UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549
                                  FORM 10-Q/A

                                Amendment No. 1

    [X] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES

                             EXCHANGE ACT OF 1934

                FOR THE QUARTERLY PERIOD ENDED JANUARY 25, 2003

                                      OR

    [_] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES

                             EXCHANGE ACT OF 1934

                 FOR THE TRANSITION PERIOD FROM _____ TO _____

                       COMMISSION FILE NUMBER 000-27273

                            SYCAMORE NETWORKS, INC.
            (Exact name of registrant as specified in its charter)

           Delaware                                  04-3410558
    (State or other jurisdiction                  (I.R.S. Employer
    of incorporation or organization)             Identification No.)

                                 220 Mill Road
                             Chelmsford, MA 01824
                   (Address of principal executive offices)
                                  (Zip code)

                                (978) 250-2900
             (Registrant's telephone number, including area code)


Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to
such filing requirements for the past 90 days.
Yes X      No___ .

Indicate by check mark whether the registrant is an accelerated filer (as
defined in Rule 12b-2 of the Exchange Act). Yes___ No X.

The number of shares outstanding of the Registrant's Common Stock as of
May 23, 2003 was 271,916,034.



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Sycamore Networks, Inc.

Index                                                             Page No.

Part I.  Financial Information


Item 4.  Controls and Procedures                                     3







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Introductory Note:

This Amendment No. 1 to the Quarterly Report on Form 10-Q of Sycamore
Networks, Inc. for the quarterly period ending January 25, 2003 is being filed
solely for the purpose of amending and restating the "accelerated filer"
status on the cover page and Item 4 of Part I, Financial Information. In
accordance with Rule 12b-15 under the Securities Exchange Act of 1934, the
complete text of Item 4, as amended, is set forth herein. In addition, in
connection with the filing of this Amendment No. 1 and pursuant to Rule
12b-15, the Company is including certain currently dated certifications. The
remainder of the Form 10-Q is unchanged and is not reproduced in this
Amendment No. 1. This Amendment No. 1 speaks as of the original filing date of
the Form 10-Q and does not reflect events occurring after the filing of the
original Form 10-Q, or modify or update the disclosures therein in any way
other than as required to reflect the amendment set forth below.


Item 4.  Controls and Procedures

(a) Evaluation of Disclosure Controls and Procedures. Within 90 days prior to
the filing date of this quarterly report, we carried out an evaluation under
the supervision and with the participation of our management, including the
Chief Executive Officer and Chief Financial Officer, of the effectiveness of
our disclosure controls and procedures. Based on that evaluation, the Chief
Executive Officer and Chief Financial Officer concluded that the Company's
disclosure controls and procedures are effective to ensure that information
required to be disclosed by the Company in reports that it files or submits
under the Securities Exchange Act of 1934 is recorded, processed, summarized
and reported within the time periods specified in Securities and Exchange
Commission rules and forms.

(b) Changes in Internal Controls. There were no significant changes in our
internal controls or in other factors that could significantly affect these
controls subsequent to the date of their last evaluation.



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                                  SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this Amendment No. 1 to be signed on its behalf by
the undersigned thereunto duly authorized.


Sycamore Networks, Inc.


 /s/ Frances M. Jewels
- ----------------------------
Frances M. Jewels
Chief Financial Officer

(Duly Authorized Officer and Principal
Financial and Accounting Officer)


Dated: May 29, 2003









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                                CERTIFICATIONS

I, Daniel E. Smith, certify that:

     1.   I have reviewed this quarterly report on Form 10-Q/A of Sycamore
          Networks, Inc.;

     2.   Based on my knowledge, this quarterly report does not contain any
          untrue statement of a material fact or omit to state a material fact
          necessary to make the statements made, in light of the circumstances
          under which such statements were made, not misleading with respect
          to the period covered by this quarterly report;

     3.   The registrant's other certifying officers and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant
          and we have:

               a)  Designed such disclosure controls and procedures to ensure
                   that material information relating to the registrant,
                   including its consolidated subsidiaries, is made known to
                   us by others within those entities, particularly during the
                   period in which this quarterly report is being prepared;

               b)  Evaluated the effectiveness of the registrant's disclosure
                   controls and procedures as of a date within 90 days prior
                   to the filing date of this quarterly report (the
                   "Evaluation Date"); and

               c)  Presented in this quarterly report our conclusions about
                   the effectiveness of the disclosure controls and procedures
                   based on our evaluation as of the Evaluation Date;

     4.   The registrant's other certifying officers and I have disclosed,
          based on our most recent evaluation, to the registrant's auditors
          and the audit committee of registrant's board of directors (or
          persons performing the equivalent function):

               a)  All significant deficiencies in the design or operation of
                   internal controls which could adversely affect the
                   registrant's ability to record, process, summarize and
                   report financial data and have identified for the
                   registrant's auditors any material weaknesses in internal
                   controls; and

               b)  Any fraud, whether or not material, that involves
                   management or other employees who have a significant role
                   in the registrant's internal controls; and

     5.   The registrant's other certifying officers and I have indicated in
          this quarterly report whether or not there were significant changes
          in internal controls or in other factors that could significantly
          affect internal controls subsequent to the date of our most recent
          evaluation, including any corrective actions with regard to
          significant deficiencies and material weaknesses.



Date:  May 29, 2003


   /S/ DANIEL E. SMITH
- ----------------------------
       Daniel E. Smith
  Chief Executive Officer



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I, Frances M. Jewels, certify that:

     1.   I have reviewed this quarterly report on Form 10-Q/A of Sycamore
          Networks, Inc.;

     2.   Based on my knowledge, this quarterly report does not contain any
          untrue statement of a material fact or omit to state a material fact
          necessary to make the statements made, in light of the circumstances
          under which such statements were made, not misleading with respect
          to the period covered by this quarterly report;

     3.   The registrant's other certifying officers and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant
          and we have:

               a)  Designed such disclosure controls and procedures to ensure
                   that material information relating to the registrant,
                   including its consolidated subsidiaries, is made known to
                   us by others within those entities, particularly during the
                   period in which this quarterly report is being prepared;

               b)  Evaluated the effectiveness of the registrant's disclosure
                   controls and procedures as of a date within 90 days prior
                   to the filing date of this quarterly report (the
                   "Evaluation Date"); and

               c)  Presented in this quarterly report our conclusions about
                   the effectiveness of the disclosure controls and procedures
                   based on our evaluation as of the Evaluation Date;

     4.   The registrant's other certifying officers and I have disclosed,
          based on our most recent evaluation, to the registrant's auditors
          and the audit committee of registrant's board of directors (or
          persons performing the equivalent function):

               a.  All significant deficiencies in the design or operation of
                   internal controls which could adversely affect the
                   registrant's ability to record, process, summarize and
                   report financial data and have identified for the
                   registrant's auditors any material weaknesses in internal
                   controls; and

               b.  Any fraud, whether or not material, that involves
                   management or other employees who have a significant role
                   in the registrant's internal controls; and

     5.   The registrant's other certifying officers and I have indicated in
          this quarterly report whether or not there were significant changes
          in internal controls or in other factors that could significantly
          affect internal controls subsequent to the date of our most recent
          evaluation, including any corrective actions with regard to
          significant deficiencies and material weaknesses.



Date: May 29, 2003


   /S/ FRANCES M. JEWELS
- -----------------------------
       Frances M. Jewels
   Chief Financial Officer