<PAGE>

                              SUBLEASE AGREEMENT


DATE OF THIS SUBLEASE:

INCORPORATION BY REFERENCE: The terms and conditions of this Sublease shall
                          include various Sections of the Over-Lease, which are
                          incorporated into this Sublease as if fully set forth,
                          except that: (i) each reference to the "Premises"
                          shall be deemed a reference to the "Subleased
                          Premises"; (ii) each reference to "Landlord" and
                          "Tenant" shall be deemed a reference to "Over-Tenant"
                          and "Under-Tenant", respectively (except as expressly
                          set forth below) and (iii) with respect to work,
                          services, repairs, restoration, the provision of
                          insurance or the performance of any other
                          obligation of Landlord under the Over-Lease,
                          Over-Tenant shall use diligent good faith efforts
                          to obtain Landlord's performance of such
                          obligations on Under-Tenant's behalf.

PARTIES TO THIS           Over-Tenant:             Olicom, Inc.
SUBLEASE:                 Address for notices:     1680 North Prospect Drive
                                                   Richardson, TX 75081

                          You, the Under-Tenant:   Sonoma Systems, Inc.
                          Address for notices:     4640 Admiralty Way, 6th Floor
                                                   Marina Del Rey, CA 90292-6695



INFORMATION FROM          Landlord:                Telegraph Properties, Inc.
OVER-LEASE:               Address for Notices:

                          Date of Over-Lease:      April 30, 1992 as amended
                                                   January 15, 1993 (First
                                                   Amendment) and August 27,
                                                   1997 (Second Amendment)

                          Term of Over-Lease:      From: July 1, 1992
                                                   To:  December 31, 2002

                          A copy of the Over-Lease is attached as an important
                          part of the Sublease.

SUBLEASE TERM:            1. Beginning: December 1, 1998
                             Ending: December 31, 2002


PREMISES RENTED           2. Premises with appurtenances of the Over-Lease to be
                          leased by Over-Tenant of approximately 21,472 sq.
                          ft., subject to the rent provision contained herein.


USE OF PREMISES:          3. The premises will be used for general office use
                          with manufacturing, sales, marketing and research and
                          development.  Nothing contained herein is contrary to
                          the use allowed in the Over-Lease.


RENT:                     4. Under-Tenant shall pay to Over-Tenant without
                          notice, set-off, or deduction of any kind, Annual Base
                          rent, Annual Estimated Operating Costs and Annual
                          Improvements Rent, if any, (collectively "Annual
                          Rent") when and as required to be paid by Over-Tenant
                          to Landlord under the Over-Lease, applicable to the
                          Premises.  Under-Tenant shall pay Annual Rent in the
                          required amount, from December 1, 1998 to January 31,
                          1999, for only 15,000 sq. ft. Effective February 1,
                          1999 through the end of the term of this Sublease,
                          Under-Tenant


                                       1
<PAGE>

                          shall pay Annual Rent for 21,472 sq. ft as and when
                          required to be paid by Over-Tenant to Landlord under
                          the Over-Lease.

UTILITIES AND OPERATING
COSTS:                    5. Under-Tenant shall be billed by the Over-Tenant for
                          its share of the monthly utilities and operating costs
                          of the entire building, and shall pay for such within
                          twenty (20) days of receipt of an invoice from
                          Over-Tenant.  Failure of Under-Tenant to pay said
                          invoice within twenty (20) days of receipt of invoice
                          shall be considered a default under this Sublease, and
                          Over-Tenant may take the same action for this default
                          as described for a default within the Overlease.
                          Under-Tenant shall be billed based upon the space
                          occupied by it, which has been calculated at
                          thirty-six (36%) percent.


SECURITY:                 6. The security for the Under-Tenant's performance is
                          NONE


AGREEMENT TO LEASE        7. Over-Tenant sublets the Premises to you, the
AND PAY RENT:             Under-Tenant, for the Term.  Over-Tenant states that
                          it has the authority to do so.  You, the Under-Tenant
                          agree to pay the Rent and other charges as required in
                          the Sub-Lease to the Over-Tenant.  You, the
                          Under-Tenant, agree to do everything required of you
                          in this Sub-Lease.


NOTICES:                  8. Any notice, request or demand ("Notice") permitted
                          or required to be given by the terms and provisions of
                          this Sublease, or by any law or government regulation,
                          either by Over-Tenant to Under-Tenant or by government
                          regulation, either by Over-tenant to Under-Tenant or
                          by Under-Tenant to Over-Tenant shall be effective only
                          if given in writing and personally delivered or, if
                          not personally delivered, if sent by registered or
                          certified mail or express mail or overnight express
                          delivery service to the addresses of the responsive
                          parties set forth on page 1 hereof.  Any such notice,
                          shall be deemed to have been rendered or given (I) if
                          sent by registered or certified mail, on the day it is
                          officially recorded as delivered to or refused by the
                          intended recipient by return receipt or equivalent,
                          and in the absence of such record of delivery, the
                          effective date shall be presumed to have been the
                          third (3rd) business day after the date when it shall
                          have been deposited in the mail as provided in this
                          Section, (II) if sent by express mail or other
                          overnight mail service carrier, on the date it is
                          officially recorded by the express mail service
                          carrier as delivered to the intended recipient or
                          (III) if delivered personally, or by expedited
                          messenger service, upon receipt.  Any party or other
                          person, may, by notice as aforesaid, designate a
                          different address for service of Notice upon it.


SUBJECT TO:               9. The Sublease is subject to the Over-Lease as it
                          applies to the Premises.  It is also subject to any
                          agreement to which the Over-Lease is subject as it
                          applies to the Premises.  You, the Under-Tenant, state
                          that you have read and initialed the Over-Lease and
                          will not violate it in any way.


UNDER-TENANT'S DUTIES AND
RIGHTS:                   10. The Over-Lease describes the Landlord's duties.
                          The Over-Tenant is not obligated to perform the
                          Landlord's duties. If the Landlord fails to perform,
                          you, the Under-Tenant, must notify the Over-Tenant of
                          the Landlord's failure to perform pursuant to the
                          Over-Lease. Under-Tenant shall indemnify the
                          Over-tenant of its actual costs incurred, including
                          reasonable attorney fees, if Under-Tenant stores
                          hazardous materials on the Premises in violation of
                          the Over-Lease. If only the Over-Tenant is in default
                          of the Over-Lease whereas it causes the Under-Tenant
                          to be actually physically evicted from the Premises by
                          legal action of the Landlord, the Over-Tenant shall
                          indemnify the Under-Tenant for its reasonable out of
                          pocket expenses, limited to: (1) reasonable attorney
                          fees, (2) the reasonable moving expenses of
                          Under-Tenant's property from the Premises to a
                          location within a thirty mile radius of the Premises,
                          and (3) the reasonable cost difference between the
                          Annual Rent of the Premises and the


                                       2
<PAGE>

                          Annual Rent of a similar class building of equal
                          square footage and amenities for the remaining term
                          length under this Sublease. If the default of the
                          Over-Tenant is caused by the Under-Tenant, then the
                          Over-Tenant shall not be liable for any expenses or
                          costs attributable to the Landlord taking legal
                          action thereby evicting the Under-Tenant.
                          Under-Tenant shall have all the rights available to
                          it at law or equity, except as specifically set out
                          herein, in the event of breach of any provisions of
                          this Sublease by the Over-Tenant.

OVER-TENANT'S DUTIES AND
RIGHTS:                   11. Over-Tenant declares, warrants, and covenants that
                          Over-Tenant shall not be in default of the Over-Lease
                          as of the beginning of the term of this Sublease.
                          Over-Tenant shall not enter into any agreements with
                          Landlord to terminate or amend the Over-Lease.
                          Over-Lease shall deliver to Under-Tenant copies of all
                          notices received form Landlord. Over-Tenant is unaware
                          of any hazardous materials, in violation of the
                          Over-Lease, on the Subleased Premises. Over-Tenant
                          shall indemnify the Under-tenant for its actual costs
                          incurred, including reasonable attorney fees, if
                          Over-Tenant stores hazardous materials on the Premises
                          in violation of the Over-Lease, and such violation
                          causes Under-Tenant to be evicted from the Premises
                          prior to the end of the term of this Sublease.
                          Over-Tenant covenants that it has had no notice of any
                          condemnation action pursuant to an action based upon
                          eminent domain. In the event the Under-Tenant defaults
                          under any of the terms, covenants, conditions or
                          agreements hereunder, Over-Tenant shall have the same
                          rights and remedies as the Landlord has in the event
                          of a default under the Over-Lease to the same extent
                          as if same were specifically set forth herein at
                          length with the following changes:
                          PARAGRAPH 9.1.: ten (10) days in line 3 shall be
                          amended to seven (7) days; thirty (30) days shall be
                          amended to twenty (20) days in lines 4 and 7; sixty
                          (60) days in line 13 shall be amended to fifty (50)
                          days. Over-Tenant shall have all the rights available
                          to it at law or equity, except as specifically set out
                          herein, in the event of breach of any provisions of
                          this Sublease by the Under-Tenant.


ADOPTING THE              12. The provisions of the Over-Lease are part of this
OVER-LEASE AND            Sublease. All the provisions of the Over-Lease
EXCEPTIONS:               applying to the Over-Tenant are binding on you, the
                          Under-Tenant, except these:

                          a)    These numbered paragraphs, as described by their
                                headings, of the Over-Lease shall not apply:

                                3.1 and 3.1.A-Initial Construction
                                3.2. and 3.2.A-Preparation of Premises for
                                  Occupancy
                                4.1.-only second sentence-Rent
                                8.1. to 8.7.-Rights of Mortgage
                                10.4-all text after first sentence-Bind and
                                  Inure
                                10.13
                                Exhibit D
                                Exhibit E
                                Paragraph 9 of the 1st Amendment
                                Paragraph 10 of the 1st Amendment
                                Paragraph 4 of the Second Amendment-Tenant
                                  Improvements
                                Paragraph 7 of the Second Amendment-Extension
                                  Time
                                Paragraph 8 of the Second Amendment


NO AUTHORITY:             13. You, the Under-Tenant, have no authority to make
                          any agreement with the Landlord.

SUCCESSORS:               14. Unless otherwise stated, this Sublease is binding
                          on all parties who lawfully succeed to the rights or
                          take the place of the Over-Tenant or you, the Under-


                                       3
<PAGE>

                          Tenant. Examples of this are a successor corporation
                          as a result of a merger or consolidation, or an heir.


CHANGES:                  15. This Sublease can be changed only by an agreement
                          in writing signed by all parties to this Sublease.


SIGNATURES:



Witnesses:                                  OVER-TENANT: OLICOM, INC.


                                            /s/ [ILLEGIBLE]
---------------------------------------     -----------------------------------

                                            Director of Finance & Admin.
---------------------------------------     -----------------------------------




Witnesses:                           You, the UNDER-TENANT: SONOMA SYSTEMS, INC.


                                            /s/ Steve M. Waszak
---------------------------------------     -----------------------------------

                                            Vice President, Finance
                                            and Operations
---------------------------------------     -----------------------------------

                                            Date: December 1, 1998






                                       4

<PAGE>

                           SECOND AMENDMENT TO LEASE


    This Second Amendment to Lease is made this 27th day of August, 1997 by and
between Connecticut General Life Insurance Company, a Connecticut corporation
("Landlord") and Olicom, Inc., a Delaware corporation ("Tenant").

                              W I T N E S S E T H

    WHEREAS, New England Mutual Life Insurance Company, as landlord (the
"Original Landlord") and Crosscom Corporation, as tenant (the "Original
Tenant") entered into that certain lease dated as of April 30, 1992 with
respect to premises located at 450 Donald J. Lynch Boulevard, Marlborough,
Massachusetts (the "Original Lease");

    WHEREAS, Landlord is the successor-in-interest to the Original Landlord's
interest as landlord under the Lease and Tenant is the successor-in-interest to
the Original Tenant's interest as tenant under the Lease;

    WHEREAS, Landlord and Tenant entered into a First Amendment to Lease dated
January 15, 1999 amending the Original Lease (as so amended, the "Lease");

    WHEREAS, Landlord and Tenant wish to extend the term of the Lease and to
otherwise amend the Lease as set forth herein.

    NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree
as follows:

    1.   Capitalized terms used herein and not defined herein shall have the
meanings ascribed to them in the Lease.

    2.   Effective January 1, 1998 (the "Effective Date"), Section 1.1 of the
Lease is hereby amended by substituting the data set forth below for the
corresponding data set forth in the Lease:

    LANDLORD'S REPRESENTATIVE:  William Bailey

    TERM EXPIRATION DATE:  December 31, 2002

    RENTABLE FLOOR AREA
    OF TENANT'S SPACE:        59,675 square feet constituting the Total
                              Rentable Floor Area of the Building.


<PAGE>

    ANNUAL BASE RENT:  (a) From January 1, 1998 through December 31, 1999:
                       $495,302.50; $8.30 (p.r.s.f.); (b) from January 1, 2000
                       through December 31, 2001: $554,977.50; $9.50
                       (p.r.s.f.); (c) from January 1, 2002 through December
                       31, 2002: $614,652.50; $10.30 (p.r.s.f.)

    ANNUAL ESTIMATED
    OPERATING COSTS:  $239,893.50; $4.02 (p.r.s.f.)(exclusive of electricity
                      and gas charges which shall be paid directly by Tenant)

    ANNUAL RENT:  The sum of Annual Base Rent, Annual Estimated Operating Costs
                  and Annual Improvement Rent, if any (subject to the adjustment
                  set forth in Section 4.1.1), by way of illustration computed
                  for the period from January 1, 1998 through December 31, 1998
                  (subject to increase for Annual Improvement Rent, if any) as
                  follows:

<TABLE>
      <S>            <C>                 <C>             <C>             <C>
         $8.30            $4.02            $12.32        59,675 sF       $735,196.00
        Annual            Annual         (p.r.s.f.)                      Annual Rent
       Base Rent        Estimated
      (p.r.s.f.)     Operating Costs
                       (p.r.s.f.)
</TABLE>

    TENANT ALLOWANCE:  $2.00 per square foot of Rentable Floor Area of
                       Tenant's Space.

    3.   Notwithstanding any provision of the Lease to the contrary, Tenant
shall pay all electricity and gas charges for the Building and the Lot
(including the Premises) directly to the utilities providing such services. All
such amounts shall be paid prior to the date the same become due.

    4.   Notwithstanding any provision of the Lease to the contrary, Tenant
shall be responsible for all improvements to Tenant's Space at Tenant's sole
cost, other than as specifically set forth herein. Landlord shall provide an
allowance for such work equal to the Tenant Allowance, provided, however, that
Tenant may, at Tenant's election, use a portion of the Tenant Allowance to pay
a brokerage fee owing to Whittier Partners in connection with this Second
Amendment to Lease, Tenant acknowledges that Tenant is fully responsible for
such brokerage fee. Upon notice from Tenant to Landlord of the amount of the
brokerage fee, accompanied by a paid invoice therefor, Landlord shall reimburse
to Tenant the amount of the brokerage fee, provided that such brokerage fee
does not exceed the Tenant Allowance. To the


                                       2

<PAGE>

extent that Tenant does not use the Tenant Allowance for the brokerage fee, or
if Tenant does so use the Tenant Allowance and any portion of the Tenant
Allowance is remaining after reimbursement of the brokerage fee, Tenant may
provide notice to Landlord after completion of improvements to Tenant's Space
("Tenant's Completion Notice"), together with invoices therefor, and Landlord
shall thereafter reimburse Tenant in an amount not to exceed the Tenant
Allowance or the remaining balance of the Tenant Allowance, if any. Such
amounts shall be reimbursed by Landlord to Tenant thirty (30) days after the
later of Tenant's Completion Notice or the Effective Date. In Tenant's
Completion Notice, Tenant my request Landlord to pay up to an additional $4.00
per square foot of Rentable Area of Tenant's Space to be used for improvements
to Tenant's space. Such additional amount will be paid to Tenant by Landlord at
Tenant's request and (i) such amount, together with interest thereon at the
rate of ten percent (10%) per annum (the "Improvement Rent"), will be amortized
over the period commencing on the Effective Date and ending on the Term
Expiration Date, (ii) the annual amount of the Improvement Rent shall be added
to the Annual Rent (the "Annual Improvement Rent"), and (iii) the Annual
Improvement Rent shall be deemed to constitute a portion of Annual Rent for all
purposes hereunder.

    5.   Effective on the Effective Date, Section 4.2 of the Lease is hereby
amended by deleting the first paragraph thereof (beginning with "Tenant's
proportionate share" and ending with "Area of the Building"), the sixth
paragraph thereof (including clauses (a) and (b) thereof) (beginning with
"Operating Cost Escalation" and ending with "Area of the Building" in clause
(b)) and the seventh paragraph thereof (beginning with "If the management fee"
and ending with "100% of operating expenses"), and substituting the following
for said sixth paragraph thereof:

         "Operating Cost Escalation" shall be equal to the excess, if any, of
         the actual amount of Landlord's Operating Costs as indicated in
         Landlord's Statement over the Annual Estimated Operating Costs."

    6.   Effective on the Effective Date, Section 6.1.6 of the Lease is hereby
amended by inserting the following at the end thereof:

              "Notwithstanding the foregoing, upon thirty (30) days prior
         written notice to Landlord, Tenant shall be permitted to sublease all
         or any portion of the Premises during the Term to a subtenant who will
         use the Premises for one or more of the Permitted Uses, provided that
         Tenant is not then in default under this Lease, and provided further
         that the prior approval of Landlord is obtained, which approval shall
         not be unreasonably withheld or delayed. Landlord shall not be deemed
         to be unreasonable in withholding its approval if the proposed
         sublessee does not have a financial standing reasonably acceptable to
         Landlord as evidenced by financial statements in scope and substance
         satisfactory to


                                       3

<PAGE>

         Landlord and in conformity with generally accepted accounting
         principles and, if requested by Landlord, certified by a certified
         public accountant reasonably acceptable to Landlord."

