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                                                                    EXHIBIT 10.1


                               COMMERCIAL LEASE

1.  PARTIES         WALFORD COMPANY, c/o Bernard H. Kayden, 550 Mamaroneck
                    Avenue, Harrison, NY 10528 ("LANDLORD"), which expression
                    shall include its successors and assigns where the context
                    so admits, does hereby lease to Shiva Corporation, 28 Crosby
                    Drive, Bedford, MA 01730-1437 ("TENANT"), which expression
                    shall include its successors and assigns where the context
                    so admits.

2.  PREMISES        TENANT hereby leases the following described premises (the
                    "Premises"): the land described in Exhibit A attached hereto
                    and incorporated herein by reference (the "Land"), together
                    with the buildings and improvements thereon, including the
                    building known as 205 Burlington Road, Bedford,
                    Massachusetts (the "Building") which Building is more
                    particularly described in Exhibit B attached hereto and
                    incorporated herein by reference.

3.  TERM            The term of this lease shall be for seven (7) years
                    commencing on September 1, 1996 (the "Commencement Date")
                    and ending on September 1, 2003. TENANT shall have two
                    options to extend the lease. The first option period shall
                    be for a term expiring on February 14, 2006 and the second
                    option period shall be for a term of five (5) years. Each
                    option period shall require six (6) months prior written
                    notice. The rental rate for any option period shall be at
                    fair market but in no event less than the prior term's
                    average annual net rental rate.

4.  RENT            In the event that the prior tenant, Pre-Owned Electronics,
                    Inc., does not deliver the Premises on or before August 31,
                    1996, the Commencement Date will be the date which is the
                    date the prior tenant vacates the Premises. TENANT shall pay
                    to the LANDLORD rent at the annual rate set forth in Exhibit
                    C attached hereto and incorporated herein by reference.
                    Annual rent shall be payable in advance in equal monthly
                    installments, on the first day of each calendar month during
                    the term, as set forth in Exhibit C.

5.  ADDITIONAL
    COVENANTS       (a) In addition to the rent stated in Section 4 above,
                    TENANT shall pay, directly to the appropriate entity all
                    costs and expenses incurred by TENANT for the following:
                    taxes, electricity and heating, rubbish removal, water and
                    sewer, pest control, snow removal, and grounds maintenance.

                    (b) The TENANT shall have the right to contest the amount or
                    validity of any real estate tax levied on the Premises, by
                    appropriate legal proceedings conducted in good faith.

                    (c) TENANT shall pay before any fine, penalty, interest or
                    cost may be added thereto for the non-payment thereof, all
                    real estate taxes, assessments, water and sewer estate
                    taxes, assessment, water and sewer charges which may be
                    assessed or levied or become a lien against the Premises.
                    TENANT shall exhibit to LANDLORD paid receipts from the
                    appropriate taxing authority showing payment of the above at
                    least 10 days prior to the time when same would become
                    delinquent.

6.  UTILITIES       The TENANT will arrange for, and pay or cause to be paid,
                    all charges for all public or private utility services at
                    any time rendered to or in connection with the Premises or
                    any part thereof. The LANDLORD, upon the request of TENANT,
                    shall grant to TENANT all utility easements reasonably
                    necessary in connection with the use of the Premises, and
                    shall, if required, consent to all applications for
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                    permits or other approvals required in connection with the
                    use of the Property and its appurtenances, as TENANT
                    reasonably deems necessary.

7.  USE OF LEASED
    PREMISES        The TENANT shall have the right to use the Premises for the
                    purpose of storage, assembly, repair, customer service,
                    disassembly and distribution, light manufacturing and office
                    use.

                    In addition, the TENANT shall have the right to use the
                    Premises for retail sales to the extent that such retail
                    sales do not violate any applicable law or regulation. The
                    LANDLORD agrees to assist the TENANT in procuring a special
                    permit, variance or similar approval that will allow retail
                    sales on the Premises.

8.  SIGNS           The TENANT shall have the right to install signs on and
                    about the Premises, provided that these signs conform to
                    applicable laws and regulations. In order to compensate the
                    TENANT for expenses related to the TENANT's purchase and
                    installation of signs, the LANDLORD shall reimburse TENANT,
                    in an amount not to exceed Eight Thousand Dollars
                    ($8,000.00), for expenses incurred by TENANT, within five
                    days after LANDLORD's receipt of a statement from TENANT
                    containing the amount of such expenses. The LANDLORD shall
                    assist TENANT in obtaining any permits or authorizations
                    required by any governmental authority in connection with
                    signs installed pursuant to this Section 8.

