
cash  and investments in  marketable securities, net of  interest expense on the
Company's bank line of credit and short-term bank loan.
 
    INCOME TAXES (BENEFIT).  An income tax benefit of $3.2 million was  recorded
for  1996  to reflect  the  benefit of  the  DSC litigation  settlement  and the
decrease in the valuation allowance recorded against the Company's deferred  tax
assets. As of December 31, 1996, the Company has recorded no valuation allowance
against  its deferred  tax assets  because management  believes such  assets are
realizable. For the second half of 1996, the Company recorded income taxes at an
effective rate that approximates the combined federal and state statutory rates.
 
                                       19
<PAGE>
1995 COMPARED WITH 1994
 
    REVENUES.  Revenues were $18.8 million  and $54.3 million in 1994 and  1995,
respectively.  The  Company began  shipping the  UMC 1000  in January  1994. The
revenue level  achieved  in 1994  reflected  initial market  acceptance  of  the
Company's  product by independent  telephone companies in  the United States, as
well as sales to a distributor in Mexico. The 189% increase in revenues in  1995
compared  with  1994 resulted  from  growth in  system sales  of  the UMC  to an
expanded customer base. During 1994,  shipments to PTI, an independent  domestic
telephone  company, accounted for approximately 27.0%  of revenues. In 1995, the
Company's  largest  customer,  ALLTEL  Supply,  Inc.,  accounted  for  15.7%  of
revenues. No other single customer accounted for 10% or more of revenues in 1994
or 1995. International revenues increased $3.6 million, or 99% from $3.6 million
in  1994 to $7.2 million in 1995, and represented 19.2% and 13.2% of revenues in
1994 and 1995, respectively.
 
    GROSS PROFIT (LOSS).   Gross profit increased from  $4.7 million in 1994  to
$20.8  million in 1995, respectively, and  gross margins increased from 24.9% in
1994 to 38.3% in 1995. Gross margins improved in 1995 due to lower product costs
resulting from engineering design improvements and greater efficiencies achieved
in purchasing and manufacturing activities associated with higher unit volumes.
 
    RESEARCH AND  DEVELOPMENT.   Research  and  development expenses  were  $2.9
million  and $5.7  million in  1994 and 1995,  respectively. As  a percentage of
revenues, research and  development expenses were  15.2% and 10.6%  in 1994  and
1995,  respectively.  The Company  increased  its engineering  staff  to support
continued product development and cost  reductions during these periods from  38
to  63 employees at  December 31, 1994  and 1995, respectively.  The decrease in
research and development expenses as a percentage of revenues from 1994 to  1995
was  the result  of the  Company's rapid  growth in  revenues. All  research and
development costs have been expensed as incurred.
 
    SELLING, GENERAL AND  ADMINISTRATIVE.  Selling,  general and  administrative
expenses were $5.1 million and $9.7 million in 1994 and 1995, respectively. As a
percentage  of revenues, selling, general and administrative expenses were 26.9%
and 17.8% in 1994 and 1995, respectively, with the decrease being the result  of
the increased revenue base. The increases in absolute dollars reflects the build
up of the Company's domestic and international direct sales team, investments in
customer  support and  marketing, costs  associated with  trade shows  and other
marketing  efforts,  expansion  of   the  Company's  administrative  staff   and
installation of information, manufacturing and financial control systems.
 
    DSC  LITIGATION  COSTS.   DSC litigation  costs were  $4.6 million  and $1.6
million in 1994 and  1995, respectively. DSC litigation  costs in 1994  included
reserves  for a  possible settlement of  $2.0 million.  See Note 10  of Notes to
Consolidated Financial Statements.
 
    GAIN ON DISSOLUTION (EQUITY  IN LOSS) OF JOINT  VENTURE, NET.  During  1995,
the  Company made a  loan of $1.0  million and other  operating expense advances
totaling approximately $516,000 to  a joint venture in  which the Company had  a
50% ownership interest. In 1995, the Company recorded its proportionate share of
the  joint venture's losses to the extent of the loan and advances. As a result,
the loan and  intercompany receivables  were reduced  to zero  on the  Company's
balance sheet as of December 31, 1995.
 
    OTHER  INCOME, NET.  Net  other income was $26,000  and $149,000 in 1994 and
1995, respectively, and  consisted of  interest income from  the Company's  cash
investments,  net of interest expense on  stockholder loans in 1994 and advances
under the Company's bank line of credit in 1995.
 
    INCOME TAXES.  Because  of operating losses sustained  in 1994, the  Company
did  not provide for  income taxes in  that year, other  than minimum California
state franchise tax. In fiscal 1995, the provision for income taxes was  $97,000
and  consisted of the federal alternative minimum tax and the California minimum
state franchise tax. See Note 7 of Notes to Consolidated Financial Statements.
 
                                       20
<PAGE>
QUARTERLY RESULTS OF OPERATIONS
 
    The following tables present  unaudited quarterly financial information  for
the  four quarters of 1995 and 1996. In the opinion of the Company's management,
this unaudited information has  been prepared on the  same basis as the  audited
financial  statements contained herein and  includes all adjustments (consisting
only  of  normal  recurring  adjustments)   necessary  to  present  fairly   the
information  set forth  therein. The operating  results for any  quarter are not
necessarily indicative of results for any future period.
<TABLE>
<CAPTION>
                                                                             QUARTER ENDED
                                        ----------------------------------------------------------------------------------------
                                         MAR. 31,    JUNE 30,   SEPT. 30,  DEC. 31,   MAR. 31,   JUNE 30,   SEPT. 30,  DEC. 31,
                                           1995        1995       1995       1995       1996     1996 (1)     1996       1996
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                                                 (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                     <C>          <C>        <C>        <C>        <C>        <C>        <C>        <C>
Revenues..............................   $   7,456   $  11,789  $  15,548  $  19,494  $  24,121  $  29,651  $  35,012  $  41,409
Cost of revenues......................       4,633       7,288      9,837     11,711     14,101     16,957     19,737     23,155
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Gross profit..........................       2,823       4,501      5,711      7,783     10,020     12,694     15,275     18,254
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Operating expenses:
  Research and development............       1,050       1,214      1,406      2,060      2,619      3,275      4,141      4,378
  Selling, general and
   administrative.....................       1,681       2,281      2,471      3,227      3,545      4,356      5,608      7,679
  DSC litigation costs................         358         392        324        549        691     18,256     --         --
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
      Total operating expenses........       3,089       3,887      4,201      5,836      6,855     25,887      9,749     12,057
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Operating income (loss)...............        (266)        614      1,510      1,947      3,165    (13,193)     5,526      6,197
Other income (expense):
  Gain on dissolution (equity in loss)
   of joint venture, net..............        (202)       (340)      (526)      (448)      (167)    --         --          1,683
  Other income (expense), net.........          26          15         (4)       112         84        (18)      (338)     1,144
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (loss) before income taxes.....        (442)        289        980      1,611      3,082    (13,211)     5,188      9,024
Income taxes (benefit)................      --               2         39         56        910     (9,498)     1,984      3,450
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Net income (loss).....................   $    (442)  $     287  $     941  $   1,555  $   2,172  $  (3,713) $   3,204  $   5,574
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
 
<CAPTION>
 
                                                                      AS A PERCENTAGE OF REVENUES
                                        ----------------------------------------------------------------------------------------
<S>                                     <C>          <C>        <C>        <C>        <C>        <C>        <C>        <C>
Revenues..............................       100.0%      100.0%     100.0%     100.0%     100.0%     100.0%     100.0%     100.0%
Costs of revenues.....................        62.1        61.8       63.3       60.1       58.5       57.2       56.4       55.9
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Gross profit..........................        37.9        38.2       36.7       39.9       41.5       42.8       43.6       44.1
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Operating expenses:
  Research and development............        14.1        10.3        9.0       10.6       10.9       11.0       11.8       10.6
  Selling, general and
   administrative.....................        22.5        19.3       15.9       16.6       14.7       14.7       16.0       18.5
  DSC litigation costs................         4.8         3.3        2.1        2.8        2.9       61.6     --         --
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
      Total operating expenses........        41.4        33.0       27.0       29.9       28.4       87.3       27.8       29.1
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Operating income (loss)...............        (3.6)        5.2        9.7       10.0       13.1      (44.5)      15.8       15.0
Other income (expense):
  Gain on dissolution (equity in loss)
   of joint venture, net..............        (2.7)       (2.9)      (3.4)      (2.3)      (0.7)    --         --            4.1
  Other income (expense), net.........         0.3         0.1     --            0.6        0.3       (0.1)      (1.0)       2.7
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Income (loss) before income taxes.....        (5.9)        2.5        6.3        8.3       12.8      (44.6)      14.8       21.8
Income taxes (benefits)...............      --          --            0.3        0.3        3.8      (32.1)       5.6        8.3
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
Net income (loss).....................        (5.9)%       2.5%       6.0%       8.0%       9.0%     (12.5)%       9.2%      13.5%
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
                                        -----------  ---------  ---------  ---------  ---------  ---------  ---------  ---------
</TABLE>
 
- ------------
(1) Includes a charge  of $15.8 million  in the quarter ended  June 30, 1996  to
    reflect  a cash payment of  $3.0 million paid in  June 1996, additional cash
    payments of $7.1 million paid in July and the issuance of 725,787 shares  of
    Common  Stock to DSC in settlement  of outstanding litigation. See "Business
    -- Legal Proceedings." Without this charge, operating income for the quarter
    ended June 30, 1996  would have been  $2.6 million, and  as a percentage  of
    revenues would have been 8.8%.
 
                                       21
<PAGE>
    The Company's operating results have been, and will continue to be, affected
by  a  wide variety  of  factors, some  of which  are  outside of  the Company's
control, that could have  a material adverse effect  on revenues and results  of
operations  during any particular period. These factors include: the mix between
domestic and  international sales;  the customer  mix; the  timing and  size  of
orders  which are received and can be  shipped in a quarter; the availability of
adequate  supplies  of  key  components  and  assemblies  and  the  adequacy  of
manufacturing  capacity;  the Company's  ability to  introduce new  products and
technologies on  a timely  basis; the  timing of  new product  introductions  or
announcements  by the  Company or its  competitors; price  competition; and unit
volume.
 
    The UMC system is sold primarily to telephone companies that install the UMC
system as part of their access  networks. Additions to those networks  represent
complex  engineering projects which can require from three to twelve months from
project conceptualization  to completion.  The UMC  system typically  represents
only a portion of a given project and, therefore, the timing of product shipment
and revenue recognition is often difficult to forecast. In developing countries,
delays  and  reductions in  the  planned project  development  can be  caused by
additional factors, including reductions in capital availability due to declines
in  the  local   economy,  currency  fluctuations,   priority  changes  in   the
government's  budget and delays in  receiving government approval for deployment
of the UMC system in the local loop. The Company's expenditures for research and
development, marketing and sales, and  the general and administrative  functions
are  based  in part  on  future revenue  projections and  in  the near  term are
relatively fixed.  The Company  may be  unable to  adjust spending  in a  timely
manner  in response to any unanticipated  declines in revenues. Accordingly, any
significant decline in  demand for  the UMC  system relative  to planned  levels
could  have a material  adverse effect on the  business, financial condition and
results of operations in that quarter  or subsequent quarters. All of the  above
factors  are difficult to forecast, and  these or other factors could materially
adversely affect  the Company's  business, financial  condition and  results  of
operations.  As a result, the Company believes that period-to-period comparisons
are not necessarily meaningful and should  not be relied upon as indications  of
future  performance. Fluctuations in  the Company's operating  results may cause
volatility in the  price of the  Company's Common Stock.  Further, it is  likely
that  in some future quarter the Company's  revenue or operating results will be
below the expectations of  public market analysts or  investors. In such  event,
the  market  price of  the  Company's Common  Stock  would likely  be materially
adversely affected.
 
LIQUIDITY AND CAPITAL RESOURCES
 
    The components of the Company's capital resources and liquidity at  December
31, 1995 and 1996 were as follows:
 
<TABLE>
<CAPTION>
                                                                              DECEMBER 31,
                                                                          --------------------
                                                                            1995       1996
                                                                          ---------  ---------
                                                                             (IN THOUSANDS)
<S>                                                                       <C>        <C>
Cash and cash equivalents...............................................  $  11,118  $  24,942
Marketable securities...................................................     --         83,488
Non-debt working capital, excluding cash and cash equivalents and
 marketable securities..................................................      7,652     36,908
</TABLE>
 
    On  October 1, 1996, the Company issued 5,175,000 shares of its Common Stock
pursuant  to   an  underwritten   initial   public  offering   which   generated
approximately $118.1 million of net proceeds. These proceeds were used to reduce
debt of approximately $14.8 million and to provide resources for general working
capital  purposes. The balance  was invested in  cash equivalents and marketable
securities.
 
    Prior to the Company's initial public  offering, the Company had funded  its
operations  primarily through a  series of preferred  stock financings. From its
incorporation  through  September  1995,  the  Company  completed  five  private
financings   of   equity  securities   providing   aggregate  net   proceeds  of
approximately $38.1  million. In  September 1995,  the Company  repurchased  and
retired  approximately $4.2 million of its outstanding preferred stock. Upon the
consummation  of  the  initial  public   offering,  all  shares  of   redeemable
convertible  preferred stock were converted into a total of 18,717,463 shares of
Common Stock.
 
                                       22
<PAGE>
    In April 1995, the Company  made a loan of $1.0  million to a joint  venture
owned  50% by the Company  which bears interest at a  rate of 5.5%. Beginning in
fiscal 1995, the Company recorded its proportionate share of the joint venture's
losses to the extent of the loan balance and advances made to the joint venture.
As a result, the loan and advances to  the joint venture were written off as  of
December  31, 1995.  On December  23, 1996,  the Company  and the  joint venture
partner entered into an  agreement to terminate  the partnership. In  connection
with   the  dissolution,  the  joint  venture  partner  reimbursed  the  Company
$1,683,000 for  all  loans  and  advances  made by  the  Company  to  date.  The
reimbursement  was  recorded as  a gain  in the  fourth quarter  of 1996  and is
reflected in gain on dissolution (equity in  loss) of joint venture, net in  the
accompanying financial statements.
 
    In  April 1996,  the Company  purchased all  of the  stock outstanding  in a
49%-owned subsidiary  that had  not  previously been  owned  by the  Company  in
exchange  for  220,000 shares  of  the Company's  Series  F Preferred  Stock and
approximately $939,000 in cash.
 
    In June 1996,  as part of  the DSC litigation  settlement, the Company  paid
$3.0  million in cash to  DSC. In July 1996,  the Company borrowed approximately
$7.1 million under a  six-month term loan  with Bank of  the West. The  proceeds
from  the  loan  were  used  to pay  the  remaining  obligations  under  the DSC
litigation settlement. The loan had an interest rate of 5.75% and a $4.0 million
compensating balance requirement. The loan was  due in January 1997. In  October
1996,  the  Company repaid  the loan  with  the proceeds  of the  initial public
offering.  See  "Business  --  Legal  Proceedings"  and  Note  10  of  Notes  to
Consolidated Financial Statements.
 
    The  $6.2  million of  cash  used by  operating  activities during  1996 was
primarily the result of increases in receivables and inventory. Receivables were
higher by $21.4 million in 1996 because of increased revenues. The $5.7  million
growth in inventory is in support of the higher revenue levels.
 
    Investing  activities used $91.1 million of  cash during 1996, primarily due
to the investment of the proceeds  of the Company's initial public offering  and
due  to $8.4  million of  capital expenditures  offset by  the $1.5  million net
reimbursement from a joint venture. The  Company continues to invest in  capital
equipment to support employee growth and research and development activities.
 
    Financing  activities provided $111.2 million of cash in 1996. The Company's
initial public offering generated $118.1 million  of net proceeds. A portion  of
the  proceeds were used  to repay $7.7  million in outstanding  balances under a
line of credit  agreement and $7.1  million outstanding under  a six-month  term
loan  arrangement  with  a  bank.  The  Company  borrowed  under  the  term loan
arrangement to fund a portion of the DSC litigation settlement.
 
    The Company has a $12.0 million line of credit with a bank bearing  interest
at  prime  plus 0.5%.  The  line of  credit expired  on  November 15,  1996, but
automatically renews  for  successive thirty  day  periods until  terminated  by
written  agreement. The amount available to  the Company for borrowing under the
line is based upon the  balance of eligible accounts  receivable at the time  of
borrowing.  As part of the bank line, the bank may issue letters of credit up to
$10.0 million and foreign exchange contracts  up to $5.0 million. The bank  line
requires  the Company to comply with certain financial covenants. As of December
31, 1995  and 1996,  no borrowings  were  outstanding under  the bank  line.  At
December  31, 1996,  $1.6 million  was reserved  under the  line for  letters of
credit and foreign exchange contracts. The Company also has lease lines totaling
$5.2 million that were used to  purchase equipment and furniture. There were  no
amounts left available under the lease lines as of December 31, 1996.
 
    The  Company believes that its existing  cash and short-term investments and
available credit facilities will be adequate to support the Company's  financial
resource  needs, including  working capital  requirements, capital expenditures,
operating lease obligations and debt payments for the next twelve months.
 
                                       23
<PAGE>
                                    BUSINESS
 
    THE FOLLOWING  BUSINESS SECTION  CONTAINS FORWARD-LOOKING  STATEMENTS  WHICH
INVOLVE  RISKS  AND UNCERTAINTIES.  THE  COMPANY'S ACTUAL  RESULTS  COULD DIFFER
MATERIALLY FROM  THOSE  ANTICIPATED IN  THESE  FORWARD-LOOKING STATEMENTS  AS  A
RESULT  OF CERTAIN FACTORS, INCLUDING THOSE  SET FORTH UNDER ``RISK FACTORS" AND
ELSEWHERE IN THIS PROSPECTUS. SEE "GLOSSARY OF TERMS" COMMENCING ON PAGE 63  FOR
DEFINITIONS OF VARIOUS ACRONYMS AND TECHNICAL TERMS USED IN THIS PROSPECTUS.
 
COMPANY OVERVIEW
 
    Advanced Fibre Communications, Inc. designs, develops, manufactures, markets
and  supports  the  UMC  system, a  cost-effective,  multi-feature  digital loop
carrier system developed  to serve  small line-size markets.  The Company's  UMC
system  is designed  to enable  telephone companies,  cable companies  and other
service providers to connect subscribers to the central office switch for  voice
and  data communications over copper, fiber, coax and analog radio networks. The
Company believes that the UMC system is  the only digital loop carrier that  can
operate  simultaneously over  a variety  of transmission  media. The  UMC system
meets the  service needs  of domestic  and international  subscribers  including
analog  services such as POTS, UVG and analog switched data service, and digital
services such as high  speed digital data service,  ISDN, ADU and SDU  services.
Through  a  relationship with  Tellabs  Operations, Inc.  (``Tellabs"),  AFC has
developed the capability to  deliver many of these  same services over cable  TV
networks.
 
    The  UMC  system  has  been  sold to  more  than  450  independent telephone
companies in the  United States, has  been initially deployed  by Ameritech  and
GTE,  and is in  laboratory or field  trials at Pacific  Bell and BellSouth. The
Company has  also sold  the UMC  system  to telephone  companies in  Hong  Kong,
France,  Brazil,  Canada,  China,  Mexico,  the  Netherlands  Antilles  and  the
Dominican Republic. The UMC system is distributed and serviced worldwide through
its direct  sales force  in the  domestic market  and through  its direct  sales
force,  distributors and agents  in international markets.  See ``-- Markets and
Customers" and "-- Proprietary Rights and Licenses."
 
INDUSTRY BACKGROUND
 
    Much of  the existing  local  loop, which  connects  the subscriber  to  the
central  office switch, was designed to  provide analog voice communications, or
POTS, over copper.  As a  transmission medium, copper  suffers from  significant
signal  degradation, particularly when transmitting  signals beyond 10,000 feet.
In addition, the traditional copper  infrastructure was designed to support  low
speed  telecommunications  services  and  offers  relatively  poor  transmission
quality, especially  in  data  communications applications.  Before  the  1970s,
various  solutions were  implemented to  address these  concerns; however, these
solutions  were  generally   costly  to   maintain  and   resulted  in   complex
architectures.  In  the early  1970s,  to decrease  the  cost and  complexity of
extending  service  beyond  10,000  feet  from  the  central  office,  telephone
companies  began to deploy digital loop carriers (``DLCs"), which convert analog
signals into  digital bit  streams  for transmission  to  and from  the  central
office.  The resulting  improved signal  quality enabled  telephone companies to
increase transmission distances from the central office to the customer.
 
    Advancements in digital technology have  enabled central office switches  to
increase  by tenfold the  number of lines served.  While these advancements have
permitted greater centralization of switch resources, they have also resulted in
increased distances  between  the  central office  and  the  subscribers.  Rapid
deployment  of DLCs  was necessary  to effectively  transmit signals  over these
greater distances. However, the copper infrastructures supported by  traditional
DLCs  lacked the bandwidth for additional lines and the transmission quality for
high speed telecommunications. In response to  these limitations as well as  the
deterioration  of the existing copper  infrastructure, telephone companies began
installing fiber  in  high  density  urban  markets  in  the  late  1980s.  Next
generation  DLCs (``NGDLCs") were  designed and introduced to  the market in the
early 1990s to support telecommunications  services over fiber-only networks  in
densely  populated urban markets with 600  to 2,000 lines within the serviceable
area of the NGDLC  (``large line-size markets"). NGDLCs  address certain of  the
limitations  inherent in DLCs. However, NGDLCs  have high installation costs and
complex, support-intensive  characteristics  and are  optimized  for  fiber-only
networks and large line-size markets.
 
                                       24
<PAGE>
    Although  urban  markets have  experienced the  greatest initial  demand for
additional  lines  and  high-speed  telecommunications  services,  the   Company
believes  that demand  for these  services is  increasing in  rural and suburban
markets as well.  The Company  also believes,  however, that  telecommunications
service  providers  in suburban  and  rural markets  generally  do not  have the
resources to  completely replace  existing copper  networks and  therefore  must
upgrade to fiber in incremental steps. These incremental infrastructure upgrades
result  in hybrid networks containing both  copper and fiber transmission lines.
In addition,  worldwide demand  for POTS  and, to  a lesser  extent, high  speed
telecommunications services, is creating the need for significant infrastructure
investments  to  increase the  effective  capacity of  existing  copper, replace
deteriorating copper and  provide services in  new areas. As  telecommunications
service  providers upgrade to fiber technology, deploy new networks and plan for
future subscriber  services,  they must  determine  how to  ensure  a  seamless,
cost-effective connection between copper and fiber within the local loop.
 
THE AFC SOLUTION
 
    The  Company  has  developed  the  UMC  system  to  provide  cost-effective,
multi-feature local loop systems for the small line-size market, incorporating a
modular architecture that supports copper, fiber and coax and the evolution from
one transmission media to another. The  Company believes that the UMC system  is
the  only digital loop carrier that can operate simultaneously over a variety of
transmission media. The  UMC system  is easily scalable  from six  to 672  lines
through  the addition of  plug-in components. Utilizing a  single platform and a
variety of line cards supporting specific services, the UMC system is capable of
providing a range of voice and data services. In addition, the UMC system can be
installed in  a  variety  of  network  configurations  to  support  the  varying
geographic  distribution of subscriber  bases. The Company  has designed the UMC
system  to  require  a  minimum  number  of  common  control  units  to  support
transmission  over a variety of media and the delivery of more advanced services
and  features  by   telephone  companies.   Thus,  the  UMC   system  offers   a
cost-effective  solution for the  small line-size market with  a wide variety of
features and advanced services.
 
AFC'S STRATEGY
 
    AFC's  objective  is   to  be  the   leading  provider  of   cost-effective,
multi-feature  local loop systems for small line-size markets worldwide. The key
elements of its strategy to achieve this objective include:
 
    TARGET DOMESTIC SMALL LINE-SIZE MARKETS.   The Company sells the UMC  system
principally  through  its  direct  sales  force  into  domestic  small line-size
markets. These markets, which are generally located in rural and suburban areas,
are served by  independent telephone  companies and  by the  RBOCs. The  Company
intends  to expand its direct sales force and augment its marketing and customer
support  efforts  to  further  penetrate  its  existing  customer  base  of  450
independent  telephone companies and penetrate  the balance of the approximately
1,300 independent  telephone  companies.  In  addition,  with  the  satisfactory
completion of a Bellcore technical audit, the Company is expanding into the RBOC
market  by offering the UMC  system as a solution  to the small line-size system
requirements of the RBOCs.
 
    PENETRATE INTERNATIONAL  MARKETS.    The  Company  markets  the  UMC  system
internationally   through  local  distributors  and  agents,  through  strategic
relationships, and directly to local  service providers. The Company intends  to
enhance  its existing international operations  with greater sales and marketing
resources to  pursue  market  opportunities in  countries  currently  undergoing
initial   infrastructure  deployment  or  upgrades  which  demand  flexible  and
cost-effective systems.
 
    PROVIDE COST-EFFECTIVE SOLUTIONS.  The UMC system enhances the  transmission
quality and capacity of existing copper facilities, enabling telephone companies
to  maximize  the  performance  of  the  existing  copper  infrastructure  while
permitting  a  cost-effective  and  easily  configurable  upgrade  solution   as
infrastructure is modernized or demands for more advanced communication services
increase. The Company believes that
the UMC system is the only digital loop carrier that can operate seamlessly over
hybrid  networks including  copper, fiber and  analog radio. The  UMC system can
also serve as a  platform for providing high  speed data transmission and  other
advanced  digital  services  such  as video  teleconferencing.  The  Company has
designed the UMC system to require a  minimum number of common control units  to
support transmission over a
 
                                       25
<PAGE>
variety  of media  and the  delivery of more  advanced services  and features by
telephone companies.  The Company's  engineering and  manufacturing efforts  are
directed  toward  preserving and  enhancing  the cost-effectiveness  of  the UMC
system as new features and designs are released.
 
    EXTEND TECHNOLOGY  LEADERSHIP.    The  UMC  system  contains  a  proprietary
software  and backplane design and  modular architecture, which enable telephone
companies  to  more  easily  support  the  varying  geographic  distribution  of
subscriber  bases by employing multiple  configurations which may be distributed
over any combination of  transmission media (including  copper, fiber, coax  and
analog  radio). The proprietary backplane design currently supports a variety of
voice and data services, and the  Company is developing improvements to  support
higher  bandwidth applications. The  Company is engaged  in ongoing research and
development to leverage its technical expertise  and to adapt its technology  to
new markets and applications. For example, the Company is engaged in development
efforts  to  increase the  scalability  of the  UMC  system for  large line-size
markets.
 
    DEVELOP STRATEGIC  RELATIONSHIPS.   The  Company  has entered  into  certain
strategic  relationships in order to  broaden the manufacturing and distribution
of the  UMC system  into developing  international markets,  such as  China  and
India,  and  to leverage  the  UMC technology  for  applications in  markets not
directly targeted by the  Company, such as the  provision of telephone  services
over  existing  cable TV  systems.  The Company  intends  to invest  in existing
strategic  relationships   and  to   seek  additional   relationships  to   gain
manufacturing  and distribution leverage, to access advanced technologies and to
broaden the acceptance of the UMC system.
 
TECHNOLOGY AND PRODUCT ARCHITECTURE
 
    The UMC architecture is based upon  a modular software and hardware  product
platform  that can be  configured and adapted to  the particular requirements of
the customer.  Each line  card,  transceiver and  common control  unit  contains
proprietary  application specific integrated circuits ("ASICs") that incorporate
the digital cross-connect function, eliminating the need for a separate  digital
cross-connect within the assembly. This design improves efficiency, allowing the
Company to deliver the common control required by telephone companies with fewer
assemblies than most NGDLCs.
 
