Document:

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                                                                  EXHIBIT 10.7

CISCO SYSTEMS
[GRAPHIC](TM)
CAPITAL

                                          Master Lease No. 2020

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                       MASTER AGREEMENT TO LEASE EQUIPMENT
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      THIS MASTER AGREEMENT TO LEASE EQUIPMENT (this "Agreement") is entered
into as of November 3, 1998 by and between CISCO SYSTEMS CAPITAL CORPORATION
("Lessor"), having its principal place of business at 170 West Tasman Drive, San
Jose, California 95134 and VIP CALLING, INC., a Delaware Corporation ("Lessee"),
having a principal place of business at 121 Middlesex Turnpike, Burlington, MA
01803.

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                                  I. THE LEASE
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      1.1 Lease of Equipment. In accordance with the terms and conditions of
this Agreement, Lessor shall lease to Lessee, and Lessee shall lease from
Lessor, the personal property, including all substitutions, replacements,
repairs, parts and attachments, improvements and accessions thereto and therein
(the "Equipment"), described in the lease schedule(s) (each, a "Lease") to be
entered into from time to time into which this Agreement is incorporated. Each
Lease shall constitute a separate, distinct, and independent lease and
contractual obligation of Lessee. Lessor or its assignee shall at all times
retain the full legal title to the Equipment, it being expressly agreed by both
parties that each Lease is an agreement of lease only.

      1.2 Term of Lease. The original term (the "Original Term") of the
Equipment shall commence on the Commencement, and, subject to Sections 3.3 and
3.5 below, shall terminate on the date specified in the Lease. Except as
specifically provided in this Section 1.2, no Lease may be terminated by Lessor
or Lessee, for any reason whatsoever, prior to the end of the Original Term (the
"Lease Term"). Notwithstanding any provision to the contrary contained in this
Agreement, Lessee shall be deemed to accept the Equipment on the Commencement
Date (as specified in each Lease).

      1.3 Rental Payments. Lessee shall pay Lessor monthly rent ("Rent") for the
Equipment in the amounts and at the times specified in the Lease provided,
however, that no Rent shall be due or accrue with respect to any Lease prior to
the date occurring six months after the date of the first lease. All Rent and
other amounts payable by Lessee to Lessor hereunder shall be paid to Lessor at
the address specified above, or at such other place as Lessor may designate in
writing to Lessee from time to time. Lessor will provide Lessee with a single
monthly invoice, detailing all Rent then owned with respect to Equipment under
all leases then in effect. Freight charges for Equipment deliver to Lessee will
be added to Lessor's invoice and billed to Lessee with the first rental payment
relating to such Equipment.

                                       1.
<PAGE>

      1.4 Return of Equipment. Upon expiration of the Lease Term of the
Equipment, Lessee shall immediately return the Equipment to Lessor as provided
in Section 3.3 below. If Lessee fails to return any of the Equipment upon demand
therefor by Lessor, Lessee shall pay Lessor, as the measure of Lessor's damages,
the Casualty Value (as defined in the applicable Lease) of such Equipment.

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              II. DISCLAIMERS AND WARRANTIES; INTELLECTUAL PROPERTY
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      2.1 Disclaimers; Warranties. Lessee represents and acknowledges that the
Equipment is of a size, design, capacity and manufacture selected by it, and
that it is satisfied that the Equipment is suitable for its purposes. LESSOR
LEASES THE EQUIPMENT AS IS, AND, NOT BEING THE MANUFACTURER OF THE EQUIPMENT,
THE MANUFACTURER'S AGENT OR THE SELLER'S AGENT, MAKES NO WARRANTY OR
REPRESENTATION, EITHER EXPRESS OR IMPLIED, AS TO THE MERCHANTABILITY, FITNESS
FOR ANY PARTICULAR PURPOSE, DESIGN OR CONDITION OF THE EQUIPMENT. LESSOR SHALL
NOT BE RESPONSIBLE FOR ANY LOSS OR DAMAGE RESULTING FROM THE INSTALLATION,
OPERATION OR OTHER USE, OR DEINSTALLATION OF THE EQUIPMENT, INCLUDING, WITHOUT
LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGE OR LOSS.
Lessee shall look solely to the manufacturer or the supplier of the Equipment
for correction of any problems that may arise with respect thereto, and,
provided no Event of Default (as defined in Section 4.1) has occurred and is
continuing, all warranties made by the manufacturer or such supplier are, to the
degree possible, hereby assigned to Lessee for the Lease Term. Lessor shall not
enter any agreement with the manufacturer or supplier of the Equipment that will
restrict Lessee's ability to look to such manufacturer or supplier to correct
any such problem. To the extent any such warranty requires performance of any
kind by the beneficiary of the warranty, Lessee shall perform in accordance
therewith.

      2.2 Intellectual Property. Except as otherwise expressly provided in each
Lease, LESSOR MAKES NO WARRANTIES OR REPRESENTATIONS WHATSOEVER WITH RESPECT TO
THE INTELLECTUAL PROPERTY RIGHTS, INCLUDING, WITHOUT LIMITATION, ANY PATENT,
COPYRIGHT AND TRADEMARK RIGHTS OF ANY THIRD PARTY WITH RESPECT TO THE EQUIPMENT,
WHETHER RELATING TO INFRINGEMENT OR OTHERWISE. Lessor shall, when requested in
writing by Lessee and at Lessee's cost and expense, exercise, rights of
indemnification, if any, for patent, copyright or other intellectual property
infringement obtained from the manufacturer under any agreement for purchase of
the Equipment. If notified promptly in writing of any action brought against
Lessee based on a claim that the Equipment infringes a United States patent,
copyright or other intellectual property right, Lessor shall promptly notify the
manufacturer thereof for purposes of exercising, for the benefit of Lessee,
Lessor's rights with respect to such claim under any such agreement.