9.  COMPLIANCE
    WITH LAWS       (a) The TENANT acknowledges that no trade or occupation
                    shall be conducted in the Premises or use made thereof which
                    will be unlawful, improper, noisy or offensive, or contrary
                    to any law or any municipal by-law or ordinance in force in
                    the city or town in which the Premises are situated.

                    (b) TENANT shall promptly comply with all laws, ordinances,
                    orders, rules and requirements of all Federal, State and
                    municipal authorities, applicable to the Premises.

10. FIRE
    INSURANCE       The Tenant shall not permit any use of the Premises which
                    will make voidable any insurance on the property of which
                    the Premises are a part, or on the contents of said property
                    or which shall be contrary to any law or regulation from
                    time to time established by the New England Fire Insurance
                    Rating Association, or any similar body succeeding to its
                    powers.

11. MAINTENANCE
    AND REPAIRS     (a) LANDLORD shall throughout the Term, at LANDLORD's sole
                    cost and expense,keep and maintain in good order, condition
                    and repair the roof and the exterior of the Building, all
                    structural portions of the improvements located on the Land,
                    including without limitation the structural portions of the
                    roof, the load bearing walls, the foundation, the structural
                    floor slabs and other structural elements of the Building,
                    and repairs to the parking lot other than routine
                    maintenance and minor repairs requiring patching only, and
                    other than repairs occasioned by the TENANT's fault. The
                    LANDLORD shall also be responsible, at the LANDLORD's sole
                    cost and expense, for the repair to good working order, of
                    the heating, ventilation and air-conditioning systems and
                    the electrical and plumbing systems, only to the extent that
                    such repairs involve other than routine maintenance. In case
                    LANDLORD is prevented or delayed in making any repairs,
                    alterations or improvements, or furnishing any services or
                    performing any other covenant or duty to be performed on
                    LANDLORD's part, by reason of any cause reasonably beyond
                    LANDLORD's control, LANDLORD shall use best efforts to avoid
                    unreasonable interference with the conduct by TENANT of

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                    TENANT's business on the Premises, and LANDLORD shall,
                    except in case of emergency repairs, give reasonably advance
                    notice to TENANT of any contemplated work by LANDLORD on the
                    Premises.

                    (b) Other than for those repairs for which LANDLORD is
                    responsible under the terms of Sections 11)(a) and 17
                    hereof, TENANT shall, from and after possession of the
                    Premises is delivered to TENANT, at TENANT's sole cost and
                    expense, keep and maintain the Premises in the same
                    condition as it was in on the Commencement Date, or as it
                    may be put in thereafter, damage by fire or other casualty,
                    taking, and reasonable wear and tear excepted. Without
                    limiting the generality of the foregoing, TENANT shall
                    perform and be solely responsible for the following: (i)
                    snow removal, to the extent required by TENANT, with respect
                    to entrance drives, parking areas, walkways, (ii) lawn
                    maintenance, trimming and the maintenance and care of trees,
                    shrubs and other plantings, (iii) routine maintenance of the
                    parking lot and minor repairs thereto requiring patching
                    only and (iv) preventative maintenance of heating,
                    ventilating and air-conditioning systems (the "HVAC") of the
                    Premises. The TENANT, at the TENANT's sole cost, shall
                    maintain, through the term, a contract with a reputable
                    service company to provide for the preventative maintenance
                    of the HVAC. At the expiration or earlier termination of
                    this leased, TENANT shall yield up the Premises in the
                    condition in which TENANT is obligated hereunder to repair
                    and maintain the same.

                    (c) TENANT shall not create or permit to remain, shall
                    discharge any mechanics or other similar lien which might be
                    or become a lien or encumbrance upon the Premises for work
                    done or material furnished on behalf of the Tenant.