    A basic UMC system consists of two terminals. Each terminal contains a power
supply,  a  central  processing unit  ("CPU"),  a  transceiver and  a  line card
providing subscriber service, such as  analog voice service. The Local  Exchange
Terminal  (``LET"), located  next to  the local  exchange switch  in the central
office, contains  a  central processing  unit  and transmits  and  receives  the
telephone  signal from the Remote Service Terminal (``RST") mounted close to the
subscriber group in a weatherproof housing. The RST receives analog signals from
the  telephone  instruments  of  subscribers,  transforms  them  into  digitally
encoded,  time divisioned  multiplexed bit  streams, and  transports them across
either copper, fiber or radio transmission media to a central office. There, the
LET either decodes the  signal and converts  it back into  an analog signal  for
connection  into the telephone network, or  connects the digital signal directly
into the network.
 
    The base UMC system permits telephone companies to offer basic analog  voice
service  to six subscribers and is priced at approximately $4,000, excluding the
cabinet.  The  base  UMC  system  can  be  expanded  to  accommodate  additional
subscribers,  to  provide advanced  services and  to  operate over  different or
multiple transmission media. The UMC system can be configured to accommodate  up
to  120 subscribers through the addition of line cards and up to 672 subscribers
through the addition of channel bank  assemblies. During 1996, UMC systems  with
capacities  of 120 and 240 lines of  POTS sold for average prices, including the
cabinet, of approximately $25,000 and $40,000, respectively.
 
                                       26
<PAGE>
    In addition, the UMC architecture enables telephone companies to more easily
support  the varying  geographic distribution  of subscriber  bases by employing
multiple configurations which may be distributed over any combination of various
transmission media, including copper, fiber  and coax. A sample installation  is
depicted below:
 
                  [Diagram of sample UMC system installation.]
 
    The  UMC system consists  of the following modules,  which may be configured
according to the needs of the Company's customers:
 
    CHANNEL BANK ASSEMBLY.  The channel bank assembly is used at both the remote
and central office  location, employing a  98 megabit backplane  and a  flexible
slot  architecture  which  supports  system expansion  (via  a  fiber connection
between channel bank  assemblies) to 672  subscribers, as well  as a variety  of
configurations to match the geographic distribution of the subscribers served.
 
    COMMON  CONTROL UNITS.  Common control  units include the central processing
unit, power supplies at both the central office and remote location,  connection
units  for expansion of the  system from 120 subscriber  lines to 672 subscriber
lines and a metallic  test unit for network  testing from the central  switching
office.
 
    TRANSCEIVERS.   Transceivers used for providing  the transport of the signal
between the subscriber and the central office switch are available in fiber, E1,
T1 and analog radio versions.
 
    LINE CARDS.  Line cards are designed to provide voice and data transmissions
in  either  analog  or  digital   form  for  both  domestic  and   international
requirements.
 
    SOFTWARE.    The  UMC  proprietary  system  software  is  menu  driven  with
self-configurable  plug  and   play  orientation,   providing  detailed   system
monitoring, alarm information, card inventory and security.
 
    CABINET.    The  UMC  cabinet  is  available  in  configurations  supporting
subscriber levels of 48, 120,  240 or 672. The  cabinet is a weather  resistant,
field  installable unit and  includes power supplies,  battery backup, lightning
protection and cross-connect capabilities.
 
                                       27
<PAGE>
MARKETS AND CUSTOMERS
 
    To date, the UMC system  has been deployed primarily  in the U.S. rural  and
suburban  markets served by  independent telephone companies.  While the Company
believes this market has substantial  revenue potential and intends to  continue
to  pursue customers in  the U.S. small  line-size market, the  Company has also
begun to pursue other potential markets  and customers for the UMC system,  such
as the RBOCs, international telecommunications service providers and competitive
access providers.
 
    DOMESTIC SMALL LINE-SIZE MARKET
 
    The  domestic small  line-size markets  for telecommunications  services are
generally located in rural  and suburban areas and  are served by  approximately
1,300  independent  telephone companies  and  the seven  RBOCs.  The independent
telephone companies range from rural companies with as few as 125 subscribers to
GTE, with approximately  17 million  subscribers. The  independent companies  in
general  do  not  require  telephone  equipment  suppliers  to  satisfy Bellcore
testing, and typically do not require specific design changes in the product  in
order  for the equipment  to be deployed. As  a result, the  Company was able to
deploy the UMC system  rapidly to independent telephone  companies and to  build
customer  acceptance  of  the  UMC  system  quickly.  In  addition,  independent
telephone companies typically have smaller budgets for telephone equipment  than
the  RBOCs and demand easily scalable and configurable cost-effective solutions.
The UMC  system's  ability  to  improve analog  transmission  and  increase  the
capacity   of  existing   networks,  together   with  its   ability  to  operate
simultaneously over a variety of transmission media, enables telephone companies
to maximize the performance of existing copper infrastructure while permitting a
cost-effective and  easily configurable  upgrade solution  as infrastructure  is
modernized  or demands for more  advanced communication services increase. Thus,
the Company believes that the UMC system provides an attractive solution for the
independent telephone companies in small  line-size markets. Moreover, with  the
satisfactory  completion of a Bellcore technical audit, the Company is expanding
into the RBOC  market by offering  the UMC system  as a solution  for the  small
line-size system requirements of the RBOCs.
 
    The  Company has segmented and prioritized the independent telephone company
market  into  the  following:  (i)   small  independents  that  use   consulting
engineering   firms  to  provide  network   design  for  service  expansion  and
modernization; (ii)  medium-size independents  that perform  the network  design
internally;  and (iii)  large independents, such  as GTE,  that have engineering
committees that approve  equipment for standardization  and may require  testing
and  equipment modifications  to meet  their specific  network requirements. The
Company has targeted each  of these segments as  sources of potential  customers
and to date over 450 independents have purchased the Company's products.
 
                                       28
<PAGE>
    The  following table lists the domestic independent telephone companies that
have purchased at  least $200,000 of  equipment from the  Company since  January
1996:
 
3 Rivers Telephone Co-op
Albany Mutual Telephone
Aliant Communications
ALLTEL
Anixter Brothers
Arvig Telephone
Atlantic Telephone Membership
BEK Communications Co-op
Ben Lomand Rural Telephone Co-op
Benkelman Telephone Company
Benton Cooperative Telephone Company
Big Bend Telephone
Blackfoot Telephone Co-op
Bledsoe Telephone Co-op
Blue Earth Valley Telephone Company
Bridgewater Telephone
Central Texas Telephone Co-op
Chibardun Telephone Co-op
Citizens Telephone
Classic Telephone
Clay County Rural Telephone
Coleman County Telephone Co-op
Commonwealth Telephone Company
Consolidated Telephone Company
Contoocook Valley Telephone
Copper Valley Telephone Company
Cross Telephone
Delta County Tele-Com
Delta Telephone Company
Dickey Rural Telephone
East Ottertail Telephone
Eastern Nebraska Telephone
Ellensburg Telephone
Evans Telephone Company
Farmers Telephone Co-op
Frontier Communications
Geneseo Telephone
Golden West Telecommunications
Granite State Telephone
GTE
Guadalupe Valley Telephone Co-op
Gulf Telephone Company
Hancock Rural Telephone
Harrisonville Telephone
Hill Country Telephone Co-op
Horry Telephone Co-op
Illinois Consolidated Telephone Company
JBN Telephone
Kerrville Telephone
Ketchikan Public Utilities
Lakedale Telephone
Logan Telephone Co-op
Mankato Citizens Telephone
Margaretville Telephone
Mid Rivers Telephone Co-op
Midplains Telephone
NE Missouri Rural Telephone
Nemont Telephone Co-op
North Central Telephone Co-op
North Pittsburgh Telephone
Northland Telephone
People's Rural Telephone Co-op
Perry-Spencer Telephone Co-op
Pioneer Telephone Association
Pioneer Telephone Co-op
Planters Telephone Co-op
Prairie Grove Telephone
PTI Communications
Pulaski-White Rural Telephone
Range Telephone Company
RT Communications
Runestone Telephone Association
Rural Telephone Service
Sanborn Telephone Co-op
Shenandoah Telephone Company
Silver Star Telephone Company
Skyline Telephone
Smithville Telephone Company
Somerset Telephone Company
South Central Rural Telephone Co-op
Southwestern Telephone
St. Joseph Telecommunications
Standard Telephone Company
TDS Telecom
The Ponderosa Telephone
Triangle Telephone Co-op
Tricom
Twin Valley-Ulen Telephone
Uintah Basin Telephone
Valley Telephone Co-op
West Carolina Rural Telephone Co-op
West Central Telephone Association
Woodbury Telephone
 
                                       29
<PAGE>
    INTERNATIONAL MARKETS
 
    The  international telephone  market is segmented  into developing countries
requiring basic  telecommunication services,  or POTS,  and developed  countries
which,   in   addition   to   POTS,   have   requirements   for   more  advanced
telecommunication services  and which  have barriers  to entry  in the  form  of
standards   or  unique  domestic  network   specifications.  In  most  of  these
international markets, a  single telephone  company, which  is typically  highly
regulated   and  government-owned,  provides  service  throughout  the  country.
Typically, these companies are  striving to install  technology that offers  the
opportunity  in the future for advanced  services, with ease of installation and
servicing at an  attractive price. In  addition, they are  striving to  optimize
existing facilities, which typically consist of copper, for a growing subscriber
base.  The Company is  pursuing selected opportunities  to develop these markets
primarily through  direct  contacts  with local  distributors  and  through  its
strategic  relationships, where the market  also requires local manufacturing to
address high import tariffs and where the Company benefits from a local  partner
that can assist customer relationships.
 
    As  part of its international strategy,  the Company is primarily focused on
the  substantial  market  opportunity  which  the  Company  believes  exists  in
developing    countries   currently    undergoing   infrastructure   deployment.
Telecommunications companies in these markets demand flexible and cost-effective
systems. The Company  has sold  UMC systems  to telephone  companies in  Brazil,
China, Mexico, the Netherlands Antilles and the Dominican Republic.
 
    Telecommunications  companies  in  more  developed  countries  require  that
products  have  modifications   and  design  specifications   that  meet   local
standardization  guidelines.  To date,  the Company  has successfully  met these
standards requirements in, and  is currently shipping  products to, both  France
and  Hong Kong.  The Company was  awarded a  contract with France  Telecom for a
multiplexer subscriber  system.  The  Company  was  also  awarded  a  three-year
contract  with  Hongkong Telecommunications  Limited to  deploy the  UMC system.
Although neither  of  these  contracts  require the  customer  to  purchase  any
specific  amount of  product from the  Company, the Company  believes that these
customers present a significant opportunity to the Company.
 
    AFC and Harris Corporation,  a stockholder of the  Company, entered into  an
agreement to form a joint venture to manufacture, distribute and support the UMC
system  in India. The joint  venture included formation of  a holding company in
Mauritius, owned 51% by AFC and 49% by  Harris, which in turn intends to form  a
joint  venture in India with local  Indian partners following receipt of certain
government approvals.  To date,  the parties  have identified  and selected  two
Indian  companies that  will collectively  own 34% of  the Indian  venture to be
located in Delhi. In addition, as a means to protect its licensed technology  in
India,  AFC formed a  100% foreign-owned subsidiary in  India, AFC India Private
(Ltd.), which  holds the  rights to  license  the UMC  technology in  India  for
manufacturing  in the local  market. To date, the  joint venture activities have
included testing and seeking type approval for the UMC system.
 
    The UMC  system  has  received  or is  currently  undergoing  type  approval
qualification  in  a  number  of countries,  including  Hungary,  Indonesia, the
Philippines and  Russia. There  can be  no assurance  that the  UMC system  will
receive  type  approval in  these or  other  countries or  that receipt  of type
approval will lead  to product  sales. In  addition, the  Company currently  has
outstanding  responses to bid requests from telephone companies in India, Panama
and Brazil. The Company's bid responses have been accepted in certain cases  and
rejected  in others in  the past, and  there can be  no assurance that currently
outstanding or future  bid responses  will be  accepted and,  even if  accepted,
there can be no assurance that such acceptance will lead to significant sales.
 
    FUTURE MARKET OPPORTUNITIES
 
    REGIONAL  BELL OPERATING  COMPANIES (RBOCS).   The  seven RBOCs  make up the
largest segment of the U.S.  telecommunications equipment market and serve  over
80%  of all  U.S. telephone  customers, primarily in  urban areas.  All of these
companies have stringent  testing and approval  requirements, known as  Bellcore
testing,  that must be met  before products can be  installed in their networks.
Bellcore testing  requires  significant  investments  in  resources  to  achieve
compliance.  In addition,  the RBOCs require  that the equipment  undergo one or
more field trials  to demonstrate  that the  equipment meets  the standards  and
satisfies their
 
                                       30
<PAGE>
service  and network requirements. The UMC system completed a Bellcore technical
audit, and the Company  intends to submit new  features for Bellcore testing  as
they  are released. In addition,  the UMC system has  been initially deployed by
Ameritech and is in laboratory or field trials at Pacific Bell and BellSouth.
 
    COMPETITIVE  ACCESS  PROVIDERS.    Deregulation  has  allowed  non-regulated
telephone companies to provide local telephone services. Through better pricing,
faster  installation  and better  customer  service, these  companies,  known as
competitive access providers, hope to attract customers away from the RBOCs  and
independent  telephone companies.  These companies historically  have focused on
high density  downtown business  customers. As  these carriers  diversify  their
sales  efforts to  include smaller  businesses and  office parks,  an increasing
number will require smaller systems. The companies active in this market segment
are attractive targets for the Company because the UMC system has the capability
to cost-effectively provide a full range of communication services. The  Company
intends  to address this market primarily through its relationship with Tellabs.
AFC intends to  serve this market  both over traditional  transmission media  as
well as over coax media.
 
    CABLE-BASED  TELEPHONY.   AFC  and Tellabs,  a  stockholder of  the Company,
entered into a general partnership in  1994 to design, develop, manufacture  and
distribute  a new  product line  derived from  the UMC  system. This  product is
designed to  allow telephone  services to  be provided  over existing  cable  TV
systems  as well  as other transmission  media. AFC  contributed a non-exclusive
license to  use  the UMC  technology,  Tellabs  contributed cash  to  the  joint
venture,   and  each  received  defined   marketing  rights  for  the  developed
technology. In early 1996, upon review of the development of the market for this
product, the Company concluded that the  market for transmitting voice and  data
over  cable systems would develop at  a slower pace than originally anticipated.
In the  interest  of  directing  its resources  towards  more  immediate  market
opportunities, AFC entered into agreements with Tellabs in 1996 that changed the
relationship  between  the  parties.  The  new  relationship  provides  AFC with
royalties and OEM revenues from Tellabs on its sales into its specified  markets
and,  in return, AFC  works on selected  developments of the  UMC technology for
Tellabs' markets on a development contract basis. AFC retains all rights in  its
technology as well as the market rights previously defined.
 
SALES, MARKETING AND CUSTOMER SUPPORT
 
    The Company markets the UMC system worldwide directly to telephone companies
and  indirectly  through OEMs,  distributors and  joint ventures  to accommodate
specific markets and  customer support requirements.  The Company's sales  force
consists  of  two  groups,  one  that focuses  on  U.S.  and  Canadian telephone
companies and one that focuses on international markets.
 
    The Company's North American sales force focuses on developing relationships
with independent telephone companies in the U.S. and Canada and on understanding
their network deployment strategies  and cost requirements.  As of December  31,
1996,   the  Company's  domestic  sales  organization  consisted  of  17  direct
salespersons, a domestic sales vice president, and technical support  personnel.
The  Company has  sales personnel  located in  Pittsburgh, Minneapolis, Atlanta,
Denver, Dallas, Chicago,  Seattle, Orlando, Birmingham,  Tulsa and Santa  Clara.
The  Company also has  sales personnel dedicated  to specific customer accounts,
such as Ameritech, BellSouth, GTE and Pacific Bell. In addition to direct  calls
on  the telephone companies, sales to  customers often involve marketing through
consulting engineers who are retained  by small independent telephone  companies
for engineering, specification and installation services.
 
    The  Company employs an international direct sales force consisting of three
salespersons and  one vice  president. The  primary tasks  of the  international
sales  force are  to market the  UMC system directly  to international telephone
companies and  to  select,  manage,  and  train  local  distributors.  Sales  to
international   customers   are  primarily   fulfilled  through   the  Company's
distributors and agents. The Company currently has an office in Hong Kong.
 
    The AFC sales  organization receives  support from  the Company's  marketing
department,  which is  responsible, among  other things,  for product marketing,
advertising and marketing communications. The marketing department works closely
with the planning and engineering departments of telephone companies in order to
provide product proposals that are optimal in terms of both performance and cost
for a specific network configuration.
 
                                       31
<PAGE>
    The Company's customer support organization is responsible for servicing the
Company's products and assisting the  Company's sales personnel. In addition  to
its  own  field technical  service  engineers, the  Company  uses Point-to-Point
Communications, Inc.  (``Point-to-Point"), a  third-party support  organization,
which  provides  first-line  support  for  the  Company's  customers  through  a
toll-free number  open  24  hours per  day,  365  days per  year,  and  provides
installation  services on a subcontract basis  for the Company. Although to date
the  Company  believes   Point-to-Point  has   provided  satisfactory   customer
assistance,  there  can be  no  assurance that  Point-to-Point  will be  able to
provide the  level  of  customer  support  demanded  by  existing  or  potential
customers.  The Company maintains a training  organization which is dedicated to
developing training curriculums  and materials  that are made  available to  the
customer  either  through a  student training  or a  train the  trainer program.
Internationally, the  Company  provides  customer  support  either  directly  or
through  authorized  distributors  or  joint  venture  partners.  The  Company's
products generally have a warranty period of 24 months.
 
RESEARCH AND DEVELOPMENT
 
    The  Company's  research  and  development  efforts  have  been  focused  on
developing  local  loop  products  with advanced  features  for  small line-size
markets. The Company has developed a modular software and hardware platform that
can be configured and adapted to particular customer requirements. In  addition,
development  efforts include extensive attention to ease of installation and use
by the customer as evidenced in the menu driven software approach as well as the
compact and efficient hardware design  demonstrated in its PCBAs. The  Company's
research  and  development  personnel  work  closely  with  sales  and marketing
personnel to  ensure development  efforts  are targeted  at customer  needs.  In
addition,   the  Company's   development  efforts  are   focused  on  developing
enhancements to the UMC system, such as a higher bandwidth backplane.
 
    The current  focus of  the  Company's research  and development  efforts  is
directed  at new releases  of the UMC  system addressing market  demands for new
features  and  services.  These  efforts  include  developing  new  transceivers
incorporating  HDSL capabilities,  new customer  features such  as ISDN  and new
interfaces such as TR303. The Company  is also incorporating MLT remote  testing
capabilities into the product in support of the RBOC market. In addition, future
releases   are  expected  to  include   capabilities  to  support  broader  star
configurations, SONET  OC3 transceivers  and multi-point  support for  the  coax
transceiver   version  of  the  product.  Finally,  the  engineering  team  also
concentrates its attention on numerous projects in the areas of cost and quality
improvements in the UMC system.
 
    In 1995 and 1996, the  Company's research and development expenditures  were
$5.7 million and $14.4 million, respectively, which represented 10.6% and 11.1%,
respectively, of total revenues in such periods. In 1993 and 1994, the Company's
research  and  development  expenditures  were $2.0  million  and  $2.9 million,
respectively. The Company considers its  research and development efforts to  be
vital  to  its  future success  and  anticipates that  research  and development
expenditures as  a  percentage  of  revenues will  remain  significant  for  the
foreseeable  future.  As  of  December  31,  1996,  the  Company's  research and
development staff consisted of 124 employees.
 
MANUFACTURING
 
    Manufacturing,  system  integration  and  certain  testing  operations   are
performed  at the Company's headquarters  in Petaluma, California. The Company's
manufacturing operations  consist  primarily  of  final  assembly  and  test  of
finished  goods from components and custom-made subassemblies (primarily printed
circuit boards) purchased from  third parties. The  Company monitors quality  at
each  stage  of the  production process,  including  the selection  of component
suppliers, warehouse  procedures,  the  assembly of  finished  goods  and  final
testing,   packaging  and  shipping.  The   Company  also  performs  functional,
environmental and  systems  testing  and quality  assurance  procedures  on  the
subassemblies which are incorporated into the UMC system and with respect to the
final products themselves.
 
    The  Company  relies on  a limited  number  of independent  contractors that
manufacture the subassemblies  to the  Company's specifications for  use in  the
Company's  products. In particular,  the Company relies  on: (i) Flextronics and
Tanon Manufacturing,  Inc.  (a  division  of  Electronic  Associates,  Inc.)  to
manufacture  the Company's printed circuit  board assemblies; (ii) Paragon, Inc.
to manufacture backplanes  and channel  bank assemblies and  (iii) Sonoma  Metal
Products,  Inc.  and Cowden  Metal  San Jose,  Inc.  to manufacture  the outside
 
                                       32
<PAGE>
cabinets. The  Company believes  that it  has good  relations with  each of  its
suppliers. As the demand for the UMC system has increased, the Company has begun
a  program to  identify, and  potentially qualify  at a  future date, additional
suppliers to manufacture key product  subassemblies. While the Company  believes
that  the subassemblies manufactured  by any of the  suppliers could be procured
from alternate suppliers, in the event that the Company's subcontractors were to
experience financial, operational, production, or quality assurance difficulties
that resulted  in  a reduction  or  interruption in  supply  to the  Company  or
otherwise failed to meet the Company's manufacturing requirements, the Company's
business,  financial  condition and  results  of operations  would  be adversely
affected until  the Company  established  sufficient manufacturing  supply  from
alternative  sources. There  can be no  assurance that the  Company's current or
alternative manufacturers will be able to meet the Company's future requirements
or that such manufacturing services will continue to be available to the Company
at favorable prices.
 
    Certain components used in the  Company's products, including the  Company's
proprietary ASICs, codecs, certain surface mount technology components and other
components,  are  only  available from  a  single  source or  limited  number of
suppliers. Some of the Company's sole-source suppliers are companies which  from
time  to time allocate parts to  telephone equipment manufacturers due to market
demand for the  telecommunication equipment. Many  of the Company's  competitors
are much larger and may be able to obtain priority allocations from these shared
suppliers, thereby limiting or making unreliable the sources of supply for these
components.  The  Company encountered  supply delays  for  codecs in  the second
quarter of 1994 which resulted in delayed shipments of the UMC system, and there
can be no assurance that similar shortages will not occur in the future or  will
not  result in the Company  having to pay a higher  price for components. If the
Company is  unable  to  obtain  sufficient quantities  of  these  or  any  other
components,  delays or  reductions in  manufacturing or  product shipments could
occur which would  have a  material adverse  effect on  the Company's  business,
financial condition and results of operations.
 
COMPETITION
 
    The  market for equipment for local telecommunications networks is extremely
competitive. The Company's competitors range from small companies, both domestic
and  international,   to  large   multinational  corporations.   The   Company's
competitors  include Alcatel Alsthom Compagnie  Generale d'Electricite, DSC, ECI
Telecom, Ltd., E/O  Networks, Fujitsu  America, Inc.,  Hitron Technology,  Inc.,
Lucent  Technologies,  Inc., NEC  America,  Inc., Northern  Telecom  Ltd., Opnet
Technologies Co. Ltd.,  RELTEC Corporation, Seiscor  Technologies Inc.,  Siemens
Corporation,  Teledata Communications, Ltd. and Vidar-SMS Co. Ltd. Many of these
competitors have  more extensive  financial, marketing  and technical  resources
than the Company and enjoy superior name recognition in the market. In addition,
the  Company has entered  into agreements with ITRI  to jointly develop products
based on the UMC system. ITRI  is a Taiwanese government-sponsored research  and
development  organization in the telecommunications field. Such agreements grant
ITRI and certain of its member companies certain rights to manufacture and  sell
the  ETSI version  of the  UMC system  outside of  North America.  Such entities
currently compete with the Company in international markets, primarily in China.
In addition, upon  termination of the  agreements with ITRI  in 2002, ITRI  will
have  a worldwide, non-exclusive,  royalty-free, irrevocable license  to use the
ETSI version of the UMC technology and, consequently, such member companies will
be able to compete with the Company worldwide at such time. There is an  ongoing
dispute  subject  to litigation  between the  Company and  ITRI and  such member
companies as to whether, among other  things, ITRI possesses the right to  grant
such  rights to manufacture and  sell the ETSI version of  the UMC system to new
member companies. Depending on the outcome of this dispute, the Company may face
competition from new member  companies for the ETSI  version of the UMC  system.
Such  companies  may  possess  substantially  greater  financial,  marketing and
technical resources than the Company. The Company may also face competition from
new market entrants.  The principal competitive  factors in the  segment of  the
telecommunications  equipment industry in  which the Company  operates are total
cost of solution, product quality  and performance, scalability, flexibility  of
configuration  and range of system  capabilities available. The Company believes
that it competes favorably with respect  to these factors, and that the  ability
of  the UMC  system to  offer voice  and data  communications over  a variety of
transmission media in a cost-effective package provides a competitive  advantage
in  the small line-size market. There can  be no assurance that the Company will
be able to compete successfully in the future.
 
                                       33
<PAGE>
COMPLIANCE WITH REGULATORY AND INDUSTRY STANDARDS
 
    The UMC system is required to comply  with a large number of voice and  data
regulations  and standards,  which vary domestically  versus internationally and
may vary by  the specific international  market to which  the Company sells  its
products. Standards setting and compliance verification in the United States are
determined  by the FCC,  by Underwriters Laboratories,  by independent telephone
companies,  by   Bellcore  and   by   other  independent   third-party   testing
organizations.  The UMC technology is certified by Underwriters Laboratories. In
international markets, the Company's  products must comply with  recommendations
by  the Consultative Committee on International Telegraph and Telephony and with
requirements established by the individual  regional carriers which specify  how
equipment  that is connected to their  local networks must operate. In addition,
the Company's  products  must  comply  with  standards  issued  by  ETSI.  These
standards  are  implemented and  enforced  by the  Telecommunications Regulatory
Authority of  each  European nation.  Standards  for new  services  continue  to
evolve,  and the Company will be required  to modify its products or develop and
support new versions of its products to meet these standards. The failure of the
Company's products to comply, or delays in meeting compliance, with the evolving
standards both in its domestic and  international markets could have a  material
adverse  affect on  the Company's business,  financial condition  and results of
operations.
 
    In addition, the Company  will need to ensure  that its products are  easily
integrated  with  the carriers'  network  management systems.  The  RBOCs, which
represent a large segment of the  U.S. telecommunications market, in many  cases
require  that equipment  integrated into their  networks be  tested by Bellcore,
indicating  that   the  products   are   interoperable  with   the   operations,
administration, maintenance and provisioning systems used by the RBOCs to manage
their  networks. Bellcore testing requires  significant investments in resources
to achieve compliance. The UMC system  completed a Bellcore technical audit  and
was  found  to  meet  applicable  requirements.  The  failure  to  maintain such
compliance and/or to obtain it on new features released in the future could have
a material adverse affect on the Company's ability to sell the UMC system to the
RBOCs, which represent a large segment of the telecommunications market.
 
