<PAGE>
 
         As filed with the Securities and Exchange Commission on October 8, 1998
                                    Registration Statement No.333-______________
================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549
                            -----------------------

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     Under
                          The Securities Act of 1933
                            -----------------------

                          ASCEND COMMUNICATIONS, INC.
            (Exact name of registrant as specified in its charter)

           DELAWARE                                        94-3092033
  (State or other jurisdiction                 (IRS Employer Identification No.)
of incorporation or organization)

                               ONE ASCEND PLAZA
                            1701 HARBOR BAY PARKWAY
                               ALAMEDA, CA 94502

              (Address of principal executive offices) (Zip Code)

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

                          ASCEND COMMUNICATIONS, INC.
                    1998 SUPPLEMENTAL STOCK INCENTIVE PLAN
                           (Full title of the Plans)

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

                                  MORY EJABAT
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                          ASCEND COMMUNICATIONS, INC.
                               ONE ASCEND PLAZA
                            1701 HARBOR BAY PARKWAY
                              ALAMEDA, CA  94502
                                (510) 769-6001

(Name, address including zip code, and telephone number, including area code, of
                              agent for service)

                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
===================================================================================
                                     Proposed        Proposed
  Title of                           Maximum         Maximum
 Securities          Amount          Offering       Aggregate        Amount of
   to be              to be           Price         Offering        Registration
 Registered        Registered(1)    per Share(2)     Price(2)           Fee(2)
------------       ----------       ---------        -----              --- 
<S>                <C>             <C>            <C>           <C> 

Common Stock       5,000,000 shares   $35.375     $176,875,000       $52,179.00
$0.001 par value
===================================================================================
</TABLE> 
(1)  This Registration Statement shall also cover any additional shares of
     Common Stock which become issuable under the Ascend Communications, Inc.
     1998 Supplemental Stock Incentive Plan by reason of any stock dividend,
     stock split, recapitalization or other similar transaction effected without
     Registrant's receipt of consideration which results in an increase in the
     number of the outstanding shares of Registrant's Common Stock.

(2)  Calculated solely for purposes of this offering under Rule 457(h) of the
     Securities Act of 1933, as amended, on the basis of the average of the high
     and low selling prices per share of the Registrant's Common Stock on
     October 6, 1998, as reported by the Nasdaq National Market.
<PAGE>
 
                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3. Incorporation of Documents by Reference
        ---------------------------------------

        Ascend Communications, Inc. (the "Registrant") hereby incorporates by
reference into this Registration Statement the following documents previously
filed with the Securities and Exchange Commission (the "SEC"):

        (a) The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 1997, as amended May 29, 1998, filed with the SEC on March
31, 1998;

        (b) The Registrant's Quarterly Reports on Form 10-Q for the quarters
ended March 31, 1998 and June 30, 1998, filed with the SEC on May 15, 1998 and
August 11, 1998;

        (c) The Registrant's Current Reports on Form 8-K filed with the SEC on
July 2, 1998 and August 14, 1998; and

        (d) The Registrant's Registration Statement No. 000-23774 on Form 8-A
filed with the SEC on March 31, 1994 pursuant to Section 12 of the Securities
Exchange Act of 1934, as amended (the "1934 Act"), in which there is described
the terms, rights and provisions applicable to the Registrant's outstanding
Common Stock.

        All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of
this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered hereby have been sold or
which deregisters all securities then remaining unsold shall be deemed to be
incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained in a
document incorporated or deemed to be incorporated by reference herein shall be
deemed to be modified or superseded for purposes of this Registration Statement
to the extent that a statement contained herein or in any subsequently filed
document which also is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

Item 4. Description of Securities
        -------------------------

        Not Applicable.

Item 5. Interests of Named Experts and Counsel
        --------------------------------------

        Not Applicable.

Item 6. Indemnification of Directors and Officers
        -----------------------------------------

        Delaware law authorizes corporations to eliminate the personal liability
of directors to corporations and their stockholders for monetary damages for
breach or alleged breach of the directors' "duty of care." While the relevant
statute does not change directors' duty of care, it enables corporations to
limit available relief to equitable remedies such as injunction or rescission.
The statute has no effect on directors' duty of loyalty, acts or omissions not
in good faith or involving intentional misconduct or knowing violations of law,
illegal payment of dividends and approval of any transaction from which a
director derives an improper personal benefit.