12. ALTERATIONS-
    ADDITIONS       The TENANT shall not make structural alterations or
                    additions to the Premises, but may make non-structural
                    alterations provided the LANDLORD consents thereof in
                    writing, which consent shall not be unreasonably withheld or
                    delayed. All such allowed alterations shall be at TENANT's
                    expense and shall be in quality at least equal to the
                    present construction. LANDLORD specifically consents to
                    TENANT's construction of a loading dock on the Premises
                    provided that such construction is at TENANT's sole expense.
                    TENANT shall not permit any mechanics' liens, or similar
                    liens, to remain upon the Premises for labor and material
                    furnished to TENANT or claimed to have been furnished to
                    TENANT in connection with work of any character performed or
                    claimed to have been performed at the direction of TENANT
                    and shall cause any such lien to be released of record
                    forthwith after receipt of notice thereof without cost to
                    LANDLORD. Any alterations or improvements made by the TENANT
                    shall become the property of the LANDLORD at the termination
                    of occupancy as provided herein. The parties agree that
                    office furniture, cubicles, removable appliances and office
                    equipment remain the property of TENANT upon termination of
                    this Lease.

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13. ASSIGNMENT-
    SUBLEASING      The TENANT shall have the right to assign this lease or
                    sublet the whole or any part of the Premises with LANDLORD's
                    prior written consent, which consent shall not be
                    unreasonably withheld or delayed. LANDLORD shall, within
                    five (5) business days after receiving the information
                    concerning a proposed sublease, give notice to TENANT to
                    permit or deny the proposed sublease. If LANDLORD denies
                    consent, it must explain the reasons for the denial. If a
                    LANDLORD does not give notice within the two (2)
                    business-day period, then TENANT may sublease or assign part
                    or all of the Premises upon the terms TENANT gave in the
                    notice of the proposed sublease. Notwithstanding such
                    consent, TENANT shall remain liable to LANDLORD for the
                    payment of all rent and for the full performance of the
                    covenants and conditions of this lease.

14. LANDLORD'S
    ACCESS          The LANDLORD or agents of the LANDLORD may, at reasonable
                    times, during normal business hours, and upon reasonable
                    notice of TENANT, enter to view the Premises and to make
                    such repairs as LANDLORD shall elect or be required to make,
                    and at any time within three (3) months before the
                    expiration of the term, may affix to any suitable part of
                    the outside of the Premises a notice for letting or selling
                    the Premises or property of which the Premises are a part
                    and keep the same so affixed without hindrance or
                    molestation.

15. INDEMNIFICATION
    AND LIABILITY   The TENANT shall save the LANDLORD harmless from all loss
                    and damage occasioned by any nuisance made or suffered on
                    the Premises caused by the negligence or willful misconduct
                    of TENANT, its agents, employees or invitees. The removal of
                    snow and ice from the sidewalks bordering upon the Premises,
                    all landscaping and garbage disposal, shall be the TENANT's
                    responsibility.

16. TENANT'S
    LIABILITY
    INSURANCE       The TENANT shall maintain with respect to the Premises and
                    the property of which the Premises are a part, comprehensive
                    public liability insurance in the amount of $1,000,000
                    combined single limit per occurrence, $2,000,000 policy
                    aggregate, in responsible companies qualified to do business
                    in Massachusetts and in good standing therein insuring the
                    LANDLORD as well as TENANT against injury to persons or
                    damage to property as provided. The TENANT shall deposit
                    with the LANDLORD certificates for such insurance at or
                    prior to the commencement of the term, and thereafter within
                    thirty (30) days prior to the expiration of any such
                    policies. All such insurance certificates shall provide that
                    such policies shall not be canceled without at least ten
                    (10) days prior written notice to each assured name therein.

17. FIRE, CASUALTY
    EMINENT DOMAIN  (a) In case of any material damage to or destruction of the
                    Premises or any part thereof, TENANT will promptly give
                    written notice thereof to LANDLORD, generally describing the
                    nature and extent of such damage or destruction.

                    (b) In case of any damage to or destruction of the Premises
                    or any part thereof, LANDLORD shall commence and prosecute
                    with reasonable diligence the restoration, replacement or
                    rebuilding of the Premises as nearly as practicable to its
                    value, condition and character immediately prior to such
                    damage or destruction (such restoration, replacement and
                    rebuilding, together with any temporary repairs and property
                    protection pending completion of the work, being herein
                    called "Casualty Restoration").