    The Company has not received ISO certification, which certifies that  design
and  manufacturing  processes  adhere  to  certain  established  standards. Many
telecommunications service providers particularly in international markets, will
not purchase products from suppliers  that have not received ISO  certification.
Accordingly,  until it is able  to obtain ISO certification,  the Company may be
precluded from selling its products to  these service providers and its  ability
to  compete with  other suppliers of  communications equipment  may be adversely
affected. The Company has initiated the formal process of applying for  ISO-9001
certification  and expects to  complete the audit  process during 1997. ISO-9001
addresses quality assurance in design, development, production, installation and
service. There can be  no assurance as  to when or if  the Company will  receive
such  certification. The failure  to obtain such  certification may preclude the
Company from selling the UMC system in certain markets.
 
    The  U.S.   Congress   recently   passed   new   regulations   that   affect
telecommunications services, including changes to pricing, access by competitive
suppliers  and  many  other broad  changes  to the  data  and telecommunications
networks and services. These changes will have a major impact on the pricing  of
existing  services,  and may  affect the  deployment  of future  services. These
changes could cause  greater consolidation in  the telecommunications  industry,
which  in turn could disrupt existing customer relationships and have a material
adverse effect on  the Company's  business, financial condition  and results  of
operations.  There can be no assurance that any regulatory changes will not have
a material  adverse  effect  on  the demand  for  the  UMC  system.  Uncertainty
regarding future policies combined with emerging new competition may also affect
the demand for telecommunications products such as the UMC system.
 
PROPRIETARY RIGHTS AND LICENSES
 
    The  Company attempts  to protect  its technology  through a  combination of
copyrights, trade secret laws and contractual obligations. The Company does  not
presently  hold  any  patents  for  its  existing  products  and  has  no patent
applications pending. There can be no assurance that the Company's  intellectual
property  protection measures will be  sufficient to prevent misappropriation of
the  Company's  technology   or  that   the  Company's   competitors  will   not
independently develop technologies that are substantially equivalent or superior
to  the Company's technology. In addition, the laws of many foreign countries do
not protect the
 
                                       34
<PAGE>
Company's intellectual property  rights to the  same extent as  the laws of  the
United States. The failure of the Company to protect its proprietary information
could  have  a  material adverse  effect  on the  Company's  business, financial
condition and results of operations.
 
    The increasing dependence of the telecommunications industry on  proprietary
technology  has  resulted in  frequent litigation  based  on allegations  of the
infringement of patents  and other intellectual  property. The Company  recently
settled  litigation with DSC  under which DSC had  claimed proprietary rights in
the UMC technology. See ``-- Legal  Proceedings." In the future the Company  may
be  subject to additional litigation to  defend against claimed infringements of
the rights of others or to determine  the scope and validity of the  proprietary
rights of others. Future litigation also may be necessary to enforce and protect
trade  secrets and other intellectual property  rights owned by the Company. Any
such litigation could be  costly and cause  diversion of management's  attention
either  of which could have a material adverse effect on the Company's business,
financial condition and  results of  operations. Adverse  determination in  such
litigation could result in the loss of the Company's proprietary rights, subject
the  Company to  significant liabilities, require  the Company  to seek licenses
from third parties,  or prevent the  Company from manufacturing  or selling  its
products, any one of which could have a material adverse effect on the Company's
business,  financial condition and results of operations. Furthermore, there can
be no assurance  that any  necessary licenses  will be  available on  reasonable
terms.
 
    In  September 1992, AFC entered into agreements (the "ITRI Agreements") with
the  Industrial  Technology  Research  Institute  ("ITRI")  to  jointly  develop
products  based  on the  ETSI version  of the  UMC system.  ITRI is  a Taiwanese
government-sponsored   research    and   development    organization   in    the
telecommunications  field.  Under the  ITRI Agreements,  ITRI has  the exclusive
right in Taiwan to use and develop  the ETSI version of the UMC technology,  and
to  manufacture such version of the UMC system through the member companies, but
does not have the right to manufacture and sell the Company's proprietary  ASICs
except  in circumstances where AFC has failed  to provide the ASICs as required.
The ASIC designs were placed in escrow in order to be available to ITRI and  the
member  companies should the  right to manufacture  ASICs become effective. ITRI
and the member companies also  have a non-exclusive right  to sell or lease  the
ETSI  version of the UMC  system in all countries  outside of North America. The
ITRI Agreements require ITRI to pay the Company a royalty on sales or leases  of
the  UMC system made through  September 2002, at which  time the license becomes
fully-paid, and  ITRI  will  have  a  worldwide,  non-exclusive,  royalty  free,
irrevocable license to use the ETSI version of the UMC technology. ITRI's member
companies currently compete with the Company in international markets, primarily
in  China. The Company is currently involved in litigation with ITRI and certain
of its  member companies  arising  out of  disputes  over, among  other  things,
payment  of royalties  and the  supply of ASICs.  See ``--  Competition" and "--
Legal Proceedings -- ITRI."
 
LEGAL PROCEEDINGS
 
    ITRI
 
    In 1995,  a dispute  arose among  the Company,  ITRI and  certain of  ITRI's
member companies (the "Member Companies") in which the Company claimed that ITRI
and the Member Companies were, among other things, failing to pay royalties when
due.  In reliance upon certain provisions of the ITRI Agreements, in April 1996,
the Company ceased delivering to the Member Companies certain proprietary  ASICs
used  in the  manufacture of  the UMC system.  Pursuant to  agreements with ITRI
reached in  1994, design  documentation for  these  ASICs are  held in  a  trust
account,  with directions that the designs can  be made available to ITRI on the
occurrence of specified conditions.  On July 9,  1996, the trustee-custodian  of
the  ASIC designs filed suit  against the Company in  the United States District
Court, Eastern District of  New York, alleging that  the Company had  wrongfully
discontinued  the sale of the ASICs to the Member Companies. Among other things,
the complaint  seeks  unspecified  damages  on behalf  of  the  trustee,  and  a
determination that the trustee can release the ASIC designs to ITRI. On July 31,
1996, the Company filed a counterclaim against the trustee claiming, among other
things,  that the trustee improperly disclosed the design documentation to third
parties.
 
    On July 30,  1996, the Company  filed suit  against ITRI and  others in  the
United States District Court, Northern District of California, for breach of the
ITRI    Agreements,    breach    of    covenants    of    good    faith,   trade
 
                                       35
<PAGE>
secret  misappropriation,  tortious  interference,   and  related  claims.   The
complaint alleges that ITRI breached the ITRI Agreements, among other things, by
failing  to  collect  royalties owed  to  the Company,  by  developing UMC-based
products not  shared with  the Company,  by transferring  UMC technology  to  an
unauthorized  company, and by  misappropriating the Company's  trade secrets and
that the  ITRI  Agreements have  been  terminated. The  Company  seeks  damages,
punitive  damages, and declaratory and injunctive relief. On September 13, 1996,
ITRI filed a  demand for  arbitration of the  dispute and  claimed, among  other
things,  that the  Company has  breached the ITRI  Agreements and  is liable for
unspecified royalties and punitive damages,  and claiming proprietary rights  in
certain UMC technology. On September 30, 1996, the Company amended the complaint
in  its suit  against ITRI to  add the  Member Companies and  another company as
parties to the suit.
 
    On August 27, 1996, the Member  Companies filed suit against the Company  in
United  States District Court, Northern  District of California, alleging breach
of contract and  unfair competition  based on the  Company's discontinuation  of
ASIC  sales to the Member Companies. The complaint filed by the Member Companies
alleges that the Company lacked justification  to discontinue the sale of  ASICs
and  that its failure to  sell ASICs to the  Member Companies constituted unfair
competition. The complaint seeks court-ordered arbitration, unspecified damages,
punitive damages and an injunction requiring  further sales of the ASICs to  the
Member   Companies.  On  September  9,  1996,  the  court  granted  a  temporary
restraining order  pursuant to  which the  Company was  required to  supply  the
Member  Companies with a specified number of  ASICs during the ensuing two month
period on the terms and conditions set forth in the ITRI Agreements. The court's
order was  granted as  an interim  measure to  preserve the  status quo  pending
adjudication   on  the  merits.  On  September   16,  1996,  the  Company  filed
counterclaims seeking  declaratory and  injunctive  relief and  damages  against
Member  Companies  for,  among  other  things,  breach  of  contract,  fraud and
misappropriation of trade secrets. On  September 23, 1996, the Member  Companies
filed  a demand for arbitration of the  dispute and claimed, among other things,
actual damages in excess  of $60 million, legal  fees and expenses and  punitive
damages.
 
    The  parties conducted discovery with respect to the royalty and ASIC supply
issues during  September and  October 1996.  A hearing  on ITRI's  motion for  a
preliminary  injunction to require  the Company to  continue supplying ASICs and
ITRI's motion to compel arbitration was held  on November 22, 1996. In an  order
dated  January 23, 1997,  the court stayed  the litigation and  granted the ITRI
parties' motion to compel  arbitration. In addition, the  court granted in  part
the  Member Companies' motion for  preliminary injunction, thereby requiring the
Company to continue to deliver ASICs to the Member Companies on the terms of the
temporary restraining order granted on September 9, 1996, pending further  order
of  the court or  an arbitrator. The  Company believes that  compliance with the
court's order will not have a material adverse effect on the Company's business,
financial condition and results of operations.
 
    The Company believes that it has meritorious defenses to the claims asserted
by ITRI  and  the Member  Companies  and it  intends  to defend  the  litigation
vigorously.  Moreover, the Company  believes that the  Member Companies' damages
claim is without  merit. The Company  further believes that  its claims  against
ITRI  and  the  Member Companies  are  meritorious  and the  Company  intends to
vigorously pursue such  claims. However,  due to the  nature of  the claims  and
because the proceedings are in the discovery stage, the Company cannot determine
the  total expense  or possible  loss, if any,  that may  ultimately be incurred
either in the context  of a trial,  arbitration or as a  result of a  negotiated
settlement.  Regardless of  the ultimate  outcome of  the proceedings,  it could
result in  significant diversion  of  time by  the Company's  management.  After
consideration  of  the  nature of  the  claims  and the  facts  relating  to the
proceedings, the Company believes  that the resolution of  this matter will  not
have  a material adverse  effect on the  Company's business, financial condition
and results of operations; however, the results of these proceedings,  including
any  potential settlement, are uncertain  and there can be  no assurance to that
effect. See "Risk Factors -- Competition" and "-- Risks Associated with  Pending
Litigation."
 
    DSC
 
    From  July 1993 until June 1996 the  Company was involved in litigation with
DSC. DSC had alleged, among other  things, that the UMC technology contained  or
was  derived from  trade secrets  and other  proprietary technology  of DSC. The
parties   entered   into   a   Settlement   Agreement   and   Mutual    Releases
 
                                       36
<PAGE>
dated  as of June 24, 1996 (the  ``Settlement Agreement"), pursuant to which the
litigation was  terminated. Under  the terms  of the  Settlement Agreement,  the
Company  paid DSC  an aggregate  of $10.1 million  and issued  725,787 shares of
Common Stock to DSC. In addition,  under the terms of the Settlement  Agreement,
AFC  maintains all rights to  the UMC technology free and  clear of any claim by
DSC. In July 1996, the Company borrowed approximately $7.1 million (representing
the present value of  the $8.5 million obligation)  under a six-month term  loan
and  repaid  its  remaining  obligations  under  the  Settlement  Agreement. See
"Selected Consolidated Financial Data,"  ``Management's Discussion and  Analysis
of  Financial  Condition and  Results of  Operations"  and Note  10 of  Notes to
Consolidated Financial  Statements.  The  Company  provided  indemnification  to
certain  stockholders in connection  with the settlement  of the DSC litigation.
See "Certain Transactions."
 
    OTHER
 
    On  June  20,  1995,  two  investment  limited  partnerships,  Equity-Linked
Investors,  L.P. and Equity-Linked Investors, L.P. II (the ``Plaintiffs"), filed
a complaint against  the Company  in the United  States District  Court for  the
Southern  District of  New York. The  Plaintiffs' complaint  contains claims for
breach of contract, promissory estoppel, and specific performance related to  an
alleged  subordinated debt  financing agreement.  The Plaintiffs  are affiliated
with Desai Capital Management Incorporated (``Desai"). From March to June  1995,
the  Company  was  involved  in negotiations  with  Desai  regarding  a proposed
subordinated debt financing  of the  Company. On  June 13,  1995, the  Company's
Board  of  Directors  disapproved  the proposed  transaction.  According  to the
Plaintiff's complaint, the Company had a binding commitment to proceed with  the
proposed financing. The complaint alleges that the Company committed to accept a
$10  million to $15  million loan from  the Plaintiffs in  exchange for interest
payments and  warrants to  purchase 350,000  shares of  the Company's  Series  E
Preferred Stock at $12.50 per share (not taking into account a two-for-one stock
split  in September  1995 and  the further  two-for-one stock  split effected in
August 1996). The complaint alleges damages of ``at least the difference between
their exercisable $12.50  per share price  on 350,000 shares  and the per  share
price of stock sold in any initial public offering."
 
    On  July  12, 1995,  and September  8,  1995, the  Company filed  motions to
dismiss the case for lack of federal jurisdiction and failure to state a  claim.
The  Company's motions to  dismiss the case remain  pending and undecided. There
has been no discovery in the case, and no trial date is set.
 
    The  Company   denies  the   allegations  of   the  Plaintiffs'   complaint,
specifically  denies that  there was  any contract,  and intends  to contest the
claims vigorously.
 
EMPLOYEES
 
    As of December 31,  1996, AFC had 425  full-time employees, including 82  in
marketing,  sales and support services, 124  in research and development, 159 in
operations and  60 in  general administrative  positions. Substantially  all  of
AFC's employees are based at the Company's headquarters in Petaluma, California.
None  of the Company's employees  are represented by a  labor union. The Company
believes its relationships with its employees are good and has never experienced
a strike or work stoppage.
 
PROPERTIES
 
    The Company's administrative, sales  and marketing, and product  development
headquarters  are  located in  Petaluma,  California, where  the  Company leases
approximately 165,000 square feet under leases expiring beginning in March 2005.
The Company believes its facilities are  adequate for its current needs and  for
its needs in the foreseeable future.
 
                                       37
<PAGE>
                                   MANAGEMENT
 
EXECUTIVE OFFICERS, KEY EMPLOYEES AND DIRECTORS
 
    The  executive officers,  key employees  and directors  of the  Company, and
their respective ages as of December 31, 1996, are as follows:
 
<TABLE>
<CAPTION>
NAME                                                  AGE      POSITION
- ------------------------------------------------      ---      ------------------------------------------------
<S>                                               <C>          <C>
EXECUTIVE OFFICERS
Donald Green....................................          65   Chairman of the Board and Chief Executive
                                                               Officer
Carl J. Grivner.................................          43   President and Chief Operating Officer and
                                                               Director
Karen Godfrey...................................          42   Corporate Controller and Assistant Secretary
Glenn Lillich...................................          49   Vice President, Domestic Sales and Marketing
Dan E. Steimle..................................          48   Vice President, Chief Financial Officer,
                                                               Treasurer and Secretary
KEY EMPLOYEES
James Hoeck.....................................          36   Vice President, Advanced Development
John Webley.....................................          38   Vice President, Advanced Development
David Arnold....................................          46   Vice President, Engineering Development
Michael Hatfield................................          34   Vice President, International and Product
                                                               Management
Peter Kilkus....................................          52   Vice President, Quality Assurance
Greg Steele.....................................          35   Vice President, Operations
OUTSIDE DIRECTORS
B.J. Cassin (1).................................          63   Director
Clifford H. Higgerson (1) (2)...................          57   Director
Brian Jackman (2)...............................          55   Director
Dan Rasdal (1)..................................          63   Director
</TABLE>
 
- ---------
(1) Member of the Audit Committee.
 
(2) Member of the Compensation Committee.
 
    DONALD GREEN was  a co-founder  of the Company  and has  been the  Company's
Chairman  of the Board  and Chief Executive  Officer since May  1992. He founded
Optilink Corporation ("Optilink") in 1987 to develop a fiber NGDLC system called
the Litespan 2000. Mr.  Green was the President  and Chief Executive Officer  of
Optilink  from 1987 until  its acquisition by  DSC in 1990.  From 1990 until the
founding of the Company, Mr. Green was Vice President and General Manager of the
Access Products division of  DSC. Prior to founding  Optilink, Mr. Green  served
for  17 years as Chief Executive Officer of Digital Telephone Systems, a company
he founded in  1969 to  develop, manufacture and  market the  D960 Digital  Loop
Carrier system. Prior to founding Digital Telephone Systems, Mr. Green served as
Project  Engineer  and, subsequently,  Vice President  of Engineering  for Lynch
Communication Inc., a  telecommunications company ("Lynch"),  as well as  Design
Engineer  for RCA Standard Telephone  Cables (UK), a telecommunications company.
Mr. Green began his career  with British Telecom, a telecommunications  company,
and is a graduate of the British Institute of Electrical Engineers.
 
    CARL J. GRIVNER has been the Company's President and Chief Operating Officer
since  December 1995 and a  Director since May 1996.  From July 1995 to December
1995 he was the Company's Chief  Operating Officer. From September 1994 to  July
1995, he was President of Enhanced Business Services of Ameritech, an RBOC. From
1986 to September 1994, Mr. Grivner held various general management positions at
Ameritech,  including  President  of  Ameritech's  Advertising  Services (Yellow
Pages) Unit. From 1977 to 1986,
 
                                       38
<PAGE>
he held a variety of technical and marketing positions at International Business
Machines, Inc.  Mr. Grivner  holds a  Bachelor of  Arts degree  in Biology  from
Lycoming  College and  an advanced degree  from the  University of Pennsylvania,
Wharton School of Business.
 
    KAREN GODFREY has been the Company's Corporate Controller since May 1994 and
its Assistant Secretary since  February 1995. From September  1992 to May  1994,
Ms.  Godfrey was self-employed as a financial management consultant. Ms. Godfrey
was the Chief Financial Officer of  Fortune's Almanac, Inc., a catalog  company,
from  September 1991 to September 1992 and  the Chief Financial Officer and Vice
President of Operations  of Paracomp,  Inc., a  software company,  from 1989  to
September  1991. Ms.  Godfrey held  various financial  management positions with
WordStar International  Corporation,  a software  company,  from 1984  to  1989,
including Corporate Controller. Ms. Godfrey started her professional career with
KPMG  Peat Marwick. She  is a C.P.A. and  holds a Bachelor  of Science degree in
Accountancy from the University of Illinois, Champaign-Urbana.
 
    GLENN LILLICH  has been  the Company's  Vice President,  Domestic Sales  and
Marketing  since June 1996. From February 1993 to June 1996, Mr. Lillich was the
Company's Vice President, Sales. From January  1992 to February 1993, he  served
as  the Western  Region Director  of Sales for  the Telecom  Division of Stratus
Company, a  manufacturer of  computer systems.  Mr. Lillich  held various  sales
positions  at DSC from 1984  to December 1991, most  recently as Vice President,
Sales;  GTE  Telenet  Systems  Corporation,  a  manufacturer  of  packet  switch
hardware,  from  1980  to  1983; and  Northern  Telecom  Systems  Corporation, a
manufacturer and distributor of data processing systems, from 1978 to 1979.  Mr.
Lillich  holds  a  Bachelor of  Science  degree  in Accounting  from  Ohio State
University and an MBA in Behavioral Management from Pepperdine University.
 
    DAN E. STEIMLE  has been the  Company's Vice President  and Chief  Financial
Officer  since  December 1993.  He  has also  been  the Company's  Secretary and
Treasurer since July  1995. He  was the  Senior Vice  President for  Operations,
Chief  Financial Officer  and Treasurer for  The Santa Cruz  Operations, Inc., a
software company, from 1991 until joining  AFC. Mr. Steimle served as  Corporate
Director  of  Business Development  at  Mentor Graphics  Corporation,  a company
supplying engineering  design software,  from 1989  to September  1991 and  held
various  financial positions  at Cipher Data  Products, Inc.,  a manufacturer of
computer peripherals, from  1982 to  1989, including  Corporate Vice  President,
Chief  Financial Officer and Treasurer. Mr.  Steimle holds a Bachelor of Science
degree in Accounting  from Ohio  State University and  an MBA  in Marketing  and
Management  from the University of Cincinnati. Mr. Steimle is also a director of
Mitek Systems, Inc., a software company.
 
    JAMES HOECK was a  co-founder of the Company  and served as Vice  President,
Engineering  from inception through January 1995  when he became Vice President,
Advanced  Development.  In  November  1990,  he  co-founded  Quadrium   Research
Corporation,  a  design  consulting  company  ("Quadrium"),  and  served  as its
President until May 1992. Previously, Mr. Hoeck served as a manager of  firmware
at Optilink and as a member of the technical staff at Teradyne, Inc., a test and
measurement  equipment company. Mr. Hoeck holds  a Bachelor of Science degree in
Electrical Engineering from Northwestern University.
 
    JOHN WEBLEY was a  co-founder of the Company  and served as Vice  President,
Engineering  from inception through January 1995  when he became Vice President,
Advanced Development. In November 1990,  he co-founded Quadrium with Mr.  Hoeck,
and  served as its Vice President until June 1992. Previously, Mr. Webley served
as manager  of  systems interface  hardware  at Optilink,  as  a member  of  the
technical  staff at  Rockwell International, a  defense contractor,  as a senior
engineer at  Lynch and  as a  network  systems engineer  for the  Department  of
Telecommunications  in Cape Town,  South Africa. Mr. Webley  holds a Bachelor of
Science degree in Electrical Engineering, an Hon. B.Sc. and a Master of  Science
degree  in  Electrical Engineering  from the  University of  Stellenbosch, South
Africa.
 
    DAVID ARNOLD has been the Company's Vice President, Engineering  Development
since April 1996. From November 1993 to November 1995, he was senior director of
telephony products research at Ericsson Raynet, a provider of telecommunications
equipment.  From 1989  to November 1993,  he served as  engineering director for
Alcatel Network Systems, a provider of telecommunications equipment. Previously,
from
 
                                       39
<PAGE>
1978 to 1983,  Mr. Arnold  held a variety  of engineering  positions at  Digital
Equipment Corporation, a provider of computer and data processing equipment. Mr.
Arnold  holds  a  Bachelor  of  Science  degree  in  Computer  Science  from the
University of California, Berkeley.
 
    MICHAEL HATFIELD has  been the Company's  Vice President, International  and
Product Management since June 1996. From September 1992 to June 1996 he was Vice
President,  Marketing.  From  July 1992  to  September  1992, he  served  as the
director of  marketing  for the  synchronization  products division  of  Telecom
Solutions,  Inc., a  telecommunications company.  Previously, Mr.  Hatfield held
various marketing positions at DSC from 1987 to July 1992. Mr. Hatfield holds  a
Bachelor  of  Science  degree  in Electrical  Engineering  from  the Rose-Hulman
Institute of Technology and an MBA in Finance from Indiana University.
 
    PETER KILKUS has been the Company's Vice President, Quality Assurance  since
March  1995. From 1990 to March 1995,  he served as the Senior Director, Quality
Assurance, for DSC. From  1988 to 1990, he  held various positions at  Optilink,
most  recently as Vice President; Operations. Mr.  Kilkus holds an MA in Physics
from the University of California, Santa  Barbara and a Bachelor of Arts  degree
in Physics from St. Mary's University of Minnesota.
 
    GREG  STEELE has been  the Company's Vice  President, Operations since April
1995. From November 1994 to March 1995, Mr. Steele was the Company's Director of
Operations. Prior to joining the Company, from 1990 to November 1994, Mr. Steele
held various  positions at  DSC,  including director  of account  marketing  and
senior  manager of manufacturing from 1990  to April 1993. Previously, from 1984
to 1990, Mr. Steele held  several manufacturing positions at Texas  Instruments.
Mr.  Steele holds  a Bachelor of  Science degree in  Industrial Engineering from
Oregon State University.
 
    B.J. CASSIN has  been a director  of the Company  since January 1993.  Since
1979,  he has been a private venture capitalist. Previously, he co-founded Xidex
Corporation, a manufacturer of data storage  media, in 1969, and served as  Vice
President, Marketing.
 
    CLIFFORD H. HIGGERSON has been a director of the Company since January 1993.
Mr.  Higgerson  has been  a  general partner  of  Vanguard Ventures  Partners, a
venture capital  firm and  a stockholder  of the  Company, since  July 1991  and
managing partner of Communications Ventures, a venture capital firm, since 1987.
Mr.  Higgerson is  also a  director of  Digital Microwave  Corporation and eight
private companies.
 
    BRIAN JACKMAN has been a director  of the Company since September 1993.  Mr.
Jackman   has  been   the  Executive   Vice  President   of  Tellabs,   Inc.,  a
telecommunications equipment company and a  stockholder of the Company, and  the
President of Tellabs Operations Inc., a subsidiary of Tellabs, Inc., since 1991.
From  1990 to  1993, Mr.  Jackman was the  Executive Vice  President of Business
Operations  of  Tellabs.   From  1989   to  1990,   he  was   the  Senior   Vice
President/General  Manager of the data  communications division of Tellabs, Inc.
Mr. Jackman is also a director of Tellabs, Inc. and Universal Electronics, Inc.
 
    DAN RASDAL  has been  a director  of the  Company since  February 1993.  Mr.
Rasdal   has   been   Chairman   of  the   Board   of   SymmetriComm,   Inc.,  a
telecommunications company,  since  July  1989,  and  the  President  and  Chief
Executive  Officer of SymmetriComm since 1985. Mr.  Rasdal is also a director of
Celeritek, Inc., a semiconductor manufacturer.
 
    The current  directors  have been  elected  pursuant  to the  terms  of  the
Company's  certificate  of incorporation  and a  voting agreement  among certain
stockholders of  the Company,  whereby holders  of the  Company's Series  A  and
Series  B Preferred Stock of the Company  had the right to elect three directors
in the aggregate and the  parties to the voting agreement  agreed to vote for  a
director  designated in accordance with  the voting agreement. Such arrangements
terminated upon closing of the initial  public offering of the Company's  Common
Stock on October 4, 1996.
 
    The  Company's certificate of incorporation  provides for a classified Board
of Directors composed of seven directors.  Accordingly, the terms of the  office
of the Board of Directors are divided into three classes. Class I will expire at
the  annual meeting of the stockholders to be held in 1997; Class II will expire
at the annual meeting of the stockholders to be held in 1998; and Class III will
expire at the annual  meeting of the  stockholders to be held  in 1999. At  each
annual   meeting   of  the   stockholders,  beginning   with  the   1997  annual
 
                                       40
<PAGE>
meeting, the  successors to  directors  whose terms  will  then expire  will  be
elected  to serve from  the time of  election and qualification  until the third
annual meeting  following election  and until  their successors  have been  duly
elected  and qualified, or  until their earlier resignation  or removal, if any.
Carl Grivner and Clifford Higgerson have  been designated as Class I  directors.
B.J. Cassin and Brian Jackman have been designated as Class II directors. Donald
Green and Dan Rasdal have been designated as Class III directors. The Company is
continuing  to seek to add one additional  director to the Board of Directors in
the future. To  the extent  there is  an increase  in the  number of  directors,
additional directorships resulting therefrom will be distributed among the three
classes  so that,  as nearly as  possible, each  class will consist  of an equal
number of directors.
 
    Each executive officer  and key  employee serves  at the  discretion of  the
Board of Directors. The Company does not have any existing employment agreements
with  any executive officer  or key employee. There  are no family relationships
among any of the directors, executive officers and key employees of the Company.
 