        The Registrant has adopted provisions in its Certificate of
Incorporation which eliminate the personal liability of its directors to the
Registrant and its stockholders for monetary damages for breach or alleged
breach of their duty of care. The Bylaws of the Registrant provide for
indemnification of its directors, officers, employees and agents to the full
extent permitted by the General Corporation Law of the State of Delaware, the
Registrant's state of incorporation, including those circumstances in which
indemnification would otherwise be discretionary under Delaware law. Section 145
of the General Corporation Law of the State of Delaware provides for
indemnification in terms sufficiently broad to indemnify such individuals, under
certain circumstances, for liabilities (including reimbursement of expenses
incurred) arising under the Securities Act of 1933, as amended (the "Securities
Act").
<PAGE>
 
Item 7. Exemption from Registration Claimed
        -----------------------------------

        Not Applicable.

Item 8. Exhibits
        --------

     Number    Exhibit
     ------    -------

     4         Instruments Defining Rights of Stockholders. Reference is made to
               Registrant's Registration Statement No. 000-23774 on Form 8-A,
               including the exhibits thereto, which is incorporated herein by
               reference pursuant to Item 3(d).
     5         Opinion and consent of Brobeck, Phleger & Harrison LLP.
     23.1      Consent of Ernst & Young LLP, Independent Auditors.
     23.2      Consent of Independent Accountants.
     23.3      Consent of Brobeck, Phleger & Harrison LLP is contained in
               Exhibit 5.
     24        Power of Attorney.  Reference is made to page II-3 of this
               Registration Statement.
     99        1998 Supplemental Stock Incentive Plan.

Item 9. Undertakings
        ------------

     A.  The undersigned Registrant hereby undertakes:  (1) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this Registration Statement (i) to include any prospectus required by Section
10(a)(3) of the 1933 Act, (ii) to reflect in the prospectus any facts or events
arising after the effective date of this Registration Statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth in this
Registration Statement and (iii) to include any material information with
respect to the plan of distribution not previously disclosed in this
Registration Statement or any material change to such information in this
Registration Statement; provided, however, that clauses (1)(i) and (1)(ii) shall
                        --------                                                
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act that are
incorporated by reference into this Registration Statement; (2) that for the
purpose of determining any liability under the 1933 Act each such post-effective
amendment shall be deemed to be a new registration statement relating to the
securities offered therein and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof; and (3) to remove
from registration by means of a post-effective amendment any of the securities
being registered which remain unsold at the termination of the Registrant's 1998
Supplemental Stock Incentive Plan.

     B.  The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act that is
incorporated by reference into this Registration Statement shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     C.  Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers, or controlling persons of the
Registrant pursuant to the foregoing indemnification provisions summarized in
Item 6 or otherwise, the Registrant has been advised that, in the opinion of the
SEC, such indemnification is against public policy as expressed in the 1933 Act,
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer, or controlling person of the Registrant
in the successful defense of any action, suit, or proceeding) is asserted by
such director, officer, or controlling person in connection with the securities
being registered, the Registrant will, unless in the opinion of its counsel the
matter has been settled by controlling precedent, submit to a court of
appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the 1933 Act and will be governed by the
final adjudication of such issue.


                                     II-2
<PAGE>
 
                                  SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8, and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Alameda, State of California on this 8th day of
October 1998.

                                       ASCEND COMMUNICATIONS, INC.


                                       By: /s/ Mory Ejabat
                                           -------------------------------------
                                           Mory Ejabat
                                           President and Chief Executive Officer


                               POWER OF ATTORNEY
                               -----------------

KNOW ALL PERSONS BY THESE PRESENTS:

        That the undersigned officers and directors of Ascend Communications,
Inc., a Delaware corporation, do hereby constitute and appoint Mory Ejabat and
Michael F.G. Ashby and each one of them, the lawful attorneys-in-fact and agents
with full power and authority to do any and all acts and things and to execute
any and all instruments which said attorneys and agents, and any one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and each of the undersigned hereby ratifies and confirms
all that said attorneys and agents, or any one of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

        IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

<TABLE> 
<CAPTION> 

Signature                           Title                                 Date
---------                           -----                                 ----
<S>                    <C>                                         <C> 
/s/ Mory Ejabat
--------------------   President and Chief Executive               October 8, 1998
Mory Ejabat            Officer (Principal Executive Officer)


/s/ Michael F.G. Ashby
---------------------- Executive Vice President, Chief             October 8, 1998
Michael F.G. Ashby     Financial Officer (Principal Financial
                       Officer and Principal Accounting Officer)
</TABLE> 


                                     II-3
<PAGE>
 
<TABLE>
<CAPTION>

Signature                           Title                                 Date
---------                           -----                                 ----
<S>                    <C>                                         <C> 
/s/ Betsy S. Atkins
--------------------              Director                         October 8, 1998
Betsy S. Atkins