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                    (c) (i) If the Premises are substantially damaged by fire or
                    other casualty or (ii) if LANDLORD fails to complete the
                    Casualty Restoration within one hundred and twenty (120)
                    days after such damage or destruction, TENANT may elect to
                    terminate this Lease giving to LANDLORD written notice of
                    such election (specifying the termination date which shall
                    not be less than 10 nor more than 90 days after the date of
                    such notice) (a) within 30 days after such fire or other
                    casualty in the case of a termination right under subsection
                    (i) above, or (b) within thirty days after the expiration of
                    such one hundred twenty (120) day period, in the case of a
                    termination right under subsection (ii) above; provided that
                    such Casualty Restoration has not been completed prior to
                    the giving of such notice. For the purposes of this Section
                    17(c), the Premises shall be deemed to have been
                    substantially damaged or destroyed if the damage is of such
                    a character that the same cannot in the ordinary course
                    reasonably be expected to be restored or repaired within one
                    hundred (100) days from the time that repair work would be
                    commenced.

                    (d) The rent and all other sums payable thereunder by TENANT
                    shall be equitably abated from the date of such damage or
                    destruction until the date on which the Casualty Restoration
                    has been completed, unless this lease has sooner terminated
                    as provided herein. In the event of any disagreement between
                    LANDLORD and TENANT as to the amount of such abatement, the
                    same shall be determined by arbitration by an appraiser
                    selected by LANDLORD and TENANT.

                    (e) In the case of a taking of all or a substantial portion
                    of the Premises by eminent domain, so that in the TENANT's
                    reasonable opinion the Premises are no longer suitable for
                    their intended use, the TENANT may elect to terminate this
                    lease by written notice to LANDLORD within thirty (30) days
                    notice to LANDLORD within thirty (30) days after TENANT
                    obtains actual notice of such taking. Upon such election to
                    terminate, this lease shall have no further effect.

                    (f) In the case of a taking whereby the TENANT does not
                    elect to terminate this lease, the Rent, Additional Rent and
                    Other sums payable by TENANT under this lease shall be
                    equitably abated.

18. DEFAULT AND
    BANKRUPTCY      In the event that:

                    (a) The TENANT shall default in the payment of any
                    installment of rent or other sum herein specified and such
                    default shall continue for ten (10) days after receipt by
                    TENANT of written notice thereof; or

                    (b) The TENANT shall default in the observance or
                    performance of any other of the TENANT's covenants,
                    agreements, or obligations hereunder and such default shall
                    not be corrected within thirty (30) days after written
                    notice thereof or, if such default cannot reasonably be
                    corrected within such thirty (30) day period, if TENANT
                    shall fail, within such period, to commence to cure such
                    default or thereafter to prosecute and complete the same
                    with due diligence; or

                    (c) The TENANT shall be declared bankrupt or insolvent
                    according to law, or, if any assignment shall be made of
                    TENANT's property for the benefit of creditors, then the
                    LANDLORD shall have the right thereafter, while such default
                    continues, to re-enter and take complete possession of the
                    Premises, to declare the term of this lease ended, and
                    remove the TENANT's effects, without prejudice to any
                    remedies which might be otherwise used for arrears of rent
                    or other default. The

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                    TENANT shall indemnify the LANDLORD against all loss of rent
                    and other reasonable payments which the LANDLORD may incur
                    by reason of such termination during the residue of the
                    term. If the TENANT shall default after reasonable notice
                    thereof, in the observance or performance of any conditions
                    or covenants on TENANT's part to be observed or performed
                    under or by virtue of any of the provisions in any article
                    of this lease, the LANDLORD, without being under any
                    obligation to do so and without thereby waiving such
                    default, may remedy such default for the account and at the
                    expense of the TENANT. If the LANDLORD makes any
                    expenditures or incurs any obligations for the payment of
                    money in connection therewith, including but not limited to,
                    reasonable attorney's fees in instituting, prosecuting or
                    defending any action or proceeding, such sums paid or
                    obligations insured shall be paid to the LANDLORD by the
                    TENANT as additional rent.