    7.   Tenant shall have the right and option to extend the Term for an
additional period of five (5) years (the "Extension Term") commencing upon
the Term Expiration Date as defined in this Second Amendment to Lease,
provided that (i) Tenant shall give Landlord notice of Tenant's exercise of
such option at least nine (9) months prior to the Term Expiration Date; (ii)
Tenant shall not be in default in any respect at the time of giving such
notice in the performance or observance of any of the terms and provisions of
this Lease on the part of the Tenant to be performed or observed; and (iii)
Tenant shall not have assigned the Lease or sublet any portion of that
Premises, except as permitted without Landlord's consent under Section 6.1.6
hereof. If Tenant is in such default in any respect at the time of that
commencement of the Extension Term, then, at the option of Landlord, in its
sole discretion, exercisable by written notice to Tenant while such default
continues, Tenant's exercise of its right and option to texted the Term shall
be null and void and of no further force and effect, the Term shall be deemed
to have expired on the Term Expiration Date, and the Landlord shall have all
rights afforded to Landlord under the Lease, including, without limitation,
all rights with respect to a holdover by Tenant if Tenant is still in
possession of the Premises.

         Prior to the exercise by Tenant of such option, the expression
"Term" shall mean the Term until the Term Expiration Date, and after the
exercise by Tenant of such option, this expression "Term" shall mean the Term
as it has been extended by the Extension Term (subject to the foregoing).
Except as expressly otherwise provided in the following paragraph and except
for the provisions of this Paragraph 6, all the terms, covenants, conditions,
provisions and agreements in the Lease contained shall be applicable to the
Extension Term. If Tenant shall give notice of its exercise of said option to
extend in the manner and within the time period provided aforesaid, the term
shall be extended upon the giving of such notice without the requirement of
any further action on the part of either Landlord or Tenant. If Tenant shall
fail to give timely notice of the exercise of any such option as aforesaid,
Tenant shall have no right to extend the term of this Lease, time being of the
essence of the foregoing provisions.

         The Annual Base Rent payable during the Extension Term shall be the
amount being the greater of (i) the Annual Base Rent in effect for the Lease
Year immediately preceding the commencement of the Extension Term or (ii) the
Fair Market Rent for the Premises, as determined below, as of the
commencement of the Extension Term. If for any reason the Annual Base Rent
payable during the Extension Term has not been determined as of the
commencement of the Extension Term, Tenant shall pay

                                       4

<PAGE>

the Annual Base Rent payable during the year immediately preceding the Term
Expiration Date until the Annual Base Rent for the Extension Term is
determined, at which time, an appropriate adjustment, if any, shall be made.

         For purposes hereof, the Fair Market Rent shall mean the fair rent
for the Premises as of the commencement of the Extension Term under market
conditions then existing. Fair Market Rent shall be determined by agreement
between Landlord and Tenant, but if Landlord and Tenant are unable to agree
upon the Fair Market Rent at least six (6) months prior to the date upon
which the Fair Market Rent is to take effect, then the Fair Market Rent shall
be determined by appraisal made as hereinafter provided by a board of three
(3) reputable independent commercial real estate consultants, appraisers, or
brokers, each of whom shall have at least ten (10) years of experience in the
Marlborough office rental market and each of whom is hereinafter referred to
as "appraiser". Tenant and Landlord shall each appoint one such appraiser and
the two (2) appraisers so appointed shall appoint the third appraiser. The
cost and expenses of each appraiser appointed separately by Tenant and
Landlord shall be borne by the party who appointed the appraiser. The cost and
expenses of the third appraiser shall be shared equally by Tenant and
Landlord. Landlord and Tenant shall appoint their respective appraisers at
least five (5) months prior to commencement of the period for which Fair
Market Rent is to be determined and shall designate the appraisers so
appointed by notice to the other party. The two appraisers so appointed and
designated shall appoint the third appraiser at least four (4) months prior
to the commencement of such period and shall designate such appraiser by
notice to Landlord and Tenant. The board of three (3) appraisers shall
determine the Fair Market Rent of the space in question as of the
commencement of the period to which the Fair Market Rent shall apply and
shall notify Landlord and Tenant of their determinations at least sixty (60)
days prior to the commencement of such period. If the determinations of the
Fair Market Rent of any two (2) or all three (3) appraisers shall be
identical in amount, said amount shall be deemed to be the Fair Market Rent
of the subject space. If the determinations of all three (3) appraisers shall
be different in the amount, the average of the two (2) values nearest in
amount shall be deemed the Fair Market Rent. The Fair Market Rent of the
subject space determined in accordance with the provisions of this Section
shall be binding and conclusive on Tenant and Landlord.

    8.   Tenant and Landlord represent and warrant that each has dealt with
no broker in connection with this transaction other than Spaulding and Stye
Colliers Limited Partnership and Whittier Partners and Tenant and Landlord
agree to defend, indemnify and hold the other harmless from and against any
and all cost, expense or liability for any compensation, commissions or
charges claimed by a broker or agent with which such party has had any
dealings other than Spaulding and Stye Colliers Limited Partnership (for
which Landlord shall be responsible) in the case of Tenant and Whittier
Partners (for which Tenant shall be responsible) in the case of Landlord,
with respect to this Second Amendment to Lease.

                                       5

<PAGE>

     9.  Except as amended hereby, the Lease shall remain modified and in
full force and effect.

    10.  Notwithstanding the foregoing, in the event that Tenant is in
default of any obligation on the Effective Date, this Second Amendment to
Lease shall at Landlord's option, in its sole discretion, be null and void of
no further force and effect, unless Tenant effects a cure of each such
default within the applicable cure period, if any.

    EXECUTED as a sealed instrument on the day and year first written above.

                                       LANDLORD:

                                       CONNECTICUT GENERAL LIFE
                                       INSURANCE COMPANY

                                       By:  CIGNA Investments, Inc.



                                            By:   /s/ James H. Rogers
                                                -----------------------
                                                Its:  JAMES H. ROGERS
                                                      MANAGING DIRECTOR

                                       TENANT:

                                       OLICOM, INC.



                                       By:   /s/ David F. Burkey
                                          -----------------------------
                                          Name: David F. Burkey
                                          Its:  Chief Financial Officer
                                          Hereunto duly authorized


                                       6

<PAGE>

                            FIRST AMENDMENT TO LEASE

This First Amendment to Lease is made the  15  day of January, 1993 by and
between Connecticut General Life Insurance Company, acting through CIGNA
Investments, Inc. ("Landlord") and CrossComm Corporation, a Delaware corporation
("Tenant").

                              W I T N E S S E T H

     WHEREAS, New England Mutual Life Insurance Company, as landlord ("NEL") and
Tenant, as tenant, are parties to that certain Lease dated as of April 30, 1992
regarding premises located at 450 Donald J. Lynch Boulevard, Marlborough,
Massachusetts (the "Lease");

     WHEREAS, Landlord is the successor in interest to NEL's interest as
landlord under the Lease;

     WHEREAS, Landlord and Tenant now desire to modify the Lease to, among other
matters, extend the term and to add additional space to the premises leased by
Tenant;

     NOW, THEREFORE, for good and valuable consideration, the Landlord and
Tenant hereby agree as follows:

     1. Capitalized terms used herein and not defined herein shall have the
meaning set forth in the Lease.

     2. Section 1.1 of the Lease is hereby amended by deleting the existing
provisions and inserting the following provisions in lieu thereof:

1.1  SUBJECTS REFERRED TO:

     Each reference in this Lease to any of the following subjects shall be
construed to incorporate the data stated for that subject in this Section 1.1;

LANDLORD:  CIGNA Investments, Inc.

MANAGING AGENT:  Spaulding and Slye Company

LANDLORD'S & MANAGING AGENT'S ADDRESS:

     c/o Spaulding and Slye Company
     25 Burlington Mall Road
     Burlington, MA  01803
     Attn:  Treasurer

LANDLORD'S REPRESENTATIVE:  Peter L. Johnson

TENANT:  CrossComm Corporation, a Delaware corporation


<PAGE>

TENANT'S ADDRESS (FOR NOTICE AND BILLING):

     450 Donald J. Lynch Boulevard, Marlborough, MA  01752

TENANT'S REPRESENTATIVE:  Arthur W. Coviello, Jr.

BUILDING ADDRESS:

     450 Donald J. Lynch Boulevard, Marlborough, MA, being the parcel more
     particularly described on EXHIBIT A (the "Lot"). The building located at
     450 Donald J. Lynch Boulevard, Marlborough, MA is referred to herein as the
     "Building". "Tenant's Original Space" in said Building is defined as the
     area indicated by cross-hatching on the plan attached hereto as EXHIBIT B.
     "Tenant's Additional Space" in said Building is the remaining area in the
     Building not cross-hatched on EXHIBIT B.

RENTABLE FLOOR AREA OF TENANT'S SPACE:  38,824 square feet, as indicated by
cross-hatching on the plan attached hereto as EXHIBIT B, provided, however, that
on the Additional Premises Term Commencement Date (as hereinafter defined) the
Rentable Floor Area of Tenant's Space shall be 59,675 square feet.

TOTAL RENTABLE FLOOR AREA OF THE BUILDING:  59,675 square feet

TENANT'S DESIGN COMPLETION DATE:  May 15, 1992

TENANT'S ADDITIONAL PREMISES DESIGN COMPLETION DATE:  December 31, 1992

ORIGINAL PREMISES TERM COMMENCEMENT DATE:  July 10, 1992

ADDITIONAL PREMISES SCHEDULED TERM COMMENCEMENT DATE:  April 1, 1993

TERM EXPIRATION DATE:  December 31, 1997

ANNUAL BASE RENT:

     With respect to the Original Premises:

          From Original Premises
          Term Commencement Date
          to 6/30/93:               $135,884;  $3.50 (p.r.s.f.)
          From 7/1/93 to 6/30/94:   $223,238;  $5.75 (p.r.s.f.)
          From 7/1/94 to 6/30/95:   $242,650;  $6.25 (p.r.s.f.)
          From 7/1/95 to 6/30/96:   $262,062;  $6.75 (p.r.s.f.)
          From 7/1/96 to 6/30/97:   $281,474;  $7.25 (p.r.s.f.)
          From 7/1/97 to 12/31/97:  $223,238;  $5.75 (p.r.s.f.)


                                      -2-
<PAGE>

     With respect to the Additional Premises:

          From Additional Premises
          Term Commencement Date
          to 6/30/93:               $72,978.50;   $3.50 (p.r.s.f.)
          From 7/1/93 to 6/30/94:   $119,893.25;  $5.75 (p.r.s.f.)
          From 7/1/94 to 6/30/95:   $130,318.75;  $6.25 (p.r.s.f.)
          From 7/1/95 to 6/30/96:   $140,744.25;  $6.75 (p.r.s.f.)
          From 7/1/96 to 6/30/97:   $151,169.75;  $7.25 (p.r.s.f.)
          From 7/1/97 to 12/31/97:  $119,893.25;  $5.75 (p.r.s.f.)

ANNUAL ESTIMATED OPERATING COSTS:

          $343,131.25; $5.75 (p.r.s.f.); which amount includes an Annual
          Estimated Electrical Cost of $1.66 p.r.s.f.

ANNUAL RENT:

     With respect to the Original Premises:

          $359,122; $9.25 (p.r.s.f.) (subject to an annual adjustment as
provided in the definition of Annual Base Rent and the adjustment set forth in
Section 4.1.1), by way of illustration computed for Year 1 as follows:

                 $3.50        +         $5.75         =        $9.25
              Annual Base         Annual Estimated            p.r.s.f.
                 Rent             Operating Costs
              (p.r.s.f.)             (p.r.s.f.)

     With respect to the Additional Premises:

          $192,871.75; $9.25 (p.r.s.f.) (subject to an annual adjustment as
provided in the definition of Annual Base Rent and the adjustment set forth in
Section 4.1.1), by way of illustration computed for Year 1 as follows:

                 $3.50        +         $5.75         =        $9.25
              Annual Base         Annual Estimated            p.r.s.f.
                 Rent             Operating Costs
              (p.r.s.f.)             (p.r.s.f.)

FIRST FISCAL YEAR FOR TENANT'S PAYING OPERATING COST ESCALATION:
YEAR ENDING December 31, 1992

SECURITY DEPOSIT:  None

GUARANTOR:  None

TENANT ALLOWANCE:  $7.00 per square foot included in the Rentable Floor Area of
Tenant's Space


                                      -3-
<PAGE>

TENANT IMPROVEMENT REIMBURSEMENT TO LANDLORD:

         Amounts expended by Landlord in excess of the Tenant Allowance.

PERMITTED USES:

         General office use, assembly and storage of electrical or electronic
         products, and research and development.

PUBLIC LIABILITY INSURANCE:   BODILY INJURY:      $2,000,000
                              PROPERTY DAMAGE:    $1,000,000

         3. Effective as of the Additional Premises Term Commencement Date
(i) the term "Original Premises" shall mean the Tenant's Original Space,
subject to the exclusions set forth in the first paragraph of Section 2.1,
the term "Additional Premises" shall mean the Tenant's Additional Space,
subject to the exclusions set forth in the first paragraph of Section 2.1,
and the term "Premises" shall mean the Original Premises and the Additional
Premises, and (ii) the second paragraph of Section 2.1 of the Lease is
deleted in its entirety and the following paragraph is inserted in lieu
thereof:

         Tenant shall have, as appurtenant to the Premises, the right to use all
of the parking spaces and loading docks provided on the Lot.

         4. Sections 2.1.1 and 2.1.2 are deleted in their entirety.

         5. Section 2.2 is hereby deleted in its entirety and the following
language is inserted in lieu thereof:

         With respect to the Original Premises, to have and to hold for a period
(the "Original Premises Term") commencing on the Original Premises Term
Commencement Date and continuing until the Term Expiration Date, unless sooner
terminated as provided in Section 3.2 or 7.1 or in Article IX.

         With respect to the Additional Premises, to have and hold for a period
(the "Additional Premises Term") commencing on the earliest of (a) if Landlord
is not obligated to perform construction work, on the Additional Premises
Scheduled Term Commencement Date, or (b) if Landlord is obligated to perform
construction work pursuant to EXHIBIT C-1, on the date on which the Additional
Premises are deemed ready for occupancy as provided in Section 3.2A, and (c) in
all events, the date on which Tenant occupies and operates Tenant's business in
all or any part of the Additional Premises (whichever of said dates is
appropriate being hereafter referred to as the "Additional Premises Term
Commencement Date"), and continuing until the Term Expiration Date, unless
sooner terminated as provided in Section 3.2 or 7.1


                                      -4-
<PAGE>

or in Article IX. The defined term "Term" shall mean the Original Premises Term
and/or the Additional Premises Term, as the context may require.

         Promptly after the Additional Premises Term Commencement Date is
ascertained as provided above, Landlord and Tenant shall execute, in recordable
form, a written declaration in the form attached hereto as EXHIBIT D-1 setting
forth the Additional Premises Term Commencement Date.

         6. Section 2.2.1 of the Lease is hereby deleted in its entirety.

         7. Sections 3.1 and 3.2 shall hereinafter be deemed to refer only to
the construction of leasehold improvements for the Original Premises only.

         8. Section 3.1.1 is hereby amended by inserting the words "and on the
exterior of the Building facing Route I-290" after the word "Building"
appearing in the fourth line thereof.

         9. Tenant acknowledges that Landlord has completed the leasehold
improvements to the Original Premises required under Sections 3.1 and 3.2 of the
Lease and has paid the entire Tenant Allowance payable with respect to the
Original Premises. Landlord shall construct leasehold improvements to the
Additional Premises in accordance with the following provisions, which shall be
added as Sections 3.1A and 3.2A, respectively, of the Lease:

3.1A  INITIAL CONSTRUCTION.

         On or before Tenant's Additional Premises Design Completion Date,
Tenant shall provide to Landlord for approval complete sets of construction
drawings and specifications (the "Additional Premises Complete Plans") prepared
at Tenant's expense by Landlord's architect or an architect approved by
Landlord and Landlord's engineer, including but not limited to:

         a.       Furniture and Equipment Layout Plans;
         b.       Dimensioned Partition Plans;
         c.       Dimensioned Electrical and Telephone Outlet Plans;
         d.       Reflected Ceiling Plans;
         e.       Door and Hardware Schedules;
         f.       Room Finish Schedules, including wall, carpet and floor tile
                  colors;
         g.       Electrical, mechanical and structural engineering plans; and
         h.       All necessary construction details and specifications for work
                  not specified in EXHIBIT C-1.

         Landlord and Tenant shall initial the Additional Premises Complete
Plans after the same have been submitted by Tenant and approved by Landlord.
Landlord shall respond to submittal of the Additional Premises Complete Plans
within five business days.


                                      -5-
<PAGE>

         All of Tenant's construction, installation of furnishings, and later
changes or additions shall be coordinated with any work being performed by
Landlord in such manner as to maintain harmonious labor relations and not to
damage the Building or Lot or interfere with Building operations. Except for
installation of furnishings and the installation of telephone outlets which must
be performed by the local telephone company at Tenant's direction and expense,
all work described in the Additional Premises Complete Plans (the "Additional
Premises Leasehold Improvements") shall be performed by Landlord's Contractor.

         In the event that the aggregate cost of the Additional Premises
Leasehold Improvements based upon bids received by Landlord exceeds the Tenant
Allowance, then at Tenant's option, Tenant shall cause Tenant's Representative,
and Landlord shall cause Landlord's Contractor, to promptly consult with each
other in order to work out modifications to the Additional Premises Complete
Plans to respond to such excess costs. Any delay caused by this process
respecting modifications shall be deemed to be a delay caused by Tenant for
purposes of Section 3.2A.