/s/ Robert K. Dahl 
--------------------              Director                         October 8, 1998
Robert K. Dahl

/s/ Roger L. Evans
--------------------              Director                         October 8, 1998
Roger L. Evans

/s/ Reed E. Hundt
--------------------              Director                         October 8, 1998
Reed E. Hundt
 
                             
-----------------------           Director                         October  , 1998
C. Richard Kramlich

/s/ James P. Lally
--------------------              Director                         October 8, 1998
James P. Lally

/s/ Martin Schoffstall 
----------------------            Director                         October 8, 1998
Martin Schoffstall
</TABLE>


 
 
                                     II-4 
<PAGE>
 
                                 EXHIBIT INDEX
                                 -------------


     Number    Exhibit
     ------    -------

     4         Instruments Defining Rights of Stockholders. Reference is made to
               Registrant's Registration Statement No. 000-23774 on Form 8-A,
               including the exhibits thereto, which is incorporated herein by
               reference pursuant to Item 3(d).
     5         Opinion and consent of Brobeck, Phleger & Harrison LLP.
     23.1      Consent of Ernst & Young LLP, Independent Auditors.
     23.2      Consent of Independent Accountants.
     23.3      Consent of Brobeck, Phleger & Harrison LLP is contained in
               Exhibit 5.
     24        Power of Attorney.  Reference is made to page II-3 of this
               Registration Statement.
     99        1998 Supplemental Stock Incentive Plan.
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 17544}]
{"company-data": {"conformed-name": "ASCEND COMMUNICATIONS INC", "cik": "0000921146", "assigned-sic": "3576", "irs-number": "943092033", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-65467", "film-number": "98722757"}, "business-address": {"street1": "1701 HARBOR BAY PKWY", "city": "ALAMEDA", "state": "CA", "zip": "94502", "phone": "5107696001"}, "mail-address": {"street1": "ONE ASCEND PLAZA", "street2": "1701 HARBOR BAY PARKWAY", "city": "ALAMEDA", "state": "CA", "zip": "94502"}}
As filed with the Securities and Exchange Commission on October 8, 1998
                                    Registration Statement No.333-______________
================================================================================

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549
                            -----------------------

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     Under
                          The Securities Act of 1933
                            -----------------------

                          ASCEND COMMUNICATIONS, INC.
            (Exact name of registrant as specified in its charter)

           DELAWARE                                        94-3092033
  (State or other jurisdiction                 (IRS Employer Identification No.)
of incorporation or organization)

                               ONE ASCEND PLAZA
                            1701 HARBOR BAY PARKWAY
                               ALAMEDA, CA 94502

              (Address of principal executive offices) (Zip Code)

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

                          ASCEND COMMUNICATIONS, INC.
                    1998 SUPPLEMENTAL STOCK INCENTIVE PLAN
                           (Full title of the Plans)

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

                                  MORY EJABAT
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                          ASCEND COMMUNICATIONS, INC.
                               ONE ASCEND PLAZA
                            1701 HARBOR BAY PARKWAY
                              ALAMEDA, CA  94502
                                (510) 769-6001

(Name, address including zip code, and telephone number, including area code, of
                              agent for service)

                        CALCULATION OF REGISTRATION FEE
===================================================================================
                                     Proposed        Proposed
  Title of                           Maximum         Maximum
 Securities          Amount          Offering       Aggregate        Amount of
   to be              to be           Price         Offering        Registration
 Registered        Registered(1)    per Share(2)     Price(2)           Fee(2)
------------       ----------       ---------        -----              ---
Common Stock       5,000,000 shares   $35.375     $176,875,000       $52,179.00
$0.001 par value
===================================================================================
(1)  This Registration Statement shall also cover any additional shares of
     Common Stock which become issuable under the Ascend Communications, Inc.
     1998 Supplemental Stock Incentive Plan by reason of any stock dividend,
     stock split, recapitalization or other similar transaction effected without
     Registrant's receipt of consideration which results in an increase in the
     number of the outstanding shares of Registrant's Common Stock.