19. NOTICE          Any notice from the LANDLORD to the TENANT relating to the
                    Premises or the occupancy thereof, shall be deemed duly
                    served upon receipt, if personally delivered or if mailed to
                    the Premises, registered or certified mail, return receipt,
                    requested, postage prepaid, addressed to the TENANT. Any
                    notice from the TENANT to the LANDLORD relating to the
                    Premises or to the occupancy thereof, shall be deemed duly
                    served, upon receipt, if mailed to the LANDLORD by
                    registered of, certified mail, return receipt requested,
                    postage prepaid, addressed to the LANDLORD at such address
                    as the LANDLORD may from time to time advise in writing. All
                    rent and notices shall be paid and sent to the LANDLORD at
                    the address set forth in Section 1 above.

20. SURRENDER       The TENANT shall at the expiration or other termination of
                    this lease remove all TENANT's goods and effects from the
                    Premises. TENANT shall deliver to the LANDLORD the Premises
                    and all keys, locks thereto, and other fixtures connected
                    therewith and all alterations and additions made to or upon
                    the Premises, in the same condition as they were at the
                    commencement of the term, or as they were put in during the
                    term hereof, reasonable wear and tear and damage by fire or
                    other casualty and taking by eminent domain excepted.

                    Notwithstanding anything herein to the contrary, the
                    Landlord shall incur the entire cost and responsibility for
                    removing the signs installed by the LANDLORD or the TENANT
                    pursuant to Section 8 hereof.

21. WAIVER OF
    SUBROGATION     Any insurance carried by either party with respect to the
                    Premises, the Building or the Land or occurrences thereon
                    shall, if it can be so written without additional premium,
                    or with an additional premium which the other party agrees
                    to pay, 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 the
                    occurrence of the injury or the loss. Each party,
                    notwithstanding other 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 such
                    insurance to the extent of the indemnification received
                    thereunder.

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22. CASUALTY
    INSURANCE       TENANT, at TENANT's sole cost and expense, shall maintain at
                    all times during the term of this lease with respect to the
                    Premises and the Building and property of which such
                    Premises are a part, insurance naming the LANDLORD as
                    insured against loss or damage under a so-called "all risk"
                    type insurance policy. Such insurance shall be in an amount
                    equal to the full replacement value of said Building and
                    other improvements on the Land, and shall be maintained with
                    responsible companies qualified to do business and in good
                    standing in the Commonwealth of Massachusetts. TENANT shall
                    provide LANDLORD with a certificate evidencing procurement
                    of insurance in accordance with this paragraph within
                    fourteen (14) days of the date hereof, and in the case of
                    the renewal of such policy, at least thirty (30) days prior
                    to the expiration of the policy.

23. DELIVERY OF
    THE PREMISES    On the Commencement Date of the term hereof, as set forth in
                    Section 3 of this Lease, LANDLORD shall deliver the Premises
                    to TENANT, broom clean, with carpets shampooed, tile floor
                    areas cleaned and waxed, free of all tenants and other
                    occupants, with all of the improvements to the Premises
                    shown on Exhibit B completed by LANDLORD, at LANDLORD's sole
                    cost and expense and with all building systems in good
                    working order. The improvements to be made by LANDLORD to
                    the Building and the Premises as shown on Exhibit B attached
                    hereto shall be of good quality, and shall be made in a good
                    and workmanlike manner, in compliance with all applicable
                    laws. The LANDLORD shall cause the TENANT to be named as a
                    beneficiary of any and all warranties and guaranties of
                    electrical, mechanical and other equipment and systems that
                    the LANDLORD has purchased for the Premises.

                    If the LANDLORD is unable to deliver the Premises to the
                    TENANT on the Commencement Date in accordance with this
                    Section 23, then, unless the delay is due to a delay beyond
                    the LANDLORD's reasonable control, the TENANT shall have the
                    option of terminating this lease. (The LANDLORD's financial
                    inability to complete improvements is not a delay beyond the
                    LANDLORD's reasonable control). Notwithstanding anything in
                    this paragraph to the contrary, if an event beyond the
                    LANDLORD's reasonable control occurs and the LANDLORD can
                    not deliver the Premises on the Commencement Date, then the
                    TENANT shall have the option of terminating this Lease if
                    the LANDLORD is unable to deliver the Premises to the Tenant
                    in accordance with this Section 23 on or before September 1,
                    1996.