         Tenant shall pay to Landlord as additional rent a sum equal to all
costs incurred by Landlord on account of the Additional Premises Leasehold
Improvements (excluding, however, the Tenant Allowance applicable to the
Additional Premises, but including in the costs so incurred the cost to Landlord
of preparing and reviewing the Additional Premises Complete Plans, of securing
all permits and licenses required for the construction of the Additional
Premises Leasehold Improvements, and of Landlord's Contractor's overhead and
profit equal to 20% of costs of work not covered by the Tenant Allowance),
hereinafter called "Additional Premises Tenant Improvement Reimbursement to
Landlord" or "APTIR". Tenant shall pay to Landlord 50 percent (50%) of the APTIR
prior to Landlord's commencement of construction of the Additional Premises
Leasehold Improvements, and thereafter as construction of the Additional
Premises Leasehold Improvements progresses, on submission by Landlord to Tenant
of a statement on or about the first day of each month showing construction and
design costs incurred. Such statement shall be accompanied by a certificate of
Landlord's Contractor that all payments then due to laborers, materialmen and
subcontractors have been made, less the aggregate amount of prior monthly
progress payments made by Tenant. On the earlier of occupancy or the Additional
Premises Term Commencement Date, Tenant shall pay to Landlord a sum equal to the
unpaid balance of APTIR. In addition to paying APTIR as above provided, Tenant
shall pay an amount equal to all costs incurred by Landlord as a result of any
change orders signed by Tenant and Landlord affecting the Additional Premises
Complete Plans, including the cost to Landlord of Landlord's Contractor's
overhead and profit equal to 20% of those costs exclusive of overhead and
profit. Amounts due and payable on account of such change orders shall be
included in the monthly statements relating to APTIR provided for


                                      -6-
<PAGE>

above, and Tenant shall pay therefor in accordance with each such statement
within 30 days, and in all events by the Additional Term Premises Commencement
Date.

     Landlord will not approve any construction, alterations, or additions
requiring unusual expenses to readapt the Additional Premises to normal office
use on lease termination or increasing the cost of construction, insurance or
taxes on the Building or of Landlord's services called for by Section 5.1 unless
Tenant first gives assurances acceptable to Landlord that such readaptation will
be made prior to such termination without expense to Landlord and makes
provisions acceptable to Landlord for payment of such increased cost.  Landlord
will also disapprove any alterations or additions requested by Tenant which will
delay completion of the Additional Premises or the Building.  All changes and
additions shall be part of the Building except such items as mutually agreed
upon by Landlord and Tenant by writing at the time of approval to be either
removed by Tenant on termination of this Lease or removed or left at Tenant's
election.

3.2A  PREPARATION OF PREMISES FOR OCCUPANCY.

     If Landlord is obligated to perform construction work pursuant to EXHIBIT
E-1, Landlord agrees to use reasonable efforts to have the Additional
Premises ready for occupancy on or before the Additional Premises Scheduled
Term Commencement Date, which shall, however, be extended for a period equal
to that of any delays due to governmental regulations, unusual scarcity of or
inability to obtain labor or materials, labor difficulties, casualty or other
causes beyond Landlord's reasonable control.  The Additional Premises shall
be deemed ready for occupancy on the date on which the Additional Premises
Leasehold Improvements, as specified in EXHIBIT E-1 and in the Additional
Premises Complete Plans, are ready for occupancy as determined by (a)
certification by Landlord's architect with the exception of minor items which
can be fully completed without material interference with Tenant's business,
and (b) issuance of a Certificate of Occupancy or a temporary Certificate of
Occupancy by the appropriate authority of the City of Marlborough; provided,
however, that if Landlord is unable to complete construction due to delay in
Tenant's compliance with the provisions of Section 3.1A of this Lease, then
the Additional Premises shall be deemed ready for occupancy no later than the
Additional Premises Scheduled Term Commencement Date.

     Landlord shall permit Tenant access for installing equipment and
furnishings in the Additional Premises prior to the Additional Premises Term
Commencement Date if it can be done without material interference with
completion of the Building or remaining portions of the Additional Premises
Leasehold Improvements.

     In the event of Tenant's failure to comply with the provisions of Section
3.1A to submit information or to deliver construction drawings and
specifications which meet Landlord's


                                      -7-
<PAGE>

approval, after 30 days' notice from Landlord, Landlord may, at Landlord's
option, exercisable by notice to Tenant, either (i) terminate this Lease with
respect to the Additional Premises on the date specified in said notice to
Tenant, and upon such termination Landlord shall have all the rights provided in
Article IX of this Lease in the event of Tenant's default, or (ii) assess Tenant
liquidated damages in an amount equal to the Annual Rent with respect to the
Additional Premises divided by 365 for each day such failure continues, which
damages shall be paid to Landlord on the Additional Premises Term Commencement
Date.  Notwithstanding the foregoing provisions, if the Additional Premises
are not deemed ready for occupancy within 60 days after the Additional Premises
Scheduled Term Commencement Date for whatever reason, other than Tenant's
default, Tenant may elect to cancel this Lease with respect to the Additional
Premises at any time thereafter while the Additional Premises are not deemed
ready for occupancy by giving notice to the Landlord of such cancellation which
shall be effective when given, it being understood that said election shall be
Tenant's sole remedy at law or in equity for Landlord's failure to have the
Additional Premises ready for occupancy.

     10.  Section 4.1 of the Lease is hereby amended by inserting the following
provision at the end of the section:

     Tenant shall receive a credit against the Annual Rent payable with respect
to the Additional Premises in the amount of $152.63 per day for the period
beginning on the Additional Premises Term Commencement Date and ending on June
30, 1993.

     11.  Except as amended hereby, the Lease is in all other respects ratified
and confirmed.

     EXECUTED as a sealed instrument in two or more counterparts on the day and
year first above written.

                                             LANDLORD

                                             CONNECTICUT GENERAL LIFE INSURANCE
                                             COMPANY

                                             BY: CIGNA Investments, Inc.



                                                  By: /s/ Robert Fair
                                                     ---------------------------
                                                     Its [ILLEGIBLE]


                                      -8-
<PAGE>

                                             TENANT:

                                             CrossComm Corporation

                                                  By: /s/ [ILLEGIBLE]
                                                      --------------------------
                                                      Its V.P. Financial
                                                      Hereunto duly authorized


                                      -9-
<PAGE>




                                   EXHIBIT C-1
                                   -----------

                              Intentionally Omitted




<PAGE>


                                   EXHIBIT D-1

                        Form of Second Amendment to Lease

     This Second Amendment to Lease, made this______day of
___________________________, 1993 by and between Connecticut General Life
Insurance Company, acting through CIGNA Investments, Inc. ("Landlord") and
CrossComm Corporation, a Delaware corporation ("Tenant").

                                   WITNESSETH:

     WHEREAS, New England Mutual Life Insurance Company, as landlord ("NEL") and
Tenant, as tenant, are parties to that certain Lease dated as of April 30, 1992
regarding premises located at 450 Donald J. Lynch Boulevard, Marlborough,
Massachusetts ( the "Original Lease");

     WHEREAS, Landlord is the successor in interest to NEL's interest as
landlord under the Lease;

     WHEREAS, Landlord and Tenant are parties to a First Amendment to Lease
dated as of January ___, 1993 (the Original Lease, as so amended, is hereinafter
referred to as the "Lease");

     WHEREAS, all terms defined in the Lease shall have the same meanings when
referred to herein; and

     WHEREAS, Landlord and Tenant agreed to confirm the Additional Premises
Term Commencement Date, pursuant to and in accordance with Article II thereof;

     NOW, THEREFORE, for consideration paid by each to the other, Landlord
and Tenant hereby agree that the Additional Premises Term Commencement Date
is ______________________, 1993.

     Except as hereby modified and amended, all other terms, provisions,
covenants and conditions of the Lease shall remain unmodified and in full force
and effect.


<PAGE>


     IN WITNESS WHEREOF, Landlord and Tenant have executed this Second
Amendment to Lease as a sealed instrument on or as of the day and year first
above written.

WITNESS:                                  LANDLORD:

                                          CONNECTICUT GENERAL LIFE INSURANCE
                                          COMPANY
-------------------------------
                                          BY: CIGNA Investments, Inc.


                                          By:___________________________
                                             Its

                                          TENANT:

                                          CrossComm Corporation

                                          By:____________________________
                                             Its
                                             Hereunto duly authorized


                                      -2-
<PAGE>

                                  EXHIBIT E-1
                                  -----------


                    Not yet available - to be agreed upon by
                      Landlord and Tenant at a later date


<PAGE>

                                     Lease

                                 by and between

              New England Mutual Life Insurance Company, Landlord


                                      and

                         CrossComm Corporation, Tenant




                 450 Donald J. Lynch Boulevard, Marlborough, MA

                              As of April 30, 1992


<PAGE>

                 DATE OF LEASE EXECUTION: as of April 30, 1992
                         (To be completed by Landlord)



                                    ARTICLE I

                                 REFERENCE DATA

1.1  SUBJECTS REFERRED TO:

     Each reference in this Lease to any of the following subjects shall be
construed to incorporate the data stated for that subject in this Section 1.1:

LANDLORD:  New England Mutual Life Insurance Company

MANAGING AGENT:  Spaulding and Slye Company

LANDLORD'S & MANAGING AGENT'S ADDRESS:

     c/o Spaulding and Slye Company
     25 Burlington Mall Road
     Burlington, MA  01803
     Attn:  Treasurer

LANDLORD'S REPRESENTATIVE:  Peter L. Johnson

TENANT:  CrossComm Corporation, a Delaware corporation

TENANT'S ADDRESS (FOR NOTICE AND BILLING):

     Prior to the Commencement Date (as defined in Section 2.2), at 140C Locke
     Drive, P. O. Box 699, Marlborough, MA 01752; from and after the
     Commencement Date, at the Premises.

TENANT'S REPRESENTATIVE:  Arthur W. Coviello, Jr.

BUILDING ADDRESS:

     450 Donald J. Lynch Boulevard, Marlborough, MA, being the parcel more
     particularly described on EXHIBIT A (the "Lot"). The building located at
     450 Donald J. Lynch Boulevard, Marlborough, MA is referred to herein as the
     "Building." "Tenant's Space" in said Building is defined as the area
     indicated by cross-hatching on the plan attached hereto as EXHIBIT B.

RENTABLE FLOOR AREA OF TENANT'S SPACE:  38,824 square feet, as indicated by
cross-hatching on the plan attached hereto as EXHIBIT B.

TOTAL RENTABLE FLOOR AREA OF THE BUILDING:  59,675 square feet


                                      -1-
<PAGE>

TENANT'S DESIGN COMPLETION DATE:  May 15, 1992

SCHEDULED TERM COMMENCEMENT DATE:   July 1, 1992

TERM EXPIRATION DATE: June 30, 1997

APPROXIMATE TERM: Five Years

ANNUAL BASE RENT:     Year 1 of Term:   $135,884;  $3.50 (p.r.s.f.)
                      Year 2 of Term:   $223,238;  $5.75 (p.r.s.f.)
                      Year 3 of Term:   $242,650;  $6.25 (p.r.s.f.)
                      Year 4 of Term:   $262,062;  $6.75 (p.r.s.f.)
                      Year 5 of Term:   $281,474;  $7.25 (p.r.s.f.)

ANNUAL ESTIMATED OPERATING COSTS: $343,131.25; $5.75 (p.r.s.f.); which amount
includes an Annual Estimated Electrical Cost of $1.66 p.r.s.f.

ANNUAL RENT: $359,122; $9.25 (p.r.s.f.) (subject to an annual adjustment as
provided in the definition of Annual Base Rent and the adjustment set forth in
Section 4.1.1.), by way of illustration computed for Year 1 as follows:

                 $3.50     +        $5.75         =    $9.25
              Annual Base      Annual Estimated       p.r.s.f.
                 Rent          Operating Costs
              (p.r.s.f)          (p.r.s.f.)

FIRST FISCAL YEAR FOR TENANT'S PAYING OPERATING COST ESCALATION: YEAR ENDING
December 31, 1992

SECURITY DEPOSIT:  None

GUARANTOR:  None

TENANT ALLOWANCE:  $7.00 per square foot included in the Rentable FLoor Area of
Tenant's Space

TENANT'S IMPROVEMENT REIMBURSEMENT TO LANDLORD:

       Amounts expended by Landlord in excess of the Tenant Allowance.

PERMITTED USES:

       General office use, assembly and storage of electrical or electronic
       products, and research and development.

PUBLIC LIABILITY INSURANCE:  BODILY INJURY:  $2,000,000
                             PROPERTY DAMAGE: $1,000,000


                                      -2-

<PAGE>

SPECIAL PROVISIONS:

       OPTION TO EXPAND: Tenant has the option to expand pursuant to Section
       2.1.1.

       RIGHT OF FIRST OFFER TO LEASE: Tenant has the right of first offer to
       lease other available space in the Building pursuant to Section 2.1.2.

       RIGHT TO TERMINATE: Tenant has the right to terminate pursuant to Section
       2.2.1.

1.2    EXHIBITS.

       The exhibits listed below in this Section are incorporated in this lease
       by reference and are to be construed as part of this Lease:

       EXHIBIT A         Description of the Lot

       EXHIBIT B         Plan showing Tenant's Space

       EXHIBIT C         Intentionally Omitted

       EXHIBIT D         Form of First Amendment to Lease setting forth the
                         Commencement Date

       EXHIBIT E         Specifications of Leasehold Improvements and Tenant
                         Layout (if applicable)

       EXHIBIT F         Landlord's Services

       EXHIBIT G         Rules and Regulations

<TABLE>
<CAPTION>

1.3    TABLE OF CONTENTS                                                         PAGE

<S>                                                                              <C>
ARTICLE II  -  PREMISES AND TERM..............................................    6

  Section 2.1      Premises...................................................    6
          2.1.1    Option to Expand...........................................    6
          2.1.2    Right of First Offer to Lease..............................    7
  Section 2.2      Term.......................................................    8
          2.2.1    Right to Terminate.........................................    9

ARTICLE III  -  CONSTRUCTION..................................................    9

  Section 3.1      Initial Construction.......................................    9
          3.1.1    Signage....................................................   11

                                      -3-

<PAGE>

<S>                                                                              <C>
  Section 3.2      Preparation of Premises for Occupancy......................   12
  Section 3.3      General Provisions Applicable to Construction..............   13
  Section 3.4      Representatives............................................   13

ARTICLE IV  -  RENT...........................................................   13

  Section 4.1      Rent.......................................................   13
  Section 4.2      Operating Costs; Escalation................................   14
  Section 4.3      Estimated Escalation Payments..............................   17
  Section 4.4      Change of Fiscal Year......................................   17
  Section 4.5      Payments...................................................   17
  Section 4.6      Tenant's Right to Review...................................   17

ARTICLE V  -  LANDLORD'S COVENANTS............................................   18

  Section 5.1      Landlord's Covenants During the Term.......................   18
          5.1.1    Building Services..........................................   18
          5.1.2    Additional Building Services...............................   18
          5.1.3    Repairs....................................................   18
          5.1.4    Quiet Enjoyment............................................   18
          5.1.5    Insurance..................................................   18
          5.1.6    Tenant's Costs.............................................   19

  Section 5.2      Interruptions..............................................   19

ARTICLE VI  -  TENANT'S COVENANTS.............................................   20

  Section 6.1      Tenant's Covenants During the Term.........................   20
          6.1.1    Tenant's Payments..........................................   20
          6.1.2    Repairs and Yielding Up....................................   20
          6.1.3    Occupancy and Use..........................................   20
          6.1.4    Rules and Regulations......................................   21
          6.1.5    Safety Appliances..........................................   21
          6.1.6    Assignment and Subletting..................................   21
          6.1.7    Indemnity..................................................   23
          6.1.8    (a) Tenant's Liability Insurance...........................   23
                   (b) Tenant's Worker's Compensation.........................   24
          6.1.9    Insurance Policies.........................................   24
          6.1.10   Landlord's Right of Entry..................................   24
          6.1.11   Loading....................................................   24
          6.1.12   Landlord's Costs...........................................   24
          6.1.13   Tenant's Property..........................................   25
          6.1.14   Labor or Materialmen's Liens...............................   25
          6.1.15   Changes or Additions.......................................   25
          6.1.16   Holdover...................................................   25

ARTICLE VII  -  CASUALTY AND TAKING...........................................   26

  Section 7.1      Casualty and Taking........................................   26
  Section 7.2      Reservation of Award.......................................   27
</TABLE>


                                      -4-
<PAGE>

<TABLE>
<S>                                                                                  <C>
ARTICLE VIII - RIGHTS OF MORTGAGEE................................................   27

         Section 8.1       Priority of Lease......................................   27
         Section 8.2       Rights of Mortgage Holders; Limitation
                                    of Mortgagee's Liability......................   28
         Section 8.3       Mortgagee's Election...................................   28
         Section 8.4       No Prepayment of Modification, Etc.....................   28
         Section 8.5       No Release or Termination..............................   29
         Section 8.6       Continuing Offer.......................................   29
         Section 8.7       Mortgagee's Approval...................................   30

ARTICLE IX - DEFAULT..............................................................   30

         Section 9.1       Events of Default......................................   30
         Section 9.2       Tenant's Obligations after Termination.................   31

ARTICLE X - MISCELLANEOUS.........................................................   32

         Section 10.1      Notice of Lease........................................   32
         Section 10.2      Intentionally Omitted..................................   32
         Section 10.3      Notices from One Party to the Other....................   32
         Section 10.4      Bind and Inure.........................................   32
         Section 10.5      No Surrender...........................................   33
         Section 10.6      No waiver, Etc.........................................   33
         Section 10.7      No Accord and Satisfaction.............................   33
         Section 10.8      Cumulative Remedies....................................   34
         Section 10.9      Landlord's Right to Cure...............................   34
         Section 10.10     Estoppel Certificate...................................   34
         Section 10.11     Waiver of Subrogation..................................   35
         Section 10.12     Acts of God............................................   35
         Section 10.13     Brokerage..............................................   35
         Section 10.14     Submission Not an Offer................................   35
         Section 10.15     Applicable Law and Construction........................   36
</TABLE>


                                      -5-
<PAGE>

                                   ARTICLE II

                               PREMISES AND TERM

2.1    PREMISES.

       Subject to and with the benefit of the provisions of this Lease, Landlord
hereby leases to Tenant, and Tenant hereby leases from Landlord, Tenant's Space
in the Building, excluding exterior faces of exterior walls, the common
facilities area and building other parts of the Building. Tenant's Space, with
such exclusions, is hereinafter referred to as the "Premises".

