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                                                                   Exhibit 10.18


                       235 LITTLETON ROAD ASSOCIATES, INC.
                               222 LITTLETON ROAD
                               WESTFORD, MA 01886


                                COMMERCIAL LEASE


1.   PARTIES

LESSOR, which expression shall include 235 LITTLETON ROAD ASSOCIATES, INC., 222
LITTLETON ROAD, WESTFORD, MA 01886 heirs, successors, and assigns where the
context so admits, does hereby lease to LESSEE, which expression shall include
UNISPHERE SOLUTIONS, INC., 5 CARLISLE ROAD, WESTFORD, MA 01886 successors,
executors, administrators, and assigns where the context so admits, and the
LESSEE hereby leases the following described premises:

2.   PREMISES

UNITS 1, 2, 3, 4 & 5 (CONTAINING APPROXIMATELY 13,929 SQUARE FEET) AT 235
LITTLETON ROAD IN WESTFORD, MA together with the right to use in common, with
others entitled thereto, the hallways, stairways, and elevators, necessary for
access to said leased premises, and lavatories thereto. The Lessee shall have
the right to use their proportionate number of parking spaces based on square
footage.

3.   TERM

The term of this lease shall be for THREE (3) YEARS commencing on JANUARY 15,
2000 and ending on JANUARY 14, 2003. The Lessee shall have one (1) three (3)
year renewal option with six (6) months prior written notice. The renewal option
rate shall be at current market rate.

4.   RENT

The LESSEE shall pay to the LESSOR rent at a rate of: $20,022.94 PER MONTH
($240,275.25 PER YEAR), payable in advance in monthly installments of
$20,022.94.

5.   SECURITY DEPOSIT

Upon the execution of this lease, the LESSEE shall pay to the LESSOR the amount
of $20,022.94 dollars, which shall be held as a security for the LESSEE'S
performance as herein provided and refunded to the LESSEE at the end of this
lease subject to the LESSEE'S satisfactory compliance with the conditions
hereof.

6.   RENT ADJUSTMENT

If in any tax year commencing with the fiscal year 2001, the real estate taxes
on the land and buildings, of which the leases premises are a part, are in
excess of the amount of the real estate taxes thereon for the fiscal year 2000
(hereinafter called the "Base Year"), LESSEE will pay to LESSOR as additional
rent hereunder, when and as designated by notice in writing by LESSOR, 100 per
cent of the Lessee's proportionate share of such excess that may occur in each
year of the term of this lease or any extension or renewal thereof and
proportionately for any part of a fiscal year.


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7.   UTILITIES

The LESSEE shall pay, as they become due, all bills for electricity and other
utilities (whether they are used for furnishing heat or other purposes) that are
furnished to the leased premises and presently separately metered, and all bills
for fuel furnished to a separate tank servicing the leased premises exclusively.

Lessor shall have no obligation to provide utilities or equipment other than the
utilities and equipment within the premises as of the commencement date of this
lease. In the event LESSEE requires additional utilities or equipment, the
installation and maintenance thereof shall be the LESSEE'S sole obligation,
provided that such installation shall be subject to the written consent of the
LESSOR.

8.   USE OF LEASED PREMISES

The LESSEE shall use the leased premises only for the purpose of: OFFICE SPACE.

9.   COMPLIANCE WITH LAWS

The LESSEE acknowledges that no trade or occupation shall be conducted in the
leased premises or use made thereof which will be unlawful, improper, noisy or
offensive, or contrary to any law or any municipal by-law or ordinance in force
in the city or town in which the premises are situated.

10.  FIRE INSURANCE

The LESSEE shall not permit any use of the leased premises which will make
voidable any insurance on the property of which the leased premises are a part,
or on the contents of said property or which shall be contrary to any law or
regulation from time to time established by the New England Fire Insurance
Rating Association, or any similar body succeeding to its powers. The LESSEE
shall on demand reimburse the LESSOR, and all other tenants, all extra insurance
premiums caused by the LESSEE'S use of the premises, not contemplated by this
lease or as a result of any use contrary to any law or regulation.

11.  MAINTENANCE

A.   LESSEE'S OBLIGATIONS

The LESSEE agrees to maintain the leased premises in the same condition as it is
at the commencement of the term or as it may be put in during the term of this
lease, damage by fire and other casualty, and normal wear and tear only
expected, and whenever necessary, to replace light bulbs, plate glass and other
glass therein, acknowledging that the leased premises are now in good order and
the glass whole. The LESSEE shall not permit the leased premises to be
overloaded, damaged, stripped, or defaced, nor suffer any waste. LESSEE shall
obtain written consent of LESSOR before erecting any sign on the premises.