                                       2.
<PAGE>

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      III. COVENANTS OF LESSEE
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      3.1 Payments Unconditional; Tax Benefits; Acceptance. EACH LEASE SHALL BE
A NET LEASE, AND LESSEE'S OBLIGATION TO PAY ALL RENT AND OTHER SUMS THEREUNDER,
AND THE RIGHTS OF LESSOR IN AND TO SUCH PAYMENTS, SHALL BE ABSOLUTE AND
UNCONDITIONAL, AND SHALL NOT BE SUBJECT TO ANY ABATEMENT, REDUCTION, SETOFF,
DEFENSE, COUNTERCLAIM, INTERRUPTION, DEFERMENT OR RECOUPMENT, FOR ANY REASON
WHATSOEVER. It is the intent of Lessor, and an inducement to Lessor, to enter
into each Lease, to claim all available tax benefits of ownership with respect
to the Equipment subject thereto. Lessee's acceptance of the Equipment subject
to a Lease shall be conclusively and irrevocably evidenced by Lessee executing
an Acceptance Certificate with respect to such Equipment, and upon acceptance,
such Lease shall be noncancellable for the Lease Term unless otherwise agreed to
in writing by Lessor. Any nonpayment of Rent or other amounts payable under any
Lease shall result in Lessee's obligation to promptly pay Lessor as additional
Rent on such overdue payment, for the period of time during which it is overdue
(without regard to any grace period), interest at a rate equal to the lesser of
(a) fourteen percent (14%) per annum, or (b) the maximum rate of interest
permitted by law.

      3.2 Use of Equipment. Lessee shall use the Equipment solely in the conduct
of its business, in a manner and for the use contemplated by the manufacturer
thereof, and in compliance with all laws, rules and regulations of every
governmental authority having jurisdiction over the Equipment or Lessee and with
the provisions of all policies of insurance carried by Lessee pursuant to
Section 3.6 below. Lessee shall pay all costs, expenses, fees and charges
incurred in connection with the use and operation of the Equipment.

      3.3 Delivery; Installation; Return; Maintenance and Repair; Inspection.
Lessee shall be solely responsible, at its own expense, for (a) the delivery of
the Equipment to Lessee, (b) the packing, rigging and delivery of the Equipment
back to Lessor, upon expiration or termination of the Lease Term, in good
repair, condition and working order, ordinary wear and tear excepted, at the
location(s) within the continental United States specified by Lessor, and (c)
the installation, de-installation, maintenance and repair of the Equipment.
During the Lease Term, Lessee shall ensure that the Equipment is covered by a
maintenance agreement, to the extent available, with the manufacturer of the
Equipment or such other party, reasonably acceptable to Lessor. Lessee shall, at
its expense, keep the Equipment in good repair, condition and working order,
ordinary wear and tear excepted, and, at the expiration or termination of the
Lease Term, or any renewal term, with respect to any of the Equipment, have such
Equipment inspected and certified acceptable for maintenance service by the
manufacturer, if such inspection and certification services are available from
the manufacturer at such time. In the event any of the Equipment, upon its
return to Lessor, is not in good repair, condition and working order, ordinary
wear and tear excepted, Lessee shall be obligated to pay Lessor for the
out-of-pocket expenses Lessor incurs in bringing such Equipment up to such
status, but not in excess of the Casualty Value (as defined in the applicable
Lease) for such Equipment, promptly after its receipt of an invoice for such
expenses. Lessor shall be entitled to inspect the Equipment at Lessee's

                                       3.
<PAGE>

location of reasonable times.

                                       4.
<PAGE>

      3.4 Taxes. Lessee shall be obligated to pay, and hereby indemnifies Lessor
and its successor and assigns against, and holds each of them harmless from, all
license fees, assessments, and sales, use, property, excise and other taxes and
charges, other than those measured by Lessor's net income, now and hereafter
imposed by any governmental body or agency upon or with respect to any of the
Equipment, or the possession, ownership, use or operation thereof, or any Lease
or the consummation of the transactions contemplated in any Lease or this
Agreement. Notwithstanding the foregoing, Lessor shall file all required
personal property tax returns, and shall pay all personal property taxes
payable, with respect to the Equipment, Lessee shall pay to Lessor, as
additional Rent, the amount of all such personal property taxes within fifteen
(15) days of its receipt of an invoice for such taxes.

      3.5 Loss of Equipment. Lessee shall bear the entire risk of the Equipment
being lost, destroyed or otherwise permanently unfit or unavailable for use from
any cause whatsoever (an "Event of Loss") after it has been delivered to common
carrier for shipment to Lessee. If an Event of Loss shall occur with respect to
any item of Equipment, Lessee shall promptly notify Lessor thereof in writing.
On the rental payment date following Lessor's receipt of such notice, Lessee
shall pay to Lessor an amount equal to the rental payment or payments due and
payable with respect to such item of Equipment on or prior to such date, plus a
sum equal to the Casualty Value of such item of Equipment as of the date of such
payment as set forth in such Lease. Upon the making of such payment by Lessee
regarding any item of Equipment, the Rent for such item of Equipment shall cease
to accrue, the term of this Lease as to such item of Equipment shall terminate
and (except in the case of loss, theft or complete destruction) Lessor shall be
entitled to recover possession of such item of Equipment in accordance with the
provisions of Section 3.3 above. Provided that Lessor has received the Casualty
Value of any item of Equipment, Lessee shall be entitled to the proceeds of any
recovery in respect of such item of Equipment from insurance or otherwise.

      3.6 Insurance. Lessee shall obtain and maintain for the Lease Term at its
own expense, property damage and liability insurance and insurance against loss
or damage to the Equipment (including so-called extended coverage), as a result
of theft and such other risks of loss as are normally maintained on equipment of
the type leased hereunder by companies carrying on the business in which Lessee
is engaged, in such amounts, in such form and with such insurers as shall be
satisfactory to Lessor. Each insurance policy will name Lessee as insured and
Lessor as an additional insured and loss payee thereof as Lessor's interests may
appear, and shall provide that it may not be canceled or altered without at
least thirty (30) days prior written notice thereof being given to Lessor or its
successor and assigns.

                                       5.
<PAGE>

      3.7 Indemnity. Except with respect to the gross negligence or willful
misconduct of Lessor, Lessee hereby indemnifies, protects, defends and holds
harmless Lessor and its successors and assigns, from and against any and all
claims, liabilities (including negligence, tort and strict liabilities),
demands, actions, suits, and proceedings, losses, costs, expenses and damages,
including without limitation, reasonable attorneys' fees and costs
(collectively, "Claims"), arising out of, connected with, or resulting from this
Agreement, any Lease or any of the Equipment, including, without limitation, the
manufacture, selection, purchase, delivery, possession, condition, use,
operation, or return of the Equipment. Each of the parties shall give the other
prompt written notice of any Claim of which it becomes aware. The provisions of
this Section 3.7 shall survive the expiration or termination of this Agreement
or any Lease.