BOARD COMMITTEES
 
    The Board of Directors has two standing committees: an Audit Committee and a
Compensation Committee.  The Audit  Committee, currently  consisting of  Messrs.
Cassin,  Higgerson and Rasdal, meets with the Company's financial management and
its independent  accountants  at various  times  during each  year  and  reviews
internal  control conditions, audit  plans and results,  and financial reporting
procedures.  The  Compensation  Committee,   currently  consisting  of   Messrs.
Higgerson   and  Jackman,  reviews  and   approves  the  Company's  compensation
arrangements for key employees and administers the 1996 Stock Incentive Plan and
the Employee Stock Purchase Plan.
 
DIRECTOR COMPENSATION
 
    Non-employee Board members do not receive any cash fees for their service on
the Board or any Board committee, but they are entitled to reimbursement of  all
reasonable  out-of-pocket expenses incurred in  connection with their attendance
at Board and Board committee  meetings. In addition, non-employee Board  members
receive  stock options pursuant to the  automatic option grant program in effect
under the Company's 1996 Stock Incentive  Plan. See `` -- Stock Incentive  Plan"
for further information concerning this program.
 
LIMITATION OF LIABILITY AND INDEMNIFICATION MATTERS
 
    The Company's certificate of incorporation limits the liability of directors
to  the maximum extent permitted by Delaware  law. This provision is intended to
allow the Company's directors  the benefit of  Delaware General Corporation  Law
which  provides  that  directors of  Delaware  corporations may  be  relieved of
monetary liabilities for breach of  their fiduciary duties as directors,  except
under  certain circumstances, including breach of their duty of loyalty, acts or
omissions not in  good faith or  involving intentional misconduct  or a  knowing
violation  of law, unlawful payments or  dividends or unlawful stock repurchases
or redemptions or any  transaction from which the  director derived an  improper
personal benefit. As a result, the Company and its stockholders may be unable to
obtain  monetary damages from  a director for  breach of duty  of care. Although
stockholders may continue to  seek injunctive or other  equitable relief for  an
alleged  breach of fiduciary duty  by a director, stockholders  may not have any
effective remedy against the  challenged conduct if  equitable remedies are  not
available.  In addition,  the Company's  bylaws provide  that the  Company shall
indemnify its executive officers and directors to the fullest extent provided by
Delaware law. The bylaws also  authorize the use of indemnification  agreements,
and  the Company has entered into such agreements with each of its directors and
executive officers. Prospective  investors should  be aware that  the effect  of
such indemnification provisions may be to shift to the Company liabilities which
may  otherwise have been payable by individual directors or officers. Insofar as
indemnification for liabilities arising under the Securities Act may be provided
to the Company's executive officers and directors, the Company has been  advised
that,   in  the  opinion  of  the   Securities  and  Exchange  Commission,  such
indemnification is against public policy as expressed in the Securities Act, and
is, therefore, unenforceable.
 
    The Company  has  obtained officer  and  director liability  insurance  with
respect to liabilities arising out of certain matters, including matters arising
under the Securities Act.
 
                                       41
<PAGE>
    There  is no pending litigation or proceeding involving a director, officer,
employee or other  agent of  the Company as  to which  indemnification is  being
sought, nor is the Company aware of any threatened litigation that may result in
claims for indemnification by any director, officer, employee or other agent.
 
EXECUTIVE COMPENSATION
 
    SUMMARY  OF CASH AND OTHER COMPENSATION.  The following table sets forth the
compensation earned by the Company's Chief Executive Officer and the other  four
executive  officers of  the Company (the  ``Named Executive  Officers"), each of
whose aggregate compensation for the year ended December 31, 1996 was in  excess
of  $100,000 for  services rendered  in all capacities  to the  Company for such
fiscal year.
 
<TABLE>
<CAPTION>
                                                                                          LONG-TERM
                                                                                        COMPENSATION
                                                                                        -------------
                                                                                          NUMBER OF
                                                                 ANNUAL COMPENSATION     SECURITIES
                                                                ----------------------   UNDERLYING      ALL OTHER
NAME AND PRINCIPAL POSITION                                       SALARY      BONUS        OPTIONS     COMPENSATION
- ---------------------------------------------------             ----------  ----------  -------------  -------------
<S>                                                  <C>        <C>         <C>         <C>            <C>
Donald Green ......................................       1996  $  275,000  $  138,903      184,902      $  --
 Chairman of the Board and Chief Executive Officer        1995     185,000     115,625       25,000         --
Carl J. Grivner (1) ...............................       1996     235,000     106,349       --             74,080(2)
 President and Chief Operating Officer                    1995     102,115      48,894      212,000         14,690(3)
Karen Godfrey .....................................       1996     105,000      25,077       --             --
 Corporate Controller and Assistant Secretary             1995     101,016      28,935       10,200         --
Glenn Lillich .....................................       1996     170,000      51,868       --             --
 Vice President, Domestic Sales and Marketing             1995     160,000      54,400       12,000         --
Dan E. Steimle ....................................       1996     170,000      51,868       --             --
 Vice President, Chief Financial Officer, Treasurer       1995     160,000      54,400       12,000         --
 and Secretary
</TABLE>
 
- ---------
(1) Mr. Grivner joined the Company in July 1995.
 
(2)  Represents  $34,377  in  relocation  expenses  paid  by  the  Company   and
    forgiveness  of $39,703 of principal  and interest on a  note payable to the
    Company. See "Certain Transactions."
 
(3) Represents relocation expenses paid by the Company.
 
                                       42
<PAGE>
    STOCK OPTION GRANTS TO  NAMED EXECUTIVE OFFICERS.  The following table  sets
forth  certain information  regarding stock  option grants  made to  each of the
Named Executive Officers in 1996. No  stock appreciation rights were granted  to
the Named Executive Officers during such year.
 
<TABLE>
<CAPTION>
                                                 INDIVIDUAL GRANTS (1)
                                --------------------------------------------------------  POTENTIAL REALIZABLE VALUE
                                 NUMBER OF                                                AT ASSUMED ANNUAL RATES OF
                                SECURITIES     PERCENT OF                                  STOCK PRICE APPRECIATION
                                UNDERLYING    TOTAL GRANTED     PER SHARE                    FOR OPTION TERM (2)
                                  OPTIONS    TO EMPLOYEES IN    EXERCISE     EXPIRATION   --------------------------
NAME                              GRANTED      FISCAL YEAR    BASE PRICE(3)     DATE           5%           10%
- ------------------------------  -----------  ---------------  -------------  -----------  ------------  ------------
<S>                             <C>          <C>              <C>            <C>          <C>           <C>
Donald Green..................     184,902           17.1%      $   12.50       6/25/06   $  1,453,548  $  3,683,577
Carl J. Grivner...............      --             --              --            --            --            --
Karen Godfrey.................      --             --              --            --            --            --
Glenn Lillich.................      --             --              --            --            --            --
Dan E. Steimle................      --             --              --            --            --            --
</TABLE>
 
- ---------
(1)  The option shown in the table is immediately exercisable for all the option
    shares. However, any shares  purchased under the option  will be subject  to
    repurchase  by the  Company, at  the exercise price  paid per  share, in the
    event the optionee terminates employment  prior to vesting in those  shares.
    The  shares vest in successive equal  monthly installments over 24 months of
    service, measured  from  the date  of  grant.  All the  option  shares  will
    immediately  vest in the  event the Company  is acquired by  merger or asset
    sale, unless the options are assumed by the acquiring entity.
 
(2) Realizable values are reported net of the option exercise price. The  dollar
    amounts  under these columns are the result of calculations based upon stock
    price appreciation at  the assumed 5%  and 10% compounded  annual rates  (as
    applied  to the estimated fair market value of the option shares on the date
    of grant, not the  current fair market  value of those  shares) and are  not
    intended to forecast any actual or potential future appreciation, if any, in
    the  value of  the Company's  stock price.  Actual gains,  if any,  on stock
    option exercises will be dependent upon the future performance of the Common
    Stock as  well  as the  option  holder's continued  employment  through  the
    vesting  period. The potential realizable value calculation assumes that the
    option holder waits until the end of the option term to exercise the option.
 
(3) The exercise price for the shares  of Common Stock subject to option  grants
    made  under the Plan may be paid in cash or in shares of Common Stock valued
    at fair market value on the exercise date. The option may also be  exercised
    through  a same-day sale program without any cash outlay by the optionee. In
    addition, the Plan Administrator may provide financial assistance to one  or
    more optionees in the exercise of their outstanding options by allowing such
    individuals  to deliver a full-recourse, interest-bearing promissory note in
    payment of the exercise price and any associated withholding taxes  incurred
    in connection with such exercise.
 
    OPTION  EXERCISES  AND HOLDINGS.   The  following  table sets  forth certain
information with respect to the Named Executive Officers concerning their option
exercises during 1996 and their option holdings as of December 27, 1996. None of
the Named Executive Officers  held any stock appreciation  rights at the end  of
that fiscal year.
 
<TABLE>
<CAPTION>
                                                             NUMBER OF SECURITIES
                                                            UNDERLYING UNEXERCISED        VALUE OF UNEXERCISED
                                                                OPTIONS AS OF             IN-THE-MONEY OPTIONS
                                                            DECEMBER 27, 1996 (2)      AS OF DECEMBER 27, 1996(3)
                           SHARES ACQUIRED     VALUE      --------------------------  ----------------------------
NAME                         ON EXERCISE    REALIZED (1)  EXERCISABLE  UNEXERCISABLE   EXERCISABLE   UNEXERCISABLE
- -------------------------  ---------------  ------------  -----------  -------------  -------------  -------------
<S>                        <C>              <C>           <C>          <C>            <C>            <C>
Donald Green.............        --         $    --          108,558        181,344    $ 5,193,968    $ 7,892,539
Carl J. Grivner..........        46,666        2,292,467      12,401        152,933        650,503      8,039,699
Karen Godfrey............        20,000          170,000      36,440         38,760      1,928,445      2,043,593
Glenn Lillich............       --               --          160,534         87,466      8,533,982      4,630,868
Dan E. Steimle...........        160,000         236,000      18,400         33,600        971,200      1,767,300
</TABLE>
 
- ---------
(1)  Based upon the  difference between the  exercise price and  the fair market
    value of the Company's Common Stock on the date of exercise.
 
                                       43
<PAGE>
(2) Although each option is immediately  exercisable for all the option  shares,
    any  shares  purchased under  the option  are subject  to repurchase  by the
    Company, at the  exercise price paid  per share, in  the event the  optionee
    terminates  employment prior to  vesting in those  shares. Twenty percent of
    the option  shares will  vest  upon optionee's  completion  of one  year  of
    service  measured  from  the vesting  date,  and  the balance  will  vest in
    successive equal monthly  installments over  the next 48  months of  service
    thereafter  (other  than  184,000  of Mr.  Green's  options,  which  vest in
    successive equal monthly  installments over  24 months  of service  measured
    from  the date of grant). All the option shares will immediately vest in the
    event the Company is  acquired by merger or  asset sale, unless the  options
    are  assumed by the  acquiring entity. Accordingly,  the table reflects such
    option shares  as  to  which  the repurchase  right  has  lapsed  under  the
    "exercisable"  column and such option shares subject to the repurchase right
    under the "unexercisable" column.
 
(3) Based on  the last  reported sale  price of  the Company's  Common Stock  on
    December  27, 1996  ($53.25 per share)  less the exercise  price payable for
    such shares.
 
COMPENSATION, TERMINATION OF EMPLOYMENT AND CHANGE IN CONTROL ARRANGEMENTS
 
    The Compensation Committee as Plan Administrator of the 1996 Stock Incentive
Plan has the authority to provide for  the accelerated vesting of the shares  of
Common  Stock subject to outstanding options held by the Chief Executive Officer
and the Company's other executive officers or any unvested shares actually  held
by  those individuals  under the  1996 Stock  Incentive Plan,  in the  event the
Company is acquired  by merger or  asset sale or  there is a  hostile change  in
control  effected by a successful tender or  exchange offer for more than 50% of
the Company's outstanding voting securities or  a change in the majority of  the
Board  as a  result of  one or  more contested  elections for  Board membership.
Alternatively, the Compensation Committee may condition such accelerated vesting
upon  the  individual's  termination  of  service  within  a  designated  period
following  the  acquisition  or  hostile  change in  control.  See  ``  -- Stock
Incentive Plan."
 
    On May 31, 1995, Mr. Green purchased 167,200 shares of Common Stock from the
Company in exchange for a note payable in the amount of $52,250, the fair market
value of such shares on such date, pursuant to a compensation agreement approved
by the Board of Directors. The Company  has the right to repurchase such  shares
at  the original purchase price per share  upon Mr. Green's cessation of service
prior to vesting in such shares. See "Certain Transactions."
 
STOCK INCENTIVE PLAN
 
    The Company's 1996 Stock  Incentive Plan (the ``1996  Plan") is intended  to
serve  as the  successor equity  incentive program  to the  Company's 1993 Stock
Option/Stock Issuance Plan (the ``Predecessor Plan"). The 1996 Plan was  adopted
by  the Board of Directors on July 12,  1996 and approved by the stockholders in
August 1996.  A  total  of  7,008,142  shares  of  Common  Stock  are  currently
authorized  for issuance under the 1996 Plan. This share reserve is comprised of
(i) the shares which remained available for issuance under the Predecessor Plan,
including the shares  subject to  outstanding options thereunder,  plus (ii)  an
additional  increase of  1,000,000 shares. As  of December 31,  1996, there were
options to purchase  4,313,544 shares  under the  Plan. In  addition, the  share
reserve  will  automatically  be increased  on  the  first trading  day  of each
calendar year, beginning with the 1997 calendar  year, by an amount equal to  3%
of  the number of shares of Common Stock  outstanding on the last trading day of
the immediately  preceding calendar  year.  However, in  no  event may  any  one
participant in the 1996 Plan receive option grants or direct stock issuances for
more  than 400,000 shares in  the aggregate per calendar  year. The 1996 Plan is
administered by the Compensation Committee of the Board of Directors (the ``Plan
Administrator").
 
    Outstanding options under the Predecessor  Plan have been incorporated  into
the  1996 Plan, and no further option  grants will be made under the Predecessor
Plan. The incorporated options  will continue to be  governed by their  existing
terms,  unless the Plan Administrator  elects to extend one  or more features of
the 1996 Plan to  those options. However, except  as otherwise noted below,  the
outstanding  options under the  Predecessor Plan contain  substantially the same
terms and conditions summarized below for the Discretionary Option Grant Program
in effect under the 1996 Plan.
 
                                       44
<PAGE>
    The   1996  Plan  is   divided  into  five   separate  components:  (i)  the
Discretionary Option  Grant Program,  under which  eligible individuals  in  the
Company's  employ or service (including officers, non-employee Board members and
consultants) may,  at  the discretion  of  the Plan  Administrator,  be  granted
options  to purchase shares of  Common Stock at an  exercise price not less than
85% of  their fair  market value  on the  grant date;  (ii) the  Stock  Issuance
Program   under  which  such  individuals   may,  in  the  Plan  Administrator's
discretion, be issued shares  of Common Stock directly  through the purchase  of
such shares at a price not less than 100% of their fair market value at the time
of  issuance or as a bonus tied to the performance of services; (iii) the Salary
Investment  Option  Grant  Program  under  which,  if  activated  by  the   Plan
Administrator  for a given year, executive officers and other highly compensated
employees may elect to apply a portion of their base salary for such year to the
acquisition of  special below-market  stock option  grants; (iv)  the  Automatic
Option  Grant Program  under which option  grants will automatically  be made at
periodic intervals to eligible non-employee Board members to purchase shares  of
Common  Stock at an exercise  price equal to 100% of  their fair market value on
the grant date; and (v) the Director  Fee Option Grant Program, if activated  by
the  Plan Administrator  for a  given year,  pursuant to  which the non-employee
Board members may apply  all or a  portion of the annual  retainer fee, if  any,
otherwise  payable  to them  in cash  each  year to  the acquisition  of special
below-market option grants.
 
    The Plan  Administrator will  have complete  discretion to  determine  which
eligible  individuals are to receive option  grants or stock issuances under the
Discretionary Option Grant,  Salary Investment  Option Grant  or Stock  Issuance
Programs, the time or times when such option grants or stock issuances are to be
made, the number of shares subject to each such grant or issuance, the status of
any  granted option as either an incentive stock option or a non-statutory stock
option under the Federal tax laws, the vesting schedule to be in effect for  the
option grant or stock issuance and the maximum term for which any granted option
is to remain outstanding. Generally, options will be immediately exercisable for
all  the option shares. However,  any shares purchased under  the option will be
subject to repurchase by the Company, at  the exercise price paid per share,  in
the  event the optionee terminates employment  prior to vesting in those shares.
The administration of the Automatic Option  Grant and Director Fee Option  Grant
Programs  will be  self-executing in accordance  with the  express provisions of
each such program.
 
    The exercise price for the shares  of Common Stock subject to option  grants
made  under the Plan may be paid in cash  or in shares of Common Stock valued at
fair market value on the exercise date. The option may also be exercised through
a same-day sale program  without any cash outlay  by the optionee. In  addition,
the Plan Administrator may provide financial assistance to one or more optionees
in  the exercise  of their outstanding  options by allowing  such individuals to
deliver a  full-recourse, interest-bearing  promissory note  in payment  of  the
exercise  price and any associated withholding taxes incurred in connection with
such exercise.
 
    In the event  that the Company  is acquired  by merger or  asset sale,  each
outstanding  option under the Discretionary Option Grant Program which is not to
be assumed by the successor  corporation will automatically accelerate in  full,
and  all unvested shares under the Stock Issuance Program will immediately vest,
except to  the extent  the Company's  repurchase rights  with respect  to  those
shares  are to be assigned to  the successor corporation. The Plan Administrator
will have the authority under the Discretionary Option Grant and Stock  Issuance
Programs  to grant options and to structure repurchase rights so that the shares
subject to those  options or repurchase  rights will automatically  vest in  the
event the individual's service is terminated, whether involuntarily or through a
resignation  for good reason, within a  specified period (not to exceed eighteen
(18) months) following (i)  a merger or  asset sale in  which those options  are
assumed  or those  repurchase rights  are assigned or  (ii) a  hostile change in
control of the Company effected by a  successful tender offer for more than  50%
of  the outstanding voting stock  or by proxy contest  for the election of Board
members. The Plan Administrator will also have the discretion to provide for the
automatic acceleration of outstanding options  and the lapse of any  outstanding
repurchase  rights upon (i) a hostile change  in control of the Company effected
by a successful  tender offer  for more than  50% of  the Company's  outstanding
voting  stock or by proxy contest for the  election of Board members or (ii) the
termination of  the individual's  service, whether  involuntarily or  through  a
resignation  for good reason, within a  specified period (not to exceed eighteen
(18) months)  following such  a  hostile change  in control.  Options  currently
outstanding  under the Predecessor  Plan will accelerate  upon an acquisition of
the Company by merger or asset sale, unless those
 
                                       45
<PAGE>
options are assumed by the acquiring entity, but such options are not subject to
acceleration upon  the  termination  of  the  optionee's  service  following  an
acquisition in which those options are assumed or a hostile change in control of
the Company.
 
    Stock   appreciation   rights  are   authorized   for  issuance   under  the
Discretionary Option Grant Program which  provide the holders with the  election
to surrender their outstanding options for an appreciation distribution from the
Company equal to the excess of (i) the fair market value of the vested shares of
Common  Stock subject to the surrendered option over (ii) the aggregate exercise
price payable for  such shares. Such  appreciation distribution may  be made  in
cash  or in  shares of  Common Stock. There  are currently  no outstanding stock
appreciation rights under the Predecessor Plan.
 
    The Plan  Administrator has  the  authority to  effect the  cancellation  of
outstanding  options  under the  Discretionary  Option Grant  Program (including
options incorporated from the Predecessor Plan)  in return for the grant of  new
options for the same or different number of option shares with an exercise price
per  share based upon the fair market value of the Common Stock on the new grant
date.
 
    In the event the Plan Administrator elects to activate the Salary Investment
Option Grant Program for one or more calendar years, each executive officer  and
other  highly compensated employee of the Company selected for participation may
elect, prior to the start of the calendar year, to reduce his or her base salary
for that calendar year by  a specified dollar amount  not less than $10,000  nor
more  than $50,000. If such election is  approved by the Plan Administrator, the
officer will  be  granted, as  soon  as practical  following  the start  of  the
calendar year for which the salary reduction is to be in effect, a non-statutory
option  to purchase that number of shares of Common Stock determined by dividing
the salary reduction amount by two-thirds of the fair market value per share  of
Common  Stock on the grant  date. The option will be  exercisable at a price per
share equal to one-third of  the fair market value of  the option shares on  the
grant  date. As a result, the  total spread on the option  shares at the time of
grant will be equal to the amount of salary invested in that option. The  option
will  vest  in a  series  of twelve  (12)  equal monthly  installments  over the
calendar year for which the salary reduction is in effect and will be subject to
full and immediate vesting upon certain  changes in the ownership or control  of
the Company.
 
    Under  the Automatic Option  Grant Program, each  individual who first joins
the Board after June  30, 1996 as  a non-employee Board  member will receive  an
option  grant  for 20,000  shares of  Common Stock  at  the time  of his  or her
commencement of Board service, provided  such individual has not otherwise  been
in  the prior  employ of  the Company.  In addition,  at each  annual meeting of
stockholders, beginning with the 1997 annual meeting, each individual who is  to
continue to serve as a non-employee Board member will receive an option grant to
purchase  6,000 shares of Common Stock, whether  or not such individual has been
in the prior  employ of the  Company and  whether or not  such individual  first
joined  the Board after June 30, 1996,  provided that such individual has served
as a non-employee Board member for at least six months.
 
    Each automatic grant will  have an exercise price  equal to the fair  market
value  per share of Common Stock on the  grant date and will have a maximum term
of 10 years, subject to  earlier termination following the optionee's  cessation
of  Board  service.  Each  automatic  option  will  be  immediately exercisable;
however, any shares  purchased upon exercise  of the option  will be subject  to
repurchase,  at the option exercise price  paid per share, should the optionee's
service as a  non-employee Board member  cease prior to  vesting in the  shares.
Each  automatic option  grant will  vest in  a series  of installments  over the
optionee's period of Board  service as follows: one-third  of the option  shares
upon  completion of one  year of Board  service, and the  balance in twenty-four
(24) successive equal  monthly installments  upon the  optionee's completion  of
each  additional month  of Board  service thereafter.  However, each outstanding
option will  immediately vest  upon  (i) certain  changes  in the  ownership  or
control  of the Company  or (ii) the  death or disability  of the optionee while
serving as a Board member.
 
    Should the Director  Fee Option Grant  Program be activated  in the  future,
each  non-employee Board  member would  have the opportunity  to apply  all or a
portion of the annual  retainer fee, if  any, otherwise payable  in cash to  the
acquisition of a below-market option grant. The option grant would automatically
be  made on the first trading day in  January in the year for which the retainer
fee would otherwise be payable in cash.  The option will have an exercise  price
per   share  equal  to  one-third  of  the  fair  market  value  of  the  option
 
                                       46
<PAGE>
shares on the grant date, and the number of shares subject to the option will be
determined by dividing the amount of the retainer fee applied to the program  by
two-thirds of the fair market value per share of Common Stock on the grant date.
As a result, the total spread on the option (the fair market value of the option
shares  on the grant  date less the  aggregate exercise price  payable for those
shares) will  be equal  to the  portion of  the retainer  fee invested  in  that
option.  The option will become exercisable for the option shares in a series of
installments over the optionee's period of Board service as follows: one half of
the option shares will become exercisable upon the optionee's completion of  six
(6) months of Board service during the calendar year of the option grant and the
balance will become exercisable in six (6) successive equal monthly installments
upon  his or her  completion of each  additional month of  Board service in such
calendar year. However, the option  will become immediately exercisable for  all
the  option  shares upon  certain changes  in  the ownership  or control  of the
Company.
 
    The Board may amend or modify the 1996 Plan at any time. The 1996 Plan  will
terminate on June 30, 2006, unless sooner terminated by the Board.
 
EMPLOYEE STOCK PURCHASE PLAN
 
    The  Company's  Employee  Stock  Purchase Plan  (the  ``Purchase  Plan") was
adopted by  the  Board  of Directors  on  July  12, 1996  and  approved  by  the
stockholders  in August  1996. The Purchase  Plan is designed  to allow eligible
employees of the Company  and participating subsidiaries  to purchase shares  of
Common   Stock,  at  semi-annual  intervals,   through  their  periodic  payroll
deductions under the Purchase Plan, and a reserve of 1,500,000 shares of  Common
Stock has been established for this purpose.
 
    The  Purchase Plan  will be implemented  in a series  of successive offering
periods, each with a maximum duration of 24 months. The initial offering  period
began on October 1, 1996 and will end on the last business day in July 1998.
 
    All   individuals  employed  by  the  Company  (or  any  current  or  future
participating subsidiary) will be eligible  to participate in the Purchase  Plan
if they are regularly scheduled to work more than twenty (20) hours per week for
more than five (5) calendar months per year.
 
    Individuals  who are  eligible employees on  the start date  of any offering
period may enter  the Purchase  Plan on  that start  date or  on any  subsequent
semi-annual  entry  date (February  1 or  August 1  each year).  Individuals who
become eligible employees after the start  date of the offering period may  join
the Purchase Plan on any subsequent semi-annual entry date within that period.
 
    Payroll  deductions may not exceed 10%  of the participant's base salary for
each semi-annual period of participation, and the accumulated payroll deductions
will be applied to the  purchase of shares on  the participant's behalf on  each
semi-annual purchase date (January 31 and July 31 each year, with the first such
purchase  date to occur on  January 31, 1997) at a  purchase price per share not
less than eighty-five percent (85%) of the LOWER of (i) the fair market value of
the Common Stock  on the participant's  entry date into  the offering period  or
(ii)  the  fair market  value on  the  semi-annual purchase  date. In  no event,
however, may  any  participant  purchase  more than  1,500  shares  on  any  one
semi-annual  purchase date. Should the fair market  value of the Common Stock on
any semi-annual purchase date be less than  the fair market value of the  Common
Stock  on the first day of the offering period, then the current offering period
will automatically end, and  a new twenty-four  (24)-month offering period  will
begin, based on the lower fair market value.
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
    The  Board of  Directors established a  Compensation Committee  in May 1994.
During the last fiscal year, Messrs. Higgerson and Jackman served as members  of
the  Compensation Committee. Neither of these individuals has served at any time
as an officer  or employee of  the Company.  Prior to the  establishment of  the
Compensation  Committee, all  decisions relating to  executive compensation were
made by the Company's Board of Directors. For a description of the  transactions
between  the  Company and  members of  the  Compensation Committee  and entities
affiliated with such members, see  "Certain Transactions." No executive  officer
of  the Company  serves as a  member of  the board of  directors or compensation
committee of any entity which  has one or more  executive officers serving as  a
member of the Company's Board of Directors or Compensation Committee.
 