24. ESTOPPEL
    CERTIFICATE     Either party will, upon the request of the other, execute,
                    acknowledge and deliver to the requesting party, within
                    fifteen (15) business days after request, a certificate
                    certifying (a) that this lease is unmodified and in full
                    force and effect (or, if there have been modifications, that
                    this lease is in full force and effect, as modified, and
                    stating the modifications), (b) the dates, if any, to which
                    the basic and additional rents have been paid, (c) whether
                    or not there are then existing any offsets or defenses
                    against the enforcement of any term hereof on the part of
                    the requesting party to be performed or complied with (and,
                    if so, specifying the same), (d) whether or not there are
                    any defaults-under this lease (and, if so, specifying the
                    same), and (e) that no notice has been received by the
                    certifying party of any default which has not been cured.



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25. ATTORNEYS'
    FEES            ln the event of any litigation between the parties to this
                    lease arising out of or resulting from the terms and
                    conditions herein contained, the prevailing party shall be
                    entitled to be reimbursed by the other party in an amount
                    equal to the sum of all attorneys' fees and expenses
                    reasonably incurred by such prevailing party in connection
                    with such litigation.

26. ENVIRONMENTAL
    MATTERS         (a) The term "Hazardous Materials" shall include, without
                    limitation, (i) any "hazardous waste" as defined by the
                    Resource Conservation and Recovery Act of 1976, or
                    Massachusetts General Laws Chapter 21C, as either may be
                    amended from time to time, the regulations promulgated
                    thereunder; (ii) any "hazardous substance" as defined by the
                    Comprehensive Environmental Response, Compensation and
                    Liability Act of 1980, as amended from time to time, or the
                    regulations promulgated thereunder; and (iii) any substance
                    the presence of which on or within the Premises, the
                    Building or on, under or above the Land is prohibited by any
                    applicable federal, state, or local law and regulations, if
                    any, promulgated pursuant thereto, including, but not
                    limited to, any "oil" or "hazardous material" as defined by
                    the Massachusetts Oil and Hazardous Material Release
                    Prevention and Response Act of 1983, Massachusetts General
                    Laws, Chapter 21E, as amended from time to time, or the
                    regulations promulgated thereunder.

                    (b) The Landlord is not aware of the existence of any
                    reports of Hazardous Materials found or disposed of on the
                    Premises, the Building or the Land other than those listed
                    on Exhibit D, attached hereto.

                    (c) In the event that concentrations of volatile organic
                    chemicals exceed the permissible exposure limits (the
                    "Excessive Levels") established (i) by regulations now or at
                    any time in the future promulgated by the Occupational
                    Safety and Health Administration, U.S. Department of Labor,
                    or (ii) under any similar federal, state or local
                    legislation or regulations governing exposure of employees
                    to such substances, then unless the LANDLORD elects to
                    remedy such condition in accordance with the following
                    subsection (d), or, in the event LANDLORD is required by
                    Federal or state government environmental regulations to
                    excavate any portion of the Building, the TENANT shall have
                    the option of terminating this lease upon written notice to
                    the LANDLORD, and upon such election the LANDLORD shall
                    return to TENANT a pro rata share of prepaid rent along with
                    the Security (as defined in Section 27 hereof), and this
                    Lease shall be of no further force and effect.

                    (d) The LANDLORD may elect to lower any Excessive Levels by
                    providing TENANT with written notice of such election within
                    ten (10) days of such discovery. Upon such election, the
                    LANDLORD shall have sixty (60) days to lower the
                    Excessive-Levels to levels that do not exceed any then
                    current law or regulation. The LANDLORD may not interfere
                    with the TENANT's business operations in order to lower the
                    levels of Hazardous Materials. If the levels are not lowered
                    by the end of the sixty (60) day period, then the TENANT
                    shall have the option to terminate this lease, and upon such
                    termination, LANDLORD shall refund any rent applicable to
                    such sixty (60) day remedial period.

                    (e) The LANDLORD and the TENANT acknowledge that the TENANT
                    bears no responsibility for subsurface conditions existing
                    at the Premises and that the TENANT bears no responsibility
                    for air and other gases that emanate from below the surface
                    of the Premises.