      3.8 Prohibitions Related to Lease and Equipment. Without the prior written
consent of Lessor, which consent shall not be unreasonably withheld or delayed,
Lessee shall not: (a) assign, transfer, pledge, encumber, hypothecate or
otherwise dispose of this Lease or any rights or obligations thereunder; (b)
sublease any of the Equipment; (c) create or incur, or permit to exist, any lien
or encumbrance with respect to any of the Equipment, or any part thereof; (d)
move any of the Equipment from the location at which it is first installed; or
(e) permit any of the Equipment to be moved outside the continental limits of
the United States.

      3.9 Identification. Lessee shall place and maintain permanent markings
provided by Lessor on the Equipment evidencing ownership, security and other
interests therein, as specified from time to time by Lessor.

      3.10 Alterations and Modifications. Lessee shall not make any additions,
attachments, alterations or improvements to the Equipment without the prior
written consent of Lessor, which consent shall not be unreasonably withheld or
delayed. Any addition, attachment, alteration or improvement to any item of
Equipment shall belong to and become the property of Lessor unless, at the
request of Lessor, it is removed prior to the return of such item of Equipment
by Lessee. Lessee shall be responsible for all costs relating to such removal
and shall restore such item of Equipment to its operating condition that existed
at the time it became subject to the applicable Lease, ordinary wear and tear
excepted.

      3.11 Equipment to be Personal Property. Lessee acknowledges and represents
that the Equipment shall be and remain personal property, notwithstanding the
manner in which it may be attached or affixed to realty, and Lessee shall do all
acts and enter into all agreements necessary to ensure that the Equipment
remains personal property.

      3.12 Financial Statements. Lessee shall promptly furnish to Lessor such
financial or other statements respecting the condition and operations of Lessee,
and information respecting the Equipment, as Lessor may from time to time
reasonably request, so long as Lessee is not subject to the periodic reporting
requirements of the Securities Exchange Act of 1934, as amended.

                                       6.
<PAGE>

      3.13 Lessee Representations. Lessee hereby represents that, with respect
to this Agreement and each Lease: (a) the execution, delivery and performance
thereof by Lessee have been duly authorized by all necessary corporate action;
and (b) the individual executing such document is duly authorized to do so; (c)
such document constitutes a legal, valid and binding obligations of Lessee,
enforceable in accordance with its terms.

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                            IV. DEFAULT AND REMEDIES
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      4.1 Events of Default. The occurrence of any of the following shall
constitute an "Event of Default" hereunder: (a) Lessee shall fail to pay any
Rent or other payment due hereunder with five (5) days after it becomes due and
payable; (b) any material representation or warranty of Lessee made in this
Agreement, any Lease, or in any document furnished pursuant to the provisions of
this Agreement or otherwise, shall prove to have been false or misleading in any
material respect as of the date when it was made; (c) Lessee shall fail to
perform any material covenant, condition or agreement made by it under any
Lease, and such failure shall continue for twenty (20) days after its receipt of
notice thereof; (d) bankruptcy, receivership, insolvency, reorganization,
dissolution, liquidation or other similar proceedings shall be instituted by or
against Lessee or all or any part of its property under the Federal Bankruptcy
Code or other law of the United States or of any other competent jurisdiction,
and, if such proceeding is brought against Lessee, it shall consent thereto or
shall fail to cause the same to be discharged within thirty (30) days after it
is filed; (e) Lessee shall be in material default under any agreement with
respect to the installation of any of the Equipment; or (f) Lessee or any
guarantor of Lessee's obligations under any Lease shall be in payment default
under any other agreement with Lessor or Cisco Systems, Inc.

      4.2 Remedies. If an Event of Default hereunder shall occur and be
continuing, Lessor may exercise any one or more of the following remedies: (a)
terminate any or all of the Leases and Lessee's rights thereunder; (b) proceed,
by appropriate court action or actions, to enforce performance by Lessee of the
applicable covenants of any or all of the Leases or to recover damages for the
breach thereof; (c) recover from Lessee an amount equal to the sum of (i) all
accrued and unpaid Rent and other amounts due under any or all of the Leases (d)
personally, or by its agents, take immediate possession of any or all of the
Equipment from Lessee and, for such purpose, enter upon Lessee's premises where
any of the Equipment is located with or without process of law and free from all
claims by Lessee other than claims for damages resulting from Lessor's
negligence, recklessness or willful misconduct during such entry; provided
however, that the Lessor provides sufficient notice to Lessee to enable Lessee
to remove from such Equipment any proprietary or confidential information of the
Lessee and any third-party software that might be stored in or on such
Equipment; and (e) require the Lessee to assemble the Equipment and deliver the
Equipment to Lessor at a location which is reasonably convenient to Lessor and
Lessee. The exercise of any of the foregoing remedies by Lessor shall not
constitute a termination of any Lease or this Agreement unless Lessor so
notifies Lessee in writing. However Lessee shall not owe any additional Rent
with respect to Equipment taken by or returned to Lessor.

                                       7.
<PAGE>

      4.3 Disposition of Equipment. In the event, upon the occurrence of an
Event of Default, Lessor repossesses any of the Equipment, Lessor may sell or
lease any or all of such Equipment, at one or more public or private sales. The
proceeds of (i) any rental of the Equipment for the balance of the Original Term
(discounted to present value at the rate of five percent (5%) per annum) and
(ii) any sale of the Equipment shall be applied to the payment of (A) all costs
and expenses (including, without limitation, reasonable attorneys' fees)
incurred by Lessor in retaking possession of, and removing, storing, repairing,
refurbishing and selling or leasing such Equipment and (B) the obligations of
Lessee to Lessor pursuant to this Agreement. Lessee shall remain liable to
Lessor for any deficiency.

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                                V. MISCELLANEOUS
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      5.1 Performance of Lessee's Obligations. Upon Lessee's failure to pay Rent
(or any other sum due hereunder) or perform any obligation hereunder when due,
Lessor shall have the right, but shall not be obligated, to pay such sum or
perform such obligation, whereupon such sum or cost of such performance shall
immediately become due and payable hereunder as additional Rent, with interest
thereon at the highest legal rate from the date such payment or performance was
made.

      5.2 Quiet Enjoyment. So long as no Event of Default shall have occurred
and be continuing, neither Lessor nor its assignee shall interfere with Lessee's
right of quiet enjoyment and use of the Equipment.