                                       47
<PAGE>
                              CERTAIN TRANSACTIONS
 
    Since  its inception, the Company has  issued and sold, in private placement
transactions, shares of Preferred Stock and warrants to purchase Common Stock to
the Company's executive officers, directors and/or greater than 5%  stockholders
as follows:
 
<TABLE>
<CAPTION>
                                                         COMMON      COMMON      COMMON      COMMON
                                                       EQUIVALENT  EQUIVALENT  EQUIVALENT  EQUIVALENT
                                                       SHARES OF   SHARES OF   SHARES OF   SHARES OF
                                                        SERIES A    SERIES B    SERIES C    SERIES D       COMMON
                                                       PREFERRED   PREFERRED   PREFERRED   PREFERRED        STOCK
INVESTOR (1)                                           STOCK (2)   STOCK (3)   STOCK (4)   STOCK (5)      WARRANTS
- -----------------------------------------------------  ----------  ----------  ----------  ----------  ---------------
<S>                                                    <C>         <C>         <C>         <C>         <C>
B.J. Cassin..........................................   1,285,458     175,029     109,656      --          339,908(6)
Coral Partners II....................................      43,862       6,838   1,353,462     208,487    1,234,280(7)
Donald Green.........................................     681,552      --          --          --          294,044(8)
Harris Corporation...................................      --          --         877,248      87,725      800,000(9)
Dan E. Steimle.......................................      --          --           5,483      --            5,000(10)
St. Paul Venture Capital, Inc........................   1,485,720     231,602     439,655     263,174      831,880(11)
Tellabs, Inc. (12)...................................      --       1,141,322      13,176   1,403,597    1,352,836(13)
Vanguard IV, L.P. (14)...............................   1,485,720     231,602     351,956      87,725      779,464(15)
</TABLE>
 
- ---------
 (1)  Shares held by  all affiliated persons and  entities have been aggregated.
    See "Principal and Selling Stockholders" for  more detail on shares held  by
    these purchasers.
 
 (2) Shares of Series A Preferred Stock were issued in January and April 1993 at
    an effective common equivalent per share price of $0.45597.
 
 (3)  Shares  of Series  B Preferred  Stock were  issued in  October 1993  at an
    effective common equivalent per share price of $2.27985.
 
 (4) Shares of Series C Preferred Stock were issued in March and May 1994 at  an
    effective common equivalent per share price of $2.27985.
 
 (5)  Shares  of Series  D Preferred  Stock were  issued in  October 1994  at an
    effective common equivalent per share price of $2.84982.
 
 (6) 80,292 of these Common Stock  Warrants were exercised in February 1995,  at
    the  following  exercise prices:  6,472 at  $0.025 per  share and  73,820 at
    $0.125 per share. The remaining 259,616  warrants have an exercise price  of
    $1.165 per share.
 
 (7)  An aggregate of 1,207,327 shares of Common Stock were issued upon exercise
    of these  Common Stock  Warrants in  October 1996  at an  exercise price  of
    $1.165 per share.
 
 (8)  These Common Stock Warrants have the following exercise prices: 255,316 at
    $0.025 per share and 38,728 at $0.125 per share.
 
 (9) These Common Stock Warrants have an exercise price of $1.165 per share.
 
(10) These Common  Stock Warrants  were exercised in  July 1995  at an  exercise
    price of $1.165 per share.
 
(11)  These Common Stock  Warrants have the following  exercise prices: 6,472 at
    $0.025 per share, 63,260 at $0.125 per share, 150,000 at $0.25 per share and
    612,148 at $1.165 per share.
 
(12) Brian Jackman, an affiliate of Tellabs, is a director of the Company.
 
(13) 1,042,836 of these Common Stock Warrants  were exercised in May 1995 at  an
    exercise  price of $1.165 per share. The remaining 310,000 warrants have the
    following exercise prices: 300,000 at $0.25  per share and 10,000 at  $1.165
    per share.
 
(14)  Clifford H.  Higgerson, an  affiliate of  Vanguard, is  a director  of the
    Company.
 
(15) An aggregate of 767,463 shares of Common Stock were issued upon exercise of
    these Common  Stock  Warrants in  October  1996 at  the  following  exercise
    prices:  6,469 at $0.025 per  share, 70,666 at $0.125  per share, 149,347 at
    $0.25 per share and 540,981 at $1.165 per share.
 
                                       48
<PAGE>
    The foregoing table  has been  adjusted to  reflect the  conversion of  each
outstanding  share of Series A, Series B,  Series C and Series D Preferred Stock
of the Company into 1.09656 shares of Common Stock in October 1996. Each  holder
of  such shares  of Common  Stock issued upon  conversion of  Preferred Stock is
entitled to certain registration rights.  See ``Description of Capital Stock  --
Registration Rights."
 
    In  connection with  the issuance and  sale of Preferred  Stock, the Company
entered into an indemnity  agreement with its  Preferred Stock investors  (other
than investors of Series F Preferred Stock) pursuant to which the Company agreed
to indemnify such investors from the financial dilution they may experience as a
result  of  the  costs  and  potential liabilities  of  the  Company  arising in
connection with the  DSC litigation. In  connection with the  settlement of  the
litigation  with DSC, the Company entered into an Amended and Restated Indemnity
Agreement (the "Amended Indemnity Agreement")  with such investors. Pursuant  to
the  Amended Indemnity Agreement,  the indemnification was  limited to the costs
and expenses  of the  litigation  and was  effected  by amending  the  Company's
Articles of Incorporation in August 1996 to adjust the rate at which each series
of Preferred Stock (other than Series F) converts into Common Stock. The rate at
which  each share of Series  A, Series B, Series C  and Series D Preferred Stock
was adjusted so that each of such shares converted into 1.09656 shares of Common
Stock and each share of Series  E Preferred Stock converted into 1.02529  shares
of  Common Stock.  Such conversion  into Common  Stock automatically  occured in
October 1996. Upon amendment  of the Articles of  Incorporation in August  1996,
the  Amended Indemnity Agreement  was terminated and  no further indemnification
obligation remains. See Note 9 of Notes to Consolidated Financial Statements.
 
    In October 1995, the Company loaned to Carl Grivner, the President and Chief
Operating Officer  of  the  Company,  the  sum of  $100,000  to  assist  him  in
relocating to Northern California. Such loan bears interest at the rate of 6.37%
per  annum, with accrued  interest due and  payable annually on  July 19 of each
year, and  the  principal  of such  loan  is  due and  payable  in  three  equal
installments  on July  19 of 1996,  1997 and  1998. In August  1996, the Company
forgave one-third of the principal balance and interest accrued through July 19,
1996. As of December 31, 1996, two-thirds of the principal balance of this  loan
remained outstanding.
 
    In  May 1995, the  Company issued an  aggregate of 563,600  shares of Common
Stock at $0.3125  per share to  certain key employees  pursuant to  compensation
agreements approved by the Company's Board of Directors. In connection with such
issuance,  each such employee paid for the restricted stock by issuing a secured
note payable to the Company. The Company has the right to repurchase such  stock
at  the  original purchase  price per  share upon  the purchaser's  cessation of
service prior  to vesting  in  such shares.  The  repurchase right  lapses  with
respect  to the shares, and each purchaser  vests in his shares, as follows: 20%
of the shares upon completion of one  year of service measured from the date  of
issuance,  and the balance of the shares in a series of equal successive monthly
installments upon the purchaser's  completion of each of  the next 48 months  of
service  thereafter. Such stock is also subject  to the Company's right of first
refusal, which is  exercisable in  the event the  purchaser decides  to sell  or
otherwise  transfer  any of  the shares  purchased prior  to the  initial public
offering of Common Stock. Donald  Green, the Company's Chief Executive  Officer,
purchased  167,200  shares of  Common Stock  and  issued a  note payable  to the
Company in the amount  of $52,250. The  note is secured  by shares of  Preferred
Stock owned by Mr. Green. Such note bears interest at the rate of 6.5% per annum
with  the entire  principal balance  of the note,  together with  all accrued or
unpaid interest, due and payable on December 13, 2000.
 
    AFC and Harris, a stockholder of  the Company, entered into an agreement  in
1995  to form  a joint  venture to manufacture,  distribute and  support the UMC
system in India. The  joint venture includes formation  of a holding company  in
Mauritius,  owned 51% by AFC and 49% by  Harris, which in turn intends to form a
joint venture in India with local  Indian partners following receipt of  certain
government  approvals. To  date, the  parties have  identified and  selected two
Indian companies that  will collectively  own 34% of  the Indian  venture to  be
located in Delhi. See "Business -- Markets and Customers."
 
    AFC  and  Tellabs, a  stockholder  of the  Company,  entered into  a general
partnership in 1994 to design, develop, manufacture and distribute a new product
line derived from the UMC system. AFC contributed a non-exclusive license to use
the UMC technology,  Tellabs contributed  cash to  the joint  venture, and  each
received  defined marketing rights for the developed technology. On December 23,
1996 the Company and
 
                                       49
<PAGE>
the  joint  venture  partner  entered   into  an  agreement  to  terminate   the
partnership.  In  connection with  the  dissolution, the  joint  venture partner
reimbursed the Company $1,683,000 for all loans and advances made by the Company
to date. In addition, the Company and  the joint venture partner entered into  a
License  and Marketing  Agreement and  an OEM  Agreement. Under  the License and
Marketing Agreement, the Company granted to the joint venture partner a  license
to  use the UMC technology in  the development, manufacture, and distribution of
coaxial systems  for specified  markets.  In return,  the Company  will  receive
royalties  from the sale of  these systems. Under the  OEM Agreement the Company
agreed to  manufacture the  UMC  products for  the  joint venture  partner.  See
"Business -- Markets and Customers."
 
    The  Company has granted  options to certain of  its directors and executive
officers. See  ``Management  --  Executive  Compensation"  and  ``Principal  and
Selling Stockholders."
 
    The  Company believes that all of the transactions set forth above were made
on terms no less  favorable to the  Company than could  have been obtained  from
unaffiliated  third parties. The  Company intends that  all future transactions,
including loans,  between the  Company and  its officers,  directors,  principal
stockholders  and their  affiliates be  approved by a  majority of  the Board of
Directors, including a  majority of  the independent  and disinterested  outside
directors  on the Board of  Directors, and be on terms  no less favorable to the
Company than could be obtained from unaffiliated third parties.
 
                                       50
<PAGE>
                       PRINCIPAL AND SELLING STOCKHOLDERS
 
    The following table sets forth certain information regarding the  beneficial
ownership  of the Company's Common Stock as of December 31, 1996 and as adjusted
to reflect the sale of shares of Common Stock offered hereby by (i) each  person
(or group of affiliated persons) who is known by the Company to own beneficially
more  than 5% of the outstanding shares of the Common Stock of the Company, (ii)
each executive officer of the Company, (iii) each director of the Company,  (iv)
all  directors and  executive officers of  the Company  as a group  and (v) each
Selling Stockholder.
 
<TABLE>
<CAPTION>
                                                         SHARES BENEFICIALLY
                                                           OWNED PRIOR TO                         SHARES BENEFICIALLY
                                                            OFFERING (1)          NUMBER OF      OWNED AFTER OFFERING
                                                      -------------------------  SHARES BEING  -------------------------
NAME OF BENEFICIAL OWNERS                                NUMBER       PERCENT    OFFERED (2)      NUMBER       PERCENT
- ----------------------------------------------------  ------------  -----------  ------------  ------------  -----------
<S>                                                   <C>           <C>          <C>           <C>           <C>
Tellabs, Inc. (3) ..................................     3,889,966       11.8%       508,939      3,381,027       10.1%
 4951 Indiana Avenue
 Lisle, IL 60532
Coral Partners II (4) ..............................     3,308,665       10.1         --          3,308,665       10.0
 60 South Sixth Street, Suite 3510
 Minneapolis, MN 55402
St. Paul Venture Capital, Inc. (5) .................     3,252,031        9.7        425,475      2,826,556        8.3
 8500 Normandale Lake Blvd., Suite 1940
 Bloomington, MN 55437
Vanguard IV, L.P. ..................................     2,946,397        9.0        250,000      2,696,397        8.1
 525 University Avenue
 Palo Alto, CA 94301
Harris Corporation (6) .............................     1,764,973        5.3        229,968      1,529,435        4.5
 DTS Division
 300 Bel Marin Keys Blvd.
 Novato, CA 94944-1188
B.J. Cassin (7).....................................     1,342,915        4.1         50,000      1,292,915        3.9
Donald Green (8)....................................     1,820,101        5.5         --          1,820,101        5.4
Carl J. Grivner (9).................................       216,000          *         --            216,000       *
Clifford H. Higgerson (10)..........................     2,946,397        9.0        250,000      2,696,397        8.1
Brian Jackman (11)..................................     3,910,932       11.9        508,939      3,401,993       10.2
Dan Rasdal (12).....................................        63,000          *         --             63,000       *
Karen Godfrey (13)..................................       101,586          *         --            101,586       *
Glenn Lillich (14)..................................       268,000          *         --            268,000       *
Dan E. Steimle (15).................................       255,407          *         --            255,407       *
All executive officers and directors as a group (9
 persons) (16)......................................    10,924,338       31.9        808,939     10,115,399       29.2
Norwest Equity Partners V (17)......................     1,004,021        3.1        131,360        872,661        2.6
Henri Sulzer (18)...................................       872,185        2.7          8,057        864,128        2.6
Japan Associated Finance Co., Ltd. (19).............       732,348        2.2         95,816        636,532        1.9
DSC Communications Corporation......................       725,787        2.2         94,958        630,829        1.9
John P. Kern and Jeanette E. Kern, TTEES
 John P. Kern and Jeanette E. Kern Living Trust U/A
 DTD 02/21/91 (20)..................................        41,931          *          5,427         36,379       *
</TABLE>
 
- ---------
 *  Less than 1%.
 
                                       51
<PAGE>
 (1) Beneficial ownership  is determined  in accordance  with the  rules of  the
    Securities   and  Exchange  Commission  and  generally  includes  voting  or
    investment power with respect to securities. Shares of Common Stock  subject
    to  options and warrants currently exercisable  within 60 days are deemed to
    be outstanding  for computing  the  percentage of  the person  holding  such
    options  or  warrants  but  are not  deemed  outstanding  for  computing the
    percentage of any other person. Except as indicated by footnote, and subject
    to community property laws where applicable, the persons named in the  table
    have  sole voting and investment power with  respect to all shares of Common
    Stock shown as beneficially owned by them.
 
 (2) Assumes (i) the  issuance of 235,395  shares of Common  Stock upon the  net
    exercise of warrants by certain Selling Stockholders and (ii) no exercise of
    the  Underwriters' over-allotment  option. If  the over-allotment  option is
    exercised in full, certain Selling Stockholders will sell additional shares,
    as follows: Tellabs, Inc. (107,217  shares); St. Paul Venture Capital,  Inc.
    (89,633 shares); Harris Corporation (48,447 shares); Norwest Equity Partners
    V  (27,673 shares);  Henri Sulzer  (1,697 shares);  Japan Associated Finance
    Co., Ltd. (4,184 shares); DSC Communications Corporation (20,005 shares) and
    John P. Kern and Jeanette E. Kern,  TTEES John P. Kern and Jeanette E.  Kern
    Living Trust U/A DTD 02/21/91 (1,144 shares).
 
 (3) Includes 300,000 shares which may be acquired upon exercise of a warrant.
 
 (4)  Includes 4,150 shares held by Yuval Almog  and 5,263 shares held in an IRA
    by Dain Bosworth, Inc. as a custodian  for the benefit of Yuval Almog.  Also
    includes 4,150 shares held by Peter McNerney. Messrs. Almog and McNerney are
    two  of the general partners  of Coral Management Partners  II, which is the
    general partner of Coral Partners II, and may be deemed to be the beneficial
    owners of  such  shares. Mr.  Almog  and Mr.  McNerney  disclaim  beneficial
    ownership of such shares.
 
 (5)  St. Paul Venture Capital, Inc. is an affiliate of St. Paul Fire and Marine
    Insurance Company, which is the record owner of the shares. Includes 831,880
    shares which may be acquired upon exercise of warrants.
 
 (6) The record  owner of the  shares is  Tap Technology, Inc.,  a wholly  owned
    subsidiary  of  Harris Corporation.  Includes  800,000 shares  which  may be
    acquired upon exercise of a warrant,  of which 235,538 shares have been  net
    exercised in connection with this offering.
 
 (7)  Includes 255,433  shares held  by Mr. Cassin  as a  conservator for Robert
    Cassin, 43,380 of which shares may  be acquired upon exercise of a  warrant,
    100,000  shares held  in trust by  The Cassin Foundation  and 100,000 shares
    held in trust by  the Cassin 1997 Charitable  Trust UTA dated 01/28/97.  The
    remaining  shares are  held in  trust by B.J.  Cassin and  Isabel B. Cassin,
    Trustees of the Cassin  Family Trust U/D/T, dated  January 31, 1996. Of  the
    50,000  shares shown in  this table as  being offered by  Mr. Cassin, 25,000
    shares are being  offered by each  of The Cassin  Foundation and the  Cassin
    1997 Charitable Trust UTA dated 01/28/97.
 
 (8)  Includes  289,902 shares  issuable upon  exercise of  options held  by Mr.
    Green, 127,467 of which shares  will be vested as  of 60 days from  December
    31,  1996. Also includes 294,044  shares which may be  acquired by Mr. Green
    upon exercise  of  warrants.  Excludes  shares held  by  Mr.  Green's  adult
    children.
 
 (9)  Includes  165,334 shares  issuable upon  exercise of  options held  by Mr.
    Grivner, 19,467 of which shares will be  vested as of 60 days from  December
    31, 1996.
 
(10)  Includes 2,946,397  shares held  by Vanguard IV,  L.P. Mr.  Higgerson is a
    general partner of  Vanguard Venture  Partners, L.P., which  is the  general
    partner of Vanguard IV, L.P. and may be deemed to be the beneficial owner of
    such  shares owned by  Vanguard IV, L.P.  Mr. Higgerson disclaims beneficial
    ownership of such shares.
 
(11) Includes 3,889,966 shares  held by Tellabs, Inc.,  300,000 of which  shares
    may  be acquired upon  exercise of a  warrant. Mr. Jackman  is the Executive
    Vice President of  Tellabs, Inc.  and the President  of Tellabs  Operations,
    Inc.  and may be deemed  to be the beneficial owner  of such shares owned by
    Tellabs. Mr. Jackman  disclaims beneficial  ownership of  such shares.  Also
    includes 10,000 shares which may be acquired by Mr. Jackman upon exercise of
    a warrant.
 
(12)  Includes  63,000 shares  issuable  upon exercise  of  options held  by Mr.
    Rasdal, 38,400 of which shares  will be vested as  of 60 days from  December
    31, 1996.
 
(13)  Includes  75,200 shares  issuable  upon exercise  of  options held  by Ms.
    Godfrey, 40,813 of which shares will be  vested as of 60 days from  December
    31, 1996.
 
                                       52
<PAGE>
(14)  Includes  248,000 shares  issuable upon  exercise of  options held  by Mr.
    Lillich, 168,800 of which shares will be vested as of 60 days from  December
    31, 1996. Also includes 20,000 shares which may be acquired upon exercise of
    a warrant.
 
(15)  Includes 58,667 shares  subject to a  right of repurchase  by the Company.
    Includes 52,000  shares  issuable  upon  exercise of  options  held  by  Mr.
    Steimle,  20,113 of which shares will be  vested as of 60 days from December
    31, 1996; 4,800 shares held in an IRA  by Alex. Brown & Sons as a  custodian
    for  the benefit of  Mr. Steimle; and 4,000  shares held in  an IRA by Alex.
    Brown & Sons as a custodian for the benefit of Jessica Steimle.
 
(16) Includes 58,667  shares subject to  a right of  repurchase by the  Company.
    Includes  893,436 shares issuable upon exercise of options, 415,080 of which
    shares will be  vested as of  60 days  from December 31,  1996, and  667,424
    shares which may be acquired upon exercise of warrants.
 
(17)  The record  owner of  the shares  being sold  in this  offering is Norwest
    Limited, Inc., a limited partner of Norwest Equity Partners V.
 
(18) Includes  130,600 shares  issuable upon  exercise of  options held  by  Mr.
    Sulzer,  107,486 of which shares will be  vested as of 60 days from December
    31, 1996.
 
(19) Represents  shares held  by the  following entities  affiliated with  Japan
    Associated  Finance Co.,  Ltd.: Japan  Associated Finance  Co., Ltd. (29,295
    shares), JAFCO  R-1(A) Investment  Enterprise Partnership  (28,302  shares).
    JAFCO  R-1(B) Investment  Enterprise Partnership (28,302  shares), JAFCO G-5
    Investment Enterprise  Partnership  (60,570  shares)  and  U.S.  Information
    Technology Investment Enterprise Partnership (585,879 shares). Of the 95,816
    shares  to be  sold in  this offering,  3,833 shares  will be  sold by Japan
    Associated Finance Co.,  Ltd., 3,703  shares will  be sold  by JAFCO  R-1(A)
    Investment Enterprise Partnership, 3,703 shares will be sold by JAFCO R-1(B)
    Investment  Enterprise Partnership, 7,924  shares will be  sold by JAFCO G-5
    Investment  Enterprise  Partnership  and  76,653   will  be  sold  by   U.S.
    Information Technology Investment Enterprise Partnership.
 
(20) Includes 20,000 shares which may be acquired upon exercise of a warrant, of
    which 5,552 shares have been net exercised in connection with this offering.
 
                                       53
<PAGE>
                          DESCRIPTION OF CAPITAL STOCK
 
    The  authorized capital stock of the  Company consists of 100,000,000 shares
of Common  Stock, par  value $0.01  per share,  and 5,000,000  shares  Preferred
Stock, par value $0.01 per share.
 
COMMON STOCK
 
    As  of  December 31,  1996,  there were  32,649,607  shares of  Common Stock
outstanding, held  of  record by  211  stockholders. There  will  be  33,085,002
shares,  of Common  Stock outstanding  after giving  effect to  the sale  of the
shares of Common Stock offered hereby after giving effect to the net exercise of
warrants to  purchase  235,395  shares  in connection  with  this  offering  and
assuming  no exercise  after December  31, 1996  of any  other outstanding stock
options and warrants.  Subject to  the rights of  the holders  of any  Preferred
Stock  which may be outstanding,  each holder of Common  Stock on the applicable
record date is  entitled to receive  such dividends  as may be  declared by  the
Board of Directors out of funds legally available therefor, and, in the event of
liquidation, to share pro rata in any distribution of the Company's assets after
payment  or  providing  for  the  payment  of  liabilities  and  the liquidation
preference of any outstanding  Preferred Stock. Each holder  of Common Stock  is
entitled to one vote for each share held of record on the applicable record date
on  all matters presented to  a vote of stockholders,  including the election of
directors. Holders of  Common Stock  have no  preemptive rights  to purchase  or
subscribe  for any stock or other securities, and there are no conversion rights
or redemption or sinking fund provisions with respect to such Common Stock.  All
outstanding  shares of Common Stock are, and  the shares of Common Stock offered
hereby will be when issued, fully paid and non-assessable.
 
PREFERRED STOCK
 
    The Board of  Directors is  authorized, without  further vote  or action  by
holders  of Common Stock, to issue 5,000,000 shares of Preferred Stock in one or
more series and to designate the rights, preferences, limitations,  restrictions
of  and upon shares of each  series, including voting, redemption and conversion
rights.  The  Board  of  Directors  may  also  designate  dividend  rights   and
preferences  in  liquidation. It  is not  possible  to state  the effect  of the
authorization and issuance of any series  of Preferred Stock upon the rights  of
holders  of Common  Stock until the  Board of Directors  determines the specific
terms, rights and preferences of such a series of Preferred Stock. However, such
effects might include, among other  things, restricting dividends on the  Common
Stock,  diluting  the  voting  power  of  the  Common  Stock  or  impairing  the
liquidation rights of such  shares without further action  by holders of  Common
Stock. In addition, under certain circumstances, the issuance of Preferred Stock
may  render more difficult or tend to discourage a merger, tender offer or proxy
contest, the assumption of control by a holder of a large block of the Company's
securities or the removal of  incumbent management, which could thereby  depress
the market price of the Company's Common Stock.
 
WARRANTS
 
    As of December 31, 1996, after giving effect to the net exercise of warrants
to  purchase 235,395  shares in connection  with this offering,  the Company had
outstanding warrants  to purchase  an aggregate  of 2,332,686  shares of  Common
Stock  with the following per share  exercise prices: 446,592 at $0.025; 101,988
at $0.125; 450,000  at $0.25; 1,304,038  at $1.165; and  30,068 at $7.00.  These
warrants  contain net  exercise provisions and  expire at  various dates between
January 1, 1998 and September 30, 2000. See ``Certain Transactions."
 
ANTI-TAKEOVER PROVISIONS
 
    DELAWARE LAW
 
    Section 203  (``Section  203")  of  the  Delaware  General  Corporation  Law
(``DGCL") is applicable to corporate takeovers of Delaware corporations. Subject
to certain exceptions set forth therein, Section 203 provides that a corporation
shall  not engage in any business combination with any ``interested stockholder"
for a three-year  period following  the date  that such  stockholder becomes  an
interested  stockholder unless (a) prior to such date, the board of directors of
the corporation  approved either  the business  combination or  the  transaction
which  resulted in the stockholder becoming  an interested stockholder, (b) upon
consummation of the transaction  which resulted in  the stockholder becoming  an
interested  stockholder, the  interested stockholder owned  at least  85% of the
voting stock  of  the  corporation  outstanding  at  the  time  the  transaction
 
                                       54
<PAGE>
commenced  (excluding certain shares) or (c) on  or subsequent to such date, the
business combination is approved  by the board of  directors of the  corporation
and  by the affirmative votes  of at least two-thirds  of the outstanding voting
stock which is not owned by  the interested stockholder. Except as specified  in
Section  203,  an interested  stockholder is  generally  defined to  include any
person that is the owner of 15% or  more of the outstanding voting stock of  the
corporation,  or is  an affiliate  or associate of  the corporation  and was the
owner of 15% or more of the  outstanding voting stock of the corporation, or  is
an affiliate or associate of the corporation and was the owner of 15% or more of
the  outstanding voting  stock of  the corporation  any time  within three years
immediately prior to  the relevant date,  and the affiliates  and associates  of
such  person. Under certain  circumstances, Section 203  makes it more difficult
for an interested  stockholder to  effect various business  combinations with  a
corporation  for a three-year period, although the stockholders may, by adopting
an amendment to the corporation's certificate of incorporation or bylaws,  elect
not  to be  governed by  this section, effective  12 months  after adoption. The
Company's certificate of incorporation and the bylaws do not exclude the Company
from the restrictions  imposed under  Section 203.  It is  anticipated that  the
provisions  of Section 203  may encourage companies  interested in acquiring the
Company to negotiate in advance with the Board of Directors of the Company since
the stockholder  approval requirement  would be  avoided if  a majority  of  the
directors  then  in  office  approve  either  the  business  combination  or the
transaction  which   resulted  in   the  stockholder   becoming  an   interested
stockholder. These provisions may have the effect of deterring hostile takeovers
or  delaying changes in control  of the Company, which  could depress the market
price  of  the  Common  Stock  and  which  could  deprive  the  stockholders  of
opportunities to realize a premium on shares of the Common Stock held by them.
 
