Exhibit 99.1




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                                                                 SYCAMORE
                                                                NETWORKS

FOR IMMEDIATE RELEASE

CONTACT:
Press Inquiries                             Investor Inquiries
Scott Larson                                Terry Adams
Public Relations                            Investor Relations
Sycamore Networks, Inc.                     Sycamore Networks, Inc.
978-250-3433                                978-250-3460
scott.larson@sycamorenet.com                investor.info@sycamorenet.com


              SYCAMORE NETWORKS PLANS TO DELAY FILING OF FORM 10-Q
                      FOR THE QUARTER ENDED APRIL 30, 2005

CHELMSFORD, Mass., June 7, 2005 - Sycamore Networks, Inc. (NASDAQ: SCMR) today
announced that it will delay the filing of its quarterly report on Form 10-Q
for the three months ended April 30, 2005 pending the conclusion of an internal
investigation being conducted under the direction of the Audit Committee of its
Board of Directors. The investigation relates to the accounting for certain
stock options granted during the period from 1999 to 2001, including whether
additional stock compensation expenses should have been recorded during the
period under review. While there can be no assurances as to the final results
of the investigation, the Company does not currently anticipate that the
outcome of the investigation will result in any material adjustments being
required to be made to the Company's historical revenues, non-stock option
related expenses or cash positions.

"The Company and its Board of Directors take these matters very seriously and
accordingly we are cooperating fully with the investigation," said Richard
Gaynor, the Sycamore Chief Financial Officer.

The Company reported that it is currently unable to estimate when it will be
able to file its Form 10-Q for the period ended April 30, 2005 but that it
intends to do so as soon as practicable following the completion of the
investigation.

About Sycamore Networks

Sycamore Networks, Inc. (NASDAQ: SCMR) develops and services optical networking
products for telecommunications service providers worldwide. The Company's
products enable service providers to cost-effectively and easily transition
their existing fiber optic network into a network infrastructure that can
provision, manage and deliver economic, high-bandwidth services to their
customers. For more information, please visit www.sycamorenet.com.


Except for the historical information contained herein, we wish to caution you
that certain matters discussed in this news release constitute forward-looking
statements that involve risks and uncertainties. Actual results or events could
differ materially from those stated or implied in forward-looking statements
including the nature and scope of the internal investigation, Sycamore's plans
to delay the filing date of its Form 10-Q for the period ended April 30, 2005
and the timing of its release of its financial results for such period. The
statements contained herein involve risks and uncertainties and actual results
may differ significantly. The risks include, but are not limited to, additional
actions and findings that may result from the continuing Audit Committee
internal investigation. Further, there can be no assurance concerning the
results of the internal investigation, timing of the filing of the Company's
Form 10-Q for the period ended April 30, 2005 or the release of the financial
results for such period. The Company disclaims any intention or obligation to
update or revise any forward-looking statements, whether as a result of new
information, future results or otherwise.