      5.3 Further Assurances. Lessee and Lessor shall, upon the request of the
other, from time to time, execute and deliver such further documents and do such
further acts as the other may reasonably request in order fully to effect the
purpose of this Agreement, any Lease and Lessor's and Lessee's rights
thereunder. Lessor is authorized to file a financing statement, signed only by
Lessor in accordance with the Uniform Commercial Code or signed by Lessor as
Lessee's attorney in fact, with respect to any of the Equipment.

      5.4 Right and Remedies. Each and every right and remedy granted to Lessor
under any Lease shall be cumulative and in addition to any other right or remedy
therein specifically granted or now or hereafter existing in equity, at law, by
virtue of statute or otherwise, and may be exercised by Lessor from time to time
concurrently or independently and as often and in such order as Lessor may deem
expedient. Any failure or delay on the part of Lessor in exercising any such
right or remedy, or abandonment or discontinuance of steps to enforce the same,
shall not operate as a waiver thereof or affect Lessor's right thereafter to
exercising the same. Waiver of any right or remedy on one occasion shall not be
deemed to be a waiver of any other right or remedy or of the same right or
remedy on any other occasion.

                                       8.
<PAGE>

      5.5 Notices. Any notice, request, demand, consent, approval or other
communication provided for or permitted hereunder shall be in writing and shall
be conclusively deemed to have been received by a party hereto on the day it is
delivered to such party at its address set forth above (or at such other
addresses such party shall specify to the other party in writing), or if sent by
registered or certified mail, return receipt requested, on the fifth day after
the day on which it is mailed, postage prepaid, addressed to such party.

      5.6 Section Headings; Counterparts. Section headings are inserted for
convenience of reference only and shall not affect any construction or
interpretation of this Agreement. This Agreement and each Lease may be executed
in counterparts, and when so executed each counterpart shall be deemed to be an
original and such counterparts together shall constitute one and the same
instrument.

      5.7 Entire Lease. This Agreement and each Lease constitute the entire
agreement between Lessor and Lessee with respect to the lease of the Equipment.
No amendment of, or any consent with respect to, any provision of this Agreement
or any Lease shall bind either party unless set forth in a writing, specifying
such waiver, consent, or amendment, signed by both parties. TO THE EXTENT
PERMITTED BY APPLICABLE LAW AND NOT OTHERWISE SPECIFICALLY PROVIDED TO LESSEE IN
THIS AGREEMENT, LESSEE HEREBY WAIVES ANY AND ALL RIGHTS OR REMEDIES CONFERRED
UPON A LESSEE UNDER THE CALIFORNIA COMMERCIAL CODE, AND ANY OTHER APPLICABLE
SIMILAR CODE OR STATUTES OF ANOTHER JURISDICTION, WITH RESPECT TO A DEFAULT BY
LESSOR UNDER THIS AGREEMENT OR ANY LEASE.

      5.8 Severability. Should any provision of this Agreement or any Lease be
or become invalid, illegal, or unenforceable under applicable law, the other
provisions of this Agreement and such Lease shall not be affected and shall
remain in full force and effect.

      5.9 Attorneys' Fees. Should either party institute any action or
proceeding to enforce this Agreement or any Lease prevailing party shall be
entitled to receive from the other party all reasonable out-of-pocket costs and
expenses, including, without limitation, attorneys' fees.

      5.10 Governing Law and Jurisdiction. THIS LEASE SHALL BE GOVERNED IN ALL
RESPECTS BY THE LAWS OF THE STATE OF CALIFORNIA WITH RESPECT TO AGREEMENTS
ENTERED INTO, AND TO BE PERFORMED, ENTIRELY IN CALIFORNIA. LESSOR AND LESSEE
WAIVE ALL RIGHTS TO TRIAL BY JURY IN ANY LITIGATION ARISING FROM THIS AGREEMENT
OR ANY LEASE. LESSEE CONSENTS TO THE NON-EXCLUSIVE JURISDICTION OF THE STATE
COURTS OF CALIFORNIA, AND THE FEDERAL COURTS SITTING IN THE STATE OF CALIFORNIA,
FOR THE RESOLUTION OF ANY DISPUTES HEREUNDER.

                                       9.
<PAGE>

                                                                            COPY

      5.11 Survival. All obligations of Lessee to make payments to Lessor under
any Lease or to indemnify Lessor, pursuant to Section 3.4 or 3.7 above, with
respect to a Lease, and all rights of Lessor hereunder with respect to a Lease,
shall survive the termination of such Lease.

LESSEE, BY THE SIGNATURE BELOW OF ITS AUTHORIZED REPRESENTATIVE, ACKNOWLEDGES
THAT IT HAS READ THIS LEASE, UNDERSTANDS IT, AND AGREES TO BE BOUND BY ITS TERMS
AND CONDITIONS. LESSOR: LESSEE:

CISCO SYSTEMS CAPITAL                  VIP CALLING, INC.
CORPORATION

By: /s/ Sam Zaidins                    By: /s/ Michael J. Hughes
    ------------------------------         -------------------------------
        (Authorized Signature)                 (Authorized Signature)

Sam Zaidins
Manager, Customer Service & Operations
Cisco Systems Capital                        Michael J. Hughes, CFO
----------------------------------     -----------------------------------
           (Name/Title)                          (Legal Name/Title)

    11/5/98                                      11/3/98
----------------------------------     -----------------------------------
              (Date)                                   (Date)

                                      10.

<PAGE>

DJ Long, Vice President, Corporate Development
iBasis, Inc.
20 Second Avenue
Burlington, MA 01803

Dear Mr. Long:

Cisco Systems Capital Corporation ("CSC"), a wholly owned subsidiary of Cisco
Systems, Inc. ("Cisco Systems"), specializes in providing innovative finance
solutions for Cisco Systems products and services. We are pleased to present
this proposal ("Proposal") for the transaction described below:

LESSOR:                      Cisco Systems Capital Corporation

LESSEE:                      iBasis, Inc.

EQUIPMENT:                   Refinance existing Portfolio of Leases

MAXIMUM EQUIPMENT COST:      Approximately $61,000,000.00

SEGMENT ONE:                 Lease Schedules 1-16

SEGMENT TWO:                 Lease Schedules 17-33

LEASE TYPE:                  Segment One Interest only, payable monthly in
                             arrears; for 6 months commencing 11-01-01 with
                             existing principal payments suspended for 6
                             months and re-amortized after the six months
                             interest only period in the remaining original
                             term of each schedule.

                             Segment Two Interest only for 6 months with
                             interest accrued and added to the original
                             principal and amortized fully over a 30 month
                             term.

