Exhibit 10.2  FIRST AMENDMENT TO LEASE  This
First Amendment to Lease (this Amendment) executed as of this 27thday of October, 2010, by and between Michelson
Farm-Westford Technology Park IV Limited Partnership, (hereinafter referred to
as Landlord), and Sonus Networks, Inc. (hereinafter referred to as Tenant).  RECITALS  WHEREAS,
by that certain Lease dated August 11, 2010 (hereinafter referred to as
the Lease), Landlord demised to Tenant certain Premises consisting of
approximately 80,000 rentable square feet of tenant space consisting of space
on the first and second floors of the existing building (the Building)
located on that certain parcel of real property known and numbered as 4
Technology Park Drive, Westford, Massachusetts and as more particularly
described in the Lease (the Property); and  WHEREAS,
Landlord and Tenant desire to amend the Lease to provide that Tenant shall
lease the entire Building so that the Premises shall now include the remaining
17,500 rentable square footage in the Building and to modify the tenant
improvement allowances provided by Landlord.  AGREEMENT  NOW,
THEREFORE, for valuable consideration, the receipt and sufficiency of which is
hereby acknowledged, Landlord and Tenant hereby agree as follows:  1.Section 1.1 of the
Lease is hereby amended by deleting all references to 80,000 in the current
definition for Premises and the Rentable Floor Area of the Premises, and by
replacing the same with the following 97,500.  2.Section 1.1 of the
Lease is hereby further amended by deleting the current definition for Tenants
Pro-Rata Share in its entirety, and replacing the same as follows:  Tenants Pro-Rata Share:100%.  3.Section 1.1 of the
Lease is hereby further amended by deleting the current definition for Fixed
Rent in its entirety, and by replacing the same with the following:  Months
  1-8:
  
  $0.00/RSF*Months
  9-44:
  
  $97,093.75/Month;
  $11.95/RSF*Months
  45-92:
  
  $110,093.75/Month;
  $13.55/RSF.


*See
Section 4.1, as amended by Section 12 of the First Amendment to
Lease, regarding rental abatement.  4.Section 1.1 of the
Lease is hereby further amended by deleting the current definition for Annual
Estimated Operating Costs For the Building in its entirety, and by replacing
the same with the following:  Landlords
actual Operating Costs for the previous calendar year ending December 31,
currently estimated at $3.30/RSF ($2.15/RSF area for common area maintenance
charges and $1.15/RSF for real estate taxes for calendar year 2010).  5.Exhibit A-1of the Lease
is hereby amended by deleting the current Exhibit A-1 Plan Showing
Premises and by replacing the same with the attached Exhibit A-1-1 Plan
Showing Premises.  All references in the
Lease to Exhibit A-1 shall now refer to Exhibit A-1-1.  6.Exhibit C of the Lease
is hereby amended by deleting the current Exhibit C Base Building
Improvements and by replacing the same with the attached Exhibit C-1
Base Building Improvements.  All
references in the Lease to Exhibit C shall now refer to Exhibit C-1.  7.Exhibits D-1 and D-2 of the
Lease are hereby amended by deleting the current Exhibit D-1 and Exhibit D-2,
and by replacing the same with the attached Exhibit D-1-1 Landlords
Services and Exhibit D-2-1 Tenants Services.  All references in the Lease to Exhibit D-1
and Exhibit D-2 shall now refer to Exhibit D-1-1 and Exhibit D-2-1,
respectively.  8.Exhibit M of the Lease
is hereby amended by adding the Amortization Table attached hereto as Exhibit M-1
as part of Exhibit M Early Termination Option.  9.Section 3.1(b) of
the Lease is deleted in its entirety and replaced with the following:  b.In addition, Landlord shall
cause certain leasehold improvements to be substantially completed in the
Premises in accordance with the Final Plans (as hereinafter defined), prior to
the Scheduled Term Commencement Date (the Tenants Work).  The Tenants Work shall include but  shall not be limited to the work to be
performed on the lab as well as the items shown on the Final Plans.  To accomplish the Tenants Work, the parties
agree that Landlord shall provide Tenant with an allowance of Two Million Four
Hundred Fifty Six Thousand Seven Hundred Fifty and 00/100 ($2,456,750.00)
Dollars (the Total Tenant Allowance). 
Tenant agrees to pay for the total Cost (as hereinafter defined) of the
Tenants Work that exceeds the Total Tenant Allowance within thirty (30) days
of receipt of an invoice from Landlord, which such invoice shall contain
reasonable backup documentation as may be reasonably requested by Tenant
(including an architects certificate confirming that the applicable work has
been completed).  The Total Tenant
Allowance shall be utilized by Landlord before any  2