       Tenant shall have, as appurtenant to the Premises, the right to use in
common with others entitled thereto: (a) the common facilities included in the
building or on the Lot, including 210 parking spaces in the parking area, on an
unreserved, first-come, first-served basis, to the extent and in the location
from time to time designated by Landlord, and (b) the building service fixtures
and equipment serving the premises. Landlord grants to Tenant the exclusive use
of (i) the existing tailboard loading dock which includes two loading bays and
is adjacent to the Premises, all as more particularly shown on EXHIBIT B, and
(ii) 30 reserved parking spaces designated by Landlord and located near the
entrance to Tenant's Space. Landlord is not responsible for monitoring use of
said loading dock or for monitoring occupancy of the reserved parking spaces and
Tenant shall be responsible for any signage on such loading dock and such
parking spaces designating reservation to Tenant.

       Landlord reserves the right from time to time, without unreasonable
interference with Tenant's use, (A) to install, repair, replace, use maintain
and relocate for service to the Premises and to other parts of the Building or
either, building service fixtures and equipment wherever located in the Building
and (B) to alter or relocate any common facilities, provided that in all events
substitutions are substantially equivalent.

       2.1.1  OPTION TO EXPAND.

           Subject to the terms and conditions hereof, Tenant shall have the
option, exercisable by notice ("Tenant's Notice") to Landlord given on or before
the first anniversary of the Commencement Date, time being of the essence, to
add space to the Tenant's Space, the size and location of such to be determined
by Landlord in its sole discretion provided that such space is approximately
5,000 rentable square feet and contiguous to the Premises. The Rentable Floor
Area of Tenants Space shall be adjusted accordingly and, with respect to such
added space, (a) Tenant's Design Completion Date shall be the date three weeks
after the date Tenant's Notice is given to Landlord, (b) the


                                      -6-
<PAGE>

Scheduled Term Commencement Date shall be the date seven weeks after the date
Tenant's Notice is given to Landlord, (c) the Tenant Allowance shall be equal to
the product of (i) $7.00 times a fraction, the numerator of which is equal to
the number of full months remaining in the Term after the Scheduled Term
Commencement Date as determined in clause (b) above and the denominator of which
is equal to 60, and (ii) the number of rentable square feet of additional space
leased to Tenant pursuant to this Section 2.1.1, and (d) the Annual Base Rent
shall be the same on a per square foot basis as that from time to time in effect
for the initial Tenant's Space.

       2.1.2  RIGHT OF FIRST OFFER TO LEASE.

           Subject to the terms and conditions hereof, and subsequent to the
commencement Date, Landlord hereby grants to Tenant a right of first offer to
lease (the "Offer Right") some or all of the Space in the Building not included
within the Premises (the "Offer Space"), if any Offer Space becomes available
for occupancy before the date which is 18 months after the Commencement Date. If
Landlord desires to lease any portion of the Offer Space, Landlord shall first
give Tenant notice of the specific terms and conditions, including rent, upon
which Landlord desires to lease such offer Space (the "Proposed Terms"). Tenant
shall have five business days subsequent to receipt by Tenant of such notice
from Landlord in which to exercise, by notice to Landlord, Tenant's right to
lease the Offer Space on the Proposed Terms. Upon Tenant's exercise of its right
to lease any such Offer Space, Tenant's right o terminate this Lease pursuant to
Section 2.2.1 shall be null and void and of no further force and effect.

       In the event Tenant does not accept the offer on the Proposed Terms
within said five-business-day period, Landlord shall be free to lease such Offer
Space to any third party on terms which are not materially more favorable than
the Proposed Terms (as determined by Landlord in good faith) without having to
offer such space to Tenant. notwithstanding the foregoing, Tenant's right to
accept any offer hereunder and to lease any Offer Space is subject to the
additional conditions precedent that at the time Tenant exercises its right to
lease any such Offer Space commences: (a) Tenant shall not be in default under
any of the terms of this Lease; and (b) Tenant shall not have sublet any portion
of the Premises or assigned this Lease to other than an affiliate of Tenant (as
defined in Section 6.1.6). Time is of the essence with respect to this Section
2.1.2.

       If Tenant fails to exercise its right of first offer to lease as provided
above, Tenant shall deliver to Landlord within five days after landlord's
request therefor a certificate in recordable form stating that Tenant has not
exercised its right of first


                                      -7-
<PAGE>

offer with respect to the Offer Space. Any person dealing with the Building
may, without further inquiry, conclusively rely upon a representation in a
certificate of Landlord as to whether or not the provisions of this
Section 2.1.2 have been satisfied.

     If Tenant exercises its right of first offer to lease Offer Space as
provided above, Landlord shall provide a Tenant Allowance, in lieu of any
tenant allowance provided in the Proposed Terms, equal to the product of (i)
$7.00 times a fraction, the numerator of which is equal to the number of full
months remaining in the Term (including extensions, if any) after the
Scheduled Term Commencement Date for such Offer Space (but in no event shall
the numerator exceed 60) and the denominator of which is equal to 60, and
(ii) the number of rentable square feet in such Offer Space leased to Tenant
pursuant to this Section 2.1.2.

     This Agreement shall not apply to (A) the sale or conveyance of the
Building or the Lot (or both), or (B) to the granting of a mortgage on the
Building or Lot (or both) or the foreclosure of or the granting of a deed in
lieu of foreclosure of any such mortgage; nor shall the Building or Lot, if
so sold, conveyed, foreclosed upon or conveyed by deed in lieu of foreclosure
thereafter be subject to the rights of first offer granted in this Lease.

     Tenant hereby acknowledges and agrees that Landlord's failure to notify
Tenant of the availability of any Offer Space shall not relieve Tenant of any
of its obligations under this Lease.

2.2  TERM.

     To have and to hold for a period (the "Term") commencing on the earliest
of (a) if Landlord is not obligated to perform construction work, on the
Scheduled Term Commencement Date, or (b) if Landlord is obligated to perform
construction work pursuant to EXHIBIT C, on the date on which the Premises
are deemed ready for occupancy as provided in Section 3.2, and (c) in all
events, the date on which Tenant occupies and operates Tenant's business in
all or any part of the Premises (whichever of said dates is appropriate being
hereafter referred to as the "Commencement Date"), and continuing until the
Term Expiration Date, unless sooner terminated as provided in Section 3.2 or
7.1 or in Article IX.

     Promptly after the Commencement Date is ascertained as provided above,
Landlord and Tenant shall execute, in recordable form, a written declaration
in the form attached hereto as EXHIBIT D setting forth the Commencement Date.


                                      -8-

<PAGE>

2.2.1  RIGHT TO TERMINATE.

       Subject to the terms and conditions hereof, Tenant shall have the
right, exercisable by notice to Landlord given on or before the date which is
two years and three months after the Commencement Date, to terminate this
Lease effective as of the third anniversary of the Commencement Date.
Notwithstanding the foregoing, Tenant's right to terminate this Lease is
subject to the additional conditions precedent that: (a) at the time Tenant
exercises its right to terminate and at the effective date of such
termination, (i) Tenant shall not be in default under any of the terms of
this Lease and (ii) Tenant shall not have exercised its right to lease any
Offer Space pursuant to Section 2.1.2; and (b) at the time Tenant exercises
its right to terminate, (i) Tenant shall pay to Landlord the amount equal to
the product of (A) $5.30 and (B) the number of square feet of the Rentable
Floor Area of Tenant's Space and (ii) Tenant shall execute, in recordable
form, and deliver to Landlord a written declaration setting forth the
expiration date of this Lease as the third anniversary of the Commencement
Date. Time is of the essence with respect to this Section 2.2.1.

       Any person dealing with the Building may, without further inquiry,
conclusively rely upon a representation in a certificate of Landlord as to
whether or not the provisions of this Section 2.2.1 have been satisfied.

       Upon Tenant's exercise of its right to lease any Offer Space pursuant
to Section 2.1.2, Tenant's right to terminate this Lease pursuant to this
Section 2.2.1 shall be null and void and of no further force and effect.


                                  ARTICLE III

                                  CONSTRUCTION

3.1  INITIAL CONSTRUCTION.

     On or before Tenant's Design Completion Date, Tenant shall provide to
Landlord for approval complete sets of construction drawings and
specifications (the "Complete Plans") prepared at Tenant's expense by
Landlord's architect or an architect approved by Landlord and Landlord's
engineer, including but not limited to:

     a.  Furniture and Equipment Layout Plans;
     b.  Dimensioned Partition Plans;
     c.  Dimensioned Electrical and Telephone Outlet Plans;
     d.  Reflected Ceiling Plans;


                                      -9-

<PAGE>

     e.  Door and Hardware Schedules;
     f.  Room Finish Schedules, including wall, carpet and floor tile colors;
     g.  Electrical, mechanical and structural engineering plans; and
     h.  All necessary construction details and specifications for work not
         specified in EXHIBIT C.

     Landlord and Tenant shall initial the Complete Plans after the same have
been submitted by Tenant and approved by Landlord. Landlord shall respond to
submittal of the Complete Plans within five business days.

     All of Tenant's construction, installation of furnishings, and later
changes or additions shall be coordinated with any work being performed by
Landlord in such manner as to maintain harmonious labor relations and not to
damage the Building or Lot or interfere with Building operations. Except for
installation of furnishings and the installation of telephone outlets which
must be performed by the local telephone company at Tenant's direction and
expense, all work described in the Complete Plans (the "Leasehold
Improvements") shall be performed by Landlord's general contractor, Spaulding
and Slye Construction Company, Incorporated ("Landlord's Contractor"). The
demising wall may, in Landlord's sole discretion, be of a temporary nature
(provided that the wall be sufficient to maintain room temperature).

     In the event that the aggregate cost of the Leasehold Improvements based
upon bids received by Landlord exceeds the Tenant Allowance, then at Tenant's
option, Tenant shall cause Tenant's Representative, and Landlord shall cause
Landlord's Contractor, to promptly consult with each other in order to work
out modifications to the Complete Plans to respond to such excess costs. Any
delay caused by this process respecting modifications shall be deemed to be a
delay caused by Tenant for purposes of Section 3.2.

     Tenant shall pay to Landlord as additional rent a sum equal to all costs
incurred by Landlord on account of the Leasehold Improvements (excluding,
however, the Tenant Allowance, but including in the costs so incurred the
cost to Landlord of preparing and reviewing the Complete Plans, of securing
all permits and licenses required for the construction of the Leasehold
Improvements, and of Landlord's Contractor's overhead and profit equal to 20%
of costs of work not covered by the Tenant Allowance), hereinafter called
"Tenant Improvement Reimbursement to Landlord" or "TIR". Tenant shall pay to
Landlord 50 percent (50%) of the TIR prior to Landlord's commencement of
construction of the Leasehold Improvements, and thereafter as construction of
the Leasehold Improvements progresses, on submission by Landlord to Tenant of
a statement on or about the first day of each month showing construction and
design costs incurred. Such statement


                                     -10-

<PAGE>

shall be accompanied by a certificate of Landlord's Contractor that all
payments then due to laborers, materialmen and subcontractors have been made,
less the aggregate amount of prior monthly progress payments made by Tenant.
On the earlier of occupancy or the Commencement Date, Tenant shall pay to
Landlord a sum equal to the unpaid balance of TIR. In addition to paying TIR
as above provided, Tenant shall pay an amount equal to all costs incurred by
Landlord as a result of any change orders signed by Tenant and Landlord
affecting the Complete Plans, including the cost to Landlord of Landlord's
Contractor's overhead and profit equal to 20% of those costs exclusive of
overhead and profit. Amounts due and payable on account of such change orders
shall be included in the monthly statements relating to TIR provided for
above, and Tenant shall pay therefor in accordance with each such statement
within 30 days, and in all events by the Commencement Date.

     Landlord shall, at its expense and prior to the Commencement Date, replace
the water-stained ceiling tiles in the Premises, repair the hole in the rug in
the Premises in a manner mutually agreeable to Landlord and Tenant, spot clean
the rug in the Premises where mutually agreed upon by Landlord and Tenant, and
paint the exterior decorative columns at the entrance to the Building.

     Landlord will not approve any construction, alterations, or additions
requiring unusual expense to readapt the Premises to normal office use on
lease termination or increasing the cost of construction, insurance or taxes
on the Building or of Landlord's services called for by Section 5.1 unless
Tenant first gives assurances acceptable to Landlord that such readaptation
will be made prior to such termination without expense to Landlord and makes
provisions acceptable to Landlord for payment of such increased cost.
Landlord will also disapprove any alterations or additions requested by
Tenant which will delay completion of the Premises or the Building. All
changes and additions shall be part of the Building except such items as
mutually agreed upon by Landlord and Tenant by writing at the time of
approval to be either removed by Tenant on termination of this Lease or
removed or left at Tenant's election.

     3.1.1  SIGNAGE.

     Subject to the limitations of applicable law and subject to any existing
park covenants, Tenant shall be permitted to install and maintain, at its sole
cost and expense, a monument sign at the driveway entrance to the Building;
provided, however, that the location, size, style, design, quality and
installation method of such signage must be reviewed and approved in writing by
Landlord prior to installation. Tenant shall secure all permits necessary for
the installation of such signage at its sole cost and expense.


                                      -11-

<PAGE>

3.2  PREPARATION OF PREMISES FOR OCCUPANCY.

     If Landlord is obligated to perform construction work pursuant to EXHIBIT
E, Landlord agrees to use reasonable efforts to have the Premises ready for
occupancy on or before the Scheduled Term Commencement Date, which shall,
however, be extended for a period equal to that of any delays due to
governmental regulations, unusual scarcity of or inability to obtain labor or
materials, labor difficulties, casualty or other causes beyond Landlord's
reasonable control. The Premises shall be deemed ready for occupancy on the date
on which the Leasehold Improvements, as specified in EXHIBIT E and in the
Complete Plans, are ready for occupancy as determined by (a) certification by
Landlord's architect with the exception of minor items which can be fully
completed without material interference with Tenant's business, and (b) issuance
of a Certificate of Occupancy or a temporary Certificate of Occupancy by the
appropriate authority of the City of Marlborough; provided, however that if
Landlord is unable to complete construction due to delay in Tenant's compliance
with the provisions of Section 3.1 of this Lease, then the Premises shall be
deemed ready for occupancy no later than the Scheduled Term Commencement Date.

     Landlord shall permit Tenant access for installing equipment and
furnishings in the Premises prior to the Term if it can be done without material
interference with completion of the Building or remaining portions of the
Leasehold Improvements.

     In the event of Tenant's failure to comply with the provisions of Section
3.1 to submit information or to deliver construction drawings and specifications
which meet Landlord's approval, after 30 days' notice from Landlord, Landlord
may, at Landlord's option, exercisable by notice to Tenant, either (i) terminate
this Lease on the date specified in said notice to Tenant, and upon such
termination Landlord shall have all the rights provided in Article IX of this
Lease in the event of Tenant's default, or (ii) assess Tenant liquidated damages
in an amount equal to the Annual Rent divided by 365 days for each day such
failure continues, which damages shall be paid to Landlord on the Commencement
Date. Notwithstanding the foregoing provisions, if the Premises are not deemed
ready for occupancy within 60 days after the Scheduled Term Commencement Date
for whatever reason, other than Tenant's default, Tenant may elect to cancel
this Lease at any time thereafter while the Premises are not deemed ready for
occupancy by giving notice to Landlord of such cancellation which shall be
effective when given, it being understood that said election shall be Tenant's
sole remedy at law or in equity for Landlord's failure to have the Premises
ready for occupancy.


                                      -12-

<PAGE>

3.3  GENERAL PROVISIONS APPLICABLE TO CONSTRUCTION.

     All construction work required or permitted by this Lease, whether by
Landlord or by Tenant, shall be done in a good and workmanlike manner and in
compliance with all applicable laws and all lawful ordinances, regulations and
orders of governmental authority and insurers of the Building. Either party may
inspect the work of the other at reasonable times and promptly shall give notice
of observed defects. Landlord's obligations under Sections 3.1 and 3.2 shall be
deemed to have been performed when Tenant commences to occupy any portion of the
Premises for the Permitted Uses except for items which are incomplete or do not
conform with the requirements of Sections 3.1 and 3.2 and as to which Tenant
shall in either case have given written notice to Landlord prior to such
commencement. If Tenant shall not have commenced to occupy the Premises for the
Permitted Uses within 30 days after they are deemed ready for occupancy as
provided in Section 3.2, a certificate of completion by a licensed architect or
registered engineer shall be conclusive evidence that Landlord has performed all
such obligations except for items stated in such certificate to be incomplete or
not in conformity with such requirements.

3.4  REPRESENTATIVES.

     Each party authorizes the other to rely in connection with their respective
rights and obligations under this Article III upon approval and other actions on
the party's behalf by Landlord's Representative in the case of Landlord or
Tenant's Representative in the case of Tenant or by any person designated in
substitution or addition by notice to the party relying.

                                   ARTICLE IV

                                      RENT

4.1  RENT.

     Tenant agrees to pay rent to Landlord without any offset or reduction
whatever (except as made in accordance with the express provisions of this
Lease), equal to 1/12th of the Annual Rent in equal installments in advance
on the first day of each calendar month included in the Term; and for any
portion of a calendar month at the beginning or end of the Term, at the
proportionate rate payable for such portion, in advance. Notwithstanding the
foregoing, in the event Tenant actually incurs costs to H. K. Properties
under Tenant's current lease at 140C Locke Drive, Marlborough, Massachusetts,
as a result of the current lease term under such lease extending beyond the
Commencement Date, then Tenant shall receive a credit for such actual costs
incurred, up to $75,000, to be applied against the next ensuing payments of
Annual Base Rent.

                                      -13-
<PAGE>

4.2  OPERATING COSTS; ESCALATION.

     Tenant's proportionate share of the Annual Estimated Operating Costs
shall be determined by multiplying Annual Estimated Operating Costs by a
fraction, the numerator of which is the Rentable Floor Area of Tenant's
Space, and the denominator of which is the Total Rentable Floor Area of the
Building.