INTEREST RATE                Segment One 12%; Segment Two 15%

                                                                  Confidential

<PAGE>

PERIODIC RENT PAYMENT:       To be recomputed based on the Lease Schedule
                             restructuring.

SERVICE COSTS AND            All Lease Schedules comprised of services will
MAINTENANCE:                 maintain their existing terms.

PREPAYMENT OPTION:           Lessee may prepay all outstanding lease
                             obligations as of 11-30-01 at 75% of the total
                             amount due.

RENTAL PAYMENTS/INTERIM      Monthly Rental Payment will be in arrears, but
RENT:                        deemed acceptance of the equipment will take
                             place 30 days after shipment of the final piece
                             of equipment per schedule and if Lessee has not
                             previously notified Lessor that such Equipment
                             fails to conform to the specifications agreed to
                             between Lessee and Lessor or the description of
                             the Equipment as set forth on the applicable
                             Equipment Schedule. There is no interim rent, and
                             commencement of rental payments will occur on
                             the 1st of the month on or after acceptance or
                             deemed acceptance date.

NET LEASE:                   This is a net lease transaction under which all
                             costs and liabilities, including without
                             limitation, for insurance, maintenance and
                             taxes, are paid by Lessee for the term of the
                             lease. Transferable manufacturer's guarantees or
                             warranties will be passed on to Lessee, assuming
                             due performance of Lessee obligations.

INSURANCE COVERAGE:          An updated binder evidencing insurance coverage
                             will be required.

ADDITIONAL                   All outstanding schedules must be executed and
REQUIREMENTS:                returned by CSC by 11-12-01 and all payments due
                             under any schedule must be paid in full by
                             11-30-01 or before the refinancing agreement is
                             consummated.

INVOICING:                   Not less frequently than monthly.

CASUALTY VALUE:              Starting at 110% of Equipment Cost, such amount
                             to decrease from month to month thereafter by
                             2.15% of Equipment Cost.

                                                                  Confidential

<PAGE>

EARLY TERMINATION:           Present Value of the remaining outstanding
                             rental discounted at 5% plus all applicable
                             taxes.

END OF LEASE OPTIONS:        As already documented for the various schedules.

UTILIZATION PERIOD:          Must be fully documented no later than 11-30-01
                             with a start date of 11-01-01.

DOCUMENTATION FEE:           None.

OTHER FEES:                  None.

CREDIT APPROVAL:             This Proposal includes only a brief description
                             of the substantive terms and conditions of the
                             contemplated lease transactions and is not
                             intended as a formal commitment of credit by CSC
                             or Cisco Systems. Any funding by CSC for the
                             purchase of equipment is subject to the ongoing
                             credit approval of CSC (including the absence of
                             any material adverse change, in the judgment of
                             CSC, in the business or financial condition or
                             prospects of Lessee) and to satisfactory
                             documentation including as described below. You
                             agree to provide two years' audited financial
                             statements, bank references, a completed credit
                             application and any other required credit
                             information along with the signed copy of this
                             Proposal. You hereby authorize CSC an/or its
                             agents to make a complete credit investigation
                             and to relate this information to others as
                             necessary to secure credit approval.

The parties acknowledge that the financing contemplated by this Proposal is
subject to the above-referenced conditions and the execution and delivery of
all appropriate documents (in form and substance satisfactory to CSC),
including without limitation, to the extent applicable, the Master Lease
Agreement, any Schedule, certificate of acceptance, lease assignment of
purchase order, UCC financing statements, legal opinion and other documents
and agreements reasonably required by CSC. You agree to execute and return to
CSC, within 5 days of receipt, the Master Lease Agreement. Please indicate
your acceptance of all of the terms and conditions set forth herein by
signing and dating this Proposal in the space provided below by no later than
November 12, 2001, at which time this Proposal will expire if not accepted.

This Proposal is confidential and may not be disclosed to any person or
entity without our consent. Lessee agrees that it shall not, without CSC's
prior written consent, disclose the existence or terms of any financing
facility with CSC, use the name or logo of CSC or Cisco Systems in any press
release, advertisement or other public pronouncement, or represent to any
person that the relationship between CSC or Cisco Systems and Lessee is other
than that of lessor and lessee and vendor and equipment purchaser.
Notwithstanding the foregoing, iBasis may disclose the proposal or the
financing facility if required by court order, investigative subpoena, or if
required to comply with U.S. Securities and Exchange Commission rules. Prior
notice must be given to the Lessor prior to any disclosure.

                                                                  Confidential

<PAGE>

Thank you for the opportunity to present this Proposal. We look forward to
doing business with you. If you have any questions, please do not hesitate to
call me at 781-402-6597.

                             Sincerely,

                             CISCO SYSTEMS CAPITAL CORPORATION

                             By:  Jim Hogan
                                ------------------------------
                                Name: James E. Hogan

                                Title: Lease Manager

ACKNOWLEDGED AND AGREED:

IBASIS, Inc.

By:
   --------------------------------------
          (Authorized Signature)

Name:
     ------------------------------------

Title:
      -----------------------------------

Dated:
     ------------------------------------

Lessee is/is not [CIRCLE ONE] willing to
accept scheduling of partial purchase order
shipments. [Note: Failure to circle either
option shall be deemed an instruction not to
schedule partial purchase order shipments.]

                                                                  Confidential<PAGE>

                                                                 Exhibit 10.30

                       [iBasis, Inc. Letterhead]

                                                            September 17, 2001

Richard G. Tennant
10703 Miller Road
Oakton, VA 22124

Dear Mr. Tennant,

We are pleased to offer you the position of Chief Financial Officer at iBasis,
Inc. This position is located in Burlington, MA. You will report to Ofer
Gneezy, Chief Executive Officer.

Your salary will be $175,000 per annum, earned and payable at the
semi-monthly rate of $7,291.66. Your annual incentive compensation, based on
individual and corporate performance, will be up to $87,500. We will outline
the specific details of your incentive compensation within a reasonable time
after your start date.

You will also be provided with relocation assistance for your move from
Virginia to the Burlington area. Details of the relocation assistance will
follow shortly.

You will be eligible to receive a comprehensive benefits package including:
Medical and Dental insurance at nominal cost to the employee, Employee Stock
Purchase Plan, Section 125 Flexible Spending Accounts, an employer-matched
401(k) plan, tuition reimbursement, Company-paid life/disability and group
travel accident insurance, three weeks accrued vacation and eleven (11)
holidays.

