EXHIBIT 10.1

                           INDEMNIFICATION AGREEMENT


     This Agreement is made as of the ___ day of ____________, by and between
Sycamore Networks, Inc., a Delaware corporation (the "Corporation), and
____________________ ("Indemnitee"), a director or officer of the Corporation.

     WHEREAS, it is essential to the Corporation to retain and attract as
directors and officers the most capable persons available, and

     WHEREAS, the substantial increase in corporate litigation subjects
directors and officers to expensive litigation risks at the same time that the
availability of directors' and officers' liability insurance has been severely
limited, and

     WHEREAS, it is now and has always been the express policy of the
Corporation to indemnify its directors and officers so as to provide them with
the maximum possible protection permitted by law, and

     WHEREAS, Indemnitee does not regard the protection available under the
Corporation's Amended and Restated Certificate of Incorporation and insurance as
adequate in the present circumstances, and may not be willing to serve as a
director or officer without adequate protection, and

     WHEREAS, the Corporation desires Indemnitee to serve as a director or
officer of the Corporation.

     NOW THEREFORE, the Corporation and Indemnitee do hereby agree as follows:

     1.   Agreement to Serve. Indemnitee agrees to serve or continue to serve as
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a director or officer of the Corporation for so long as he is duly elected or
appointed or until such time as he tenders his resignation in writing

     2.   Definitions.  As used in this Agreement:
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          (a)  The term "Proceeding" shall include any threatened, pending or
completed action, suit, or proceeding, whether brought by or in the right of the
Corporation or otherwise and whether of a civil, criminal, administrative or
investigative nature, and any appeal therefrom.


          (b)  The term "Corporate Status" shall mean the status of a person who
is or was a director or officer of the Corporation, or is or was serving, or has
agreed to serve, at the request of the Corporation, as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise.

          (c)  The term "Expenses" shall include, without limitation, attorneys'
fees, retainers, court costs, transcript costs, fees of experts, travel
expenses, duplicating costs, printing and binding costs, telephone charges,
postage, delivery service fees and other disbursements or expenses of the types
customarily incurred in connection with investigations, judicial or
administrative proceedings or appeals, but shall not include the amount of
judgments, fines or penalties against Indemnitee or amounts paid in settlement
in connection with such matters.

          (d)  References to "other enterprise" shall include employee benefit
plans; references to "fines" shall include any excise tax assessed with respect
to any employee benefit plan; references to "serving at the request of the
Corporation" shall include any service as a director, officer, employee or agent
of the Corporation which imposes duties on, or involves services by, such
director, officer, employee, or agent with respect to an employee benefit plan,
its participants, or beneficiaries; and a person who acted in good faith and in
a manner he reasonably believed to be in the interests of the participants and
beneficiaries of an employee benefit plan shall be

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deemed to have acted in a manner "not opposed to the best interests of the
Corporation" as referred to in this Agreement.

     3.   Indemnification in Third-Party Proceedings.  The Corporation shall
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indemnify Indemnitee in accordance with the provisions of this Paragraph 3 if
Indemnitee was or is a party to or threatened to be made a party to or otherwise
involved in any Proceeding (other than a Proceeding by or in the right of the
Corporation to procure a judgment in its favor) by reason of his Corporate
Status or by reason of any action alleged to have been taken or omitted in
connection therewith, against all Expenses, judgments, fines, penalties and
amounts paid in settlement actually and reasonably incurred by Indemnitee or on
his behalf in connection with such Proceeding, if Indemnitee acted in good faith
and in a manner which he reasonably believed to be in, or not opposed to, the
best interests of the Corporation and, with respect to of any criminal
Proceeding, had no reasonable cause to believe that his conduct was unlawful.
The termination of any Proceeding by judgment, order, settlement, conviction or
upon a plea of nolo contendere, or its equivalent, shall not, of itself, create
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a presumption that Indemnitee did not act in good faith and in a manner which he
reasonably believed to be in, or not opposed to, the best interests of the
Corporation, and, with respect to any criminal Proceeding, had reasonable cause
to believe that his conduct was unlawful.