     With respect to the First Fiscal Year for Tenant's Paying Operating Cost
Escalation, or fraction thereof, and any fiscal year or fraction thereof
thereafter, Tenant shall pay to Landlord, as additional rent, Operating Cost
Escalation (as defined below), if any, on or before the thirtieth day
following receipt by Tenant of Landlord's Statement (as defined below). As
soon as practicable after the end of each Fiscal Year ending during the Term
and after Lease termination, Landlord shall render a statement ("Landlord's
Statement") in reasonable detail and according to usual accounting practices
certified by Landlord and showing for the preceding Fiscal Year or fraction
thereof, as the case may be, Landlord's Operating Costs,

     EXCLUDING: the interest and amortization on mortgages for the Building
and Lot or leasehold interests therein; the cost of special services rendered
to tenants (including Tenant) for which a special charge is made; advertising
or promotional fees, leasing commissions and accounting and legal fees
associated with this Lease, except as are incurred in connection with the
normal operation of the Building; and renovation costs associated with
leases with other tenants of the Building,

     BUT INCLUDING, without limitation: real estate taxes on the Building and
Lot; installments and interest on assessments for public betterments or
public improvements provided the same are apportioned equally over the
longest period permitted by law; expenses of any proceedings for abatement of
taxes and assessments with respect to any fiscal year or fraction of a fiscal
year; premiums for insurance; fees payable to third parties for financial
audits of Landlord's Operating Costs; compensation and all fringe benefits,
worker's compensation insurance premiums and payroll taxes paid by Landlord
to, for or with respect to all persons engaged in the operating, maintaining,
or cleaning of the Building and Lot; all utility charges not billed directly
to tenants by Landlord or the utility; payments to independent contractors
under service contracts for cleaning, operating, managing, maintaining and
repairing the Building and Lot (which payments may be to affiliates of
Landlord provided the same are at reasonable rates consistent with the type
of occupancy); interest on working capital borrowed by Landlord for
reasonably unanticipated prepaid operating costs; if the Building shares
common areas of facilities with another building or buildings, the Building's
pro rata share (as reasonably determined by Landlord)


                                     -14-

<PAGE>

of the cost of landscaping, street lighting, security (if required in
Landlord's judgment), cleaning, operating, managing (including the cost of
the management office for such buildings and facilities), maintaining,
repairing and snow plowing such common areas and facilities; fixed and
additional rent payable under any ground lease of the Lot; and all other
reasonable and necessary expenses paid in connection with the cleaning,
operating, managing, maintaining and repairing of the Building and Lot, or
either, and properly chargeable against income, it being agreed that if
Landlord installs a new or replacement capital item for the purpose of
reducing Landlord's Operating Costs, the cost thereof as reasonably amortized
by Landlord, with interest on the unamortized amount at the average prime
commercial rate in effect from time to time at the three largest national
banks in Boston, Massachusetts (the "Average Rate") if Landlord does not
obtain outside financing, or if Landlord obtains outside financing therefor
at the lesser of the rate actually paid by Landlord or the Average Rate,
shall be included in Landllord's Operating Costs.

     "Operating Costs Escalation" shall be equal to the difference, if any,
between:

     (a)  the product of Landlord's Operating Costs as indicated in
Landlord's Statement and fraction, the numerator of which shall be the
Rentable Floor Area of Tenant's Space and the denominator of which shall be
the Total Rentable Floor Area of the Building, and

     (b)  the product of the Annual Estimated Operating Costs and a fraction,
the numerator of which shall be the Rentable Floor Area of Tenant's Space and
the denominator of which shall be the Total Rentable Floor Area of the
Building.

     If the management fee is reduced by reason of a tenant's default in the
payment of Annual Rent or additional rent, Landlord shall reduced the Annual
Estimated Operating Costs by the amount of such reduction in the management
fee.  In case of special services which are not rendered to all areas on a
comparable basis, the proportion allocable to the Premises shall be the same
proportion which the Rentable Floor Area of Tenant's Space bears to the total
rentable floor area to which such service is so rendered (such latter area to
be determined in the same manner as the Total Rentable Floor  Area of the
Building). Regardless of the actual percentage of occupancy of the Building,
for the purpose of determining Landlord's Operating Costs, the operating
expenses will be extrapolated on a line item basis as though the Building
were 100% occupied, but not in a manner to enable Landlord to collect more
than 100% of operating expenses.

     The term "real estate taxes" as used above shall mean all taxes of every
kind and nature assessed by any governmental authoirity on the Lot, the
Building and improvements, or both,


                                     -15-
<PAGE>

which the Landlord shall become obligated to pay because of or in connection
with the ownership, leasing and operation of the Lot, the Building and
improvements, or both, subject to the following:  There shall be excluded
from such taxes all income taxes, excess profits taxes, excise taxes,
franchise taxes,and estate, succession, inheritance and transfer taxes,
provided, however, that if at any time during the Term the present system of
ad valorem taxation of real property shall be changed so that in lieu of the
whole or any part of the ad valorem tax on real property, there shall be
assessed on Landlord a capital levy or other tax on the gross rents received
with respect to the Lot, Building and improvements, or both, or a federal,
state, county, municipalm or other local income, franchise, excise or similar
tax assessment, levy or charge (distinct from any now in effect) measured by
or based, in whole or in part, upon any such gross rents, then any and all of
such taxes, assessments, levies or charges, to the extent so measured or
based, shall be deemed to be included within the term "real estate taxes."

     Notwithstanding the preceding paragraph, if Landlord shall fail to seek
an abatement of real estate taxes, and if Tenant shall deem itself aggrieved
by an amount of any such real estate taxes, Tenant may, upon prior notice to
Landlord, seek an abatement of such taxes by the commencement and diligent
prosecution of appropriate proceedings at Tenant's sole cost and expense.  To
the extent required by law, such proceedings may be maintained in the name of
Landlord, and to the extent so required, Landlord agrees to execute such
applications and other documents as may reasonably be required to effectuate
the foregoing.  Tenant shall not thereafter discontinue any abatement
proceedings begun by it without first giving Landlord prior notice of its
intent to do so and reasonable opportunity to be substituted in such
proceedings.  Tenant shall reimburse Landlord for, and indemnify and hold
Landlord harmless from and against, all loss, cost or expenses arising in
connection with such abatement proceedings, including, without limitation,
reasonable legal fees and expenses, and other administrative costs and
expenses.

     Notwithstanding any other provision of this Section 4.2, if the Term
expires or is terminated as of a date other than the last day of a fiscal
year, then for such fraction of a fiscal year at the end of the Term,
Tenant's last payment to Landlord under this Section 4.2 shall be made on the
basis of Landlord's best estimate of the items otherwise includable in
Landlord's Statement and shall be made on or before the later of (i) 10 days
after Landlord delivers such estimate to Tenant or (ii) the last day of the
Term, with an appropriate payment or refund to be made upon submission of
Landlord's Statement.


                                     -16-
<PAGE>


4.3   ESTIMATED ESCALATION PAYMENTS.

      If, with respect to any fiscal year or fraction thereof during the Term,
Landlord estimates that Tenant shall be obligated to pay Operating Cost
Escalation, then Tenant shall pay, as additional rent, on the first day of each
month of such fiscal year and each ensuing fiscal year thereafter, Estimated
Monthly Escalation Payments equal to 1/12th of the estimated Operating Cost
Escalation for the respective fiscal year, with an appropriate additional
payment or refund to be made within 30 days after Landlord's Statement is
delivered to Tenant. Landlord may adjust such Estimated Monthly Escalation
Payment from time to time and at any time during a fiscal year, and Tenant
shall pay, as additional rent, on the first day of each month following receipt
of Landlord's notice thereof, the adjusted Estimated Monthly Escalation Payment.

4.4   CHANGE OF FISCAL YEAR.

      Landlord shall have the right from time to time to change the periods of
accounting under Section 4.2 to any annual period other than a fiscal year, and
upon any such change all items referred to in this Section 4.4 shall be
appropriately apportioned. In all Landlord's Statements rendered under this
Section 4.4, amounts for periods partially within and partially without the
accounting periods shall be appropriately apportioned, and any items which are
not determinable at the time of a Landlord's Statement shall be included
therein on the basis of Landlord's estimate, and with respect thereto Landlord
shall render promptly after determination a supplemental Landlord's Statement,
and appropriate adjustment shall be made according thereto. All Landlord's
Statements shall be prepared on an accrual basis of accounting.

4.5   PAYMENTS.

      All payments of Annual Rent and additional rent shall be made to Managing
Agent, or to such other person as Landlord may from time to time designate. If
any installment of Annual Rent or additional rent or on account of leasehold
improvements is paid more than five days after the due date thereof, at
Landlord's election, ti shall bear interest at a rate equal to the average
prime commercial rate from time to time established by the three largest
national banks in Boston, Massachusetts plus 4% per annum from such due date,
which interest shall be immediately due and payable as further additional rent.

4.6   TENANT'S RIGHT TO REVIEW.

      Tenant shall have the right, upon reasonable prior notice, to examine
Landlord's books and records with respect to the items in the Landlord's
Statement during normal business hours at Landlord's offices where such books
and records are maintained


                                      -17-

<PAGE>

within 180 days following the delivery by Landlord to Tenant of such statement
or, in lieu thereof, at Landlord's sole option, Landlord will provide an audit
prepared by an independent public accountant. Within the aforesaid 180-day
period, Tenant may file written exception to any items of expense; provided,
however, that nothing herein shall be deemed to afford Tenant any right to
withhold any disputed payment claimed by Landlord to be due form Tenant to
Landlord, and Tenant shall promptly make all such payments as aforesaid. All
information and calculations set forth in the Landlord's Statement shall be
binding upon Tenant and no longer subject to challenge or dispute following the
aforesaid 180-day period unless and to the extent Tenant shall have timely
disputed the same and such dispute shall not have been resolved.


                                    ARTICLE V

                              LANDLORD'S COVENANTS

5.1   LANDLORD'S COVENANTS DURING THE TERM.

      Landlord covenants during the term:

      5.1.1  Building Services - To furnish, through Landlord's employees or
independent contractors, the services listed in EXHIBIT F;

      5.1.2  Additional Building Services - To furnish, through Landlord's
employees or independent contractors, reasonable additional Building operation
services upon reasonable advance request of Tenant at equitable rates from time
to time established by Landlord to be paid by Tenant;

      5.1.3  Repairs -   Except as otherwise provided in Article VII, to
make such repairs to the roof, HVAC systems, exterior walls, floor slabs,
other structural components and common facilities of the Building as may be
necessary to keep them in serviceable condition;

      5.1.4  Quiet Enjoyment - That Landlord has the right to make this Lease
ant that Tenant on paying the rent and performing its obligations hereunder
shall peacefully and quietly have, hold and enjoy the Premises throughout the
Term without any manner of hindrance or molestation from Landlord or anyone
claiming under Landlord, subject however to all the terms and provisions hereof;

      5.1.5  Insurance - To maintain casualty insurance for the Building
against loss or damage by fire, lightning, windstorm, tornado, hail and such
other further and additional hazards of whatever kind or nature as are now or
hereafter may be covered by standard extended coverage "all risk" endorsements,
which policy


                                      -18-

<PAGE>

shall contain a "replacement cost endorsement" and an "agreed value
endorsement" in such amounts as Landlord may consider reasonably appropriate;

      Landlord shall have no obligation to insure Tenant's personal property or
chattels, including, without limitation, Tenant's trade fixtures; and

      5.1.6  Tenant's Costs - To pay all costs and fees incurred by Tenant in
connection with the successful enforcement by Tenant of any obligations of
Landlord under this Lease.

5.2   INTERRUPTIONS.

      Landlord shall not be liable to Tenant for any compensation or reduction
of rent by reason of inconvenience or annoyance or for loss of business arising
from power losses or shortages or from the necessity of Landlord's entering the
Premises for any of the purposes in this Lease authorized, or for repairing the
Premises or any portion of the Building or Lot, provided that Landlord shall
use reasonable efforts to avoid necessary inconvenience to Tenant by reason
thereof. In case Landlord is prevented or delayed from making any repairs,
alterations or improvements, or furnishing any service or performing any other
covenant or duty to be performed on Landlord's part, by reason of any cause
beyond Landlord's reasonable control, Landlord shall not be liable to Tenant
therefor, nor, except as expressly otherwise provided in Article VII, shall
Tenant be entitled to any abatement or reduction of rent by reason thereof, nor
shall the same give rise to a claim in Tenant's favor that such failure
constitutes actual or constructive total or partial, eviction from the Premises.

      Landlord reserves the right to stop any service or utility system when
necessary by reason of accident or emergency or until necessary repairs have
been completed. Except in case of emergency repairs, Landlord will give Tenant
reasonable advance notice of any contemplated stoppage and will use reasonable
efforts to avoid unnecessary inconvenience to Tenant be reason thereof.

      Notwithstanding anything herein to the contrary, in the event that any
service or utility system is interrupted and such interruption interferes
materially with the use and occupation of the Premises by Tenant and such
interruption continues due to Landlord's negligence for 30 consecutive days,
Tenant shall be entitled, after notice to Landlord, to make the necessary
repairs and to be reimbursed by Landlord for the reasonable costs incurred in
connection with making such necessary repairs; provided, however, that nothing
herein shall be deemed to afford Tenant any right to offset such costs against
rent.


                                      -19-

<PAGE>

     Landlord also reserves the right to institute such policies, programs
and measures as may be necessary, required or expedient for the conservation
or preservation of energy or energy services or as may be necessary or
required to comply with applicable codes, rules, regulations or standards.

                                  ARTICLE VI

                              TENANT'S COVENANTS

6.1  TENANT'S COVENANTS DURING THE TERM.

     Tenant covenants during the Term and such further time as Tenant
occupies any part of the Premises:

     6.1.1  Tenant's Payments - To pay when due (a) all Annual Rent and
additional rent, (b) all taxes which may be imposed on Tenant's personal
property in the Premises (including, without limitation, Tenant's fixtures
and equipment) regardless to whomever assessed, (c) all charges by public
utilities for telephone and other utility services (including service
inspections therefor) rendered to the Premises not otherwise required
hereunder to be furnished by Landlord without charge, and (d) as additional
rent, all charges to Landlord for services rendered pursuant to Section 5.1.2
hereof.

     6.1.2  Repairs and Yielding Up - Except as otherwise provided in Article
VII and Section 5.1.3, to keep the Premises in good order, repair and
condition, reasonable wear and tear and casualty and taking only excepted; and
at the expiration or termination of this Lease peaceably to yield up the
Premises and all changes and additions therein in such order, repair and
condition, first removing all goods and effects of Tenant and any items, the
removal of which is required by agreement or specified herein to be removed
at Tenant's election and which Tenant elects to remove, and repairing all
damage caused by such removal and restoring the Premises and leaving them
clean and neat.

     6.1.3  Occupancy and Use - Continuously from the Commencement Date, to
use and occupy the Premises only for the Permitted Uses; not to injure or
deface the Premises, Building, or Lot; and not to permit in the Premises any
use thereof which is improper, offensive, contrary to law or ordinances, or
liable to create a nuisance or to invalidate or increase the premiums for any
insurance on the Building or its contents or liable to render necessary any
alteration or addition to the Building; not to dump, flush, or in any way
introduce any hazardous substances or any other toxic substances into the
septic, sewage or other waste disposal system serving the Premises, the
Building or the Lot; not

                                     -20-

<PAGE>

to generate, store or dispose of hazardous substances in or on the Premises,
the Building or the Lot or dispose of hazardous substances from the
Premises, the Building or the Lot to any other location without the prior
written consent of Landlord and then only in compliance with the Resource
Conversation and Recovery Act of 1976, as amended, 42 U.S.C. Section 6901 et
seq., and all other applicable laws, ordinances and regulations; to notify
Landlord of any incident which would require the filing of a notice under
applicable federal, state, or local law; not to store hazardous substances on
the Premises without first submitting to Landlord a list of all such
hazardous substances and all permits required therefor and thereafter
providing to Landlord on an annual basis Tenant's certification that all such
permits have been renewed with copies of such renewed permits; and to comply
with the orders and regulations of all governmental authorities with respect
to zoning, building, fire, health and other codes, regulations, ordinances
or laws applicable to the Premises. "Hazardous substances" as used in this
paragraph shall mean "hazardous substances" as defined in the Comprehensive
Environmental Response Compensation and Liability Act of 1980, as amended, 42
U.S.C. Section 9601 and regulation adopted pursuant to said Act.

     Landlord hereby represents that, to its knowledge without further
inquiry, the Premises, the Building and the Lot are free of hazardous
substances.

     6.1.4  Rules and Regulations - To comply with the Rules and Regulations
set forth in EXHIBIT G and all other reasonable Rules and Regulations
hereafter made by Landlord, or which Tenant has been given notice, for he
care and use of the Building and Lot and their facilities and approaches, it
being understood that Landlord shall not be liable to Tenant for the failure
of other tenants of the Building to conform to such Rules and Regulations.

     6.1.5  Safety Appliances - To keep the Premises equipped with all safety
appliances required by law or ordinance or any other regulation of any public
authority because of any use made by Tenant and to procure all licenses and
permits so required because of such use and, if requested by Landlord, to do
any work so required because of such use, it being understood that the
foregoing provisions shall not be construed to broaden in any way Tenant's
Permitted Uses.