excess
Cost, if any, shall be paid by Tenant as aforesaid, and may be utilized to pay
for plan preparation and revisions in connection with the Tenants Work.In the event that
any portion of the Total Tenant Allowance is not fully utilized directly for
the Tenants Work, such allowances may be used by Tenant towards other
improvements to the Premises, including but not limited to moving expenses,
infrastructure costs or other related furniture expenses, but in no event shall
Landlords reimbursement for non Tenants Work exceed $100,000.00, and any
excess amount of the Total Tenant Allowance shall be applied to Fixed Rent due
from Tenant.  In such case, Landlord
shall reimburse Tenant for such costs within fifteen (15) days after receipt of
an invoice for such work, which such invoice shall contain such reasonable
documentation evidencing Tenants out-of-pocket costs for such items as
reasonably requested by Landlord.  Additionally,
all references in the Lease to the Lab Upgrade Allowance and/or to the TI
Allowance, including without limitation in Section 3.1(h) and in Exhibit M
of the Lease, shall now refer to the Total Tenant Allowance.  10.Section 3.1(e) of
the Lease is hereby amended by deleting the following sentence in its entirety
in lines 5-8 thereof: The parties shall amend this Lease upon final
determination of the square footage of the Premises to reflect such correct
square footage and any applicable adjustments in the Fixed Rent, Tenants
Pro-Rata Share and other provisions of this Lease, as necessary.  The parties hereby acknowledge and agree that
the square footage of the Premises as set forth in this Amendment is correct
and accurate.  11.For purposes of deeming the
Premises Ready for Occupancy pursuant to Section 3.4 of the Lease and
commencing the Term pursuant to Section 2.2 of the Lease, and therefore
Tenants obligation to pay Fixed Rent pursuant to Section 4.1 of the
Lease, Landlord and Tenant hereby agree that the completion of the 17,500
rentable square feet of space in the Building assumed by Tenant under the terms
of this Amendment (the Additional Premises) shall not be a precondition for
such dates and/or conditions to have occurred and that the foregoing Lease
provisions shall continue to apply to the Premises (other than the Additional
Premises) for purposes establishing the same, all in accordance with the terms
and provisions of the Lease.  In
connection therewith, Landlord agrees to use diligent efforts to complete the
Tenant Improvement work in the Additional Premises, in accordance with and
subject to the provisions of Article III, except as otherwise set forth in
this Amendment, on or before February 15, 2011, as such date may be
extended due to Tenant Delays and/or Force Majeure (as more particularly set
forth in the Lease), provided that the Tenant Plans for the Additional Space
are delivered to Landlord by November 1, 2010.  12.Section 4.1(b) of
the Lease is hereby amended by (i) deleting the $5.50/RSF estimate in
line five thereof and replacing it with $3.30/RSF; and (ii) adding the
following sentence at the end of Section 4.1(b): Additionally, subject to
the preceding terms and conditions of this subparagraph (b), Tenant shall
receive an additional abatement of Fixed Rent on the Additional Premises until January 1,
2012.  3