B.   LESSOR'S OBLIGATIONS

The LESSOR agrees to maintain the structure of the building of which the leased
premises are a part in the same condition as it is at the commencement of the
term or as it may be put in during the term of this lease, reasonable wear and
tear, damage by fire and other casualty only excepted, unless such maintenance
is required because of the LESSEE or those for whose conduct the LESSEE is
legally responsible.

12.  ALTERATIONS-ADDITIONS

The LESSEE shall not make any alterations or additions the leased premises
without the written consent of the LESSOR. All such allowed alterations shall be
with written consent and at LESSEE'S expense and shall be in quality at least
equal to the present construction. LESSEE shall not permit any mechanic's


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liens, or similar liens, to remain upon the leased premises for labor and
material furnished to LESSEE or claimed to have been furnished to LESSEE in
connection with work of any character performed or claimed to have been
performed at the direction of LESSEE and shall cause any such lien to be
released of record forthwith without cost to LESSOR. Any alterations or
improvements made by the LESSEE shall become the property of the LESSOR at the
termination of occupancy as provided herein.

13.  ASSIGNMENTS-SUBLEASING

The LESSEE shall not assign or sublet the whole or any part of the leased
premises without the LESSOR'S prior written consent which shall not be
unreasonably withheld. Notwithstanding such consent, LESSEE shall remain liable
to LESSOR for the payment of all rent and for the full performance of the
covenants and conditions of this lease.

14.  SUBORDINATION

This lease shall be subject to any and all mortgages, deeds of trust and other
instruments in the nature of a mortgage, now or at any time hereafter, a lien or
liens on the property of which the leased premises are a part and the LESSEE
shall, when requested, promptly execute and deliver such written instruments as
shall be necessary to show the subordination of this lease to said mortgages,
deeds of trust or other such instruments in the nature of a mortgage.

15.  LESSOR'S ACCESS

The LESSOR or agents of the LESSOR may, at reasonable times and for reasonable
cause, enter to view the leased premises and may remove placards and signs not
approved and affixed as herein provided, and make repairs and alterations as
LESSOR should elect to do and may show the leased premises to others, and at any
time within three (3) months before the expiration of the term, may affix to any
suitable part of the leased premises a notice for letting the or selling the
leased premises or property of which the leased premises are a part and keep the
same so affixed without hindrance or molestation. The LESSOR and or Lessor's
agent will retain keys to the leased premises to enable access in the event of
an urgent situation, in such situation the Lessee agrees to wave all advance
notice requirements but will be notified as soon as possible.

16.  INDEMNIFICATION AND LIABILITY

The LESSEE shall save the LESSOR harmless from all loss and damage occasioned by
the use or escape of water or by the bursting of pipes within the leased
premises, or by any nuisance made or suffered on the leased premises, unless
such loss is caused by the neglect of the LESSOR. The removal of snow and ice
from the sidewalks bordering upon the leased premises shall be 235 LITTLETON
ROAD ASSOCIATES, INC. responsibility.

17.  LESSEE'S LIABILITY INSURANCE

The LESSEE shall maintain with respect to the leased premises and the property
of which the leased premises are a part comprehensive public liability insurance
in the amount of $1,000,000.00 with property damage insurance in limits of
$500,000.00 and fire legal liability insurance in the amount of $500,000.00 in
responsible companies qualified to do business in Massachusetts and in good
standing therein insuring the LESSOR as well as LESSEE against injury to persons
or damage to property as provided. The LESSEE shall deposit with the LESSOR
certificates for such insurance at or prior to the commencement of the term, and
thereafter within thirty (30) days prior to the expiration of any such policies.
All such insurance certificates shall provide that such policies shall not be
cancelled without at least ten (10) days prior written notice to each assured
named therein.


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18.  FIRE, CASUALTY - EMINENT DOMAIN

Should a substantial portion of the leased premises, or of the property of which
they are a part, be substantially damaged by fire or other casualty, or be taken
by eminent domain, the LESSOR may elect to terminate this lease. When such fire,
casualty, or taking renders the leased premises substantially unsuitable for
their intended use, a just and proportionate abatement of rent shall be made,
and the LESSEE may elect to terminate this lease if:

     (a)  The LESSOR fails to give written notice within thirty (30) days of
          intention to restore leased premises, or

     (b)  The LESSOR fails to restore the leased premises to a condition
          substantially suitable for their intended use within ninety (90) days
          of said fire, casualty or taking.

The LESSOR reserves, and the LESSEE grants to the LESSOR, all rights which the
LESSEE may have for damages or injury to the leased premises for any taking by
eminent domain, except for damage to the LESSEE'S fixtures, property, or
equipment.