     4.   Indemnification in Proceedings by or in the Right of the Corporation.
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The Corporation shall indemnify Indemnitee in accordance with the provisions of
this Paragraph 4 if Indemnitee is a party to or threatened to be made a party to
or otherwise involved in any Proceeding by or in the right of the Corporation to
procure a judgment in its favor by reason of his Corporate Status or by reason
of any action alleged to have been taken or omitted in connection therewith,
against all Expenses and, to the extent permitted by law, amounts paid in
settlement actually and reasonably incurred by Indemnitee or on his behalf in
connection with such Proceeding, if he acted in good faith and in a manner which
he reasonably believed to be in, or not opposed to, the best interests of the
Corporation, except that no indemnification shall be made under this Paragraph 4
in respect of any claim, issue, or matter as to which Indemnitee shall have been
adjudged to be liable to the Corporation, unless and only to the extent that the
Court of Chancery of Delaware shall determine upon application that, despite the
adjudication of such liability but in view of all the circumstances of the case,
Indemnitee is fairly and reasonably entitled to indemnity for such Expenses as
the Court of Chancery shall deem proper.

     5.   Exceptions to Right of Indemnification.  Notwithstanding anything to
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the contrary in this Agreement, except as set forth in Paragraph 10, the
Corporation shall not indemnify the Indemnitee in connection with a Proceeding
(or part thereof) initiated by the Indemnitee unless the initiation thereof was
approved by the Board of Directors of the Corporation.  Notwithstanding anything
to the contrary in this Agreement, the Corporation shall not indemnify the
Indemnitee to the extent the Indemnitee is reimbursed from the proceeds of
insurance, and in the event the Corporation makes any indemnification payments
to the Indemnitee and the Indemnitee is subsequently reimbursed from the
proceeds of insurance, the Indemnitee shall promptly refund such indemnification
payments to the Corporation to the extent of such insurance reimbursement.

     6.   Indemnification of Expenses of Successful Party.  Notwithstanding any
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other provision of this Agreement, to the extent that Indemnitee has been
successful, on the merits or otherwise, in defense of any Proceeding or in
defense of any claim, issue or matter therein, Indemnitee shall be indemnified
against all Expenses incurred by him or on his behalf in connection therewith.
Without limiting the foregoing, if any Proceeding or any claim, issue or matter
therein is disposed of, on the merits or otherwise (including a disposition
without prejudice), without (i) the disposition being adverse to the Indemnitee,
(ii) an adjudication that the Indemnitee was liable to the Corporation, (iii) a
plea of guilty or nolo contendere by the Indemnitee, (iv) an adjudication that
the Indemnitee did not act in good faith and in a manner he reasonably believed
to be in or not opposed to the best interests of the Corporation, and (v) with
respect to any criminal proceeding, an adjudication that the Indemnitee had
reasonable cause to believe his conduct was unlawful, the Indemnitee shall be
considered for the purposes hereof to have been wholly successful with respect
thereto.

     7.   Notification and Defense of Claim.  As a condition precedent to his
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right to be indemnified, the Indemnitee must notify the Corporation in writing
as soon as practicable of any Proceeding for which indemnity will or could be
sought by him and provide the Corporation with a copy of any summons, citation,
subpoena, complaint,

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indictment, information or other document relating to such Proceeding with which
he is served. With respect to any Proceeding of which the Corporation is so
notified, the Corporation will be entitled to participate therein at its own
expense and/or to assume the defense thereof at its own expense, with legal
counsel reasonably acceptable to the Indemnitee. After notice from the
Corporation to the Indemnitee of its election so to assume such defense, the
Corporation shall not be liable to the Indemnitee for any legal or other
expenses subsequently incurred by the Indemnitee in connection with such claim,
other than as provided below in this Paragraph 7. The Indemnitee shall have the
right to employ his own counsel in connection with such claim, but the fees and
expenses of such counsel incurred after notice from the Corporation of its
assumption of the defense thereof shall be at the expense of the Indemnitee
unless (i) the employment of counsel by the Indemnitee has been authorized by
the Corporation, (ii) counsel to the Indemnitee shall have reasonably concluded
that there may be a conflict of interest or position on any significant issue
between the Corporation and the Indemnitee in the conduct of the defense of such
action or (iii) the Corporation shall not in fact have employed counsel to
assume the defense of such action, in each of which cases the fees and expenses
of counsel for the Indemnitee shall be at the expense of the Corporation, except
as otherwise expressly provided by this Agreement. The Corporation shall not be
entitled, without the consent of the Indemnitee, to assume the defense of any
claim brought by or in the right of the Corporation or as to which counsel for
the Indemnitee shall have reasonably made the conclusion provided for in clause
(ii) above.