In addition, a recommendation will be made to the Board of Directors to grant
you 150,000 shares of iBasis Inc. Incentive Stock Options. The Compensation
Committee of the Board of Directors meets at the end of the quarter to
approve grants. The option price is based on fair market value. You will
receive a copy of the stock plan and your option grant agreement within
ninety (90) days of its approval by the Board. These options vest over a
four-year period.

If iBasis terminates your employment without cause, or if you terminate your
employment with "good reason," in either case within six months after the
occurrence of an acquisition or change in control, then your stock options
will immediately vest and iBasis will continue to pay your salary for nine
months. Such vesting and payment are subject to the terms and conditions
generally applicable within iBasis for such policies.

Enclosed, please find a copy of iBasis' "Proprietary Information and
Inventions Agreement". Upon joining the Company, we ask you to provide us
with a signed copy of this document.

Additionally, we are required by the Immigration Reform and Control Act
(IRCA), to ask you to provide proof that you are authorized to work in the
U.S.

<PAGE>

Dick, we look forward to you joining our senior executive team and being part
of our continued leadership in Internet based communications.

We look forward to your formal acceptance of this offer. Please sign and
return the duplicate letter to Tamah Rosker, Vice President, Human Resources.
This offer will remain open until September XX, 2001.

Sincerely,

/s/ Ofer Gneezy

Ofer Gneezy
Chief Executive Officer

I accept this offer of employment and will begin work on Monday, October 22,
2001.

Signature:  /s/ Richard G. Tennant               Date:   Sept. 20, 2001
          ---------------------------               ---------------------

<PAGE>

                           IBASIS EMPLOYMENT AGREEMENT

         This Employment Agreement (the "AGREEMENT") is made and entered into by
and between iBasis, Inc., a Delaware corporation having its principal place of
business at 20 Second Avenue, Burlington, MA 01803 (together with its successors
and assigns, and any of its present or future subsidiaries, or organizations
controlled by, controlling or under common control with it, the "COMPANY") and
its Employee (the "EMPLOYEE").

                                    RECITALS

         WHEREAS, the Company recognizes that the Employee's talents and
liabilities are unique and valuable, and thus wishes to secure the services of
the Employee on the terms and conditions set forth herein; and

         WHEREAS, the Company desires to engage the Employee based on the
Employee's particular qualifications, in a capacity in which the Employee may
receive, initiate, contribute to or come in contact with Confidential and
Proprietary Information (as hereinafter defined), and the Employee desires to be
engaged in such a capacity; and

         WHEREAS, the Employee specifically acknowledges that this engagement
may include inventing, discovering, initiating or contributing to Confidential
or Proprietary Information and that the rights to such information are intended
to belong solely to the Company;

         NOW, THEREFORE, in consideration of the mutual promises and conditions
hereinafter contained, and other good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree as
follows:

SECTION 1.        EMPLOYMENT.

         1.1      EMPLOYMENT. The Company hereby agrees to employ the Employee
                  under the terms set forth in this Agreement and the letter
                  confirming employment sent to Employee by the Company.

         1.2      DUTIES. The Employee shall have such duties as are assigned to
                  the Employee by the Company. The Employee agrees to use the
                  Employee's best efforts to promote the success of the
                  Company's business, and to advance the best interests of the
                  Company. The Employee shall devote substantially all of the
                  Employee's working time, attention and energies during normal
                  business hours (other then absences due to illness or
                  vacation) to the performance of the Employee's duties for the
                  Company. During the term of the Employee's employment with the
                  Company, the Employee will not engage in any other employment
                  or consulting activities for any third party for direct or
                  indirect remuneration without written consent of the Company.

         1.3      SALARY. During the Employee's engagement by the Company, the
                  Company will pay the Employee an annual salary, to be paid in
                  accordance with the Company's payroll practices and policies
                  and subject to applicable withholdings. "Exempt" positions are
                  exempt from overtime pay, and the Employee's salary will
                  compensate the Employee for all hours worked. "Non-exempt"
                  positions will be eligible to earn overtime on any time in
                  excess of forty (40) hours worked in a week.

SECTION 2.        TERM.

         There is no specified length of employment. Accordingly, either the
Employee or the Company may terminate the employment relationship at will, with
or without cause, at any time. In conjunction with this policy of "at-will"
employment, the Employee may also be disciplined, demoted or have her or his job
responsibilities reassigned by the Company for any reason at the Company's sole
discretion.

<PAGE>

SECTION 3.        INVENTIONS AND OTHER INTELLECTUAL PROPERTY

         3.1      DEFINITIONS. As used in this Agreement, the term "COMPANY'S
                  FACILITIES, MATERIAL OR PERSONNEL" means facilities, material
                  or personnel owned, leased, occupied or controlled by the
                  Company as well as the facilities, materials or personnel of
                  third parties rented, leased or otherwise hired by the Company
                  for the conduct of aspects of the business of the Company, and
                  the term "INVENTIONS AND OTHER INTELLECTUAL PROPERTY" means
                  inventions, discoveries, concepts, developments, and ideas,
                  whether patentable or not, including but not limited to
                  software and hardware systems and services, devices,
                  processes, methods, formulae, and works of authorship
                  including computer programs, and operations, training and
                  maintenance manuals.

         3.2      OWNERSHIP. The Employee hereby agrees that all right, title
                  and interest in and to all of the Employee's Inventions and
                  Other Intellectual Property made during the period of
                  employment with the Company, whether pursuant to this
                  Agreement or otherwise, and whether or not during the hours of
                  the Employee's engagement or with the use or assistance of
                  Company Facilities, Materials or Personnel, either solely or
                  jointly with others, shall belong solely to the Company,
                  whether or not they are protected or protectable under
                  applicable patent, trademark, service mark, copyright or trade
                  secret laws.

         3.3      ASSIGNMENT OF RIGHTS. The Employee hereby assigns and agrees
                  to assign to the Company or its designee, all of the
                  Employee's right to and title and interest in all Inventions
                  and Other Intellectual Property, made or created during the
                  Employee's period of employment with the Company, and to
                  applications for United States and foreign letters patent and
                  United States and foreign letters patent granted upon such
                  Inventions and to all maskworks, copyrightable materials,
                  trademark materials, and materials related thereto made or
                  created during the Employee's period of employment with the
                  Company.