(2)  Calculated solely for purposes of this offering under Rule 457(h) of the
     Securities Act of 1933, as amended, on the basis of the average of the high
     and low selling prices per share of the Registrant's Common Stock on
     October 6, 1998, as reported by the Nasdaq National Market.
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference
        ---------------------------------------

        Ascend Communications, Inc. (the "Registrant") hereby incorporates by
reference into this Registration Statement the following documents previously
filed with the Securities and Exchange Commission (the "SEC"):

        (a) The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 1997, as amended May 29, 1998, filed with the SEC on March
31, 1998;

        (b) The Registrant's Quarterly Reports on Form 10-Q for the quarters
ended March 31, 1998 and June 30, 1998, filed with the SEC on May 15, 1998 and
August 11, 1998;

        (c) The Registrant's Current Reports on Form 8-K filed with the SEC on
July 2, 1998 and August 14, 1998; and

        (d) The Registrant's Registration Statement No. 000-23774 on Form 8-A
filed with the SEC on March 31, 1994 pursuant to Section 12 of the Securities
Exchange Act of 1934, as amended (the "1934 Act"), in which there is described
the terms, rights and provisions applicable to the Registrant's outstanding
Common Stock.

        All reports and definitive proxy or information statements filed
pursuant to Section 13(a), 13(c), 14 or 15(d) of the 1934 Act after the date of
this Registration Statement and prior to the filing of a post-effective
amendment which indicates that all securities offered hereby have been sold or
which deregisters all securities then remaining unsold shall be deemed to be
incorporated by reference into this Registration Statement and to be a part
hereof from the date of filing of such documents. Any statement contained in a
document incorporated or deemed to be incorporated by reference herein shall be
deemed to be modified or superseded for purposes of this Registration Statement
to the extent that a statement contained herein or in any subsequently filed
document which also is deemed to be incorporated by reference herein modifies or
supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
Registration Statement.

Item 4. Description of Securities
        -------------------------

        Not Applicable.

Item 5. Interests of Named Experts and Counsel
        --------------------------------------

        Not Applicable.

Item 6. Indemnification of Directors and Officers
        -----------------------------------------

        Delaware law authorizes corporations to eliminate the personal liability
of directors to corporations and their stockholders for monetary damages for
breach or alleged breach of the directors' "duty of care." While the relevant
statute does not change directors' duty of care, it enables corporations to
limit available relief to equitable remedies such as injunction or rescission.
The statute has no effect on directors' duty of loyalty, acts or omissions not
in good faith or involving intentional misconduct or knowing violations of law,
illegal payment of dividends and approval of any transaction from which a
director derives an improper personal benefit.

        The Registrant has adopted provisions in its Certificate of
Incorporation which eliminate the personal liability of its directors to the
Registrant and its stockholders for monetary damages for breach or alleged
breach of their duty of care. The Bylaws of the Registrant provide for
indemnification of its directors, officers, employees and agents to the full
extent permitted by the General Corporation Law of the State of Delaware, the
Registrant's state of incorporation, including those circumstances in which
indemnification would otherwise be discretionary under Delaware law. Section 145
of the General Corporation Law of the State of Delaware provides for
indemnification in terms sufficiently broad to indemnify such individuals, under
certain circumstances, for liabilities (including reimbursement of expenses
incurred) arising under the Securities Act of 1933, as amended (the "Securities
Act").
Item 7. Exemption from Registration Claimed
        -----------------------------------

        Not Applicable.

Item 8. Exhibits
        --------

     Number    Exhibit
     ------    -------

     4         Instruments Defining Rights of Stockholders. Reference is made to
               Registrant's Registration Statement No. 000-23774 on Form 8-A,
               including the exhibits thereto, which is incorporated herein by
               reference pursuant to Item 3(d).
     5         Opinion and consent of Brobeck, Phleger & Harrison LLP.
     23.1      Consent of Ernst & Young LLP, Independent Auditors.
     23.2      Consent of Independent Accountants.
     23.3      Consent of Brobeck, Phleger & Harrison LLP is contained in
               Exhibit 5.
     24        Power of Attorney.  Reference is made to page II-3 of this
               Registration Statement.
     99        1998 Supplemental Stock Incentive Plan.

Item 9. Undertakings
        ------------

     A.  The undersigned Registrant hereby undertakes:  (1) to file, during
any period in which offers or sales are being made, a post-effective amendment
to this Registration Statement (i) to include any prospectus required by Section
10(a)(3) of the 1933 Act, (ii) to reflect in the prospectus any facts or events
arising after the effective date of this Registration Statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth in this
Registration Statement and (iii) to include any material information with
respect to the plan of distribution not previously disclosed in this
Registration Statement or any material change to such information in this
Registration Statement; provided, however, that clauses (1)(i) and (1)(ii) shall
                        --------                                                
not apply if the information required to be included in a post-effective
amendment by those paragraphs is contained in periodic reports filed by the
Registrant pursuant to Section 13 or Section 15(d) of the 1934 Act that are
incorporated by reference into this Registration Statement; (2) that for the
purpose of determining any liability under the 1933 Act each such post-effective
amendment shall be deemed to be a new registration statement relating to the
securities offered therein and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof; and (3) to remove
from registration by means of a post-effective amendment any of the securities
being registered which remain unsold at the termination of the Registrant's 1998
Supplemental Stock Incentive Plan.