    CHARTER AND BYLAW PROVISIONS
 
    The  Company's  certificate  of  incorporation  and  bylaws  contain certain
provisions that  could  discourage potential  takeover  attempts and  make  more
difficult  attempts  by stockholders  to change  management. The  certificate of
incorporation and the  bylaws provide for  a classified Board  of Directors  and
permit the Board to create new directorships and to elect new directors to serve
for  the full term  of the class of  director in which  the new directorship was
created. The terms of the directors are staggered to provide for the election of
approximately one- third  of the  Board members  each year,  with each  director
serving a three-year term. The Board (or its remaining members, even though less
than  a quorum) is also  empowered to fill vacancies  on the Board occurring for
any reason for the remainder of the term of the class of directors in which  the
vacancy  occurred. Stockholders may  remove a director or  the entire Board, and
such removal requires  the affirmative vote  of two- thirds  of the  outstanding
voting   stock.  The  Company's  certificate   of  incorporation  provides  that
stockholders may not take action by written consent but only at a  stockholders'
meeting,  and that special meetings of the  stockholders of the Company may only
be called by the Chairman of the Board or a majority of the Board.
 
    The Company's certificate of incorporation provides that, in addition to the
requirements of  the  DGCL,  any  ``Business Combination"  (as  defined  in  the
certificate of incorporation) requires the affirmative vote of two-thirds of the
votes  entitled to  be cast  by the  holders of  the Company's  then outstanding
capital stock, voting together  as a class, unless  two-thirds of the  directors
(excluding  certain directors affiliated with persons interested in the Business
Combination) approve the proposed transaction.
 
    A ``Business  Combination,"  as  defined in  the  Company's  certificate  of
incorporation,  includes (i) a merger or consolidation  of the Company or any of
its  subsidiaries  with  an  ``Interested   Stockholder"  (as  defined  in   the
certificate  of incorporation) or any other  corporation which is, or after such
transaction would be, an ``Affiliate" or ``Associate" (as such terms are defined
in the Securities Exchange Act of  1934) of an Interested Stockholder; (ii)  any
sale,  lease, exchange,  mortgage, pledge, transfer  or other  disposition to or
with, or  proposed  by  or on  behalf  of,  any Interested  Stockholder  or  any
Affiliate or Associate of any Interested Stockholder involving any assets of the
Company  or any  subsidiary that  constitute five percent  or more  of the total
assets of the  Company; (iii) the  issuance or  transfer by the  Company or  any
subsidiary of any securities of the Company or any subsidiary to, or proposed by
on  behalf of,  an Interested  Stockholder or any  Affiliate or  Associate of an
Interested Stockholder in exchange for  cash, securities or other property  that
constitute  five percent or  more of the  total assets of  the Company; (iv) the
adoption of  any plan  or proposal  for the  liquidation or  dissolution of  the
Company   or  any  spin-off  or   split-up  of  any  kind   of  the  Company  or
 
                                       55
<PAGE>
any subsidiary, proposed  by or on  behalf of an  Interested Stockholder or  any
Affiliate   or   Associate   of   an   Interested   Stockholder;   or   (v)  any
reclassification, recapitalization, or  merger or consolidation  of the  Company
with  any of  its subsidiaries  or any  other transaction  that has  the effect,
directly or indirectly, of  increasing the proportionate share  of any class  or
series  of  capital stock  of the  Company or  any of  its subsidiaries  that is
beneficially owned by any Interested Stockholder or an Affiliate or Associate of
any Interested Stockholder.
 
    The  Company's  certificate   of  incorporation   defines  an   ``Interested
Stockholder"  as (i)  an individual, corporation  or other  entity (a ``person")
which is or was at any time within the two-year period preceding the date of the
transaction in question, the beneficial owner of 15% or more of the  outstanding
voting  securities of the Company; (ii) an Associate or Affiliate of the Company
who within the two-year period preceding the date of the transaction in question
was the beneficial owner of 15% or more of the outstanding voting securities  of
the  Company; or (iii)  under certain circumstances,  an assignee of  any of the
foregoing persons. A person is a ``beneficial owner" of any stock of the Company
(a) which such person or any of its Affiliates and Associates beneficially owns,
directly or  indirectly; (b)  which such  person  or any  of its  Affiliates  or
Associates  has, directly or indirectly, (i)  the right to acquire (whether such
right is  exercisable immediately  or  subject only  to  the passage  of  time),
pursuant  to any agreement, arrangement or understanding or upon the exercise of
conversion rights, exchange warrants or options, or otherwise, or (ii) the right
to vote pursuant to  any agreement, arrangement or  understanding; or (c)  which
are  beneficially owned, directly or indirectly,  by any other person with which
such  person  or  any  of  its  Affiliates  or  Associates  has  any  agreement,
arrangement  or understanding for  the purpose of  acquiring, holding, voting or
disposing of any shares of capital stock.
 
    The foregoing provisions of the  certificate of incorporation and bylaws  of
the Company may deter any potential unfriendly offers or other efforts to obtain
control of the Company that are not approved by the Board of Directors and could
thereby  deprive the stockholders of opportunities to realize a premium on their
Common Stock and could  make removal of incumbent  directors more difficult.  At
the  same time,  these provisions  may have the  effect of  inducing any persons
seeking control of  the Company or  a business combination  with the Company  to
negotiate  terms acceptable  to the Board  of Directors. Such  provisions of the
Company's certificate of incorporation and bylaws can be changed or amended only
by the affirmative vote of the holders  of at least two-thirds of the  Company's
then outstanding voting stock.
 
REGISTRATION RIGHTS
 
    Following  this offering, the holders  of approximately 19,869,482 shares of
Common Stock outstanding or issuable upon exercise of outstanding warrants  (the
``Holders")  will be entitled to certain rights with respect to the registration
of such shares under the Securities Act. Under the terms of an agreement between
the Company and  the Holders, if  the Company  proposes to register  any of  its
securities  under the Securities Act, the Holders are entitled to notice of such
registration and are entitled  to include shares of  such Common Stock  therein;
provided, among other conditions, that the underwriters of any offering have the
right  to limit  the number  of such  shares included  in such  registration. In
addition, upon the request  of the Holders  of at least  50% of the  registrable
securities  at  any time  after January  1,  1997, the  Holders may  require the
Company on not more than one occasion to file a registration statement under the
Securities Act with respect to such shares,  and the Company is required to  use
its  best efforts to effect such registration, subject to certain conditions and
limitations. The Holders may require the Company to register all or a portion of
their shares  with  registration rights  on  Form  S-3 when  such  form  becomes
available  to the Company, on not more  than three occasions, subject to certain
conditions  and  limitations.  If  the  Holders,  by  exercising  their   demand
registration  rights, cause  a large number  of securities to  be registered and
sold in the public market, such sales could have an adverse effect on the market
price for the Company's Common Stock.  Moreover, if the Company were to  include
in  a  Company initiated  registration shares  held by  the Holders  pursuant to
exercise of their piggyback registration rights, such sales may have an  adverse
effect on the Company's ability to raise additional capital.
 
TRANSFER AGENT AND REGISTRAR
 
    The  transfer agent and registrar of the  Common Stock is The First National
Bank of Boston.
 
                                       56
<PAGE>
                        SHARES ELIGIBLE FOR FUTURE SALE
 
    Sales of a substantial number of shares of Common Stock in the public market
following  this  offering  could  adversely  affect  the  market  price  for the
Company's Common Stock. The number of shares of Common Stock available for  sale
in  the public market is limited by restrictions under the Securities Act and by
the following lock-up agreements: (i)  in connection with the Company's  initial
public  offering,  the Company's  officers,  directors and  certain stockholders
agreed (the "IPO Lock-Up Agreement") not to sell or otherwise dispose of any  of
their  shares for 180  days following the  date of the  Company's initial public
offering without the  prior consent of  Morgan Stanley &  Co. Incorporated;  and
(ii)  in  connection  with  this  offering,  the  Company's  executive officers,
directors and the Selling Stockholders have entered into agreements with  Morgan
Stanley  &  Co. Incorporated  (the "Follow-On  Lock-Up Agreements")  pursuant to
which such holders  agreed not  to sell  or otherwise  dispose of  any of  their
shares  for 90 days following completion of  this offering. Morgan Stanley & Co.
Incorporated may,  however, in  its  sole discretion  at  any time  and  without
notice,  release  all  or  any  portion of  the  securities  subject  to Lock-Up
Agreements. Upon completion of this offering, the Company will have  outstanding
33,085,002  shares of Common Stock. Of these shares: 7,193,750 shares (including
the 5,175,000  shares sold  in the  Company's initial  public offering  and  the
2,000,000  shares sold in  this offering) will be  available for immediate sale;
10,412,264 shares  will  become  eligible  for  sale  on  March  30,  1997  upon
expiration  of  the IPO  Lock-Up Agreements  pursuant  to Rule  701 or  Rule 144
(subject in certain cases to the volume limitations of Rule 144); 13,237  shares
will  become eligible  for sale  pursuant to Rule  701 at  various dates between
March 30, 1997  and the  expiration date  of the  Follow-On Lock-Up  Agreements;
11,862,058  shares will become eligible for sale 90 days after the completion of
this offering upon expiration  of the Follow-On  Lock-Up Agreements pursuant  to
Rule 701 or Rule 144 (subject in certain cases to the volume limitations of Rule
144);  and the remaining 3,603,693 shares will become eligible for sale pursuant
to Rule  144  (subject  in certain  cases  to  the applicable  Rule  144  volume
limitations)  at  various dates  following expiration  of the  Follow-On Lock-Up
Agreements.
 
    In general, under  Rule 144  as currently in  effect, a  person (or  persons
whose shares are aggregated) who has beneficially owned Restricted Shares for at
least  two years  (including the  holding period  of any  prior owner  except an
affiliate) would be entitled to sell  within any three-month period a number  of
shares  that does not  exceed the greater of:  (i) one percent  of the number of
shares  of  Common   Stock  then  outstanding   (approximately  330,000   shares
immediately  after this offering); of (ii)  the average weekly trading volume of
the Common stock during the four calendar  weeks preceding the filing of a  Form
144  with respect to such sale. Sales under Rule 144 are also subject to certain
manner of sale  provisions and notice  requirements and to  the availability  of
current public information about the Company. Under Rule 144(k), a person who is
not  deemed to have been an  affiliate of the Company at  any time during the 90
days preceding a sale, and who has beneficially owned the shares proposed to  be
sold  for at least three years (including  the holding period of any prior owner
except an affiliate), is entitled to sell such shares without complying with the
manner of sale, public  information, volume limitation  or notice provisions  of
Rule 144.
 
    Subject  to  certain  limitations  on  the  aggregate  offering  price  of a
transaction and other conditions,  Rule 701 may be  relied upon with respect  to
the resale of securities originally purchased from the Company by its employees,
directors,  officers,  consultants  or advisers  prior  to the  closing  of this
offering, pursuant to  written compensatory benefit  plans or written  contracts
relating  to the compensation  of such persons. In  addition, the Securities and
Exchange Commission has  indicated that  Rule 701  will apply  to stock  options
granted by the Company before this offering, along with the shares acquired upon
exercise  of such options. Securities issued in  reliance on Rule 701 are deemed
to be Restricted Shares and, beginning 90 days after the date of this Prospectus
(unless subject to the contractual restrictions described above), may be sold by
persons other than affiliates subject only  to the manner of sale provisions  of
Rule  144 and by affiliates under Rule  144 without compliance with its two-year
minimum holding period requirements.
 
    In addition, as of December 31,  1996, the Company had outstanding  warrants
to  purchase  an aggregate  of 2,332,686  shares of  Common Stock  (after giving
effect to the net exercise of warrants to purchase 235,395 shares in  connection
with   this  offering).   These  warrants   contain  net   exercise  provisions.
Accordingly, any  shares issued  upon net  exercise will  be eligible  for  sale
immediately  upon expiration of any lock-up  agreements to which such shares are
subject  pursuant  to  Rule   144.  In  addition,  the   Company  has  filed   a
 
                                       57
<PAGE>
registration  statement on  Form S-8  with the  Commission registering 8,675,676
shares of Common Stock reserved for issuance under the Company's Employee  Stock
Purchase  Plan and 1996  Stock Incentive Plan. Of  such shares, 4,313,544 shares
subject to stock  options outstanding under  the 1996 Stock  Incentive Plan  are
subject  to lock-up agreements and will be  eligible for sale upon expiration of
such lock-up agreements as follows: 3,289,508  shares on March 30, 1997 and  the
remaining  1,024,036  shares  90 days  from  the  date of  this  Prospectus. The
1,500,000 shares  reserved  under  the  Employee Stock  Purchase  Plan  will  be
eligible  for  sale upon  issuance. In  addition,  the holders  of approximately
19,869,482 shares  of Common  Stock  outstanding or  issuable upon  exercise  of
outstanding  warrants have  certain rights  to require  the Company  to register
those shares under  the Securities  Act. If  such holders,  by exercising  their
demand  registration rights, cause a large number of shares to be registered and
sold in the public market,  such sales could have  a material adverse effect  on
the market price for the Company's Common Stock. If the Company were required to
include in a Company-initiated registration shares held by such holders pursuant
to  the exercise of their piggyback registration  rights, such sales may have an
adverse  effect  on  the  Company's   ability  to  raise  needed  capital.   See
"Description of Capital Stock" and "Underwriters."
 
                                       58
<PAGE>
                                  UNDERWRITERS
 
    Under  the  terms and  subject to  conditions  contained in  an Underwriting
Agreement, the U.S.  Underwriters named  below, for  whom Morgan  Stanley &  Co.
Incorporated,  Merrill  Lynch,  Pierce,  Fenner &  Smith  Incorporated,  Cowen &
Company and Hambrecht & Quist LLC are acting as U.S. Representatives (the ``U.S.
Underwriters"), have severally agreed to purchase, and the Company has agreed to
sell to them, and  the International Underwriters named  below, for whom  Morgan
Stanley  &  Co.  International  Limited, Merrill  Lynch  International,  Cowen &
Company and Hambrecht &  Quist LLC are  acting as International  Representatives
(the  ``International Underwriters"), have severally agreed to purchase, and the
Company has agreed to sell  to them, the respective  number of shares of  Common
Stock set forth opposite their respective names below:
 
<TABLE>
<CAPTION>
                                                                                             NUMBER OF
                                           NAME                                              OF SHARES
- -------------------------------------------------------------------------------------------  ----------
<S>                                                                                          <C>
U.S. Underwriters:
  Morgan Stanley & Co. Incorporated........................................................     240,000
  Merrill Lynch, Pierce, Fenner & Smith
            Incorporated...................................................................     240,000
  Cowen & Company..........................................................................     240,000
  Hambrecht & Quist LLC....................................................................     240,000
  Alex. Brown & Sons Incorporated..........................................................      80,000
  Dain Bosworth Incorporated...............................................................      40,000
  Donaldson, Lufkin & Jenrette Securities Corporation......................................      80,000
  EVEREN Securities, Inc...................................................................      40,000
  Fahnestock & Co. Inc.....................................................................      40,000
  Furman Selz LLC..........................................................................      40,000
  Needham & Company, Inc...................................................................      40,000
  Nutmeg Securities, Ltd...................................................................      40,000
  Parker/Hunter Incorporated...............................................................      40,000
  Brad Peery Inc...........................................................................      40,000
  Pennsylvania Merchant Group Ltd..........................................................      40,000
  Smith Barney Inc.........................................................................      80,000
  Soundview Financial Group, Inc...........................................................      40,000
                                                                                             ----------
    Subtotal...............................................................................   1,600,000
                                                                                             ----------
 
International Underwriters:
  Morgan Stanley & Co. International Limited...............................................     100,000
  Merrill Lynch International..............................................................     100,000
  Cowen & Company..........................................................................     100,000
  Hambrecht & Quist LLC....................................................................     100,000
                                                                                             ----------
    Subtotal...............................................................................     400,000
                                                                                             ----------
      Total................................................................................   2,000,000
                                                                                             ----------
                                                                                             ----------
</TABLE>
 
    The  U.S. Underwriters  and the International  Underwriters are collectively
referred to as the ``Underwriters." The Underwriting Agreement provides that the
obligations of the several  Underwriters to pay for  and accept delivery of  the
shares  of Common Stock  offered hereby are  subject to the  approval of certain
legal matters by their counsel and to certain other conditions. The Underwriters
are obligated to  take and pay  for all of  the shares of  Common Stock  offered
hereby  (other than those covered by the over-allotment option described below),
if any are taken.
 
    Pursuant to the Agreement Between U.S. and International Underwriters,  each
U.S.  Underwriter has represented  and agreed that,  with certain exceptions set
forth below, (a) it is not purchasing any of the U.S. Shares (as defined  below)
for  the account  of anyone other  than a  United States or  Canadian Person (as
 
                                       59
<PAGE>
defined below) and (b) it has not offered  or sold, and will not offer or  sell,
directly  or indirectly,  any of  the U.S.  Shares or  distribute any prospectus
relating to the U.S.  Shares outside the  United States or  Canada or to  anyone
other than a United States or Canadian Person. Pursuant to the Agreement Between
U.S.   and  International  Underwriters,   each  International  Underwriter  has
represented and agreed that, with certain exceptions set forth below, (a) it  is
not  purchasing  any of  the  International Shares  (as  defined below)  for the
account of any United States  or Canadian Person and (b)  it has not offered  or
sold,  and  will  not  offer  or  sell,  directly  or  indirectly,  any  of  the
International Shares or distribute any prospectus relating to the  International
Shares  in  the United  States or  Canada or  to any  United States  or Canadian
Person. The foregoing limitations do not apply to stabilization transactions  or
to  certain  other  transactions specified  in  the Agreement  Between  U.S. and
International Underwriters. As used herein, ``United States or Canadian  Person"
means  any  national  or  resident  of  the  United  States  or  Canada  or  any
corporation, pension, profit-sharing  or other trust  or other entity  organized
under  the laws of the  United States or Canada  or of any political subdivision
thereof (other than a branch located outside of the United States and Canada  of
any United States or Canadian Person) and includes any United States or Canadian
branch  of a person who is not otherwise a United States or Canadian Person, and
``United States"  means  the United  States  of America,  its  territories,  its
possessions  and all  areas subject  to its  jurisdiction. All  shares of Common
Stock to  be offered  by the  U.S. Underwriters  and International  Underwriters
under  the Underwriting Agreement  are referred to herein  as the ``U.S. Shares"
and the ``International Shares," respectively.
 
    Pursuant to the Agreement Between U.S. and International Underwriters, sales
may be made between the U.S. Underwriters and the International Underwriters  of
any  number  of  shares  of  Common  Stock  to  be  purchased  pursuant  to  the
Underwriting Agreement  as may  be  mutually agreed.  The  per share  price  and
currency  settlement of any shares  of Common Stock so  sold shall be the public
offering price set  forth on the  cover page hereof,  in United States  dollars,
less  an  amount not  greater than  the per  share amount  of the  concession to
dealers set forth below.
 
    Pursuant to the Agreement Between U.S. and International Underwriters,  each
U.S. Underwriter has represented that it has not offered or sold, and has agreed
not  to offer or  sell, any shares  of Common Stock,  directly or indirectly, in
Canada or to, or for the benefit  of, any resident of any province or  territory
of  Canada in contravention  of the securities laws  thereof and has represented
that any  offer of  such shares  in  Canada will  be made  only pursuant  to  an
exemption from the requirement to file a prospectus in the province or territory
of  Canada in which such offer is made. Each U.S. Underwriter has further agreed
to send to any dealer who purchases from it any shares of Common Stock a  notice
stating in substance that, by purchasing such shares, such dealer represents and
agrees  that it has not offered or sold  and will not offer or sell, directly or
indirectly, any of  such shares  in Canada  or to, or  for the  benefit of,  any
resident  of  any  province  or  territory of  Canada  in  contravention  of the
securities laws thereof and that any offer  of shares of Common Stock in  Canada
will  be  made only  pursuant to  an exemption  from the  requirement to  file a
prospectus in the province or territory of  Canada in which such offer is  made,
and  that such dealer will deliver  to any other dealer to  whom it sells any of
such shares a notice to the foregoing effect.
 
    Pursuant to the Agreement Between U.S. and International Underwriters,  each
International  Underwriter has represented  that (i) it has  not offered or sold
and prior to the expiration of the period of six months from the date of closing
will not offer  or sell  any shares  of Common Stock  to persons  in the  United
Kingdom  except to persons whose ordinary  activities involve them in acquiring,
holding, managing or disposing  of investments (as principal  or agent) for  the
purposes  of  their  businesses or  otherwise  in circumstances  which  have not
resulted and will not  result in an  offer to the public  in the United  Kingdom
within  the meaning  of the  Public Offers  of Securities  Regulations 1995 (the
``Regulations"); (ii)  it  has complied  and  will comply  with  all  applicable
provisions  of the Financial Services Act  1986 and the Regulations with respect
to anything  done  by it  in  relation to  such  shares in,  from  or  otherwise
involving the United Kingdom; and (iii) it has only issued or passed on and will
only  issue or pass on to any person in the United Kingdom any document received
by it in connection with the issue of such  shares to a person who is of a  kind
described  in  Article  11(3) of  the  Financial Services  Act  1986 (Investment
Advertisements) (Exemptions) Order 1996,  or is a person  to whom such  document
may otherwise lawfully be issued or passed on.
 
                                       60
<PAGE>
    Pursuant  to the Agreement Between U.S. and International Underwriters, each
International Underwriter has represented and agreed that it has not offered  or
sold,  and will not offer or sell, directly or indirectly, in Japan or to or for
the account of  any resident  thereof, any shares  of Common  Stock acquired  in
connection   with  this  offering,  except  for  offers  or  sales  to  Japanese
International Underwriters or dealers and except pursuant to any exemption  from
the  registration  requirements of  the Securities  and  Exchange Law  and other
relevant laws  and  regulations of  Japan.  Each International  Underwriter  has
further agreed to send to any dealer who purchases from it any of such shares of
Common  Stock a notice stating in substance  that by purchasing such shares such
dealer may not  offer or sell  any of  such shares, directly  or indirectly,  in
Japan  or to or  for the account of  any resident thereof,  except for offers or
sales to Japanese International Underwriters  or dealers and except pursuant  to
any  exemption from the registration requirements of the Securities and Exchange
Law and other relevant laws and regulations of Japan, and that such dealer  will
send  to any other dealer  to whom it sells  any of such shares  a notice to the
foregoing effect.
 
    The Underwriters initially  propose to offer  part of the  shares of  Common
Stock directly to the public at the public offering price set forth on the cover
page hereof and part to certain dealers at a price which represents a concession
not  in excess of $1.33 a share under the public offering price. Any Underwriter
may allow, and such dealers may reallow,  a concession not in excess of $0.10  a
share to other Underwriters or to certain other dealers.
 
    Certain  Selling  Stockholders  have  granted to  the  U.S.  Underwriters an
option, exercisable for 30 days from the date of this Prospectus, to purchase up
to an  aggregate of  300,000 additional  shares of  Common Stock  at the  public
offering  price set forth on the  cover page hereof, less underwriting discounts
and commissions.  The U.S.  Underwriters may  exercise such  option to  purchase
solely for the purpose of covering over-allotments, if any, incurred in the sale
of the shares of Common Stock offered hereby.
 
    The  Company, the Selling  Stockholders and the  Underwriters have agreed to
indemnify each other  against certain liabilities,  including liabilities  under
the Securities Act.
 
    The  Company has agreed not  to offer, pledge, sell,  contract to sell, sell
any option or  contract to purchase,  purchase any option  or contract to  sell,
grant any option, right or warrant to purchase, or otherwise transfer or dispose
of,  directly  or  indirectly, any  shares  of  Common Stock  or  any securities
convertible into or exercisable or exchangeable for Common Stock, or enter  into
any  swap or similar agreement that transfers, in whole or in part, the economic
risk of ownership of the Common Stock, for a period of 90 days after the date of
this Prospectus,  without the  prior written  consent of  Morgan Stanley  &  Co.
Incorporated, subject to certain limited exceptions.
 
    See  ``Shares  Eligible  for  Future  Sale"  for  a  description  of certain
arrangements by which all  officers, directors and  stockholders of the  Company
have  agreed not to sell or otherwise dispose of the Common Stock of the Company
for a period of  90 days after  the date of this  Prospectus, without the  prior
written consent of Morgan Stanley & Co. Incorporated.
 
    Pursuant   to  regulations  promulgated  by   the  Securities  and  Exchange
Commission (the  "Commission"),  market  makers  in the  Common  Stock  who  are
Underwriters  or prospective underwriters ("passive market makers") may, subject
to certain limitations,  make bids for  or purchases of  shares of Common  Stock
until  the  earlier of  the time  of commencement  (the "Commencement  Date") of
offers or sales of the Common Stock contemplated by this Prospectus or the  time
at which a stabilizing bid for such shares is made. In general, on and after the
date  two business days prior  to the Commencement Date  (1) such market maker's
net daily purchases of the Common Stock may not exceed 30% of its average  daily
trading  volume  in such  stock  for the  two  full consecutive  calendar months
immediately preceding the  filing date  of the registration  statement of  which
this  Prospectus forms a part, (2) such market maker may not effect transactions
in, or display bids for,  the Common Stock at a  price that exceeds the  highest
bid  for the Common Stock  by persons who are not  passive market makers and (3)
bids made by passive market makers must be identified as such.
 
                                       61
<PAGE>
                                 LEGAL MATTERS
 
    The validity of the Common Stock offered hereby will be passed upon for  the
Company  by Brobeck, Phleger & Harrison  LLP, San Francisco, California. Certain
legal matters  in connection  with this  offering will  be passed  upon for  the
Underwriters by Wilson Sonsini Goodrich & Rosati, Professional Corporation, Palo
Alto, California.
 
                                    EXPERTS
 
    The consolidated financial statements of the Company as of December 31, 1995
and  1996, and for each of the years in the three-year period ended December 31,
1996, have been included herein and in the Registration Statement in reliance on
the report of KPMG Peat  Marwick LLP, independent auditors, appearing  elsewhere
herein  and  upon  the  authority  of  said  firm  as  experts  in  auditing and
accounting.
 
                             ADDITIONAL INFORMATION
 
    The Company has filed with the  Commission a registration statement on  Form
S-1  (together  with all  amendments  and exhibits  thereto,  the ``Registration
Statement") under the Securities  Act with respect to  the Common Stock  offered
hereby. This Prospectus, which constitutes a part of the Registration Statement,
does not contain all of the information set forth in the Registration Statement,
certain  parts of which are omitted in accordance with the Rules and Regulations
of the Commission. For further information  with respect to the Company and  the
Common Stock offered hereby, reference is made to the Registration Statement and
to  the exhibits  and schedules  filed therewith.  Statements contained  in this
Prospectus as  to  the  contents of  any  contract  or other  document  are  not
necessarily complete, and in each instance reference is made to the copy of such
contract  or other document  filed as an exhibit  to the Registration Statement,
each such  statement being  qualified in  all respects  by such  reference.  The
Company  is  also  subject to  the  information requirements  of  the Securities
Exchange  Act  of  1934,  and  in  accordance  therewith  files  reports,  proxy
statements and other information with the Commission. Copies of the Registration
Statement  and the exhibits and schedules thereto, reports, proxy statements and
other information filed by the Company may be inspected or copied at the  public
reference facilities maintained by the Commission at Room 1024, Judiciary Plaza,
450 Fifth Street, N.W., Washington, D.C. 20549, and at the Commission's regional
offices  located at Northwestern  Atrium Center, 500  West Madison Street, Suite
1400, Chicago, Illinois 60661 and at  Seven World Trade Center, 13th Floor,  New
York,  New York 10048. Copies of the Registration Statement may also be obtained
from the Public Reference Section of  the Commission at 450 Fifth Street,  N.W.,
Washington,  D.C. 20549  at prescribed  rates. The  Commission also  maintains a
World Wide Web site that contains reports, proxy and information statements  and
other  information  regarding  registrants,  such  as  the  Company,  that  file
electronically   with   the   Commission.   The   address   of   the   site   is
http://www.sec.gov.  In addition, the  Common Stock of the  Company is quoted on
the Nasdaq National Market. Reports and other information concerning the Company
may be inspected at the National Association of Securities Dealers, Inc., 1735 K
Street, Washington, D.C.
 