     8.   Advancement of Expenses.  Subject to the provisions of Paragraph 9
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below, in the event that the Corporation does not assume the defense pursuant to
Paragraph 7 of this Agreement of any Proceeding to which Indemnitee was or is a
party or is threatened to be made a party by reason of his Corporate Status or
by reason of any action alleged to have been taken or omitted in connection
therewith and of which the Corporation receives notice under this Agreement, any
Expenses incurred by the Indemnitee in defending such Proceeding shall be paid
by the Corporation in advance of the final disposition of such matter; provided,
however, that the payment of such Expenses incurred by the Indemnitee in advance
of the final disposition of such matter shall be made only upon receipt of an
undertaking by or on behalf of the Indemnitee to repay all amounts so advanced
in the event that it shall ultimately be determined that the Indemnitee is not
entitled to be indemnified by the Corporation as authorized in this Agreement.
Such undertaking shall be accepted without reference to the financial ability of
the Indemnitee to make repayment.

     9.   Procedure for Indemnification.  In order to obtain indemnification or
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advancement of Expenses pursuant to Paragraphs 3, 4, 6 or 8 of this Agreement,
Indemnitee shall submit to the Corporation a written request, including in such
request such documentation and information as is reasonably available to
Indemnitee and is reasonably necessary to determine whether and to what extent
Indemnitee is entitled to indemnification or advancement of Expenses.  Any such
indemnification or advancement of Expenses shall be made promptly, and in any
event within 60 days after receipt by the Corporation of the written request of
the Indemnitee, unless with respect to requests under Paragraphs 3, 4 or 8 the
Corporation determines within such 60-day period that such Indemnitee did not
meet the applicable standard of conduct set forth in Paragraph 3 or 4, as the
case may be.  Such determination shall be made in each instance by (a) a
majority vote of the directors of the Corporation consisting of persons who are
not at that time parties to the Proceeding ("disinterested directors"), whether
or not a quorum, (b) a majority vote of a quorum of the outstanding shares of
stock of all classes entitled to vote for directors, voting as a single class,
which quorum shall consist of stockholders who are not at that time parties to
the Proceeding, (c) independent legal counsel (who may, to the extent permitted
by applicable law, be regular legal counsel to the Corporation), or (d) a court
of competent jurisdiction.

     10.  Remedies.  The right to indemnification or advancement of Expenses as
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provided by this Agreement shall be enforceable by the Indemnitee in any court
of competent jurisdiction if the Corporation denies such request, in whole or in
part, or if no disposition thereof is made within the 60-day period referred to
above in Paragraph 9.  Unless otherwise required by law, the burden of proving
that indemnification is not appropriate shall be on the Corporation.  Neither
the failure of the Corporation to have made a determination prior to the
commencement of such action that indemnification is proper in the circumstances
because Indemnitee has met the applicable standard of conduct, nor an actual
determination by the Corporation pursuant to Paragraph 9 that Indemnitee has not
met such applicable standard of conduct, shall be a defense to the action or
create a presumption that Indemnitee has not met the applicable standard of
conduct.  Indemnitee's expenses (of the type described in the

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definition of "Expenses" in Paragraph 2(c)) reasonably incurred in connection
with successfully establishing his right to indemnification, in whole or in
part, in any such Proceeding shall also be indemnified by the Corporation.

     11.  Partial Indemnification.  If Indemnitee is entitled under any
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provision of this Agreement to indemnification by the Corporation for some or a
portion of the Expenses, judgments, fines, penalties or amounts paid in
settlement actually and reasonably incurred by him or on his behalf in
connection with any Proceeding but not, however, for the total amount thereof,
the Corporation shall nevertheless indemnify Indemnitee for the portion of such
Expenses, judgments, fines, penalties or amounts paid in settlement to which
Indemnitee is entitled.