     6.1.6  Assignment and Subletting - Not without the prior written consent
of Landlord to assign this Lease, to make any sublease, or to permit
occupancy of the Premises or any part thereof by anyone other than Tenant,
voluntarily or by operation of law (it being understood that in no event
shall Landlord consent to any such assignment, sublease or occupancy if the
same is on terms more favorable to the successor occupant than to the then
occupant); as additional rent, to reimburse Landlord promptly for reasonable
legal and other expenses incurred by Landlord in

                                     -21-

<PAGE>

connection with any request by Tenant for consent to assignment or subletting;
no assignment or subletting shall affect the continuing primary liability of
Tenant (which, following assignment, shall be joint and several with the
assignee); no consent to any of the foregoing in a specific instance shall
operate as a waiver in any subsequent instance. Landlord's consent to any
proposed assignment of subletting is required both as to the terms and
conditions thereof, and as to the creditworthiness of the proposed assignee
or subtenant and the consistency of the proposed assignee's or subtenant's
business with other uses and tenants in the Building. Landlord's consent to
assignment or subletting by Tenant shall not be unreasonably withheld,
provided that Tenant is not the in default under this Lease and such assignee
or subtenant pays therefor the greater of the Annual Rent and additional rent
then payable hereunder, or the then fair market rent for the Premises; and
provided further that Landlord shall not be deemed unreasonable for
withholding its consent to any assignment or subletting the arrangements for
which are to be made through any broker other than Landlord or its
affiliates. In the event that any assignee or subtenant pays to rent than
payable hereunder, or pro rata portion thereof on a square footage basis for
any portion of the Premises, Tenant shall promptly pay said excess to
Landlord as and when received by Tenant.

     If, at any time during the Term of this Lease, Tenant is:

            (i)  a corporation or a trust (whether or not having shares of
beneficial interest) and there shall occur any change in the identity of any
of the persons then having power to participate in the election or
appointment of the directors, trustees or other persons exercising like
functions and managing the affairs of Tenant; or

           (ii)  a partnership or association or otherwise not a natural
person (and is not a corporation or a trust) and there shall occur any change
in the identity of any of the persons who then are members of such
partnership or association or who comprise Tenant;

Tenant shall so notify Landlord and Landlord may terminate this Lease by
notice to Tenant given within 90 days thereafter if, in Landlord's reasonable
judgment, the credit of Tenant is thereby impaired. This paragraph shall not
apply if the initial Tenant named herein is a corporation and the
outstanding voting stock thereof is listed on a recognized securities
exchange.

     Notwithstanding the foregoing, upon prior notice to Landlord, without
the prior written consent of Landlord, Tenant shall be able to assign this
Lease or sublease the whole or a portion of the Premises to an affiliate or
Tenant (as defined below)

                                     -22-

<PAGE>

provided that (a) no such assignment or subletting shall affect the continuing
primary liability of Tenant and, following such assignment or subletting,
Tenant shall be jointly and severally liable with the assignee or subleasee for
all obligations under this Lease, (b) the creditworthiness of the proposed
assignee or sublessee is substantially the same as that of Tenant, (c) the
identity and character of the business of the assignee or sublessee and uses
proposed by such assignee or sublessee are consistent with the Permitted Uses,
and (d) Tenant is not then in default under this Lease.  The term "affiliate of
Tenant" for purposes of this Lease shall mean any entity controlling, controlled
by or under common control with Tenant or any successor of Tenant by merger,
consolidation or acquisition of substantially all of the assets of Tenant.

     6.1.7 Indemnity - To defend, with counsel approved by Landlord, all actions
against Landlord, any partner, trustee, stockholder, officer, director, employee
or beneficiary of Landlord, holders of mortgages secured by the Premises or the
Building and Lot and any other party having an interest in the Premises
("Indemnified Parties") with respect to, and to pay, protect, indemnify and save
harmless, to the extent permitted by law, all Indemnified Parties from and
against, any and all liabilities, losses, damages, costs, expenses (including
reasonable attorneys' fees and expenses), causes of action, suits, claims,
demands or judgments of any nature (a) to which any Indemnified Party is
subject because of its estate or interest in the Premises, or (b) arising from
(i) injury to or death of any person, or damage to or loss of property, on the
Premises or on adjoining sidewalks, streets or ways, or connected with the use,
condition or occupancy of any thereof unless caused by the negligence of the
respective Indemnified Party or any person or entity for whose conduct the
respective Indemnified Party is responsible, (ii) violation of this Lease, or
(iii) any act, fault, omission, or other misconduct of Tenant or its agents,
contractors, licensees, sublessees or invitees.

     6.1.8 (a) Tenant's Liability Insurance - To maintain public liability
insurance on the Premises indemnifying Landlord and Tenant against all claims
and demands for (i) injury to or death of any person or damage to or loss of
property, on the Premises or adjoining walks, streets or ways, or connected with
the use, condition or occupancy of any thereof unless caused by the negligence
of Landlord or its servants or agents, (ii) violation of this Lease, or (iii)
any act, fault or omission, or other misconduct of Tenant or its agents,
contractors, licensees, sublessees or invitees, in amounts which shall, at the
beginning of the Term, be at least equal to the limits set forth in Section 1.1,
and from time to time during the Term, shall be for such higher limits, if any,
as are customarily carried in the area in which the Premises are located on
property similar to the Premises


                                      -23-
<PAGE>

and used for similar purposes, and shall be written on the "Occurrence Basis"
and include Host Liquor liability insurance, and to furnish Landlord with
certificates thereof.

     (b) Tenant's Worker's Compensation Insurance - To keep all of Tenant's
employees working in the Premises covered by worker's compensation insurance
in statutory amounts and to furnish Landlord with certificates thereof.

     6.1.9  Insurance Policies - All policies for insurance required under
Section 6.1.8 shall be obtained from responsible companies qualified to do
business in the state in which the Premises are located and in good standing
therein, which companies and the amount of insurance allocated thereto shall
be subject to Landlord's approval. Tenant agrees to furnish Landlord with
certificates of all such insurance which Tenant is obligated to obtain
pursuant to Section 6.1.8 prior to the beginning of the Term and with each
renewal policy at least 30 days prior to the expiration of the policy it
renews. Each such policy shall prohibit cancellation and reduction of
coverage without at least 30 days' prior written notice to Landlord.

     6.1.10  Landlord's Right of Entry - To permit Landlord and Landlord's
agents entry: to examine the Premises at reasonable times and to make repairs
or replacements; to remove, at Tenant's expense, any changes, additions,
signs, curtains, blinds, shades, awnings, aerials, flagpoles, or the like not
consented to in writing; and to show the Premises to prospective tenants
during the 12 months preceding expiration of the Term and to prospective
purchasers and mortgagees at all reasonable times.

     6.1.11  Loading - Not to place Tenant's Property, as defined in Section
6.1.13, upon the Premises so as to exceed a rate of 50 pounds of live load per
square foot and not to move any safe, vault or other heavy equipment in, about
or out of the Premises except in such manner and at such times as Landlord
shall in each instance approve; Tenant's business machines and mechanical
equipment which cause vibration or noise that may be transmitted to the Building
structure or to any other leased space in the Building shall be placed and
maintained by Tenant in settings of cork, rubber, spring, or other types of
vibration eliminators sufficient to eliminate such vibration or noise.

     6.1.12  Landlord's Costs - In case Landlord shall be made party to any
litigation commenced by or against Tenant or by or against any parties in
possession of the Premises or any part thereof claiming under Tenant, to pay, as
additional rent, all costs, including but not limited to reasonable counsel
fees, incurred by or imposed upon Landlord in connection with such litigation,
unless such costs and fees were incurred by Landlord in connection with the
successful enforcement by Tenant of any obligations of Landlord under this
Lease; and, as additional rent,


                                      -24-
<PAGE>

also to pay all such costs and fees incurred by Landlord in connection with the
successful enforcement by Landlord of any obligations of Tenant under this
Lease.

     6.1.13 Tenant's Property - All the furnishings, fixtures, equipment,
effects and property of every kind, nature and description of Tenant and of all
persons claiming by, through or under Tenant which, during the continuance of
this Lease or any occupancy of the Premises by Tenant or anyone claiming under
Tenant, may be on the Premises or elsewhere in the Building or on the Lot shall
be at the sole risk and hazard of Tenant, and if the whole or any part thereof
shall be destroyed or damaged by fire, water or otherwise, or by the leakage or
bursting of water pipes, steam pipes, or other pipes, by theft, or from any
other cause, no part of said loss or damage is to be charged to or to be borne
by Landlord unless due to the negligence of Landlord.

     6.1.14 Labor or Materialmen's Liens - To pay promptly when due the entire
cost of any work done on the Premises by Tenant, its agents, employees, or
independent contractors; not to cause or permit any liens for labor or materials
performed or furnished in connection therewith to attach to the Premises; and
immediately to discharge any such liens which may so attach.

     6.1.15 Changes or Additions - Not to make any changes or additions to the
Premises without Landlord's prior written consent (which consent shall not be
unreasonably withheld or delayed), provided that Tenant shall reimburse Landlord
for all costs incurred by Landlord in reviewing Tenant's proposed changes or
additions, and provided further that, in order to protect the functional
integrity of the Building, all such changes and additions shall be performed by
contractors selected from a list of approved contractors prepared by Landlord
from time to time.

     6.1.16 Holdover - To pay to Landlord the greater of twice (a) the then fair
market rent as conclusively determined by Landlord or (b) the total of the
Annual Rent and additional rent then applicable for each month or portion
thereof Tenant shall retain possession of the Premises or any part thereof after
the termination of this Lease, whether by lapse of time or otherwise, and also
to pay all damages sustained by Landlord on account thereof; the provisions of
this subsection shall not operate as a waiver by Landlord of the right of
re-entry provided in this Lease.


                                      -25-
<PAGE>

                                  ARTICLE VII

                              CASUALTY AND TAKING

7.1      CASUALTY AND TAKING.

         In case during the Term all or any substantial part of the Premises,
Building, or Lot or any one or more of them, are damaged materially by fire or
any other cause or by action of public or other authority in consequence thereof
or are taken by eminent domain or Landlord receives compensable damage by reason
of anything lawfully done in pursuance of public or other authority, this Lease
shall terminate at Landlord's election, which may be made, notwithstanding
Landlord's entire interest may have been divested, by notice to Tenant within 30
days after the occurrence of the event giving rise to the election to terminate,
which notice shall specify the effective date of termination which shall be not
less than 30 nor more than 60 days after the date of notice of such termination.
If in any such case the Premises are rendered unfit for use and occupation and
the Lease is not so terminated, Landlord shall use due diligence to put the
Premises, or, in case of a taking, what may remain thereof (excluding any items
installed or paid for by Tenant which Tenant may be required or permitted to
remove) into proper condition for use and occupation to the extent permitted by
the net award of insurance or damages available to Landlord, and a just
proportion of the Annual Rent and additional rent according to the nature and
extent of the injury shall be abated until the Premises or such remainder shall
have been put by Landlord in such condition; and in case of a taking which
permanently reduces the area of the Premises, a just proportion of the Annual
Rent and additional rent shall be abated for the remainder of the Term and an
appropriate adjustment shall be made to the Annual Estimated Operating Expenses.

         Notwithstanding the foregoing, if such damage (a) cannot, in Landlord's
reasonable opinion asserted in a notice delivered within 30 days of such
casualty ("Landlord's Notice"), be fully repaired within six months after
Landlord's Notice, or (b) is not in fact repaired within six months after
Landlord's Notice (plus up to an additional 30 days required by reason of causes
beyond Landlord's control), Tenant shall have the right, by written notice to
Landlord given within 30 days after Landlord's Notice, or, as the case may be,
within 30 days after the expiration of said six-month construction period (as so
extended) if the repairs are not then completed to terminate this Lease,
effective as of the date of such casualty as if that date were the date set
forth in this Lease for the expiration of the Term; provided, however, that
Tenant's failure to provided Landlord with such notice within said 30-day period
shall waive Tenant's right to terminate under this Section 7.1; and provided,
further, that Tenant shall have no right to terminate if the casualty which
damaged the Premises or


                                      -26-
<PAGE>

Building was caused solely by the negligence of Tenant, its agents, employees,
invitees, licensees, subtenants or assignees or any combination of such parties.

7.2      RESERVATION OF AWARD.

         Landlord reserves to itself any and all rights to receive awards made
for damages to the Premises, Building or Lot and the leasehold hereby created,
or any one or more of them, accruing by reason of exercise of eminent domain or
by reason of anything lawfully done in pursuance of public or other authority.
Tenant hereby releases and assigns to Landlord all Tenant's rights to such
awards, and covenants to deliver such further assignments and assurances thereof
as Landlord may from time to time request, and hereby irrevocably designates and
appoints Landlord its attorney-in-fact to execute and deliver in Tenants's name
and behalf all such further assignments thereof. It is agreed and understood,
however, that Landlord does not reserve to itself, and Tenant does not assign to
Landlord, any damages payable for (a) movable trade fixtures installed by Tenant
or anybody claiming under Tenant, at its own expense or (b) relocation expenses
recoverable by Tenant from such authority in a separate action.

                                  ARTICLE VIII

                               RIGHTS OF MORTGAGEE

8.1      PRIORITY OF LEASE.

         This Lease is and shall continue to be subject and subordinate to any
presently existing mortgage or deed of trust of record covering the Lot or
Building or both (the "mortgaged premises"). The holder of any such presently
existing mortgage or deed of trust shall have the election to subordinate the
same to the rights and interests of Tenant under this Lease exercisable by
filing with the appropriate recording office a notice of such election,
whereupon the Tenant's rights and interests hereunder shall have priority over
such mortgage or deed of trust.

         Unless the option provided for in the next following sentence shall be
exercised, this Lease shall be superior to and shall not be subordinate to, any
mortgage, deed of trust or other voluntary lien hereafter placed on the
mortgaged premises. The holder of any such mortgage, deed of trust or other
voluntary lien shall have the option to subordinate this Lease to the same,
provided that such holder enters into an agreement with Tenant by the terms of
which the holder will agree to recognize the rights of Tenant under this Lease
and to accept Tenant as tenant of the Premises under the terms and conditions of
this Lease in the event of acquisition of title by such holder through
foreclosure proceedings or otherwise and Tenant will agree to recognize the


                                      -27-
<PAGE>

holder of such mortgage as Landlord in such event, which agreement shall be made
to expressly bind and inure to the benefit of the successors and assigns of
Tenant and of the holder and upon anyone purchasing the mortgaged premises at
any foreclosure sale. Any such mortgage to which this Lease shall be
subordinated may contain such terms, provisions and conditions as the holder
deems usual or customary.

8.2      RIGHTS OF MORTGAGE HOLDERS; LIMITATION OF MORTGAGEE'S LIABILITY.

         The word "mortgage" as used herein includes mortgages, deeds of trust
or other similar instruments evidencing other voluntary liens or encumbrances,
and modifications, consolidations, extensions, renewals, replacements and
substitutes thereof. The word "holder" shall mean a mortgagee, and any
subsequent holder or holders of a mortgage. Until the holder of a mortgage shall
enter and take possession of the Premises for the purpose of foreclosure such
holder shall have only such rights of Landlord as are necessary to preserve the
integrity of this Lease as security. Upon entry and taking possession of the
Premises for the purpose of foreclosure, such holder shall have all the rights
of Landlord. Notwithstanding any other provision of this Lease to the contrary
including without limitation Section 10.4, no such holder of a mortgage shall be
liable, either as mortgagee or as assignee, to perform, or be liable, either as
mortgagee or as assignee, to perform, or be liable in damages for failure to
perform any of the obligations of Landlord unless and until such holder shall
enter and take possession of the Premises for the purpose of foreclosure, and
such holder shall not in any event be liable to perform or for failure to
perform the obligations of Landlord under Section 3.1. Upon entry for the
purpose of foreclosure such holder shall be liable to perform all of the
obligations of Landlord (except for the obligations under Section 3.1), subject
to and with the benefit of the provisions of Section 10.4, provided that a
discontinuance of any foreclosure proceeding shall be deemed a conveyance under
said provisions to the owner of the equity of the Premises.

8.3      MORTGAGEE'S ELECTION.

         Notwithstanding any other provision to the contrary contained in this
Lease, if prior to substantial completion of Landlord's obligations under
Article III, any holder of a first mortgage on the mortgaged premises enters and
takes possessions thereof for the purpose of foreclosing the mortgage, such
holder may elect, by written notice given to the Tenant and Landlord at any time
within 90 days after such entry and taking of possession, not to perform
Landlord's obligations under Article III, and in such event such holder and all
persons claiming  under it shall be relieved of all obligations to
perform, and all liability for failure to perform, said Landlord's obligations
under Article III, and Tenant may


                                      -28-
<PAGE>

terminate this Lease and all its obligations hereunder by written notice to
Landlord and such holder given within 30 days after the day on which such holder
shall have given its notice as aforesaid.

8.4  NO PREPAYMENT OR MODIFICATION, ETC.

     Tenant shall not pay Annual Rent, additional rent, or any other charge more
than 10 days prior to the due date thereof. No prepayment of Annual Rent,
additional rent or other charge, no assignment of this Lease (except as
permitted by Section 6.1.6 to an affiliate of Tenant (as defined in Section
6.1.6)) and no agreement to modify so as to reduce the rent, change the Term,
or otherwise materially change the rights of Landlord under this Lease, or to
relieve Tenant of any obligations or liability under this Lease, shall be
valid unless consented to in writing by Landlord's mortgagees of record, if
any.

8.5  NO RELEASE OR TERMINATION.

     No act or failure to act on the part of Landlord which would entitle
Tenant under the terms of this Lease, or by law, to be relieved of Tenant's
obligations hereunder or to terminate this Lease, shall result in a release
or termination of such obligations or a termination of this Lease unless (a)
Tenant shall have first given written notice of Landlord's act or failure to
act to Landlord's mortgagees of record, if any, specifying the act or failure
to act on the part of Landlord which could or would give basis to Tenant's
rights and (b) such mortgagees, after receipt of such notice, have failed or
refused to correct or cure the condition complained of within a reasonable
time thereafter, but nothing contained in this Section 8.5 shall be deemed to
impose any obligation on any such mortgagee to correct or cure any such
condition. "Reasonable time" as used above in this section shall mean 30 days
or such longer period as may be necessary to complete such correction or cure
if such condition is determined to exist and shall include additional
reasonable time to obtain possession of the mortgaged premises, if the
mortgagee elects to do so.

