Exhibit 10.1

LEASE TERMINATION AGREEMENT

This Lease Termination Agreement (this “Agreement”), dated as of the 5th day of
January, 2010, but effective for all purposes as of the Effective Date as
defined below, is entered into by and among RREEF AMERICA REIT III-Z1 LLC, a
Delaware limited liability company (“Landlord”) and SOAPSTONE NETWORKS,
INCORPORATED, a Delaware corporation (“Tenant”).

WHEREAS, Landlord and Tenant are parties to that certain Lease dated April 2,
2008 (the “Lease”) respecting certain premises located at One Federal Street,
Billerica, Massachusetts (as more particularly described in the Lease, the
“Premises”); and

WHEREAS, Landlord and Tenant desire to terminate the Lease.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency
of which are mutually acknowledged, and in consideration of the mutual covenants
and agreements hereinafter set forth, Landlord and Tenant agree as follows:

1. Capitalized Terms. All capitalized terms not otherwise defined herein shall
have the meanings set forth in the Lease.

2. Termination of Existing Lease and Sublease. Landlord and Tenant hereby
terminate the Lease as of the Effective Date. The “Effective Date” is the date
upon which Landlord receives the Termination Payment, as defined below.

3. Surrender of Premises. Landlord acknowledges that Tenant has vacated the
Premises, except for (a) certain written records of Tenant presently located in
Iron Mountain storage boxes; and (b) the personal effects and personally-owned
office equipment located in the offices of Mr. William Stuart, President, and
Mr. James McMaster, Controller (the “Excluded Personal Property”). Except for
the removal of the Excluded Personal Property, which Tenant shall do on or
before January 15, 2010, repairing any damage caused thereby, Landlord hereby
accepts the Premises in their presently existing condition in full satisfaction
of the terms and provisions contained in Article 26 of the Lease. Tenant shall
not remove any wiring, fixtures, equipment, furniture or other personal property
(other than the Excluded Personal Property) from the Premises. Tenant hereby
conveys, transfers, set over, and grants to Landlord all of Tenant’s right,
title and interest in and to all furniture, fixtures, equipment and other
personal property currently remaining in the Premises other than the Excluded
Personal Property (the “Remaining Personal Property”), and simultaneously with
its execution and delivery of this Agreement, Tenant has executed and delivered
to Landlord a Bill of Sale with respect to the Remaining Personal Property, in
the form attached hereto as Exhibit A.

4. Termination Payment. Within three (3) business days following the date upon
which this Lease Termination Agreement is executed and delivered by Landlord and
Tenant, Tenant shall pay to Landlord, by wire transfer to the account designated
in Exhibit B attached hereto, the sum of $3,500,000.00 (the “Termination
Payment”). Tenant acknowledges and agrees that the Termination Payment is not a
penalty and is fair and reasonable compensation to Landlord for the loss of
expected rentals from Tenant over the remainder of the scheduled term of the
Lease. Landlord acknowledges and agrees that the effectiveness of this Agreement
is not

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conditioned upon Landlord’s entering into any lease or other occupancy agreement
for the Premises or any portion thereof covering any period of time subsequent
to the date of this Agreement (each, a “New Lease”), and Landlord agrees to be
solely responsible for and shall pay in full, without contribution by Tenant,
any costs and expenses of any kind or nature which become due in connection with
or as a result of any New Lease, including, without limitation, marketing
expenses, advertising expenses, free rent or other tenant concessions, broker’s
fees and tenant improvement costs. Within one (1) business day after Landlord’s
receipt of the Termination Payment, Landlord shall return to Tenant or at
Tenant’s direction that certain Irrevocable Standby Letter of Credit No.
SVBSF006100 dated December 4, 2009, in the amount of $1,896,206.75 (the “Letter
of Credit”), which is currently held by Landlord as an additional Security
Deposit.

5. Renewal Option. Tenant’s option to renew the Lease under Article 40 thereof
is null and void and of no further effect.

6. Mutual Releases. Conditioned upon and subject to payment by Tenant of the
Termination Payment return by Landlord of the Letter of Credit and payment by
Landlord to Tenant of the Reconciliation Payment described in Section 11 below,
Tenant hereby releases, remises and forever discharges Landlord from all debts,
demands, actions, causes of action, suits, accounts, covenants, contracts,
agreements, damages, and all claims and liabilities arising out of, connected
with or incidental to the Lease or the Premises, and Landlord hereby releases,
remises and forever discharges Tenant from all debts, demands, actions, causes
of action, suits, accounts, covenants, contracts, agreements, damages, and all
claims and liabilities arising out of, connected with or incidental to the Lease
or the Premises. Notwithstanding the foregoing, all indemnifications, covenants
and agreements given by either party under the terms and provisions contained in
the Lease which by their terms survive the termination of the Lease shall
survive the termination and are excluded from the releases contained in this
Section 6, except each party hereby waives any right to reconcile or otherwise
adjust for Taxes or Expenses pursuant to the terms contained in Article 4 of the
Lease, with Tenant’s waiver becoming effective only upon receipt by Tenant of
the Reconciliation Payment described in Section 11 below.

7. Authority. The individuals executing this Agreement hereby represent and
warrant that they are empowered and duly authorized to so execute this Agreement
on behalf of the parties they represent, that all required approvals and that
this Agreement constitutes the valid and binding obligation of Landlord or
Tenant, respectively.

8. Representation of Parties. Each party represents that it has not made any
assignment, sublease, transfer, conveyance, or other disposition of the Lease,
or interest in the Lease, or any claim, demand, obligation, liability, action,
or cause of action arising from the Lease.