13.Section 5.1.3 of the
Lease is hereby amended by deleting the existing Section and by replacing
the same with the following:  Repairs.  Except as
otherwise provided in Article 7 or in Exhibit D-1-1 or in Exhibit D-2-1,
to make such repairs to the roof, ceilings (to the extent there is any damage
as a result of leaks not caused by Tenant), windows, exterior walls, floor
slabs, structural components, exterior plumbing (including exterior water and
sewer lines), and exterior parking lots and parking lot lighting as may be
necessary to keep them in good and serviceable condition and in the condition
set forth in Section 5.1.5 below. 
Landlord shall also maintain in good order and condition the other buildings
and improvements located within the Park, including, but not limited to, the
Common Areas of the Park;  14.The penultimate sentence in
the first paragraph of Section 6.1.2 is hereby deleted in its entirety.  15.Tenant and Landlord warrant
and represent that they have not dealt with any brokers other than Cushman &
Wakefield of Massachusetts and The McCormick Company in connection with this
Amendment and the Lease.  16.Landlord and Tenant hereby
further agree that Landlord shall replace three (3) roof top HVAC units at
the Building, and the cost thereof shall be reasonably amortized by Landlord
over the useful life of such units in accordance with generally accepted
accounting principles, pursuant to the provisions of Section 4.2(b) of
the Lease; and in connection therewith, Tenant shall pay its Pro-Rata Share
thereof as an Operating Cost in accordance with Section 4.2 of the Lease,
specifically subparagraph (f) thereof.  17.This Amendment may be
executed in two (2) or more counterparts, each of which shall be an
original but such counterparts together shall constitute one (1) and the
same instrument notwithstanding that both Landlord and Tenant are not
signatories to the same counterpart.  The
parties agree that facsimile copies of this Amendment, bearing their respective
signatures, shall be enforceable as originals.  18.This Amendment shall be
binding on and inure to the benefit of the subsequent assignees of Landlord and
Tenant.  19.All capitalized terms as
used herein, but not defined herein, shall have the same meaning ascribed to
them in the Lease.  20.Except as amended by this
Amendment, all other terms, conditions, covenants and provisions as appear in
the Lease are hereby ratified and confirmed and shall remain unchanged.  [Signature Page Follows]  4


EXECUTED as of the day and
year first written above.   LANDLORD:MICHELSON FARM-WESTFORDTECHNOLOGY PARK IV LIMITEDPARTNERSHIPBY:
  THE GUTIERREZ COMPANY,ITS SOLE GENERAL PARTNERBy:
  /s/ Gloria M. GutierrezGloria M. GutierrezExecutive Vice President
  and Corporate CounselTENANT:SONUS NETWORKS, INC.By:
  /s/ Wayne PastoreName:
  Wayne PastoreTitle:
  Senior Vice President andChief Financial Officer,Hereunto Duly Authorized  5


EXHIBIT A-1-1 PLAN SHOWING PREMISES (ATTACHED)  6


EXHIBIT C-1 BASE BUILDING IMPROVEMENT  Landlord agrees to perform
the following base building work:  ·Landlord will deliver all
mechanical, HVAC, plumbing, life safety, elevators and electrical equipment in
good working order; ·Landlord will add enclosed
weather separation vestibule at entrance to the Building; ·Landlord will add a canopy
at the front entry curtainwall of the Building; ·Landlord will replace the
floor tile with new tile and stair service with carpet at the rear stair
vestibule; ·Landlord and Tenant to
mutually agree to selective landscape trimming and Landlord to provide such
landscape trimming; ·Landlord shall relocate
existing flagpole to a location approved by Tenant; ·Landlord to remove existing
mobile and replace with pendant lighting and other access lighting in the
Building lobby; ·Landlord shall remove
existing revolving door and replace with one pair of doors, along with a
vestibule; ·Landlord shall paint
existing exterior lobby curtainwall system and adjacent window elevations; ·Landlord shall replace glass
in lobby curtainwall to match adjacent building; ·Landlord shall furnish and
install one new glass tenant entry in Building lobby ; ·Landlord shall remove
outdoor brick seating area and replace with loam and grass; ·Landlord shall remove metal
railings at the second floor lobby and replace with glass rail; ·Landlord shall remove
existing lobby tile and replace with 24x 24 ceramic tile similar to 6
Technology Park Drive; ·Landlord shall paint lobby
area in a color approved by Tenant from Landlords standard color selections,
not to be unreasonably withheld or delayed by Tenant; ·Landlord shall remove the
shed located behind the Building by the loading dock; ·Landlord shall provide an
additional, separate credit in the amount of Thirty Five Thousand and 00/100
($35,000.00) Dollars in lieu of performance upgrades to the main lobby
stairs.  Tenant may utilize this credit
for alterations to the Premises, including but not limited to Tenants Work or
other tenant improvements; and ·Landlord will supply and
install three (3) new roof top air conditioning units and perform all
maintenance required on the existing three (3) RTUs and deliver to Tenant
such units in good working order.  All
work required for installing new RTUs will be performed during off-hours to
avoid disruption of business to the Tenant.  For clarity, the cost of the
services noted in this Exhibit C shall not be included in the Total Tenant
Allowance.  7