8.6  CONTINUING OFFER.

     The covenants and agreements contained in this Lease with respect to the
rights, powers and benefits of a mortgagee (particularly, without limitation
thereby, the covenants and agreements contained in this Article VIII) constitute
a continuing offer to any person, corporation or other entity, which by
accepting or requiring an assignment of this Lease or by entry or foreclosure
assumes the obligations herein set forth with respect to such mortgagee; such
mortgagee is hereby constituted a party to this Lease as an obligee hereunder to
the same extent as though its name were written hereon as such; and such
mortgagee shall be entitled to enforce such provisions in its own name. Tenant


                                      -29-
<PAGE>


agrees on request of Landlord to execute and deliver from time to time any
agreement which may reasonably be deemed necessary to implement the provisions
of this Article VIII.

8.7  MORTGAGEE'S APPROVAL.

     Landlord's obligation to perform its covenants and agreements hereunder is
subject to the condition precedent that this Lease be approved by the holder of
any mortgage of which the Premises are a part and by the issuer of any
commitment to make a mortgage loan which is in effect on the date hereof. Unless
landlord gives Tenant written notice within 30 business days after the date
hereof that such holder or issuer, or both, disapprove of this Lease, then this
condition shall be deemed to have been satisfied or waived and the provisions of
this Section 8.7 shall be of no further force or effect.

                                   ARTICLE IX

                                    DEFAULT

9.1  EVENTS OF DEFAULT.

     If any default by Tenant continues after notice, in case of Annual Rent,
additional rent, Tenant Improvement Reimbursement or any other monetary
obligation to Landlord for more than 10 days, or in any other case for more than
30 days and such additional time, if any, as is reasonably necessary to cure the
default if the default is of such a nature that it cannot reasonably be cured in
30 days and Tenant diligently endeavors to cure such default; or if the Tenant
becomes insolvent, fails to pay its debts as they fall due, files a petition
under any chapter of the U.S. Bankruptcy Code, 11 U.S.C. 101 et seq., as it may
be amended (or any similar petition under any insolvency law of any
jurisdiction), or if such petition is filed against Tenant and such petition is
not dismissed within 60 days of such filing; or if Tenant proposes any
dissolution, liquidation, composition, financial reorganization or
recapitalization with creditors, makes an assignment or truest motrgage for
benefit of creditors, or if a receiver, trustee, custodian or similar agent is
appointed or takes possession with respect to any property of Tenant; or if the
leasehold hereby created is taken on execution or other process of law in any
action against Tenant; then, and in any such case, Landlord and the agents and
servants of Landlord may, in addition to and not in derogation of any remedies
for any preceding breach of covenant, immediately or at any time thereafter
while such default continues and without further notice, at Landlord's election,
do any one or more of the following: (a) give Tenant written notice stating that
the Lease is terminated, effective upon the giving of such notice or upon a date
stated in such notice, as Landlord may elect, in which event the Lease shall be


                                      -30-
<PAGE>


irrevocably extinguished and terminated as stated in such notice without any
further action, or (b) with or without process of law, in a lawful manner enter
and repossess the Premises as of Landlord's former estate, and expel Tenant and
those claiming through or under Tenant, and remove its and their effects,
without being guilty of trespass, in which event the Lease shall be irrevocably
extinguished and terminated at the time of such entry, or (c) pursue any other
rights or remedies permitted by law.  Any such termination of the Lease shall be
without prejudice to any remedies which might otherwise be used for arrears of
rent or prior breach of covenant, and in the event of such termination Tenant
shall remain liable under this Lease as hereinafter provided. Tenant hereby
waives all statutory rights (including, without limitation, rights of
redemption, if any) to the extent such rights may be lawfully waived, and
Landlord, without notice to Tenant, may store Tenant's effects and those of any
person claiming through or under Tenant at the expense and risk of Tenant and,
if Landlord so elects, may sell such effects at public auction or private sale
and apply the net proceeds to the payment of all sums due to Landlord from
Tenant, if any, and pay over the balance, if any, to Tenant.

9.2  TENANT'S OBLIGATIONS AFTER TERMINATION.

     In the event that this Lease is terminated under any of the provisions
contained in Section 9.1 or shall be otherwise terminated for breach of any
obligation of Tenant, Tenant covenants to pay forthwith to Landlord, as
compensation, the excess of the total rent reserved for the residue of the Term
over the rental value of the Premises for said residue of the Term. In
calculating the rent reserved, there shall be included, in addition to the
Annual Rent and all additional rent, the value of all other consideration agreed
to be paid or performed by Tenant for said residue. Tenant further covenants as
an additional and cumulative obligation after any such ending to pay punctually
to Landlord all the sums and perform all the obligations which Tenant covenants
in this Lease to pay and to perform in the same manner and to the same extent
and at the same time as if this Lease had not been terminated. In calculating
the amounts to be paid by Tenant under the next foregoing covenant, Tenant shall
be credited with any amount paid to Landlord as compensation as provided in the
first sentence of this Section 9.2 and also with the net proceeds of any rents
obtained by Landlord by reletting the Premises, after deducting all Landlord's
expenses in connection with such reletting, including, without implied
limitation, all repossession costs, brokerage commissions, fees for legal
services and expenses of preparing the Premises for such reletting, it being
agreed by Tenant that Landlord may (a) relet the Premises or any part or parts
thereof for a term or terms which may at Landlord's option be equal to or less
than or exceed the period which would otherwise have constituted the balance of
the term and may grant such concessions and free rent as Landlord in its sole


                                      -31-
<PAGE>

judgment considers advisable or necessary to relet the same and (b) make such
alterations, repairs and decorations in the Premises as Landlord in its sole
judgment considers advisable or necessary to relet the same, and no action of
Landlord in accordance with the foregoing or failure to relet or to collect
rent under reletting shall operate or be construed to release or reduce
Tenant's liability as aforesaid.

       Nothing contained in this Lease shall, however, limit or prejudice the
right of Landlord to prove and obtain in proceedings for bankruptcy or
insolvency by reason of the termination of this Lease, an amount equal to the
maximum allowed by any statute or rule of law in effect at the time when, and
governing the proceedings in which, the damages are to be proved, whether or not
the amount be greater, equal to, or less than the amount of the loss or damages
referred to above.

                                   ARTICLE X

                                 MISCELLANEOUS

10.1   NOTICE OF LEASE.

       Upon request of either party, both parties shall execute and deliver,
after the Term begins, a short form of this Lease in form appropriate for
recording or registration, and if this Lease is terminated before the Term
expires, an instrument is such form acknowledging the date of termination.

10.2   INTENTIONALLY OMITTED.

10.3   NOTICES FROM ONE PARTY TO THE OTHER.

       All notices required or permitted hereunder shall be in writing and
addressed, if to the Tenant, at Tenant's Address or such other address as Tenant
shall have last designated by notice in writing to Landlord and, if to Landlord,
at Landlord's Address or such other address as Landlord shall have last
designated by notice in writing to Tenant. Any notice shall have been deemed
duly given if mailed to such address postage prepaid, registered or certified
mail, return receipt requested, when deposited with the U.S. Postal Service or
if delivered to such address by hand, when so delivered.

10.4   BIND AND INURE.

       The obligations of this Lease shall run with the land, and this Lease
shall be binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns, except that the Landlord named herein and
each successive owner of the Premises shall be liable only for the obligations
accruing during


                                      -32-
<PAGE>

the period of its ownership. The obligations of Landlord shall be binding
upon the assets of Landlord which comprise the Premises but not upon other
assets of Landlord. No individual partner, trustee, stockholder, officer,
director, employee or beneficiary of Landlord shall be personally liable
under this Lease and Tenant shall look solely to Landlord's interest in the
Premises in pursuit of its remedies upon an event of default hereunder, and
the general assets of the individual partners, trustees, stockholders,
officers, employees or beneficiaries of Landlord shall not be subject to
levy, execution or other enforcement procedure for the satisfaction of the
remedies of Tenant.

10.5   NO SURRENDER.

       The delivery of keys to any employee of Landlord or to Landlord's agent
or any employee thereof shall not operate as a termination of this Lease or a
surrender of the Premises.

10.6   NO WAIVER, ETC.

       The failure of Landlord or of Tenant to seek redress for violation of, or
to insist upon the strict performance of any covenant or condition of this
Lease or, with respect to such failure of Landlord, any of the Rules and
Regulations referred to in Section 6.1.4, whether heretofore or hereafter
adopted by Landlord, shall not be deemed a waiver of such violation nor prevent
a subsequent act, which would have originally constituted a violation, from
having all the force and effect of an original violation, nor shall the failure
of Landlord to enforce any of said Rules and Regulations against any other
tenant in the Building be deemed a waiver of any such Rules or Regulations. The
receipt by Landlord of Annual Rent or additional rent with knowledge of the
breach of any covenant of this Lease shall not be deemed a waiver of such breach
by Landlord, unless such waiver by in writing and signed by Landlord. No consent
or waiver, express or implied, by Landlord or Tenant to or of any breach of any
agreement or duty shall be construed as a waiver or consent to or of any other
breach of the same or any other agreement or duty.

10.7   NO ACCORD AND SATISFACTION.

       No acceptance by Landlord of a lesser sum than the Annual Rent and
additional rent then due shall be deemed to be other than on account of the
earliest installment of such rent due, nor shall any endorsement or statement on
any check or any letter accompanying any check or payment as rent be deemed as
accord and satisfaction, and Landlord may accept such check or payment without
prejudice to Landlord's right to recover the balance of such installment or
pursue any other remedy in this Lease provided.


                                      -33-
<PAGE>

10.8   CUMULATIVE REMEDIES.

       The specific remedies to which Landlord may resort under the terms of
this Lease are cumulative and are not intended to be exclusive of any other
remedies or means of redress to which it may be lawfully entitled in case of any
breach or threatened breach by Tenant of any provisions of this Lease. In
addition to the other remedies provided in this Lease, Landlord shall be
entitled to the restraint by injunction of the violation or attempted or
threatened violation of any of the covenants, conditions or provisions of this
Lease or to a decree compelling specific performance of any such covenants,
conditions or provisions.

10.9   LANDLORD'S RIGHT TO CURE.

       If Tenant shall at any time default in the performance of any obligation
under this Lease, Landlord shall have the right, but shall not be obligated, to
enter upon the Premises and to perform such obligation, notwithstanding the fact
that no specific provision for such substituted performance by Landlord is made
in this Lease with respect to such default. In performing such obligation,
Landlord may make any payment of money or perform any other act. All sums so
paid by Landlord (together with interest at the rate of 4% per annum in excess
of the then average prime commercial rate of interest being charged by the three
largest national banks in Boston, Massachusetts) and all necessary incidental
costs and expenses in connection with the performance of any such act by
Landlord, shall be deemed to be additional rent under this Lease and shall be
payable to Landlord immediately on demand. Landlord may exercise the foregoing
rights without waiving any other of its rights or releasing Tenant from any of
its obligations under this Lease.

10.10  ESTOPPEL CERTIFICATE.

       Tenant agrees, from time to time, upon not less than 15 days' prior
written request by Landlord, to execute, acknowledge and deliver to Landlord
a statement in writing certifying that this Lease is unmodified and in full
force and effect; that Tenant has no defenses, offsets or counterclaims
against its obligations to pay the Annual Rent and additional rent and to
perform its other covenants under this Lease; that there are no uncured
defaults of Landlord or Tenant under this Lease (or, if there have been
modifications, that this Lease is in full force and effect as modified and
stating the modifications, and, if there are any defenses, offsets,
counterclaims, or defaults, setting them forth in reasonable detail); and the
dates to which the Annual Rent, additional rent and other charges have been
paid. Any such statement delivered pursuant to this Section 10.10 shall be in a

                                      -34-
<PAGE>


form reasonably acceptance to and may be relied upon by any prospective
purchaser or mortgagee of premises which include the Premises or any prospective
assignee of any such mortgagee.

10.11    WAIVER OF SUBROGATION.

         Any insurance carried by either party with respect to the Premises and
property therein or occurrences thereon shall include a clause or endorsement
denying to the insurer rights of subrogation against the other party to the
extent rights have been waived by the insured prior to occurrences of injury or
loss. Each party, notwithstanding any provisions of this Lease to the contrary,
hereby waives any rights of recovery against the other for injury or loss due to
hazards covered by insurance containing such clause or endorsement to the extent
of the indemnification received thereunder.

10.12    ACTS OF GOD.

         In any case where either party hereto is required to do any act, delays
caused by or resulting from Acts of God, war, civil commotion, fire, flood or
other casualty, labor difficulties, shortages of labor, materials or equipment,
government regulations, usually severe weather, or other causes beyond such
party's reasonable control shall not be counted in determining the time during
which work shall be completed, whether such time be designated by a fixed date,
a fixed time or a "reasonable time", and such time shall be deemed to be
extended by the period of such delay.

10.13    BROKERAGE.

         Each of Landlord and Tenant represents and warrants to the other that
it has dealt with no broker in connection with this transaction other than
spaulding and Slye Company and The Codman Company and each agrees to defend,
with counsel approved by the other, indemnify and save the other harmless from
and against any and all cost, expense or liability for any compensation,
commissions or charges claimed by a broker and in breach of its foregoing
representation and warranty.

10.14    SUBMISSION NOT AN OFFER.

         The Submission of a draft of this Lease or a summary of some or all of
its provisions does not constitute an offer to Lease or demise the Premises, it
being understood and agreed that neither Landlord nor Tenant shall be legally
bound with respect to the leasing of the Premises unless and until this Lease
has been executed by both Landlord and Tenant and a fully executed copy has been
delivered to each of them.


                                      -35-
<PAGE>


10.15    APPLICABLE LAW AND CONSTRUCTION.

         This Lease shall be governed by and construed in accordance with the
laws of the state in which the Premises are located. If any term, covenant,
condition or provision of this Lease or the application thereof to any person or
circumstances shall be declared invalid or unenforceable by the final ruling of
a court of competent jurisdiction having final review, the remaining terms,
covenants, conditions and provisions of this Lease and their application to
persons or circumstances shall no be affected thereby and shall continue to be
enforced and recognized as valid agreements of the parties, and in the place of
such invalid or unenforceable provision, there shall be substituted a like, but
valid and enforceable provision which comports to the finding of the aforesaid
court and most nearly accomplishes the original intention of the parties.

         There are no oral or written agreements between Landlord and Tenant
affecting this Lease. This Lease may be amended, and the provisions hereof may
be waived or modified, only by instruments in writing executed by Landlord and
Tenant.

         The titles of the several Articles and Sections contained herein are
for convenience only and shall not be considered in construing this Lease.

         Unless repugnant to the context, the words "Landlord" and "Tenant"
appearing in this Lease shall be construed to mean those named above and their
respective heirs, executors, administrators,


                                      -36-
<PAGE>


successors and assigns, and those claiming through or under them respectively.
If there be more than one tenant, the obligations imposed by this Lease upon
Tenant shall be joint and several.

         EXECUTED as a sealed instrument in two or more counterparts on the day
and year first above written.

                               LANDLORD:

                                         NEW ENGLAND MUTUAL LIFE INSURANCE
                                         COMPANY

                                         By:    Copley Real Estate Advisors,
                                                Inc., its duly authorized asset
                                                manager and advisor

                                                By: Michael H. Harrity
                                                   ---------------------------
                                                   Name: MICHAEL H. HARRITY
                                                         ---------------------
                                                   Title: VICE PRESIDENT
                                                          --------------------
                                         A copy of Landlord's corporate
                                         authorization for such execution is
                                         attached hereto.

                               TENANT:

                                         CROSSCOMM CORPORATION

                                         By: [ILLEGIBLE]
                                             ----------------------------

                                         Name: [ILLEGIBLE]
                                               --------------------------
                                                (please print or type)

                                         Title: V. P. Finance
                                                -------------------------
                                                  (please print or type)

                                         A copy of Tennant's corporate
                                         authorization for such execution is
                                         attached hereto.


                                      -37-
<PAGE>

COMMONWEALTH OF MASSACHUSETTS)
                             )ss.
COUNTY OF SUFFOLK            )

    On May 13, 1992, before me, the undersigned, a Notary Public in and for
said Commonwealth, personally appeared Michael H. Harrity, personally known
to me to be the person who executed the within instrument as Vice President
of Copley Real Estate Advisors, Inc., a Massachusetts Corporation, as duly
authorized asset manager and advisor to New England Mutual Life Insurance
Company, a Massachusetts corporation, the corporation therein named, pursuant
to its bylaws or a resolution of its board of directors, and acknowledged to
me that Copley Real Estate Advisors, Inc. executed the within instrument on
behalf of New England Mutual Life Insurance Company as its free act and deed.

     WITNESS my hand a official seal.




                                 /s/ Linda J. Barove
                                 ------------------------------------------
                                 Notary Public in and for said Commonwealth

                                              LINDA J. BAROVE, Notary Public
                                            My Commission Expires Sept. 2, 1994


<PAGE>

                                       EXHIBIT A
                                       ----------

                                          Lot 8

     A parcel of land on Donald J. Lynch Boulevard located in Marlborough,
Middlesex County, Commonwealth of Massachusetts, shown as Lot 8 on a plan
entitled "Plan of Land Marlborough, Mass." dated April 7, 1986, prepared by
GLM Engineering Consultants, Inc., recorded with the Middlesex South Registry
of Deeds on May 12, 1986 as Plan No. 601 of 1986 (the "Plan"), and bounded
and described as follows:

NORTHERLY:        by Donald J. Lynch Boulevard, 603.56 feet;

NORTHERLY:        by Donald J. Lynch Boulevard by a curved line
                  with a radius of 940.00 feet, a distance of
                  124.11 feet;

NORTHEASTERLY:    by Parcel A as shown on said plan, 84.73 feet;

NORTHEASTERLY:    by said Parcel A by a curved line with a
                  radius of 130.00 feet, a distance of 127.78
                  feet;

EASTERLY:         by said Parcel A, 20.00 feet;

NORTHERLY:        by said Parcel A by a curved line with a
                  radius of 150.00 feet, a distance of 78.54
                  feet;

NORTHEASTERLY:    by said Parcel A, 120.92 feet;

SOUTHEASTERLY:    by Interstate Route 290 by a curved line with
                  a radius of 8630.00 feet, a distance of 105.85
                  feet;

SOUTHEASTERLY:    by Interstate Route 290, 785.87 feet; and

SOUTHWESTERLY:    by Lot 9 as shown on said plan, 398.59 feet.