         3.4      ASSIGNMENT OF COPYRIGHTS. To the extent that any work is not
                  assigned by provision of PARAGRAPHS 3.2 and 3.3 of this
                  Agreement, all work by the Employee under the Agreement,
                  regardless of where or when the work is performed, is deemed
                  to be a "work made for hire" to which copyright vests with the
                  Company. To the extent any work performed by the Employee
                  under this Agreement is not a "work made for hire," the
                  Employee hereby assigns and transfers, and agrees to assign
                  and transfer, the Employee's copyright in the work to the
                  Company.

         3.5      DUTY TO COOPERATE. The Employee agrees for himself and the
                  Employee's heirs, personal representatives, successors and
                  assigns, upon request of the Company, to at all times during
                  and after employment, perform all acts that are reasonable and
                  deemed necessary or desirable by the Company to secure the
                  full benefits, enjoyment, rights and title to the Inventions
                  or Other Intellectual Property and otherwise to carry into
                  full force and effect the text and the intent of the
                  assignment agreement set out in PARAGRAPHS 3.2, 3.3 and 3.4
                  preceding, including but not limited to giving testimony in
                  support of the Employee's inventorship, and to execute and
                  deliver promptly to the Company such papers, instruments and
                  documents without expense to the Employee, as from time to
                  time may be necessary or useful in the Company's opinion to
                  apply for, secure, enforce, maintain, reissue or defend the
                  Company's or its designee's worldwide rights in the Inventions
                  and Other Intellectual Property made or created during the
                  Employee's period of employment with the Company or in any or
                  all United States letters patent and in any and all letters
                  patent in any country foreign to the United States. This
                  obligation shall survive the term and termination of this
                  Agreement. Employee shall be compensated by the Company at
                  reasonable rates for time in complying with this provision
                  after his termination from Employment.

         3.6      NO VIOLATION OF THIRD PARTY AGREEMENTS OR POLICIES. The
                  Employee warrants and represents to the Company that she or he
                  is not subject to any agreement or company or university
                  policy inconsistent with the Agreement regarding Inventions
                  and Other Intellectual Property set forth herein.

         3.7      ATTORNEY-IN-FACT. In the event that the Company is unable for
                  any reason to secure the Employee's signature on any document
                  required to apply for or execute any patent, copyright, mask
                  work or other applications with respect to any Inventions and
                  Other Intellectual Property rights (including improvements,
                  renewals, extensions, continuations, decisions or
                  continuations-in-part thereof), the Employee hereby
                  irrevocably designates and appoints the Company and its duly
                  authorized officers and agents as his/her agents and
                  attorneys-in-fact to act on his/her behalf and instead of
                  Employee, to execute and file any such application

                                       2

<PAGE>

                  and to do all other lawfully permitted acts to further the
                  prosecution and issuance of patents, copyrights, mask works or
                  other rights made or created during the Employee's period of
                  Employment with the Company thereon with the same legal force
                  and effects as if executed by the Employee.

SECTION 4.        SHOP RIGHT.

         Notwithstanding any provision of this Agreement creating greater
rights, the Company shall have the royalty-free worldwide right to use in its
business, and to make, have made, use, sell, offer for sale, or import products,
processes and services derived from, any inventions, discoveries, concepts and
ideas, whether or not patentable, including but not limited to systems, devices,
software, processes, methods, formulae, and techniques, as well as improvements
thereof and know-how related thereto, that are not Inventions as defined herein,
but which are made or conceived by the Employee during the Employee's engagement
by the Company or associated companies or with the use or assistance of the
Company's Facilities, Materials or Personnel to the extent permitted by
applicable federal and state law.

SECTION 5.        CONFIDENTIALITY

         5.1      DEFINITIONS. As used in this Agreement, the term "CONFIDENTIAL
                  AND PROPRIETARY INFORMATION" means Company trade secrets, as
                  well as any and all information disclosed to or known by the
                  Employee as a consequence of or through the Employee's
                  engagement by the Company or associated companies or
                  employees, or which the Employee has assigned or is under an
                  obligation to assign to the Company, about the Company's
                  plans, products, processes and services, including, without
                  limitation, (a) information of a technical nature, such as
                  information regarding past, present and future research,
                  discoveries, ideas, concepts, know-how, techniques, designs,
                  specifications, drawings, blueprints, tracings, diagrams,
                  models, samples, data, product information, marketing plans,
                  computer programs (whether in source or object code form or
                  other form and whether contained on program listings, magnetic
                  tape, magnetic disks, CD ROMs or other media), computer
                  program documentation, disks, diskettes, tapes, logic, flow
                  charts, specifications, documentation and ideas relating to
                  the activities of the Company, (b) information of a business
                  nature, such as information regarding past, present and future
                  client development, financial data, prospective and actual
                  customer names, lists, or proposals, patent applications,
                  business information, strategic and development plans,
                  employee lists, business manuals, marketing plans, strategies,
                  procurement specifications, contacts, quotations, and (c) all
                  documents, drawings, reports, client lists, and other physical
                  embodiments of all such information.

         5.2      Except as specifically directed or consented to by the Company
                  in writing, the Employee will not, directly or indirectly,
                  during or after the term of the Employee's engagement by the
                  Company, communicate, disclose, or cause to have communicated
                  or disclosed, in any way, any trade secrets of the Company or
                  other Confidential and Proprietary Information. Nothing
                  contained herein shall prevent Employee from disclosing trade
                  secrets or Confidential and Proprietary Information if so
                  directed by a court of competent jurisdiction or to her or his
                  legal advisors and others with a legitimate reason to know as
                  part of any legal proceedings or dispute concerning such
                  Information.

         5.3      The restriction of PARAGRAPH 5.2 shall not apply to
                  information that the Employee can establish, by competent
                  proof: (i) was known, other than under binder of secrecy, to
                  the Employee prior to the Employee's engagement by the
                  Company; (ii) has passed into the public domain prior to or
                  after its development by or for the Company other than through
                  acts or omissions attributable to the Employee; or (iii) was
                  subsequently obtained other than under binder of secrecy from
                  a third party other than the Company or associated companies.

         5.4      Upon termination of the Employee's engagement by the Company,
                  or at any other time upon the request of the Company, the
                  Employee shall forthwith deliver to the Company any and all
                  documents, notes, notebooks, letters, manuals, prints,
                  drawings, block diagrams, photocopies of documents, devices,
                  hardware, data, databases, source code, object code, and data
                  or computer programming code stored on an optical or
                  electronic medium, relating to the Company's business and
                  affairs, including all materials that are in the possession of
                  or under the control of the Employee and that incorporate any
                  Confidential and Proprietary Information or any reference
                  thereto.