9. Attorney’s Fees. If either party commences an action against the other party
arising out of or in connection with this Agreement, the prevailing party shall
be entitled to recover from the non-prevailing party reasonable attorney’s fees
and costs of suit.

10. Further Assurances. Each party agrees to cooperate with the other and to
execute and deliver all such further instruments and documents and do all such
further acts and things as such party may be reasonably requested to do from
time to time by the other party in order to carry out the provisions and
objectives of this Agreement.

 

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11. Waiver of Reconciliation for 2009 Taxes and Expenses. Within three (3) days
following the date upon which Tenant removes the Excluded Personal Property from
the Premises and repairs any damage caused thereby (but not before January 4,
2010), Landlord shall pay to Tenant the sum of Six Thousand Six Hundred Dollars
($6,600.00) (the “Reconciliation Payment”) in full satisfaction of the
reconciliation of Taxes and Expenses for calendar year 2009 that otherwise would
have been undertaken pursuant to the terms and provisions contained in Article 4
of the Lease had the Lease not been terminated. Landlord and Tenant acknowledge
and agree that the Reconciliation Payment is not a penalty to either party and
that it represents a fair and reasonable estimate of the amount which would have
been payable to Tenant had a reconciliation been undertaken in accordance with
the terms and provisions contained in Article 4 of the Lease.

12. Miscellaneous. This Agreement shall be deemed to have been executed and
delivered within and shall be governed by the laws of The Commonwealth of
Massachusetts. This Agreement is binding upon and shall inure to the benefit of
the parties hereto and their respective successors and permitted assigns. Each
party has cooperated in the drafting and preparation of this Agreement and,
therefore, in any construction to be made of this Agreement, the same shall not
be construed against either party. This Agreement may be executed in
counterparts, and when each party has signed and delivered at least one such
counterpart, each counterpart shall be deemed an original, and, when taken
together with other signed counterparts, shall constitute one Agreement, which
shall be binding upon and effective as to all parties. To facilitate the
execution and delivery of this Agreement, facsimile or other electronic
signatures shall have the same force as original ink signatures. This Agreement
may not be amended except by a written instrument signed by Landlord and Tenant.
In case any one or more of the provisions contained in this Agreement shall for
any reason be held to be invalid, illegal or unenforceable in any respect, such
invalidity, illegality, or unenforceability shall not affect any other provision
of this Agreement, and this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein.

 

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13. Limitation of Liability. Redress for any claim against Landlord under this
Agreement shall be limited to and enforceable only against and to the extent of
Landlord’s interest in the Building and the rents and profits therefrom, as well
as the Letter of Credit. Except for Landlord’s obligations to return the Letter
of Credit and make the Reconciliation Payment, the obligations of Landlord under
this Agreement are not intended to be and shall not be personally binding on,
nor shall any resort be had to any other properties of, any of its or its
investment manager’s trustees, directors, officers, partners, beneficiaries,
members, stockholders, employees, or agents, and in no case shall Landlord or
Tenant be liable to the other party hereunder for any lost profits, damage to
business, or any form of special, indirect or consequential damages.

EXECUTED as of the day and year first above written.

 

LANDLORD:

 

RREEF AMERICA REIT III-Z1 LLC

a Delaware limited liability company

By:   RREEF AMERICA LLC,   a Delaware limited liability company,   its
authorized agent   By:  

/s/ Robert D. Seaman

    Name:   Robert D. Seaman     Title:   Vice President — Asset Management

TENANT:  

SOAPSTONE NETWORKS INCORPORATED,

a Delaware corporation

By:  

/s/ William J. Stuart

  Name:   William J. Stuart   Title:   President

 

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EXHIBIT A

BILL OF SALE

For valuable consideration, the receipt and sufficiency of which are hereby
expressly acknowledged, SOAPSTONE NETWORKS, INC., a Delaware corporation
(hereinafter “Tenant”), hereby grants to RREEF AMERICA REIT III-Z1 LLC, a
Delaware limited liability company (hereinafter “Landlord”), the following
(collectively, the “Personal Property”):

All of Tenant’s right, title and interest (if any) in and to all of the
furniture, fixtures, equipment, machines, apparatus, supplies and personal
property, of every nature and description, belonging to Tenant and affixed to,
attached to, placed upon, within or used exclusively in connection with that
certain real estate commonly known as One Federal Street, Billerica,
Massachusetts, including, without limitation, any and all wall-to-wall
carpeting, loading dock door openers, blinds, window shades, screens, doors,
awnings, refrigerators, dishwashers, stoves, microwaves and other appliances,
heaters, heating and cooling equipment, hot water heaters, plumbing and bathroom
fixtures, electric and other lighting fixtures and antennas.

Notwithstanding the foregoing, excluded from the Personal Property are:
(a) certain written records of Tenant presently located in Iron Mountain storage
boxes; and (b) the personal effects located in the offices of Mr. William
Stuart, President, and Mr. James McMaster, Controller.

This Bill of Sale, and the conveyance contemplated hereby, is made without
warranty or representation of any kind, either express or implied, including
without limitation any warranties of title, quality, fitness for a particular
purpose, or merchantability; without limiting the generality of the foregoing
the Personal Property is sold AS IS.

By accepting this Bill of Sale, Landlord acknowledges and agrees that no
officer, director, trustee, employee, or representative of Tenant shall ever
have any personal liability under this Bill of Sale.

IN WITNESS WHEREOF, Tenant has caused this Bill of Sale to be signed and sealed
this 5th day of January, 2010.

 

SOAPSTONE NETWORKS INCORPORATED, a Delaware corporation By:  

/s/ William J. Stuart

  Name: William J. Stuart   Title: President