                                       62
<PAGE>
                               GLOSSARY OF TERMS
 
<TABLE>
<S>                                            <C>
Analog.......................................  A form of transmission employing a continuous
                                               electrical signal  (rather than  a pulsed  or
                                               digital  system) that varies in frequency and
                                               amplitude.
Application Specific Integrated Circuit        A  broad  term  that  refers  to  custom   or
 (ASIC)......................................  semi-custom integrated circuits.
Asynchronous Data Channel Service (ADU)......  A  low speed asynchronous  data interface for
                                               rates up to 38.4 Kbps.
Backplane Design.............................  The  design   of  the   circuit  board   that
                                               interconnects   a  wide  variety  of  service
                                               types. The interconnection  of the traces  on
                                               the  backplane  defines  the  performance and
                                               flexibility of the system.
Bandwidth....................................  A relative range of frequencies that carry  a
                                               signal  without distortion  on a transmission
                                               medium.
Bellcore.....................................  Bell  Communications  Research.  A  standards
                                               body   funded   by   the   telecommunications
                                               industry   that    proposes    new    network
                                               architectures and performs validation testing
                                               and analysis.
Beta Testing.................................  A step in the engineering cycle prior to full
                                               manufacturing release.
Central Office...............................  A term commonly used to describe the location
                                               of  the switching  equipment that  is used to
                                               re-direct telephone calls.
Central Office Switch........................  Used synonomously with Central Office.
Central Processing Unit (CPU)................  The  circuit  pack  that  contains  the  main
                                               operating  software  for  the  system.  It is
                                               responsible for co-ordination  of all  system
                                               level functionality.
Channel Bank.................................  A multiplexer that puts many slow speed voice
                                               or  data  conversations onto  one  high speed
                                               link   and   controls   the   flow   of   the
                                               conversations.
Coaxial......................................  A  type  of  electrical  cable  in  which one
                                               conductor  is  wrapped  around  another   and
                                               insulates the inner conductor.
Codec........................................  Electronic  circuitry  employed  to  digitize
                                               analog signals  and  to convert  the  digital
                                               signals back into analog form.
Digital......................................  The representation of information as discrete
                                               value (i.e., 1s and 0s). These digital values
                                               can  be processed,  manipulated, exchanged or
                                               stored by electronic systems.
Digital Loop Carrier (DLC)...................  A  device  used  to  concentrate  susbscriber
                                               telephone  circuits  onto  one  or  more high
                                               speed digital  loops in  a carrier's  central
                                               office  by  converting  analog  signals  into
                                               digital bit streams.
E1 Transceivers..............................  A transmitter and receiver (transceiver)  for
                                               sending   digital  data  at  2.04  Mbps  over
                                               twisted pair cabling.
</TABLE>
 
                                       63
<PAGE>
<TABLE>
<S>                                            <C>
Frequency....................................  The number  of identical  cycles per  second,
                                               measured  in hertz, of a periodic oscillation
                                               or wave in radio propagation.
Hertz........................................  One cycle per second. The unit for  measuring
                                               frequency signals.
High Speed Digital Subscriber Line (HDSL)....  A   technology   that   enables   high  speed
                                               transmission  of  data  over  copper   wires.
                                               Utilization   of  this   technology  requires
                                               minimal  changes  to  existing  copper  phone
                                               lines.
Integrated Services Digital Network (ISDN)...  An   internationally  accepted  standard  for
                                               voice, data  and  signaling  that  makes  all
                                               transmission  circuits end-to-end digital and
                                               defines  a  standard  out-of-band   signaling
                                               system.
ISO-9001.....................................  ISO    is    the    International   Standards
                                               Organisation responsible for drafting quality
                                               procedures. 9001 is the quality procedure for
                                               manufacturing.
Large Line-Size Market.......................  Market with  600 to  2,000 lines  within  the
                                               serviceable  area of the  NGDLC, generally in
                                               urban areas.
Line Cards...................................  A term  commonly  used to  refer  to  service
                                               interfaces  that terminate on plug-in circuit
                                               packs.
Local Exchange Terminal (LET)................  The term  the Company  uses to  describe  the
                                               terminal   that  is  housed  in  the  Central
                                               Office. Exchange  is the  international  word
                                               for switch.
Local Loop...................................  A  term  used to  describe the  copper cables
                                               that  connect  a  customer's  phone  to   the
                                               Central Office.
MLT Remote Testing Capabilities..............  MLT or mechanized loop testing is a technique
                                               the   telephone  companies  use   to  test  a
                                               customer's telephone  line.  When  a  DLC  is
                                               used, special interfaces must be developed to
                                               provide this test interface.
Next Generation Digital Loop Carrier           The  next generation  of DLC's,  designed and
 (NGDLC).....................................  introduced in the market  in the early  1990s
                                               to  support telecommunications  services over
                                               fiber-only  networks  in  densely   populated
                                               urban  markets with 600 to 2,000 lines within
                                               the serviceable area of the NGDLC.
PCBA.........................................  Printed Circuit Board Assembly.
Plain Old Telephone Service (POTS)...........  Basic  telephone  service  with  no  enhanced
                                               features  such  as  call  waiting, conference
                                               calling or call forwarding.
Printed Circuit Boards.......................  A  fiberglass  laminated  board  with  etched
                                               copper traces.
RBOC.........................................  Regional Bell Operating Company.
Remote Service Terminal (RST)................  A  term  the  Company  uses  to  describe its
                                               outside enclosures  located  at or  near  the
                                               customers that are being served from it.
</TABLE>
 
                                       64
<PAGE>
<TABLE>
<S>                                            <C>
Small Line-Size Market.......................  Market  with less  than 600  lines within the
                                               serviceable area  of  the DLC,  generally  in
                                               rural and suburban areas.
Synchronous Data Channel Service (SDU).......  A  low  speed data  interface for  rates less
                                               than 64 Kbps.
Synchronous Optical Network (SONET)..........  A standard  designed to  establish a  digital
                                               hierarchical   network   that   enables   the
                                               transmission  of  data   over  a   consistent
                                               transport scheme at speeds up to 2.4 Gbps.
SONET OC3 Transceivers.......................  An   optical   bi-directional   circuit  pack
                                               operating at the SONET OC3 rate (155.52 Mbps)
                                               that  meets   the  SONET   requirements   for
                                               inter-operability.
T1 Transceivers..............................  A  transmitter and receiver (transceiver) for
                                               sending  digital  data  at  1.544  Mbps  over
                                               twisted pair cabling.
Universal Voice Grade Service (UVG)..........  A  multipurpose circuit pack  that fulfills a
                                               variety of interface requirements for modems,
                                               etc.
</TABLE>
 
                                       65
<PAGE>
                   INDEX TO CONSOLIDATED FINANCIAL STATEMENTS
 
<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                             ---------
 
<S>                                                                                                          <C>
Independent Auditors' Report...............................................................................        F-2
 
Consolidated Balance Sheets as of December 31, 1995 and 1996...............................................        F-3
 
Consolidated Statements of Operations for the years ended December 31, 1994, 1995 and 1996.................        F-4
 
Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) for
 the years ended December 31, 1994, 1995 and 1996..........................................................        F-5
 
Consolidated Statements of Cash Flows for the years ended December 31, 1994, 1995 and 1996.................        F-6
 
Notes to Consolidated Financial Statements.................................................................        F-7
</TABLE>
 
                                      F-1
<PAGE>
                          INDEPENDENT AUDITORS' REPORT
 
The Board of Directors
Advanced Fibre Communications, Inc.:
 
    We  have audited  the accompanying  consolidated balance  sheets of Advanced
Fibre Communications, Inc. and subsidiaries  (the "Company") as of December  31,
1995 and 1996, and the related consolidated statements of operations, redeemable
convertible  preferred stock and  stockholders' equity (deficit)  and cash flows
for each of the years  in the three-year period  ended December 31, 1996.  These
financial  statements are  the responsibility  of the  Company's management. Our
responsibility is to express an opinion  on these financial statements based  on
our audits.
 
    We  conducted  our audits  in  accordance with  generally  accepted auditing
standards. Those standards require that we plan and perform the audit to  obtain
reasonable assurance about whether the financial statements are free of material
misstatement.  An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also  includes
assessing  the  accounting principles  used  and significant  estimates  made by
management, as well as evaluating the overall financial statement  presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
    In  our  opinion, the  consolidated financial  statements referred  to above
present fairly, in all material respects, the financial position of the  Company
as of December 31, 1995 and 1996, and the results of its operations and its cash
flows for each of the years in the three-year period ended December 31, 1996, in
conformity with generally accepted accounting principles.
 
                                          KPMG PEAT MARWICK LLP
 
San Francisco, California
January 20, 1997
 
                                      F-2
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
 
                                     ASSETS
 
<TABLE>
<CAPTION>
                                                                                                 DECEMBER 31,
                                                                                            ----------------------
                                                                                               1995        1996
                                                                                            ----------  ----------
<S>                                                                                         <C>         <C>
Current assets:
  Cash and cash equivalents, including restricted cash of
   $1,730 and $150 in 1995 and 1996, respectively.........................................  $   11,118  $   24,942
  Marketable securities...................................................................      --          83,488
  Accounts receivable.....................................................................      10,993      32,779
  Inventories.............................................................................      10,149      17,349
  Deferred income taxes...................................................................      --           2,889
  Prepaid expenses........................................................................         132         742
                                                                                            ----------  ----------
    Total current assets..................................................................      32,392     162,189
Property and equipment, net...............................................................       1,828       9,589
Other assets..............................................................................       2,460       3,901
                                                                                            ----------  ----------
      Total assets........................................................................  $   36,680  $  175,679
                                                                                            ----------  ----------
                                                                                            ----------  ----------
 
                       LIABILITIES, REDEEMABLE CONVERTIBLE PREFERRED STOCK AND
                                    STOCKHOLDERS' EQUITY (DEFICIT)
Current liabilities:
  Accounts payable........................................................................  $    7,121  $    8,799
  Accrued liabilities.....................................................................       6,501       8,052
                                                                                            ----------  ----------
    Total current liabilities.............................................................      13,622      16,851
Long-term liabilities.....................................................................       1,046         805
Redeemable convertible preferred stock, $0.01 par value; 35,345,816 shares authorized in
 1995; 17,011,204 shares issued and outstanding in 1995...................................      37,777      --
Stockholders' equity (deficit):
  Preferred stock, $0.01 par value; 5,000,000 shares authorized in 1996; no shares issued
   and outstanding in 1996................................................................      --          --
  Common stock, $0.01 par value; 84,654,184 and 100,000,000 shares authorized in 1995 and
   1996, respectively; 5,015,168 and 32,649,607 shares issued and outstanding in 1995 and
   1996, respectively.....................................................................          50         326
  Additional paid-in capital..............................................................      (2,248)    164,002
  Notes receivable from stockholders......................................................        (176)       (151)
  Accumulated deficit.....................................................................     (13,391)     (6,154)
                                                                                            ----------  ----------
    Total stockholders' equity (deficit)..................................................     (15,765)    158,023
                                                                                            ----------  ----------
      Total liabilities, redeemable convertible preferred stock, and stockholders' equity
       (deficit)..........................................................................  $   36,680  $  175,679
                                                                                            ----------  ----------
                                                                                            ----------  ----------
</TABLE>
 
          See accompanying notes to consolidated financial statements.
 
                                      F-3
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
                     CONSOLIDATED STATEMENTS OF OPERATIONS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                      YEAR ENDED DECEMBER 31,
                                                                                  --------------------------------
                                                                                    1994       1995        1996
                                                                                  ---------  ---------  ----------
<S>                                                                               <C>        <C>        <C>
Revenues........................................................................  $  18,802  $  54,287  $  130,193
Cost of revenues................................................................     14,124     33,469      73,950
                                                                                  ---------  ---------  ----------
    Gross profit................................................................      4,678     20,818      56,243
                                                                                  ---------  ---------  ----------
Operating expenses:
  Research and development......................................................      2,867      5,730      14,413
  Selling, general, and administrative..........................................      5,051      9,660      21,188
  DSC litigation costs..........................................................      4,551      1,623      18,947
                                                                                  ---------  ---------  ----------
    Total operating expenses....................................................     12,469     17,013      54,548
                                                                                  ---------  ---------  ----------
    Operating income (loss).....................................................     (7,791)     3,805       1,695
Other income (expense):
  Gain on dissolution (equity in loss) of joint venture, net....................     --         (1,516)      1,516
  Other income, net.............................................................         26        149         872
                                                                                  ---------  ---------  ----------
    Income (loss) before income taxes...........................................     (7,765)     2,438       4,083
Income taxes (benefit)..........................................................     --             97      (3,154)
                                                                                  ---------  ---------  ----------
    Net income (loss)...........................................................  $  (7,765) $   2,341  $    7,237
                                                                                  ---------  ---------  ----------
                                                                                  ---------  ---------  ----------
Pro forma net income per share..................................................             $    0.09  $     0.21
                                                                                             ---------  ----------
                                                                                             ---------  ----------
Shares used in per share computations...........................................                27,329      34,282
</TABLE>
 
          See accompanying notes to consolidated financial statements.
 
                                      F-4
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
                     CONSOLIDATED STATEMENTS OF REDEEMABLE
         CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT)
                 YEARS ENDED DECEMBER 31, 1994, 1995, AND 1996
                       (IN THOUSANDS, EXCEPT SHARE DATA)
<TABLE>
<CAPTION>
                                       REDEEMABLE
                                  CONVERTIBLE PREFERRED
                                          STOCK               COMMON STOCK       ADDITIONAL
                                  ---------------------  ----------------------    PAID-IN    NOTES RECEIVABLE   ACCUMULATED
                                    SHARES     AMOUNT     SHARES      AMOUNT       CAPITAL    FROM STOCKHOLDERS    DEFICIT
                                  ----------  ---------  ---------  -----------  -----------  -----------------  ------------
<S>                               <C>         <C>        <C>        <C>          <C>          <C>                <C>
Balances as of December 31,
 1993...........................  10,152,908  $   9,145  3,006,472   $      30    $     (15)      $  --           $   (7,967)
Issuance of preferred stock.....   3,000,000      7,436     --          --           --              --               --
Conversion of notes payable to
 preferred stock................     200,000        500     --          --           --              --               --
Issuance of preferred stock.....   2,080,000      6,465     --          --           --              --               --
Exercise of common stock
 options and warrants...........      --         --         86,252           1           10          --               --
Net loss........................      --         --         --          --           --              --               (7,765)
                                  ----------  ---------  ---------       -----   -----------          -----      ------------
Balances as of December 31,
 1994...........................  15,432,908     23,546  3,092,724          31           (5)         --              (15,732)
Issuance of preferred stock.....   2,193,540     14,539     --          --           --              --               --
Repurchase of preferred stock...    (615,244)      (308)    --          --           (3,848)         --               --
Sale of common stock for notes
 receivable.....................      --         --        563,600           6          170            (176)          --
Exercise of common stock options
 and warrants...................      --         --      1,358,844          13        1,435          --               --
Net income......................      --         --         --          --           --              --                2,341
                                  ----------  ---------  ---------       -----   -----------          -----      ------------
Balances as of December 31,
 1995...........................  17,011,204     37,777  5,015,168          50       (2,248)           (176)         (13,391)
Issuance of preferred stock.....     220,000      1,540     --          --           --              --               --
Issuance of common stock in
 settlement of litigation.......      --         --        725,787           7        8,986          --               --
Exercise of common stock options
 and warrants...................      --         --      3,016,189          30          112          --               --
Initial public offering of
 common stock...................                         5,175,000          52      118,022
Conversion of preferred stock to
 common stock...................  (17,231,204)   (39,317) 18,717,463        187      39,130          --               --
Payment of notes receivable from
 stockholder....................      --         --         --          --           --                  25           --
Net income......................      --         --         --          --           --              --                7,237
                                  ----------  ---------  ---------       -----   -----------          -----      ------------
Balances as of December 31,
 1996...........................      --      $  --      32,649,607  $     326    $ 164,002       $    (151)      $   (6,154)
                                  ----------  ---------  ---------       -----   -----------          -----      ------------
                                  ----------  ---------  ---------       -----   -----------          -----      ------------
 
<CAPTION>
 
                                      TOTAL
                                  STOCKHOLDERS'
                                     EQUITY
                                    (DEFICIT)
                                  -------------
<S>                               <C>
Balances as of December 31,
 1993...........................    $  (7,952)
Issuance of preferred stock.....       --
Conversion of notes payable to
 preferred stock................       --
Issuance of preferred stock.....       --
Exercise of common stock
 options and warrants...........           11
Net loss........................       (7,765)
                                  -------------
Balances as of December 31,
 1994...........................      (15,706)
Issuance of preferred stock.....       --
Repurchase of preferred stock...       (3,848)
Sale of common stock for notes
 receivable.....................       --
Exercise of common stock options
 and warrants...................        1,448
Net income......................        2,341
                                  -------------
Balances as of December 31,
 1995...........................      (15,765)
Issuance of preferred stock.....       --
Issuance of common stock in
 settlement of litigation.......        8,993
Exercise of common stock options
 and warrants...................          142
Initial public offering of
 common stock...................      118,074
Conversion of preferred stock to
 common stock...................       39,317
Payment of notes receivable from
 stockholder....................           25
Net income......................        7,237
                                  -------------
Balances as of December 31,
 1996...........................    $ 158,023
                                  -------------
                                  -------------
</TABLE>
 
          See accompanying notes to consolidated financial statements.
 
                                      F-5
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                        YEAR ENDED DECEMBER 31,
                                                                                    -------------------------------
                                                                                      1994       1995       1996
                                                                                    ---------  ---------  ---------
<S>                                                                                 <C>        <C>        <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net income (loss)...............................................................  $  (7,765) $   2,341  $   7,237
  Adjustments to reconcile net income (loss) to net cash used in operating
   activities:
    Noncash portion of litigation settlement......................................     --         --         12,807
    Deferred income taxes.........................................................     --         --         (3,679)
    Depreciation and amortization.................................................        199        547        956
    Equity in loss (gain on dissolution) of joint venture, net....................     --          1,516     (1,149)
    Changes in operating assets and liabilities:
      Accounts receivable.........................................................     (4,815)    (5,802)   (21,403)
      Inventories.................................................................     (2,513)    (5,529)    (5,714)
      Prepaid expenses and other assets...........................................       (109)      (169)      (588)
      Accounts payable............................................................      1,266      4,516      1,602
      Accrued liabilities.........................................................      3,215      1,626      3,442
      Long-term liabilities.......................................................        (30)       (17)       258
                                                                                    ---------  ---------  ---------
       NET CASH USED IN OPERATING ACTIVITIES......................................    (10,552)      (971)    (6,231)
                                                                                    ---------  ---------  ---------
CASH FLOWS FROM INVESTING ACTIVITIES:
  Net purchases of marketable securities..........................................     --         --        (83,488)
  Acquisition of technology license...............................................     --         (1,000)    --
  Purchase of property and equipment..............................................       (452)    (1,084)    (8,367)
  Reimbursement of loans (advances) to joint venture..............................     --         (1,516)     1,516
  Business acquisition, net of cash acquired......................................     --         --           (783)
                                                                                    ---------  ---------  ---------
       NET CASH USED IN INVESTING ACTIVITIES......................................       (452)    (3,600)   (91,122)
                                                                                    ---------  ---------  ---------
CASH FLOWS FROM FINANCING ACTIVITIES:
  Proceeds from bank borrowings...................................................     --          1,550     16,806
  Repayment of bank borrowings....................................................     --         (1,550)   (16,806)
  Prepayment of long-term portion of litigation settlement........................     --         --         (7,064)
  Proceeds from stockholder loans.................................................      1,000     --         --
  Repayment of stockholder loans..................................................       (500)    --         --
  Proceeds from initial public offering of common stock...........................     --         --        118,074
  Proceeds from issuance of redeemable convertible preferred stock................     13,901     14,539     --
  Repurchase of redeemable convertible preferred stock............................     --         (4,156)    --
  Proceeds from exercise of common stock options and warrants.....................         11      1,448        167
                                                                                    ---------  ---------  ---------
       NET CASH PROVIDED BY FINANCING ACTIVITIES..................................     14,412     11,831    111,177
                                                                                    ---------  ---------  ---------
INCREASE IN CASH AND CASH EQUIVALENTS.............................................      3,408      7,260     13,824
 
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR......................................        450      3,858     11,118
                                                                                    ---------  ---------  ---------
CASH AND CASH EQUIVALENTS, END OF YEAR............................................  $   3,858  $  11,118  $  24,942
                                                                                    ---------  ---------  ---------
                                                                                    ---------  ---------  ---------
NONCASH FINANCING AND INVESTING ACTIVITIES:
  Conversion of notes payable to redeemable convertible preferred stock...........  $     500  $  --      $  --
  Issuance of common stock for notes receivable...................................     --            176     --
  Deferred portion of technology license fee......................................     --          1,500     --
  Issuance of preferred stock for business acquisition............................     --         --          1,540
CASH PAID:
  Interest........................................................................         21         37        398
  Income taxes....................................................................     --         --            265
</TABLE>
 
          See accompanying notes to consolidated financial statements.
 
                                      F-6
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
 
NOTE 1 -- SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
    Advanced Fibre Communications, Inc. (the "Company") operates in one business
segment and designs, develops, manufactures, markets, and supports the Universal
Modular  Carrier  1000-TM-  (the UMC  system),  a  cost-effective, multi-feature
digital loop  carrier system  developed to  serve small  line-size markets.  The
Company's UMC system is designed to enable telephone companies, cable companies,
and  other service providers to connect subscribers to the central office switch
for voice and data communications over  copper wire, fiber optic cable,  coaxial
cable and analog radio networks.
 
    PRINCIPLES OF CONSOLIDATION
 
    The  consolidated financial statements  include the accounts  of the Company
and its  subsidiaries. All  significant intercompany  balances and  transactions
have  been  eliminated. The  Company's investments  in 50%  or less  owned joint
ventures are accounted for under the equity method.
 
    CASH AND CASH EQUIVALENTS
 
    The Company considers all highly liquid investments with original maturities
of three months or less  to be cash equivalents.  Cash and cash equivalents  are
generally  invested in money market funds, are classified as available-for-sales
securities and their cost approximates their market value. Included in cash  and
cash  equivalents is  $833,000 and  $150,000 as of  December 31,  1995 and 1996,
respectively, held in escrow as collateral for bonds on certain contracts.  Also
included  in cash and cash equivalents as  of December 31, 1995 is $897,000 held
in escrow related to  sales to a particular  customer pending resolution of  the
litigation described in Note 10.
 
    MARKETABLE SECURITIES
 
    All  marketable  securities  are classified  as  available-for-sale  and are
stated at estimated fair value. Unrealized  gains and losses were immaterial  as
of December 31, 1996, and realized gains and losses were immaterial for the year
ended December 31, 1996.
 
    INVENTORIES
 
    Inventories are valued at the lower of first-in, first-out cost or market.
 
    PROPERTY AND EQUIPMENT
 
    Property  and equipment are recorded at cost. Depreciation is computed using
the straight-line  method over  the estimated  useful lives,  generally five  to
seven years, of the related assets.
 
    REVENUE RECOGNITION
 
    Revenue  is generally recognized when  products are shipped. Product returns
and uncollectible accounts have been insignificant to date.
 
    WARRANTY
 
    The Company provides for estimated warranty costs at the time of sale.
 
    INCOME TAXES
 
    The Company accounts for income taxes using the asset and liability  method.
Deferred  tax  assets and  liabilities are  recognized based  on the  future tax
consequences  attributable  to  differences  between  the  financial   statement
carrying  amounts of  existing assets and  liabilities and  their respective tax
bases. The measurement  of deferred tax  assets is reduced,  if necessary, by  a
valuation allowance for any tax benefits that are not expected to be realized.
 
    EQUITY-BASED COMPENSATION PLANS
 
    The Company accounts for equity-based compensation plans using the intrinsic
value method.
 
                                      F-7
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 1 -- SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (CONTINUED)
    PRO FORMA NET INCOME PER SHARE
 
    Pro forma net income per share is computed using the weighted average number
of  shares of  common stock  and redeemable  convertible preferred  stock, on an
as-if converted basis, outstanding and common equivalent shares from options and
warrants to  purchase  common  stock  using  the  treasury  stock  method,  when
dilutive.  In accordance with  certain Securities and  Exchange Commission Staff
Accounting  Bulletins,  such  computations   included  all  common  and   common
equivalent  shares  issued within  the 12  months  preceding the  initial public
offering ("IPO")  date  as  if  they were  outstanding  for  all  prior  periods
presented using the treasury stock method and the estimated IPO price.
 
    CONCENTRATION OF CREDIT RISK
 
    Financial  instruments potentially exposing the Company to concentrations of
credit risk consist primarily  of cash and cash  equivalents and trade  accounts
receivable.  The  Company manufactures  and  sells its  products  principally to
telephone companies. To reduce credit risk, the Company performs ongoing  credit
evaluations  of  its  customers'  financial  condition.  The  Company  does  not
generally require collateral. For international shipments, the Company generally
requires prepayment or letters of credit.
 
    USE OF ESTIMATES
 
    The Company has made a number  of estimates and assumptions that affect  the
reported  amount of assets  and liabilities and  disclosure of contingent assets
and liabilities at the date of the financial statements and the reported amounts
of revenues  and expenses  during  the reporting  period. Actual  results  could
differ from these estimates.
 
    IMPAIRMENT OF LONG-LIVED ASSETS AND LONG-LIVED ASSETS TO BE DISPOSED OF
 
    The  Company  adopted the  provisions of  Statement of  Financial Accounting
Standards No.  121,  ACCOUNTING FOR  THE  IMPAIRMENT OF  LONG-LIVED  ASSETS  AND
LONG-LIVED  ASSETS TO BE DISPOSED OF,  effective January 1, 1996. This statement
requires long-lived assets  to be  evaluated for impairment  whenever events  or
changes  in circumstances indicate that the carrying amount of the asset may not
be recoverable. Adoption of this statement did not have a material effect on the
Company's consolidated financial position or results of operations.
 
NOTE 2 -- JOINT VENTURES
 
    ADVANCED ACCESS LABS
 
    During fiscal 1994, the  Company entered into  a joint venture  partnership,
Advanced  Access  Labs,  with  a stockholder.  The  joint  venture  designed and
developed a product  to allow telephone  services to be  provided over  existing
cable  TV  coaxial systems  as  well as  other  transmission media.  The Company
contributed the right to use its technology  in exchange for a 50% ownership  in
the joint venture partnership. During 1995, the Company loaned $1,000,000 to the
joint  venture. In addition,  during 1995 and  1996, the Company  made other net
advances to the joint venture totaling $516,000 and $167,000, respectively.  The
Company  has recorded its  proportionate share of the  joint venture's losses to
the extent of the  Company's loans and advances  therein. As a consequence,  the
Company's loans and advances to the joint venture had been reduced to zero.
 
    On December 23, 1996, the Company and the joint venture partner entered into
an  agreement to terminate the partnership.  In connection with the dissolution,
the joint venture partner  reimbursed the Company $1,683,000  for all loans  and
advances  made by the Company to date.  The reimbursement was recorded as a gain
and is reflected in gain on dissolution  (equity in loss) of joint venture,  net
in  the accompanying consolidated financial statements. In addition, the Company
and the joint venture partner entered into a License and Marketing Agreement and
an OEM Agreement.
 