19.  DEFAULT AND BANKRUPTCY

In the event that:

     (a)  The LESSEE shall default in the payment of any installment of rent or
          other sum herein specified; or
     (b)  The LESSEE shall default in the observance or performance of any other
          of the LESSEE'S covenants, agreements, or obligations hereunder; or
     (c)  The LESSEE shall be declared bankrupt or insolvent according to law,
          or, if any assignment shall be made of LESSEE'S property for the
          benefit of creditors,

then the LESSOR shall have the right thereafter, to re-enter and take complete
possession of the leased premises, to declare the term of this lease ended, and
remove the LESSEE'S effects, without prejudice to any remedies which might be
otherwise used for arrears of rent of other default. The LESSEE shall indemnify
the LESSOR against all loss of rent and other payments which the LESSOR may
incur by reason of such termination during the residue of the term. If the
LESSEE shall default, in the observance or performance of any conditions or
covenants on LESSEE'S part to be observed or performed under or by virtue of any
of the provisions in any article of this lease, the LESSOR, without being under
any obligation to do so and without thereby waiving such default, may remedy
such default for the account and at the expense of the LESSEE. If the LESSOR
makes any reasonable and customary expenditures in connection therewith,
including but not limited to, attorney's fees in instituting, prosecuting or
defending any action or proceeding, such sums paid or obligations insured, with
interest at the rate of 10 percent per annum and costs, shall be paid to the
LESSOR by the LESSEE as additional rent.

20.  NOTICE

Any notice from the LESSOR to the LESSEE relating to the leased premises or to
the occupancy thereof, shall be deemed duty served, if hand delivered to the
leased premises by the LESSOR or LESSORS agent, or if mailed to the leased
premises, registered or certified mail, return receipt requested, postage
prepaid, addressed to the LESSEE. Any notice from the LESSEE to the LESSOR
relating to the leased premises or to the occupancy thereof, shall be deemed
duly served, if mailed to the LESSOR by registered or certified mail, return
receipt requested, postage prepaid, addressed to the LESSOR at such address as
the LESSOR may from time to time advise in writing. All rent notices shall be
paid and sent to the LESSOR at 222 LITTLETON ROAD, WESTFORD, MA 01886.


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21.  SURRENDER

The LESSEE shall at the expiration or other termination of this lease remove all
LESSEE'S goods and effects from the leased premises, (including, without hereby
limiting the generality of the foregoing, all signs and lettering affixed or
painted by the LESSEE, either inside or outside the leased premises). LESSEE
shall deliver to the LESSOR the leased premises and all keys, locks thereto, and
other fixtures connected therewith and all alterations and additions made to or
upon the leased premises, in good condition, damage by fire or other casualty
only excepted. In the event of the LESSEE'S failure to remove any of the
LESSEE'S property from the premises, LESSOR is hereby authorized, without
liability to LESSEE for loss or damage thereto, and at the sole risk of LESSEE,
to remove and store any of the property at the LESSEE'S expense, or to retain
same under LESSOR'S control or to sell at public or private sale, without notice
any or all of the property not so removed and to apply the net proceeds of such
sale to the payment of any sum due hereunder, or to destroy such property.

22.  OTHER PROVISIONS

It is also understood and agreed that: THE LESSEE SHALL HAVE ACCESS TO LEASED
UNITS FROM DECEMBER 15, 1999 THROUGH JANUARY 14, 2000 SPECIFICALLY FOR THE
PURPOSE OF WORKING ON TENANT IMPROVEMENTS. PRIOR TO STARTING ANY TENANT
IMPROVEMENTS THE LESSEE SHALL PROVIDE THE LESSOR WITH SATISFACTORY PROOF OF ALL
INSURANCE REQUIRED BY THIS LEASE AND SATISFACTORY PROOF OF INSURANCE FOR ALL
CONTRACTORS OR SUB CONTRACTORS WORKING FOR THE LESSEE. THE LESSEE AGREES TO PAY
TO THE LESSOR 82% OF THE ACTUAL DUMPSTER FEES FOR THE BUILDING, WHICH WILL BE
BILLED EVERY THREE MONTHS BY THE LESSOR. THE LESSEE WILL HAVE THE OPTION, AS AN
ALTERNATIVE TO THE ABOVE, TO SUPPLY AND PAY FOR THEIR OWN DUMPSTER SERVICE
PROVIDED THAT THE LESSEE IS GIVEN 60 DAYS NOTICE AND THAT THE LESSEE'S CONTAINER
IS PLACED NEXT TO THE LESSOR'S.




IN WITNESS WHEREOF, the said Parties hereunto set their hands and seals this
15th day of December, 1999.



/s/ Robert T. Curtin                          /s/ Richard W. Lewis
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LESSEE Unisphere Solutions, Inc.              LESSOR Richard W. Lewis, President
      By: Robert T. Curtin
          Controller

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LESSEE                                        LESSOR