Containing 6.79 acres according to said plan.

     The above described premises include a parcel of registered land shown
as "Lot 11" on Land Court Plan No. 3652-I filed with the Land Court
Engineer's office in Boston, Massachusetts.


<PAGE>

     Together with the right to use the adjacent portion of the adjoining
Parcel A shown as "Access & Utility Easement" on a plan entitled "Plan of
Land Marlborough, Mass." dated July 22, 1986, prepared by GLM Engineering
Consultants, Inc., recorded with said Deeds as Plan No. 1064 of 1986, and
that portion of the adjoining Lot 9 shown as "Access & Utility Easement" on a
plan entitled "Plan of Land, Marlborough, Mass." dated April 7, 1986,
prepared by GLM Engineering Consultants, Inc., recorded with the Middlesex
South Registry of Deeds on May 12, 1986 as Plan No. 602 of 1986, for purposes
of access, ingress and egress as may from time to time be necessary. Said
easements shall be in the locations designated by Landlord from time to time.



                                   A-2
<PAGE>








                                    EXHIBIT C
                                    ---------
                             Intentionally Omitted.
                             ----------------------

                                       C-1
<PAGE>









                                   EXHIBIT D

                        Form Of First Amendment To Lease

     THIS FIRST AMENDMENT TO LEASE, made this _____ day of _________, 1992 by
and between NEW ENGLAND MUTUAL LIFE INSURANCE COMPANY ("Landlord"), and
CROSSCOMM CORPORATION, a Delaware corporation ("Tenant").


                                  WITNESSETH:

     THAT, WHEREAS, Landlord and Tenant did enter into that certain Lease dated
_____________________, 1992, for the demise of the Premises described therein
(hereinafter the "Lease"); and

     WHEREAS, all terms defined in the Lease shall have the same meanings when
referred to herein; and

     WHEREAS, Landlord and Tenant agreed to confirm the Commencement Date of the
Lease, pursuant to and in accordance with Article II thereof;

     NOW, THEREFORE, for consideration paid by each to the other, Landlord and
Tenant hereby agree that the Commencement Date of the Lease shall be
______________________________.

     EXCEPT as hereby modified and amended, all other terms, provisions,
covenants and conditions of the Lease shall remain unmodified and in full force
and effect.

     IN WITNESS WHEREOF, Landlord and Tenant have executed this First Amendment
to Lease as a sealed instrument on or as of the day and year first above
written.

WITNESS:                                LANDLORD:

                                        NEW ENGLAND MUTUAL LIFE INSURANCE
                                        COMPANY

                                        By:  Copley Real Estate Advisors,
                                             Inc., its duly authorized asset
                                             manager and advisor


________________________________             By:________________________________

                                                Name:___________________________
                                                Title:__________________________


                                       D-1

<PAGE>


WITNESS:                                TENANT:

                                        CROSSCOMM CORPORATION


_________________________________       By:_____________________________________
                                           Name:________________________________
                                           Title:_______________________________


                                       D-2
<PAGE>

                                   EXHIBIT E
                                   ---------

Leasehold Improvements as specified in the approved Complete Plans (not
available on the date hereof).

<PAGE>

                                   EXHIBIT F
                              LANDLORD'S SERVICES

I.   CLEANING
     A.   General
          1.   All cleaning work will be performed between 8 a.m. and 12
               midnight, Monday through Friday, unless otherwise necessary for
               stripping, waxing, etc.
          2.   Abnormal waste removal (e.g., computer installation paper, bulk
               packaging, wood or cardboard crates, refuse from cafeteria
               operation, etc.) shall be Tenant's responsibility.
     B.   Daily Operations (5 times per week)
          1.   Tenant Areas
               a.   Empty and clean all waste receptacles; wash receptacles as
                    necessary.
               b.   Vacuum all rugs and carpeted areas.
               c.   Empty, damp-wipe and dry all ashtrays.
          2.   Lavatories
               a.   Sweep and wash floors with disinfectant.
               b.   Wash both sides of toilets seats with disinfectant.
               c.   Wash all mirrors, basins, bowls, urinals.
               d.   Spot clean toilet partitions.
               e.   Empty and disinfect sanitary napkin disposal receptacles.
               f.   Refill toilet tissue, towel, soap, and sanitary napkin
                    dispensers.
          3.   Public Areas
               a.   Wipe down entrance doors and clean glass (interior and
                    exterior).
               b.   Vacuum elevator carpets and wipe down doors and walls.
               c.   Clean water coolers.
     C.   Operations as Needed (but not less than every other day)
          1.   Tenant and Public Areas
               a.   Buff all resilient floor areas.
     D.   Weekly Operations
          1.   Tenant Areas, Lavatories, Public Areas
               a.   Hand-dust and wipe clean all horizontal surfaces with
                    treated cloths to include furniture, office equipment,
                    window sills, door ledges, chair rails, baseboards,
                    convector tops, etc., within normal reach.
               b.   Remove finger marks from private entrance doors, light
                    switches, and doorways.
               c.   Sweep all stairways.
     E.   Monthly Operations
          1.   Tenant and Public Areas
               a.   Thoroughly vacuum seat cushions on chairs, sofas, etc.
               b.   Vacuum and dust grillwork.
          2.   Lavatories
               a.   Wash down interior walls and toilet partitions.
     F.   As Required and Weather Permitting
          1.   Entire Building
               a.   Clean inside of all windows.
               b.   Clean outside of all windows.
     G.   Yearly
          1.   Tenant and Public Areas
               a.   Strip and wax all resilient tile floor areas.
II.  HEATING, VENTILATING, AND AIR CONDITIONING
          1.   Heating, ventilating, and air conditioning as required to provide
               reasonably comfortable temperatures for normal business day
               occupancy (excepting holidays); Monday through Friday from 8:00
               a.m. to 5:00 p.m. and Saturday from 8:00 a.m. to 1:00 p.m.
          2.   Maintenance of any additional or special air conditioning
               equipment and the associated operating cost will be at Tenant's
               expense.


                                      F-1
<PAGE>

III. WATER
     Hot water for lavatory purposes and cold water for drinking, lavatory and
     toilet purposes.
IV.  ELEVATORS (if Building is Elevatored)
          Elevators for the use of all tenants and the general public for access
          to and from all floors of the Building. Programming of elevators
          (including, but not limited to, service elevators) shall be as
          Landlord from time to time determines best for the Building as a
          whole.
V.   RELAMPING OF LIGHT FIXTURES
          Tenant will reimburse Landlord for the cost of lamps, ballasts and
          starters and the cost of replacing same within the Premises.
VI.  CAFETERIA AND VENDING INSTALLATIONS
          1.   Any space to be used primarily for lunchroom or cafeteria
               operation shall be Tenant's responsibility to keep clean and
               sanitary, it being understood that Landlord's approval of such
               use much be first obtained in writing.
          2.   Vending machines or refreshment service installations by Tenant
               must be approved by Landlord in writing and shall be restricted
               in use to employees and business callers. All cleaning
               necessitated by such installations shall be at Tenant's expense.
VII. ELECTRICITY
     A.   Landlord, at Landlord's expense, shall furnish electrical energy
          required for lighting, electrical facilities, equipment, machinery,
          fixtures, and appliances used in or for the benefit of Tenant's Space,
          in accordance with the provisions of the lease of which this Exhibit
          is part.
     B.   Tenant shall not, without prior written notice to Landlord in each
          instance, connect to the Building electric distribution system any
          fixtures, appliances or equipment other than normal office machines
          such as desk-top calculators and typewriters, or any fixtures,
          appliances or equipment which Tenant on a regular basis operates
          beyond normal building operating hours. In the event of any such
          connection, Tenant agrees to an increase in the ANNUAL ESTIMATED
          ELECTRICAL COST TO TENANT'S SPACE and a corresponding increase in
          Annual Rent by an amount which will reflect the cost to Landlord of
          the additional electrical service to be furnished by Landlord, such
          increase to be effective as of the date of any such installation.
          If Landlord and Tenant cannot agree thereon, such amount shall be
          such amount shall be conclusively determined by a reputable
          independent electrical engineer or consulting firm to be selected
          by Landlord and paid equally by both parties, and the cost to
          Landlord will be included in Landlord's Operating Costs provided in
          Section 4.2 hereof.
     C.   Tenant's use of electrical energy in Tenant's Space shall not at any
          time exceed the capacity of any of the electrical conductors or
          equipment in or otherwise serving Tenant's Space. In order to insure
          that such capacity is not exceeded and to avert possible adverse
          effect upon the Building electric service, Tenant shall not, without
          prior written notice to Landlord in each instance, connect to the
          Building electric distribution system any fixtures, appliances or
          equipment which operate on a voltage in excess of 120 volts nominal or
          make any alteration or addition to the electric system of Tenant's
          Space. Unless Landlord shall reasonably object to the connection of
          any such fixtures, appliances or equipment, all additional risers or
          other equipment required therefor shall be provided by Landlord, and
          the cost thereof shall be paid by Tenant upon Landlord's demand. In
          the event of any such connection, Tenant agrees to an increase in the
          ANNUAL ESTIMATED ELECTRICAL COST TO TENANT'S SPACE and a corresponding
          in Annual Rent by an amount which will reflect the cost to Landlord of
          the additional service to be furnished by Landlord, such increase to
          be effective as of the date of any such connection. If Landlord and
          Tenant cannot agree thereon, such amount shall be conclusively
          determined by a reputable independent electrical engineer or
          consulting firm to be selected by Landlord and paid equally by both
          parties, and the cost to Landlord will be included in Landlord's
          Operating Costs provided in Section 4.2 hereof.
     D.   If at any time after the date of this Lease, the rates at which
          Landlord purchases electrical energy from the public utility supplying
          electric service to the Building, or any charges incurred or taxes
          payable by Landlord in connection therewith, shall be increased or
          decreased, the Annual Rent and ANNUAL ESTIMATED ELECTRICAL COST TO
          TENANT'S SPACE shall be increased or decreased, as the case may be, by
          an amount equal to the estimated increase or decrease, as the case may
          be, in Landlord's cost of furnishing the electricity referred to in
          Paragraph A above as a result of such increase or decrease in rates,
          charges, or taxes. If Landlord and Tenant cannot agree thereon, such
          amount shall be conclusively determined by a reputable independent
          electrical engineer or consulting firm to be selected by Landlord


                                      F-2

<PAGE>

    and paid equally by both parties, and the cost to Landlord will be included
    in Landlord's Operating Costs as provided in Section 4.2 hereof.  Any such
    increase or decrease shall be effective as of the date of the increase or
    decrease in such rate, charges, or taxes.
E.  Landlord may, at any time, elect to discontinue the furnishing of
    electrical energy.  In the event of any such election by Landlord:  (1)
    Landlord agrees to give reasonable advance notice of any such
    discontinuance to Tenant;  (2) Landlord agrees to permit Tenant to
    receive electrical service directly from the public utility supplying
    service to the Building and to permit the existing feeders, risers,
    wiring and other electrical facilities serving Tenant's Space to be used by
    Tenant and/or such public utility for such purpose to the extent they are
    suitable and safely capable;  (3) Landlord agrees to pay such charges and
    costs, if any, as such public utility may impose in connection with the
    installation of Tenant's meters and to make or, at such public utility's
    election, to pay for such other installations as such public utility may
    require, as a condition of providing comparable electrical service to
    Tenant;  (4) the Annual Rent shall be equitably decreased to reflect
    such discontinuance by an amount equal to the ANNUAL ESTIMATED ELECTRICAL
    COST TO TENANT'S SPACE then in effect; and  (5) Tenant shall thereafter
    pay, directly to the utility furnishing the same, all charges for
    electrical services to the Premises.
F.  Whenever the Annual Rent is increased or decreased pursuant to any of the
    foregoing paragraphs of this Article, the parties agree, upon request of
    either, to execute and deliver each to the other an amendment to this
    Lease confirming such increase or decrease.


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<PAGE>

                                    EXHIBIT G

                              RULES AND REGULATIONS

1.  The entrances, lobbies, passages, corridors, elevators, halls, courts,
    sidewalks, vestibules, and stairways shall not be encumbered or
    obstructed by Tenant, Tenant's agents, servants, employees, licensees or
    visitors or used by them for any purposes other than ingress or egress to
    and from the Premises.

2.  The moving in or out of all safes, freight, furniture, or bulky matter of
    any description shall take place during the hours which Landlord may
    determine from time to time.  Landlord reserves the right to inspect all
    freight and bulky matter to be brought into the Building and to exclude
    from the Building all freight and bulky matter which violates any of
    these Rules and Regulations or the Lease of which these Rules and
    Regulations are a part.  Landlord reserves the right to have Landlord's
    structural engineer review Tenant's floor loads on the Premises at
    Tenant's expense.

3.  Tenant, or the employees, agents, servants, visitors or licensees of
    Tenant shall not at any time place, lease or discard any rubbish, paper,
    articles, or objects of any kind whatsoever outside the doors of the
    Premises or in the corridors or passageways of the Building.  No animals
    or birds shall be brought or kept in or about the Building.  Bicycles
    shall not be permitted in the Building.

4.  Tenant shall not place objects against glass partitions or doors or
    windows or adjacent to any common space which would be unsightly from the
    Building corridors or from the exterior of the Building and will promptly
    remove the same upon notice from Landlord.

5.  Tenant shall not make noises, cause disturbances, create vibrations,
    odors or noxious fumes or use or operate any electric or electrical
    devices or other devices that emit sound waves or are dangerous to other
    tenants and occupants of the Building or that would interfere with the
    operation of any device or equipment or radio or television broadcasting
    or reception from or within the Building or elsewhere, or with the
    operation of roads or highways in the vicinity of the Building, and shall
    not place or install any projections, antennae, aerials, or similar
    devices inside or outside of the Premises, without the prior written
    approval of Landlord.


                                       G-1

<PAGE>

6.  Tenant may not (without Landlord's approval therefor, which approval will
    be signified on Tenant's Plans submitted pursuant to the Lease) and
    Tenant shall not permit or suffer anyone to:  (a) cook in the Premises;
    (b) place vending or dispensing machines of any kind in or about the
    Premises;  (c) at any time sell, purchase or give away, or permit the
    sale, purchase, or gift of food in any form.

7.  Tenant shall not:  (a) use the Premises for lodging, manufacturing or for
    any immoral or illegal purposes;  (b) use the Premises to engage in the
    manufacture or sale of, or permit the use of spirituous, fermented,
    intoxicating or alcoholic beverages on the Premises;  (c) use the Premises
    to engage in the manufacture or sale of, or permit the use of, any
    illegal drugs on the Premises.

8.  No awning or other projections shall be attached to the outside walls or
    windows.  No curtains, blinds, shades, screens or signs other than those
    furnished by Landlord shall be attached to, hung in, or used in connection
    with any window or door of the Premises without prior written consent of
    Landlord.

9.  No signs, advertisement, object, notice or other lettering shall be
    exhibited, inscribed, painted or affixed on any part of the outside or
    inside of the Premises if visible from outside of the Premises.  Interior
    signs on doors shall be painted or affixed for Tenant by Landlord or by sign
    painters first approved by Landlord at the expense of Tenant and shall be of
    a size, color and style acceptable to Landlord.

10. Tenant shall not use the name of the Building or use pictures or
    illustrations of the Building in advertising or other publicity without
    prior written consent of Landlord.  Landlord shall have the right to
    prohibit any advertising by Tenant which, in Landlord's opinion, tends to
    impair the reputation of the Building or its desirability for offices,
    and, upon written notice from Landlord, Tenant will refrain from or
    discontinue such advertising.

11. Door keys for doors in the Premises will be furnished at the Commencement
    of the Lease by Landlord.  Tenant shall not affix additional locks on
    doors and shall purchase duplicate keys only from Landlord and will
    provide to Landlord the means of opening of safes, cabinets, or vaults
    left on the Premises.  In the event of the loss of any keys so furnished
    by Landlord, Tenant shall pay to Landlord the cost thereof.


                                       G-2

<PAGE>

12. Tenant shall cooperate and participate in all security programs
    affecting the Building.  Subject to Landlord's consent, Tenant may
    install, at Tenant's sole cost and expense, a security system for the
    Premises;  Tenant shall coordinate such measures with Landlord to assure
    Landlord's access to the Premises and the Building, to assure reasonable
    access to that portion of the Building not occupied by Tenant, and to
    assure integration with base building systems and requirements in an
    appropriate way.

13. Tenant assumes full responsibility for protecting its space from theft,
    robbery and pilferage, which includes keeping doors locked and other
    means of entry to the Premises closed and secured.

14. Tenant shall not make any room-to-room canvass to solicit business from
    other tenants in the Building, and shall not exhibit, sell or offer to
    sell, use, rent or exchange any item or services in or from the Premises
    unless ordinarily embraced within Tenant's use of the Premises as specified
    in its Lease.  Canvassing, soliciting and peddling in the Building are
    prohibited and Tenant shall cooperate to prevent the same.  Peddlers,
    solicitors and beggars shall be reported to the Management Office.

15. Tenant shall not mark, paint, drill into, or in any way deface any part
    of the Building or Premises.  No boring, driving of nails, or screws,
    cutting or stringing of wires shall be permitted, except with the prior
    written consent of Landlord, and as Landlord may direct.  Tenant shall
    not install any resilient tile or similar floor covering in the Premises
    except with the prior written approval of Landlord.  The use of cement or
    other similar adhesive material is expressly prohibited.

16. Tenant shall not waste electricity or water and agrees to cooperate fully
    with Landlord to assure the most effective operation of the Building's
    heating and air conditioning and shall refrain from attempting to adjust
    controls.  Tenant shall keep corridor doors closed except when being used
    for access.

17. The water and wash closets and other plumbing fixtures shall not be used
    for any purposes other than those for which they were constructed, and no
    sweepings, rubbish, rags, or other substances shall be thrown therein.


                                     G-3