EXHIBIT D-1-1  LANDLORDS SERVICES  The Landlord shall provide
the following services:  [SEE SECTION 4.2
AND ARTICLE 5]  8


EXHIBIT D-2-1 TENANTS SERVICES  The Tenant shall provide the
following services pursuant to, and subject to, the provisions of Section 6.1.2
of the Lease:  I.CLEANING  Tenant shall be responsible
for securing janitorial service for the Premises, at such times and with such
services that are consistent with other class A office and laboratory buildings
in the Merrimack Valley area.  II.HEATING, VENTILATING AND AIR
CONDITIONING  1.Tenant shall control and be
responsible for heating, ventilation and air conditioning (HVAC) to the
Premises and the Building.  Landlord
represents and warrants that the HVAC equipment is in good working order and
that it will provide adequate service to the Building and to the Premises and
is able to provide reasonably comfortable temperatures for normal occupancy.  2.intentionally deleted  3.Maintenance on any additional
or special air conditioning equipment owned or installed by Tenant for
exclusive service to the Premises, and the associated operating cost thereof,
will be at Tenants expense.  4.Tenant shall control and
maintain all of the Building systems, including but not limited to the HVAC,
elevators, electrical, fire safety, sprinkler, water and the life safety
systems as set forth in this Exhibit D-2.  III.ELEVATORS  Elevators,
including programming of elevators (including, but not limited to, service elevators),
shall be as Tenant from time to time determines best for the Building as a
whole, taking into account reasonable recommendations from Landlord.  The elevators shall operate 24 hours per day,
7 days per week, subject to repairs, failures and interrupted service beyond
Tenants control.  IV.SECURITY/ACCESS  Twenty-four
(24) hour entry to the Building and Premises is available to Tenant and Tenants
employees.  Tenant shall have
unrestricted access to its Premises at all times, and not just during normal
building hours and operation.  All
security  shall be the  9


responsibility
of the Tenant.  Tenant shall  install its own interior and exterior
security card or electronic keypad access system for the Building.  Tenant shall control keying for perimeter
exterior doors of the Building, as well as mechanical, electrical and sprinkler
rooms, and Tenant shall provide Landlord with access to  such areas. 
Tenant shall provide  the Westford
Fire Department with keys and access cards to be placed in the knox box to the
Premises.  V.CAFETERIA,
VENDING AND PLUMBING INSTALLATIONS/INTERIOR LAVATORIES AND SHOWERS  1.Any space to be
used primarily for lunchroom or cafeteria operation within the Premises shall
be Tenants responsibility to keep clean and sanitary.    All maintenance, repairs and additional
cleaning necessitated by such installations shall be at Tenants expense.  2.Tenant is
responsible for the maintenance and repair of plumbing fixtures and related equipment
installed in the Premises for its exclusive use (such as in coffee room).  3.All lavatories
and showers located within the Premises 
shall be Tenants responsibility to maintain, repair and clean.  At Tenants request, Landlord shall perform
the same at reasonable and competitive rates from time to time established by
Landlord to be paid by Tenant.  VI.SIGNAGE  Tenant
shall be entitled to the Buildings standard signage at Tenants main entry and
on the Buildings lobby directories, as well as monument style signage at the
Building.See
also Section 6.1.18 of the Lease regarding signage on the exterior of the
Building and other signage related provisions.  VII.ELECTRICITY  1.Tenant shall pay for all
electricity consumed in the Building. 
Tenant shall pay for such consumption directly to the provider of such
electricity.  2.Tenants use of electrical
service in the Premises shall not at any time exceed the capacity of any of the
electrical conductors or other equipment in or otherwise serving the Premises
or the Building standard, as hereinafter provided.  To ensure that such capacity is not exceeded
and to avert possible adverse effects upon the Buildings electrical system,
Tenant shall not, without at least thirty (30) days prior written notice to and
consent of Landlord in each instance and compliance with the alteration section
of this Lease, connect to the Building electric distribution system any
fixtures, appliances or equipment which operates on a voltage in excess of
277/480 volts nominal, or make any alteration or addition to the electric
system of the Premises.  In the event
Tenant shall use (or request that it be allowed to use) electrical service in
excess of that deemed by Landlord to be standard for the Building, Landlord may
refuse to provide such excess  10