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                    (f) LANDLORD shall indemnify and save harmless the TENANT
                    against all penalties, claims or demands from a governmental
                    authority or third party (including reasonable attorney's
                    fees incurred in defending such claims or demands) arising
                    from the presence of Hazardous Materials on or about the
                    Premises, except for those caused by TENANT's negligence or
                    misconduct provided however, that TENANT shall have no right
                    to recover any of its own business losses (including, but
                    not limited to TENANT's moving costs and lost profits)
                    incurred by TENANT as a result of the presence of Hazardous
                    Materials on or about the Premises. TENANT agrees that
                    TENANT's sole remedy related to business losses resulting
                    from Hazardous Materials on or about the Premises is
                    TENANT's option to terminate this lease in accordance with
                    subsections 26(c) and 26(d) of this lease.

                    (g) The remedies provided herein are in addition to other
                    remedies available under law.

27. SECURITY
    DEPOSIT         TENANT has delivered to LANDLORD on the date hereof the sum
                    of $33,003.38 as security (the "Security") for the
                    performance by the TENANT of the terms, provisions,
                    covenants and conditions of this lease. The LANDLORD shall
                    deposit this sum in a federally insured interest bearing
                    account that is segregated from all of the LANDLORD's other
                    accounts. If the TENANT defaults under this lease, and such
                    default is not cured within the time periods stated in
                    Section 18 hereof, then the LANDLORD may use, apply and
                    retain the whole or any part of the security for the payment
                    of any monies owed by the TENANT under this Lease, and
                    the-LANDLORD shall thereafter promptly provide the TENANT
                    with an accounting of such use, application or retention. If
                    the TENANT complies with the terms, provisions, covenants
                    and conditions of this lease, then the Security, or any
                    balance thereof, plus any interest accrued thereon, shall be
                    returned to the TENANT on or prior to three business days
                    after the expiration or termination of the term of this
                    lease.

28. NON-
    DISTURBANCE     Upon written request by LANDLORD, TENANT shall execute and
                    deliver an agreement subordinating this lease to any first
                    mortgage upon the Premises; provided, however, such
                    subordination shall be upon the express condition that the
                    validity of this lease shall be recognized by the persons
                    succeeding to the interest of the LANDLORD, including a
                    purchaser at a foreclosure sale, and that, notwithstanding
                    any default by the mortgagor with respect to said mortgage
                    or any foreclosure thereof, TENANT's possession and right of
                    use under this lease in and to the Premises shall not be
                    disturbed by such successor unless and until TENANT shall
                    breach any of the provisions hereof and this lease or
                    TENANT's right to possession hereunder shall have been
                    terminated in accordance with the provisions of this lease.

29. TENANT'S
    INDEMNITY       TENANT indemnifies, defends, and holds LANDLORD harmless
                    from claims:

                    (i) for personal injury, death, or property damage;

                    (ii) for incidents occurring on or about the Premises; and

                    (iii) caused by the negligence or willful misconduct of
                    TENANT, its agents, employees, or invitees.

                    When the claim is caused by the joint negligence or willful
                    misconduct of TENANT and LANDLORD or TENANT and a third
                    party unrelated to TENANT, except TENANT's agent employees,
                    or invitees, TENANT's duty to defend, indemnify, and hold
                    LANDLORD harmless shall be in proportion to TENANT's
                    allocable share of the joint negligence or willful
                    misconduct.



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    LANDLORD'S
    INDEMNITY       LANDLORD indemnifies, defends, and holds TENANT harmless
                    from claims:

                    (i) for personal injury, death, or property damage;

                    (ii) for incidents occurring in or about the Premises; and

                    (iii) caused by the negligence or willful misconduct of
                    LANDLORD, its agents, employees, or invitees.

                    When the claim is caused by the joint negligence or willful
                    misconduct of LANDLORD and TENANT or LANDLORD and a third
                    party unrelated to LANDLORD, except LANDLORD's agents,
                    employees, or invitees, LANDLORD's duty to defend,
                    indemnify, and hold TENANT harmless shall be in proportion
                    to LANDLORD's allocable share of the joint negligence or
                    willful misconduct.

    Release of
    Claims          Notwithstanding TENANT's Indemnity and LANDLORD's Indemnity,
                    the parties release each other from any claims either party
                    (Injured Party) has against the other. This release is
                    limited to the extent the claim is covered by the Injured
                    Party's insurance.