     B.  The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the 1933 Act, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the 1934 Act that is
incorporated by reference into this Registration Statement shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     C.  Insofar as indemnification for liabilities arising under the 1933 Act
may be permitted to directors, officers, or controlling persons of the
Registrant pursuant to the foregoing indemnification provisions summarized in
Item 6 or otherwise, the Registrant has been advised that, in the opinion of the
SEC, such indemnification is against public policy as expressed in the 1933 Act,
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer, or controlling person of the Registrant
in the successful defense of any action, suit, or proceeding) is asserted by
such director, officer, or controlling person in connection with the securities
being registered, the Registrant will, unless in the opinion of its counsel the
matter has been settled by controlling precedent, submit to a court of
appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the 1933 Act and will be governed by the
final adjudication of such issue.

                                     II-2
SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8, and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Alameda, State of California on this 8th day of
October 1998.

                                       ASCEND COMMUNICATIONS, INC.

                                       By: /s/ Mory Ejabat
                                           -------------------------------------
                                           Mory Ejabat
                                           President and Chief Executive Officer

                               POWER OF ATTORNEY
                               -----------------

KNOW ALL PERSONS BY THESE PRESENTS:

        That the undersigned officers and directors of Ascend Communications,
Inc., a Delaware corporation, do hereby constitute and appoint Mory Ejabat and
Michael F.G. Ashby and each one of them, the lawful attorneys-in-fact and agents
with full power and authority to do any and all acts and things and to execute
any and all instruments which said attorneys and agents, and any one of them,
determine may be necessary or advisable or required to enable said corporation
to comply with the Securities Act of 1933, as amended, and any rules or
regulations or requirements of the Securities and Exchange Commission in
connection with this Registration Statement. Without limiting the generality of
the foregoing power and authority, the powers granted include the power and
authority to sign the names of the undersigned officers and directors in the
capacities indicated below to this Registration Statement, to any and all
amendments, both pre-effective and post-effective, and supplements to this
Registration Statement, and to any and all instruments or documents filed as
part of or in conjunction with this Registration Statement or amendments or
supplements thereof, and each of the undersigned hereby ratifies and confirms
all that said attorneys and agents, or any one of them, shall do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.

        IN WITNESS WHEREOF, each of the undersigned has executed this Power of
Attorney as of the date indicated.

        Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.
Signature                           Title                                 Date
---------                           -----                                 ----
/s/ Mory Ejabat
--------------------   President and Chief Executive               October 8, 1998
Mory Ejabat            Officer (Principal Executive Officer)

/s/ Michael F.G. Ashby
---------------------- Executive Vice President, Chief             October 8, 1998
Michael F.G. Ashby     Financial Officer (Principal Financial
                       Officer and Principal Accounting Officer)
II-3
Signature                           Title                                 Date
---------                           -----                                 ----
/s/ Betsy S. Atkins
--------------------              Director                         October 8, 1998
Betsy S. Atkins

/s/ Robert K. Dahl 
--------------------              Director                         October 8, 1998
Robert K. Dahl

/s/ Roger L. Evans
--------------------              Director                         October 8, 1998
Roger L. Evans

/s/ Reed E. Hundt
--------------------              Director                         October 8, 1998
Reed E. Hundt
 
                             
-----------------------           Director                         October  , 1998
C. Richard Kramlich

/s/ James P. Lally
--------------------              Director                         October 8, 1998
James P. Lally

/s/ Martin Schoffstall 
----------------------            Director                         October 8, 1998
Martin Schoffstall
II-4
EXHIBIT INDEX
                                 -------------

     Number    Exhibit
     ------    -------

     4         Instruments Defining Rights of Stockholders. Reference is made to
               Registrant's Registration Statement No. 000-23774 on Form 8-A,
               including the exhibits thereto, which is incorporated herein by
               reference pursuant to Item 3(d).
     5         Opinion and consent of Brobeck, Phleger & Harrison LLP.
     23.1      Consent of Ernst & Young LLP, Independent Auditors.
     23.2      Consent of Independent Accountants.
     23.3      Consent of Brobeck, Phleger & Harrison LLP is contained in
               Exhibit 5.
     24        Power of Attorney.  Reference is made to page II-3 of this
               Registration Statement.
     99        1998 Supplemental Stock Incentive Plan.