usage
or refuse to consent to such usage or may consent upon such conditions as
Landlord reasonably elects (including, but not limited to, the installation of
utility service upgrades, air handlers or cooling units), and all such
additional usage (except to the extent prohibited by law), installation and
maintenance thereof shall be paid for by Tenant,  upon Landlords demand.  3.It is understood that the
electrical generated service to the Premises may be furnished by one or more
generators of electrical power and that the cost of electricity may be billed
as a single charge or divided into and billed in a variety of categories, such
as distribution charges, transmission charges, generation charges, congestion
charges, capacity charges, public good charges, and other similar categories,
and that Tenant shall not be responsible for any fee, commission or other
charge by an unaffiliated broker, aggregator or other intermediary for obtaining
or arranging the supply of generated electricity.  Landlord shall have the right to select the
generator of electricity to the Premises and the Building and to purchase
generated electricity for the Premises and the entire Building through a broker,
aggregator or other intermediary and/or buyers group or other group and to
change the generator of electricity and/or manner of purchasing electricity
from time to time.  4.If Landlord successfully
undertakes electrical generation activities for the purpose of reducing Tenants
electrical related operating costs (such as negotiating an agreement with a
utility or another energy generator or engaging an energy consultant or undertaking
conservation or other energy efficient measures that may require capital
expenditures), Tenant shall pay its proportionate share of such electric
related increases with respect to Landlords electrical generator activities
hereunder, however, such amount shall in no event exceed 10% of the prior years
Operating Costs.  In no event shall the
foregoing be a cap on actual electrical utility charges payable by Tenant
hereunder.  In no event shall Tenant pay
for capital expenditures related to such electrical generation activities,
either directly or through a Landlord Operating Cost charge.  5.As used herein, the term generator
of electricity shall mean one or more companies (including, but not limited
to, an electric utility, generator, independent or non-regulated company) that
provides generated power to the Building, Premises or to the Landlord to be
provided to the Premises, as the case may be.  VIII.OTHER UTILITIES  Tenant
shall be responsible for the payment of all other utilities consumed by Tenant
in the Premises, including water, telephone, cable, and other
communications.  Tenant shall pay for
such consumption directly to the provider of such utilities.  11


IX.LIFE SAFETY  Tenant
shall control and maintain, in good order and repair and in compliance with all
applicable laws and codes, the fire extinguishers for the Premises and the fire
suppression system for the Premises.  12


EXHIBIT M-1 AMORTIZATION TABLE  SONUS TERMINATION FEE   Tenant Improvements
  
  $
  2,456,750.00Commissions·
  Cushman &
  Wakefield
  
  682,500.00·
  Cushman &
  Wakefield
  
  143,592.00·
  Jones
  Lang LaSalle
  
  380,000.00Fixed Rent
  
  776,750.00TRANSACTION COSTS
  
  $
  4,339,592.00
  @
  6.5%= SEE ATTACHED SCHEDULE
  
  $
  746,733.95Plus 2 months rent
  
  220,187.50TERMINATION FEE
  
  $
  966,921.45  13