30. RENT
    INSURANCE       TENANT shall, at TENANT's sole cost and expense, naming the
                    LANDLORD as insured, maintain during the term of this lease
                    rent insurance in an amount equal to rent and real estate
                    taxes for the next twelve month period.

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        IN WITNESS WHEREOF, the LANDLORD and TENANT have hereunto set their
hands and common seals this 24th day of May, 1996.

Witness:                                        TENANT:  SHIVA CORPORATION

/s/ M. Elizabeth Potthoff                       By: /s/ Cynthia M. Deysher
- -------------------------                           -----------------------




Witness:                                        LANDLORD:  WALFORD COMPANY

/s/ Rita Levitan                                By: /s/ Bernard H. Kayden
- -------------------------                           -----------------------
                                                        General Partner


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                                    EXHIBIT A

                               DESCRIPTION OF LAND

That certain parcel of land situated in Bedford in the County of Middlesex and
the Commonwealth of Massachusetts, bounded and described as follows:

        Northeasterly by Burlington Road, four hundred and twenty-two feet;
        Southeasterly by lot 22 as shown on plan hereinafter mentioned, four
        hundred eighty-seven and 67/100 feet;
        Southwesterly by lot 21 on said plan, three hundred forty-four and
        35/100 feet;
        Southwesterly again, one hundred nine and 81/100 feet, and
        Northwesterly, four hundred ten and 02/100 feet by land nor or formerly
        of Bedford Research and Office Park.

Said parcel is shown as lot 28 on said plan.

All of said boundaries are determined by the Court to be located as shown on a
subdivision plan, as approved by the Court, filed in the Land Registration
Office, and copy of which is filed in the Registry of Deeds for the South
Registry District of Middlesex County in Registration Book 648, Page 48, with
Certificate 103598.



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                                    EXHIBIT B

                               205 BURLINGTON ROAD

                     TENANT ALLOWANCES FOR SHIVA CORPORATION

                    INTERIOR OFFICE FINISHES AND IMPROVEMENTS

- - premises delivered "as is"

- - 51,502 ventable square feet

- - 1200A 480/227V 3 phase electrical service


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                                   EXHIBIT C

                                 RENT SCHEDULE



Lease Year                        Annual Rent               Monthly Rent
- ----------                        -----------               ------------
                                                      
(1) 09/01/96 - 08/31/97           $396,040.00               $33,003.38*
(2) 09/01/97 - 08/31/98           $396,040.00               $33,003.38
(3) 09/01/98 - 08/31/99           $396,040.00               $33,003.38
(4) 09/01/99 - 08/31/00           $396,040.00               $33,003.38
(5) 09/01/00 - 08/31/01           $396,040.00               $33,003.38
(6) 09/01/01 - 08/31/02           $396,040.00               $33,003.38
(7) 09/01/02 - 08/31/03           $396,040.00               $33,033.38




*The first month's rent will be $16,003.38. If the Commencement Date under the
Lease is not September 1, 1996, then the beginning and end of each Lease Year
shall be adjusted accordingly so that each of the seven Lease Years will always
be a full calendar year. Rent for any period which is less than as full calendar
month shall be prorated accordingly.


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                                    EXHIBIT D

                      ENVIRONMENTAL REPORTS AND INFORMATION

                          205 Burlington Road, Bedford

11/15/90        Goldberg-Zoino Associates, Inc. Report to Pre-Owned Electronics,
                Inc.

9/12/90         Goldberg-Zoino Associates, Inc. Report to Pre-Owned Electronics,
                Inc. (GZA File No. 12190).

6/21/90         Clean Harbors "Results of Laboratory Analysis for Groundwater
                Samples Collected at the Walford Company, 205 Burlington Road,
                Bedford, Massachusetts. CHE Job No. E1459."

8/9/89          Clean Harbors Letter Report (no title)

2/1/89          Clean Harbors Letter Report (no title)

12/15/88        Clean Harbors Letter Report concerning the additional work
                undertaken to remove the remaining oil beneath the building at
                205 Burlington Road, Bedford, Massachusetts.

Sept., 1988     Clean Harbors Report (Insert Title)

5/5/87          DEQE Notice of Responsibility letter to the John Aitken Company,
                requiring remedial response actions including, at a minimum, the
                investigation and assessment of site conditions.




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