Exhibit 10.1

FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT

THIS FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT (this “First Amendment”),
dated as of February 24, 2015 (the “Effective Date”), is made and entered into
by and between SYCAMORE NETWORKS, INC. (the “Seller”) and PRINCETON TYNGSBORO
COMMONS LLC (the “Buyer”).

R E C I T A L S

A. Seller and Buyer are parties to that certain Purchase and Sale Agreement
dated as of October 10, 2014 (together, the “Purchase Agreement”) wherein the
Buyer has agreed to purchase and Seller has agreed to sell that certain property
consisting of 102.3 acres, more or less, located off Westford Road,
Tyngsborough, Massachusetts as more particularly described in the Purchase
Agreement, as well as the Supplemental Escrow Agreement dated October 14, 2014
regarding the Escrow Agent’s duties regarding deposits.

B. The time of the performance and delivery of the Deed for the transaction
contemplated by the Purchase Agreement, as affected by that certain letter dated
December 31, 2014 from the Buyer to the Seller, is presently scheduled to take
place on February 27, 2015 (the “Current Closing Date”).

C. Seller and Buyer wish to extend the time of performance of the transaction
contemplated by the Purchase Agreement.

AGREEMENT:

NOW, THEREFORE, in consideration of the premises, the sum of Ten Dollars and
other good and valuable consideration, the receipt and sufficiency of which is
hereby acknowledged and confessed, Seller and Buyer hereby agree as follows:

1. Extended Time of Performance.

The time of performance and delivery of the Deed for the transaction
contemplated by the Purchase Agreement is hereby extended from the Current
Closing Date to March 27, 2015.

2. Additional Deposit.

Within forty-eight (48) hours following the full execution of this First
Amendment, the Buyer shall deliver an additional nonrefundable deposit of
$100,000.00 to the Escrow Agent, which amount shall be added to the deposit
presently held by the Escrow Agent and be subject to retention as set forth in
Section 7 as amended by the new Closing Date set forth herein, Sections 17 and
18 of the Purchase Agreement, and the terms and conditions of Section 34 of the
Purchase Agreement and the Supplemental Escrow Agreement. All deposits shall be
credited towards the Purchase Price.

3. Ratification. Except as amended by this First Amendment, all other terms,
conditions, covenants and provisions as appear in the Purchase Agreement and the
Supplemental Escrow Agreement are hereby ratified and confirmed and shall remain
unchanged.

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IN WITNESS WHEREOF, the parties have caused this First Amendment to be duly
executed under seal as of the date first written above.

 

SELLER: SYCAMORE NETWORKS, INC. BY:

/s/ David Guerrera

TITLE: President and General Counsel BUYER: PRINCETON TYNGSBOROUGH COMMONS LLC
BY: Princeton MGR Inc., its Manager BY:

/s/ Terry Flahive

TITLE: Vice President As duly authorized and not individually