     12.  Subrogation.  In the event of any payment under this Agreement, the
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Corporation shall be subrogated to the extent of such payment to all of the
rights of recovery of Indemnitee, who shall execute all papers required and take
all action necessary to secure such rights, including execution of such
documents as are necessary to enable the Corporation to bring suit to enforce
such rights.

     13.  Term of Agreement.  This Agreement shall continue until and terminate
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upon the later of (a) six years after the date that Indemnitee shall have ceased
to serve as a director or officer of the Corporation or, at the request of the
Corporation, as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise or (b) the final
termination of all Proceedings pending on the date set forth in clause (a) in
respect of which Indemnitee is granted rights of indemnification or advancement
of Expenses hereunder and of any proceeding commenced by Indemnitee pursuant to
Paragraph 10 of this Agreement relating thereto.

     14.  Indemnification Hereunder Not Exclusive.  The indemnification and
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advancement of Expenses provided by this Agreement shall not be deemed exclusive
of any other rights to which Indemnitee may be entitled under the Certification
of Incorporation, the By-Laws, any agreement, any vote of stockholders or
disinterested directors, the General Corporation Law of Delaware, any other law
(common or statutory), or otherwise, both as to action in his official capacity
and as to action in another capacity while holding office for the Corporation.
Nothing contained in this Agreement shall be deemed to prohibit the Corporation
from purchasing and maintaining insurance, at its expense, to protect itself or
the Indemnitee against any expense, liability or loss incurred by it or him in
any such capacity, or arising out of his status as such, whether or not the
Indemnitee would be indemnified against such expense, liability or loss under
this Agreement; provided that the Corporation shall not be liable under this
Agreement to make any payment of amounts otherwise indemnifiable hereunder if
and to the extent that Indemnitee has otherwise actually received such payment
under any insurance policy, contract, agreement or otherwise.

     15.  No Special Rights.  Nothing herein shall confer upon Indemnitee any
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right to continue to serve as an officer or director of the Corporation for any
period of time or at any particular rate of compensation.

     16.  Savings Clause.  If this Agreement or any portion thereof shall be
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invalidated on any ground by any court of competent jurisdiction, then the
Corporation shall nevertheless indemnify Indemnitee as to Expenses, judgments,
fines, penalties and amounts paid in settlement with respect to any Proceeding
to the full extent permitted by any applicable portion of this Agreement that
shall not have been invalidated and to the fullest extent permitted by
applicable law.

     17.  Counterparts.  This Agreement may be executed in any number of
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counterparts, each of which shall constitute the original.

     18.  Successors and Assigns.  This Agreement shall be binding upon the
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Corporation and its successors and assigns and shall inure to the benefit of the
estate, heirs, executors, administrators and personal representatives of
Indemnitee.

     19.  Headings.  The headings of the paragraphs of this Agreement are
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inserted for convenience only and shall not be deemed to constitute part of this
Agreement or to affect the construction thereof.

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     20.  Modification and Waiver.  This Agreement may be amended from time to
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time to reflect changes in Delaware law or for other reasons.  No supplement,
modification or amendment of this Agreement shall be binding unless executed in
writing by both of the parties hereto.  No waiver of any of the provisions of
this Agreement shall be deemed or shall constitute a waiver of any other
provision hereof nor shall any such waiver constitute a continuing waiver.

     21.  Notices.  All notices, requests, demands and other communications
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hereunder shall be in writing and shall be deemed to have been given (i) when
delivered by hand or (ii) if mailed by certified or registered mail with postage
prepaid, on the third day after the date on which it is so mailed:

     (a)  if to the Indemnitee, to:

     (b)  if to the Corporation, to:

          Sycamore Networks, Inc.
          10 Elizabeth Drive
          Chelmsford, MA  01824
          Attn: General Counsel

or to such other address as may have been furnished to Indemnitee by the
Corporation or to the Corporation by Indemnitee, as the case may be.

     22.  Applicable Law.  This Agreement shall be governed by and construed in
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accordance with the laws of the State of Delaware.

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


                                          SYCAMORE NETWORKS, INC.

Attest:                                   By:   ____________________________

By: __________________________            Name: ____________________________

                                          Title: ___________________________


                                          INDEMNITEE:

                                          __________________________________

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