                                      F-8
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 2 -- JOINT VENTURES (CONTINUED)
    AFTEK HONG KONG
 
    On April 11,  1996, the Company  acquired all of  the outstanding shares  of
AFTEK  Hong Kong, of  which the Company  had previously been  a 49% stockholder.
AFTEK Hong Kong is  a holding company  that owns 60% of  a joint venture,  AFTEK
Hangzhou,   that   is   licensed   to  manufacture   and   sell   the  Company's
telecommunications equipment  in China.  Total  consideration consisted  of  the
following (in thousands):
 
<TABLE>
<S>                                                            <C>
Issuance of Series F preferred stock.........................  $   1,540
Cash paid to retire note payable.............................        939
Acquisition costs incurred...................................         79
                                                               ---------
                                                               $   2,558
                                                               ---------
                                                               ---------
</TABLE>
 
    The  acquisition  has  been  accounted  for  using  the  purchase  method of
accounting, and,  accordingly, the  purchase  price has  been allocated  to  the
assets purchased and the liabilities assumed based upon their fair values at the
date  of acquisition. The excess  of the purchase price  over the fair values of
the net assets acquired was $932,000 and has been recorded as goodwill, which is
being amortized on a straight-line basis over 5 years.
 
    Historical results of AFTEK  Hong Kong and pro  forma results of  operations
giving   effect  to  the  acquisition  have  not  been  presented  because  such
information is immaterial in relation to the Company's results of operations.
 
    On August 10, 1996, AFTEK Hong Kong and its joint venture partner agreed  to
liquidate  AFTEK  Hangzhou. The  partners appointed  a liquidation  committee to
facilitate the  liquidation procedures  and to  ensure that  the liquidation  is
completed  in accordance with  the relevant stipulations  contained in the joint
venture agreement.  The  Company  has  recorded  a  provision  of  approximately
$383,000  reflecting the  reduction in  the net  realizable value  of AFTEK Hong
Kong's interest  in  the joint  venture's  net  assets to  be  distributed  upon
liquidation.
 
    The Company had sales to AFTEK Hong Kong of $2,020,000 in 1995.
 
NOTE 3 -- MARKETABLE SECURITIES
    Marketable  securities were  comprised of the  following as  of December 31,
1996 (in thousands):
 
<TABLE>
<CAPTION>
                                                                                    FAIR
                                                                                    VALUE
                                                                                  ---------
<S>                                                                               <C>
Municipal debt securities.......................................................  $  61,488
Corporate debt securities.......................................................     22,000
                                                                                  ---------
Total marketable securities.....................................................  $  83,488
                                                                                  ---------
                                                                                  ---------
</TABLE>
 
    The fair value of securities maturing in one year or less and those maturing
between one year and five years was $54,128,000 and $29,360,000, respectively.
 
NOTE 4 -- INVENTORIES
    The major components of inventories are as follows (in thousands):
 
<TABLE>
<CAPTION>
                                                                        DECEMBER 31,
                                                                    --------------------
                                                                      1995       1996
                                                                    ---------  ---------
<S>                                                                 <C>        <C>
Raw materials.....................................................  $   5,155  $   7,631
Work-in-progress..................................................        899        155
Finished goods....................................................      4,095      9,563
                                                                    ---------  ---------
                                                                    $  10,149  $  17,349
                                                                    ---------  ---------
                                                                    ---------  ---------
</TABLE>
 
                                      F-9
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 5 -- PROPERTY AND EQUIPMENT
    A summary of property and equipment follows (in thousands):
 
<TABLE>
<CAPTION>
                                                                           DECEMBER 31,
                                                                       --------------------
                                                                         1995       1996
                                                                       ---------  ---------
<S>                                                                    <C>        <C>
Furniture and fixtures...............................................  $     375  $   1,266
Computer and office equipment........................................      1,204      4,306
Engineering equipment................................................        865      5,508
                                                                       ---------  ---------
                                                                           2,444     11,080
Less: accumulated depreciation.......................................        616      1,491
                                                                       ---------  ---------
  Net property and equipment.........................................  $   1,828  $   9,589
                                                                       ---------  ---------
                                                                       ---------  ---------
</TABLE>
 
NOTE 6 -- ACCRUED LIABILITIES
    A summary of accrued liabilities follows (in thousands):
 
<TABLE>
<CAPTION>
                                                                           DECEMBER 31,
                                                                       --------------------
                                                                         1995       1996
                                                                       ---------  ---------
<S>                                                                    <C>        <C>
DSC litigation costs.................................................  $   2,674  $  --
Warranty.............................................................        852      2,550
Other................................................................      2,975      5,502
                                                                       ---------  ---------
                                                                       $   6,501  $   8,052
                                                                       ---------  ---------
                                                                       ---------  ---------
</TABLE>
 
NOTE 7 -- INCOME TAXES
    A  summary  of  the  components  of  income  taxes  (benefit)  follows   (in
thousands):
 
<TABLE>
<CAPTION>
                                                                   CURRENT    DEFERRED     TOTAL
                                                                 -----------  ---------  ---------
<S>                                                              <C>          <C>        <C>
Year ended December 31, 1995:
  Federal......................................................   $      82   $  --      $      82
  State........................................................          15      --             15
                                                                      -----   ---------  ---------
                                                                  $      97   $  --      $      97
                                                                      -----   ---------  ---------
                                                                      -----   ---------  ---------
 
Year ended December 31, 1996:
  Federal......................................................   $     523   $  (2,764) $  (2,241)
  State........................................................           2        (915)      (913)
                                                                      -----   ---------  ---------
                                                                  $     525   $  (3,679) $  (3,154)
                                                                      -----   ---------  ---------
                                                                      -----   ---------  ---------
</TABLE>
 
    Income taxes (benefit) differs from the amount computed by applying the U.S.
federal  statutory rate of 34%  to income (loss) before  income taxes as follows
(in thousands):
 
<TABLE>
<CAPTION>
                                                                      YEAR ENDED DECEMBER 31,
                                                                  -------------------------------
                                                                    1994       1995       1996
                                                                  ---------  ---------  ---------
<S>                                                               <C>        <C>        <C>
Income taxes (benefit) at statutory rate........................  $  (2,640) $     829  $   1,388
Current losses and temporary differences for which no benefit
 was recognized.................................................      2,640     --            476
Alternative minimum tax.........................................     --             82     --
State taxes net of federal benefit..............................     --             15       (167)
Change in valuation allowance...................................     --           (847)    (4,687)
Other...........................................................     --             18       (164)
                                                                  ---------  ---------  ---------
                                                                  $  --      $      97  $  (3,154)
                                                                  ---------  ---------  ---------
                                                                  ---------  ---------  ---------
</TABLE>
 
                                      F-10
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 7 -- INCOME TAXES (CONTINUED)
    The tax  effects of  temporary  differences that  give rise  to  significant
portions of deferred tax assets and liabilities are as follows (in thousands):
 
<TABLE>
<CAPTION>
                                                                          DECEMBER 31,
                                                                 -------------------------------
                                                                   1994       1995       1996
                                                                 ---------  ---------  ---------
<S>                                                              <C>        <C>        <C>
Deferred tax assets:
  Net operating loss carryforwards.............................  $   4,099  $   3,316  $  --
  DSC settlement costs.........................................     --         --          1,257
  Allowances and accruals......................................      1,789      1,914      1,618
  Research tax credit carryforwards............................        374     --            588
  Other........................................................         52          6        216
                                                                 ---------  ---------  ---------
                                                                     6,314      5,236      3,679
Deferred tax liability -- investment in joint venture..........     --           (549)    --
                                                                 ---------  ---------  ---------
                                                                     6,314      4,687      3,679
Less valuation allowance.......................................     (6,314)    (4,687)    --
                                                                 ---------  ---------  ---------
Net deferred tax asset.........................................  $  --      $  --      $   3,679
                                                                 ---------  ---------  ---------
                                                                 ---------  ---------  ---------
</TABLE>
 
    The  net change in the  valuation allowance for the  year ended December 31,
1996 was  a decrease  of approximately  $4,687,000. Management  believes that  a
valuation   allowance  is  not  required,   based  upon  current  and  projected
profitability of the Company.
 
    The Company has research credit carryforwards for federal income tax  return
purposes  of approximately  $588,000. The federal  research credit carryforwards
expire from 2008  through 2011.  The Company also  has California  manufacturing
credits of approximately $276,000; which expire from 2002 through 2004.
 
    The  Tax Reform Act of 1986 and the California Conformity Act of 1987 impose
restrictions  on  the  utilization  of   net  operating  loss  and  tax   credit
carryforwards  in the event of an "ownership  change" as defined by the Internal
Revenue Code. The Company's  ability to utilize its  net operating loss and  tax
credit carryforwards is subject to restriction pursuant to these provisions.
 
NOTE 8 -- BANK BORROWINGS
    The  Company  has a  revolving  line of  credit  with a  bank  providing for
borrowings up to $12,000,000 at an interest rate of prime plus 0.5%.  Borrowings
under  the line are  secured by the  Company's accounts receivable.  The line of
credit expired on  November 15,  1996, but automatically  renews for  successive
thirty  day periods  until terminated by  written agreement. The  line of credit
agreement also contains covenants that  require the Company to maintain  certain
financial  ratios. As of December  31, 1996, the Company  was in compliance with
the covenants contained in the agreement. As  of December 31, 1995 and 1996,  no
borrowings  were  outstanding  under  the line  of  credit,  and  $1,642,000 was
reserved for letters of credit and foreign exchange contracts.
 
    In  July  1996,  the  Company  borrowed  approximately  $7,106,000  under  a
six-month  term loan bearing interest at 5.75%.  The proceeds from the loan were
used to pay the remaining obligations  under the DSC litigation settlement  (See
Note 10). The loan had a $4.0 million compensating balance requirement. The loan
was repaid in October 1996 with a portion of the proceeds from the IPO.
 
NOTE 9 -- REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY
(DEFICIT)
 
    IPO
 
    In  October 1996,  the Company issued  5,175,000 shares of  its common stock
pursuant to the IPO, which generated approximately $118,074,000 of net  proceeds
to the Company.
 
                                      F-11
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 9 -- REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY
(DEFICIT) (CONTINUED)
    In  conjunction with  the IPO,  17,231,204 shares  of outstanding redeemable
convertible preferred stock were converted into a total of 18,717,463 shares  of
common  stock.  Prior to  the IPO,  the  Company had  outstanding six  series of
redeemable convertible preferred stock.
 
    COMMON STOCK WARRANTS
 
    Warrants to purchase shares of common stock were issued to investors as part
of the preferred  stock agreements. The  warrants expire beginning  in 1998  and
ending in 2000 and are summarized as follows:
 
<TABLE>
<CAPTION>
                                                                                             EXERCISE
                                                                                 NUMBER        PRICE
                                                                                OF SHARES    PER SHARE
                                                                               -----------  -----------
<S>                                                                            <C>          <C>
Warrants outstanding as of December 31, 1994.................................    6,496,204  $ 0.03-1.17
  Issued.....................................................................       30,068     7.00
  Exercised..................................................................   (1,305,192)   0.03-1.17
                                                                               -----------
Warrants outstanding as of December 31, 1995.................................    5,221,080    0.03-7.00
  Exercised..................................................................   (2,599,763)   0.03-1.17
  Retired....................................................................      (47,541)   0.03-1.17
                                                                               -----------
Warrants outstanding as of December 31, 1996.................................    2,573,776    0.03-7.00
                                                                               -----------
                                                                               -----------
</TABLE>
 
    COMMON STOCK OPTIONS
 
    The  Company's 1996  Stock Incentive Plan  (the "1996 Plan")  is intended to
serve as the  successor equity  incentive program  to the  Company's 1993  Stock
Option/Stock  Issuance Plan (the "Predecessor Plan"). As of December 31, 1996, a
total of 7,008,142 shares of Common Stock were authorized for issuance under the
1996 Plan. This  share reserve  is comprised of  (i) the  shares which  remained
available  for issuance under the Predecessor Plan, including the shares subject
to outstanding options thereunder, plus (ii) an additional increase of 1,000,000
shares. In addition, the  share reserve will automatically  be increased on  the
first  trading day of each calendar year, beginning with the 1997 calendar year,
by an amount equal to 3% of the number of shares of Common Stock outstanding  on
the  last  trading  day  of the  immediately  preceding  calendar  year. Options
generally vest 20% on the first anniversary date and ratably over the  following
48  months. The options expire 10 years from  the date of grant and are normally
canceled three months after termination of employment.
 
    A summary of the Company's stock option plan activity is presented below:
 
<TABLE>
<CAPTION>
                                                                          YEAR ENDED DECEMBER 31,
                                                        ------------------------------------------------------------
                                                                             1995                     1996
                                                                    -----------------------  -----------------------
                                                                                 WEIGHTED                 WEIGHTED
                                                           1994                   AVERAGE                  AVERAGE
                                                        ----------               EXERCISE                 EXERCISE
OPTIONS                                                   SHARES      SHARES       PRICE       SHARES       PRICE
- ------------------------------------------------------  ----------  ----------  -----------  ----------  -----------
<S>                                                     <C>         <C>         <C>          <C>         <C>
Outstanding at beginning of year......................   1,608,000   2,734,280   $    0.14    3,890,016   $    0.35
Granted...............................................   1,238,080   1,274,036        0.81    1,083,082       12.33
Exercised.............................................     (21,780)    (53,652)       0.21     (416,426)       0.17
Canceled..............................................     (90,020)    (64,648)       0.24     (243,128)       1.21
                                                        ----------  ----------               ----------
Outstanding at end of year............................   2,734,280   3,890,016        0.35    4,313,544        3.32
Options exercisable at year end.......................               1,189,402                1,705,659
Weighted average fair value of options granted
 during the year......................................                                0.21                     5.89
</TABLE>
 
                                      F-12
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 9 -- REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY
(DEFICIT) (CONTINUED)
    The following table summarizes  information about stock options  outstanding
as of December 31, 1996:
 
<TABLE>
<CAPTION>
                                 WEIGHTED
      RANGE                       AVERAGE    WEIGHTED
       OF            NUMBER      REMAINING    AVERAGE     NUMBER
    EXERCISE       OUTSTANDING  CONTRACTUAL  EXERCISE   EXCERCISABLE
     PRICES        AT 12/31/96     LIFE        PRICE    AT 12/31/96
- -----------------  -----------  -----------  ---------  -----------
<C>                <C>          <S>          <C>        <C>
      $0.03         1,256,600   6.3 years    $    0.03     973,478
   0.25 - 0.63      1,665,646   8.1               0.38     598,298
   1.50 - 4.70        821,096   9.1               1.63      86,591
  12.00 - 25.00       475,402   9.6              14.30      47,292
  57.63 - 59.63        94,800   9.9              58.54      --
</TABLE>
 
    EMPLOYEE STOCK PURCHASE PLAN
 
    Under the 1996 Employee Stock Purchase Plan (the "Purchase Plan") adopted on
July  12, 1996,  the Company is  authorized to  issue up to  1,500,000 shares of
Common  Stock  to   eligible  employees   of  the   Company  and   participating
subsidiaries.  The Purchase Plan  will be implemented in  a series of successive
offering periods,  each  with a  maximum  duration  of 24  months.  The  initial
offering  period commenced on October 4, 1996  and ends on the last business day
in July 1998. Under the  terms of the Purchase  Plan, eligible employees on  the
start  date of  any offering period  can enter  the Purchase Plan  on that start
date, or  on  any subsequent  semi-annual  entry date.  Individuals  who  become
eligible  after the  start date  may join  the Purchase  Plan on  any subsequent
semi-annual entry date within that period.  Employees may have up to 10  percent
of  their  base  salary  withheld through  payroll  deductions  to  purchase the
Company's Common Stock.  The purchase  price of  the stock  is the  lower of  85
percent  of (i) the fair  market value of the  Common Stock on the participant's
entry date  into the  offering  period or  (ii) the  fair  market value  on  the
semi-annual  purchase  date. Under  the Purchase  Plan,  the purchase  dates are
January 31 and July 31 of each year.
 
    PRO FORMA FAIR VALUE INFORMATION
 
    The Company  applies the  intrinsic value  method prescribed  by  Accounting
Principles  Board Opinion No.  25, ACCOUNTING FOR STOCK  ISSUED TO EMPLOYEES, in
accounting for its stock-based compensation plans. Had compensation cost for the
Company's stock-based  compensation plans  been determined  consistent with  the
fair  value  approach set  forth  in SFAS  No.  123, ACCOUNTING  FOR STOCK-BASED
COMPENSATION, the Company's net  income and earnings per  share would have  been
reduced  to the pro forma amounts indicated below (in thousands except per share
amounts):
 
<TABLE>
<CAPTION>
                                                                 1995        1996
                                                              ----------  ----------
<S>                                                           <C>         <C>
Net income:
  As reported...............................................  $    2,341  $    7,237
  Pro forma.................................................       2,334       6,638
 
Fully diluted earnings per share:
  As reported...............................................  $     0.08  $     0.21
  Pro forma.................................................        0.08        0.19
</TABLE>
 
    The fair value of option grants prior to the IPO is estimated on the date of
grant using  the  minimum  value  method with  the  following  weighted  average
assumptions:  no dividend yield; risk-free interest rates of 6.22% to 6.25%, and
an expected life of 5 years. The  fair value of option grants subsequent to  the
IPO  is estimated  on the date  of grant using  the Black-Scholes option-pricing
model with  the  following  weighted average  assumptions:  no  dividend  yield,
expected  volatility of 55%;  risk-free interest rate of  6.32%; and an expected
life of 5 years.  Compensation cost related to  the Purchase Plan is  recognized
for  the fair value of the employees' purchase rights, which are estimated using
the Black-Scholes model. No compensation expense has been disclosed for 1996 and
1995 as the first purchase date will occur on January 31, 1997.
 
                                      F-13
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 9 -- REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY
(DEFICIT) (CONTINUED)
    STOCK SPLIT AND REINCORPORATION
 
    In August  1996, the  Company's Board  of Directors  approved a  two-for-one
stock  split. The accompanying financial statements and notes have been restated
to give effect to the stock split.
 
NOTE 10 -- COMMITMENTS AND CONTINGENCIES
 
    LEASES
 
    The Company  leases  office  space and  certain  equipment  under  operating
leases.  Future minimum payments under operating  leases with an initial term of
more than  one year  as  of December  31, 1996  are  summarized as  follows  (in
thousands):
 
<TABLE>
<S>                                                                  <C>
1997...............................................................  $   3,952
1998...............................................................      4,093
1999...............................................................      3,064
2000...............................................................      2,353
2001...............................................................      2,373
Thereafter.........................................................      9,714
                                                                     ---------
Total minimum lease payments.......................................  $  25,549
                                                                     ---------
                                                                     ---------
</TABLE>
 
    Total  rent expense  for all  operating leases  was $462,000,  $887,000, and
$3,030,000 for the years ended December 31, 1994, 1995 and 1996, respectively.
 
    EMPLOYEE BENEFIT PLAN
 
    The Company has a 401(k) plan under which employees may contribute a portion
of their compensation on a tax deferred  basis to the plan. The Company, at  its
discretion,  may contribute to the  plan on a matching basis  up to a maximum of
$5,000 per employee per year. The Company is the plan administrator. During 1995
and 1996, the Company  contributed $133,000 and  $466,000, respectively, to  the
plan.
 
    LITIGATION
 
    DSC:
 
    From  July 1993 until June 1996 the  Company was involved in litigation with
DSC Communications Corporation  ("DSC"). DSC alleged,  among other things,  that
the Company's Universal Modular Carrier 1000-TM- ("UMC") technology contained or
was  derived from  trade secrets  and other  proprietary technology  of DSC. The
parties entered into a Settlement Agreement and Mutual Releases dated as of June
24, 1996  (the "Settlement  Agreement")  pursuant to  which the  litigation  was
terminated.  Under the terms  of the Settlement Agreement,  the Company paid DSC
$3,000,000 in June 1996 and $7,106,000  in July 1996, and issued 725,787  shares
of  common stock to DSC. The settlement amount was recorded during the first six
months of 1996 as  a charge of  $15,807,000. Under the  terms of the  Settlement
Agreement, the Company maintains all rights to the UMC technology free and clear
of any claim by DSC.
 
    ITRI:
 
    In  1995,  a  dispute arose  among  the Company,  the  Industrial Technology
Research Institute  ("ITRI"),  a  Taiwanese  government-sponsored  research  and
development  organization in the telecommunications field, and certain of ITRI's
member companies (the "Member Companies") in which the Company claimed that ITRI
and the Member Companies were, among other things, failing to pay royalties when
due. In reliance upon certain provisions of the ITRI Agreements, in April  1996,
the  Company  ceased  delivering  to the  Member  Companies  certain proprietary
application specific integrated circuits ("ASICs") used in manufacturing the UMC
system.
 
                                      F-14
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 10 -- COMMITMENTS AND CONTINGENCIES (CONTINUED)
    Pursuant to agreements with ITRI  reached in 1994, design documentation  for
these ASICs are held in a trust account, with directions that the designs can be
made  available to ITRI  on the occurrence  of specified conditions.  On July 9,
1996, the trustee-custodian of the ASIC  designs filed suit against the  Company
in the United States District Court, Eastern District of New York, alleging that
the  Company had  wrongfully discontinued  the sale of  the ASICs  to the Member
Companies. Among other things, the complaint seeks unspecified damages on behalf
of the  trustee, and  a determination  that  the trustee  can release  the  ASIC
designs  to ITRI. On July 31, 1996, the Company filed a counterclaim against the
trustee claiming, among other things, that the trustee improperly disclosed  the
design documentation to third parties.
 
    On  July 30,  1996, the Company  filed suit  against ITRI and  others in the
United States District Court, Northern District of California, for breach of the
ITRI  Agreements,   breach   of   covenants  of   good   faith,   trade   secret
misappropriation,  tortious  interference,  and  related  claims.  The complaint
alleges that ITRI breached the ITRI  Agreements, among other things, by  failing
to  collect royalties owed to the  Company, by developing UMC-based products not
shared with  the Company,  by  transferring UMC  technology to  an  unauthorized
company,  and by misappropriating the Company's  trade secrets and that the ITRI
Agreements have been  terminated. The Company  seeks damages, punitive  damages,
and  declaratory  and injunctive  relief. On  September 13,  1996, ITRI  filed a
demand for arbitration of the dispute and claimed, among other things, that  the
Company has breached the ITRI Agreements and is liable for unspecified royalties
and punitive damages, and claiming proprietary rights in certain UMC technology.
On  September 30, 1996,  the Company amended  the complaint in  its suit against
ITRI to add the Member Companies and another company as parties to the suit.
 
    On August 27, 1996, the Member  Companies filed suit against the Company  in
United  States District Court, Northern  District of California, alleging breach
of contract and  unfair competition  based on the  Company's discontinuation  of
ASIC  sales to the Member Companies. The complaint filed by the Member Companies
alleges that the Company lacked justification  to discontinue the sale of  ASICs
and  that its failure to  sell ASICs to the  Member Companies constituted unfair
competition. The complaint seeks court-ordered arbitration, unspecified damages,
punitive damages and an injunction requiring  further sales of the ASICs to  the
Member   Companies.  On  September  6,  1996,  the  court  granted  a  temporary
restraining order pursuant to which the  Company will be required to supply  the
Member  Companies with a specified number of  ASICs during the ensuing two month
period on the terms and conditions set forth in the ITRI Agreements. The court's
order was  granted as  an interim  measure to  preserve the  status quo  pending
adjudication  on  the  merits. The  Company  believes that  compliance  with the
court's order will not have a material adverse effect on the Company's business,
financial condition  and  results of  operations.  On September  16,  1996,  the
Company  filed  counterclaims  seeking  declaratory  and  injunctive  relief and
damages against Member Companies  for, among other  things, breach of  contract,
fraud  and misappropriation of trade secrets.  On September 23, 1996, the Member
Companies filed a demand for arbitration of the dispute and claimed, among other
things, actual damages  in excess of  $60 million, legal  fees and expenses  and
punitive damages.
 
    The  parties conducted discovery with respect to the royalty and ASIC supply
issues during September  and October,  1996. A hearing  on ITRI's  motion for  a
preliminary  injunction to require  the Company to  continue supplying ASICs and
ITRI's motion to compel arbitration was held  on November 22, 1996. In an  order
dated  January 9,  1997, the  court stayed the  litigation and  granted the ITRI
parties' motion  to compel  arbitration. The  court has  promised, but  not  yet
issued, an opinion explaining the nature and scope of its arbitration order, and
has issued no ruling on the motion for a preliminary injunction.
 
    The Company believes that it has meritorious defenses to the claims asserted
by  ITRI  and the  Member  Companies and  it  intends to  defend  the litigation
vigorously. Moreover, the  Company believes that  the Member Companies'  damages
claim  is without  merit. The Company  further believes that  its claims against
ITRI and  the  Member Companies  are  meritorious  and the  Company  intends  to
vigorously  pursue such  claims. However,  due to the  nature of  the claims and
because the proceedings are in the discovery stage, the
 
                                      F-15
<PAGE>
                      ADVANCED FIBRE COMMUNICATIONS, INC.
             NOTES TO CONSOLIDATED FINANCIAL STATEMENTS (CONTINUED)
 
NOTE 10 -- COMMITMENTS AND CONTINGENCIES (CONTINUED)
Company cannot determine the  total expense or possible  loss, if any, that  may
ultimately  be incurred either  in the context  of a trial,  arbitration or as a
result of a  negotiated settlement.  After consideration  of the  nature of  the
claims  and the facts relating to the proceedings, the Company believes that the
resolution of  this  matter will  not  have a  material  adverse effect  on  the
Company's  business, financial condition and results of operations; however, the
results of these proceedings, including any potential settlement, are  uncertain
and there can be no assurance to that effect.
 
NOTE 11 -- COMPANY INFORMATION AND CERTAIN CONCENTRATIONS
    During  1994, one customer  accounted for 27% of  revenues. During 1995, one
customer accounted  for  approximately  16%  of  revenues.  International  sales
constituted 19%, 13% and 21% during 1994, 1995 and 1996, respectively.
 
    The Company currently derives substantially all of its revenue from the UMC,
and expects that this concentration will continue for the foreseeable future. As
a  result, any factor adversely affecting the demand for, or pricing of, the UMC
could have a material  adverse effect on the  Company's business and results  of
operations.
 
    The  Company's manufacturing operations consist  primarily of final assembly
and test  of  finished  goods  from  components  and  custom-made  subassemblies
purchased  from  third parties.  Although the  Company's product  designs employ
primarily industry  standard hardware,  certain  components are  only  available
through   limited  sources  of  supply.  The  Company's  proprietary  integrated
circuits, codec components,  and some  surface mount  technology components  and
other  components  are available  from limited  sources.  If the  Company cannot
obtain essential  components as  required, the  Company may  be unable  to  meet
demand  for its products, thereby adversely  affecting its operating results. In
addition, scarcity  of  such components  could  result in  cost  increases  that
adversely affect the Company's gross margin.
 
    The  Company's printed circuit board  assemblies and channel bank assemblies
are provided by  a limited  number of outside  turnkey suppliers.  In the  event
operations of these turnkey suppliers are impaired or they are unable to support
the  manufacturing requirements of the  Company, the Company's operating results
could be adversely affected.
 
                                      F-16
<PAGE>
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