         5.5      The Employee acknowledges that the Company's Confidential and
                  Proprietary Information constitutes unique and valuable assets
                  of the Company, the loss or unauthorized disclosure of which
                  would cause the Company irreparable harm. Upon the breach or
                  threatened breach by the Employee of any of the provisions of
                  this SECTION 5, the Company shall be entitled to an
                  injunction, without bond, restraining the Employee from
                  committing such breach. This right to an injunction shall not
                  be construed to prohibit the Company from pursuing any other
                  remedies available to it at law or in equity for such breach
                  or threatened breach, including the recovery of damages. In
                  case of any dispute hereunder, the parties will submit to the
                  jurisdiction and venue of any court of competent jurisdiction,
                  including such courts in Suffolk County, Massachusetts, and
                  will comply with all requirements necessary to give such court
                  jurisdiction over the parties and the controversy. EACH PARTY
                  HEREBY WAIVES ANY RIGHT TO A JURY TRIAL AND TO CLAIM OR
                  RECOVER PUNITIVE DAMAGES.

                                       3

<PAGE>

The Employee acknowledges that the Company's Confidential and Proprietary
Information constitutes unique and valuable assets of the Company, the loss or
unauthorized disclosure of which would cause the Company irreparable harm. Upon
the breach or threatened breach by the Employee of any of the provisions of this
SECTION 5, the Company shall be entitled to an injunction, without bond,
restraining the Employee from committing such breach. This right to an
injunction shall not be construed to prohibit the Company from pursuing any
other remedies available to it at law or in equity for such breach or threatened
breach, including the recovery of damages. In case of any dispute hereunder, the
parties will submit to the jurisdiction and venue of any court of competent
jurisdiction, and will comply with all requirements necessary to give such court
jurisdiction over the parties and the controversy. EACH PARTY HEREBY WAIVES ANY
RIGHT TO A JURY TRIAL AND TO CLAIM OR RECOVER PUNITIVE DAMAGES.

SECTION 6.        COVENANT NOT TO COMPETE

         6.1      DEFINITIONS. As used in this Agreement, the term "COMPETING
                  ORGANIZATION" means any person or organization engaged in or
                  with specific plans to become engaged in research on, or
                  development, production, marketing or selling of a Competing
                  Product, and the term "COMPETING PRODUCT" means any product,
                  process or service of any person or organization other than
                  the Company, whether or not in existence, that competes or is
                  likely to compete, directly or indirectly, with a product,
                  process or service that is being developed, sold or marketed
                  at the time the Company seeks to enforce this paragraph and
                  upon or with which the Employee has worked for the Company or
                  about which the Employee acquired Confidential and Proprietary
                  Information by virtue of engagement with the Company.

         6.2      The Employee agrees and acknowledges that in order to assure
                  the Company that it will retain its value as a going concern,
                  it is necessary that the Employee undertake not to utilize the
                  Employee's special knowledge of the technology and the
                  business of the Company and the Employee's relationships with
                  customers and suppliers to compete with the Company. Employee
                  further acknowledges that:

              i.      The Employee occupies a position of trust and confidence
                      with the Company and, during Employee's engagement under
                      this Agreement, the Employee will become familiar with the
                      Company's trade secrets and with other Confidential and
                      Proprietary Information;

              ii.     The agreements and covenants contained in this Section 6
                      are essential to protect the Company and its associated
                      goodwill; and

              iii.    The Employee's engagement with the Company has special,
                      unique and extraordinary value to the Company, and the
                      Company would be irreparably damaged if the Employee were
                      to provide services to any person or entity in violation
                      of the provisions of this Agreement.

         6.3      During the term of this Agreement and for a period of one year
                  thereafter, the Employee will not render services, directly or
                  indirectly, to any Competing Organization which is engaged in
                  marketing or selling of a Competing Product in the United
                  States, except that the Employee may accept employment with,
                  or render services to, (i) a Competing Organization whose
                  business is diversified, but only to the parts of such
                  business which are not a Competing Organization, provided that
                  the Company, prior to the Employee's accepting such employment
                  or rendering such services, shall receive separate written
                  assurance satisfactory to the Company from such Competing
                  Organization and from the Employee that the Employee will not
                  render services directly or indirectly in connection with any
                  Competing Product or (ii) any university or academic
                  institution

                                       4

<PAGE>

                  so long as such employment or engagement does not involve use
                  or disclosure of any Confidential and Proprietary Information
                  or research on or development of any Competing Product.
                  Nothing contained herein shall preclude Employee from
                  participating, directly or indirectly, as a passive investor
                  in the securities of any publicly-traded corporation. The
                  Employee agrees to disclose to every Competing Organization,
                  by which the Employee may subsequently be employed or engaged,
                  the restrictions upon the Employee's services herein
                  contained.

         6.4      During the Employee's engagement by the Company and for a
                  period of one year after the Employee ceases to be engaged by
                  the Company, the Employee shall not, directly or indirectly,
                  solicit as employees, partners, or in any other personal or
                  representative capacity any present employee of the Company
                  for the purpose of securing business or contracts related to
                  the business in which Company is engaged, or competing with
                  Company.

         6.5      During Employee's engagement by the Company and for a period
                  of one year after Employee ceases to be engaged by Company,
                  the Employee shall not, directly or indirectly, solicit
                  business from, divert business from, or attempt to convert to
                  other methods of using the same or similar products or
                  services as provided by Company, any existing client, account
                  or location of Company at the time of any such solicitation or
                  attempted diversion with which the Employee has had any
                  contact as a result of the Employee's engagement by Company.

         6.6      If any court of competent jurisdiction shall at any time deem
                  the term of this Agreement or any particular restrictive
                  covenant too lengthy or the territory too extensive, the other
                  provisions of this Section 6 shall nevertheless stand, the
                  restricted period shall be deemed to be the longest period
                  permissible by law under the circumstances and the territory
                  shall be deemed to comprise the largest territory permissible
                  by law under the circumstances. The court in each case shall
                  reduce the restricted period and/or territory to permissible
                  duration or size.

         6.7      The Employee will not assert any rights under any Inventions
                  and Other Intellectual Property, discoveries, concepts or
                  ideas or improvements thereof or know-how related thereto, as
                  having been made or acquired by the Employee prior to the
                  Employee's engagement by the Company except as disclosed in
                  writing in EXHIBIT A to this Agreement. The Employee
                  represents that the list in EXHIBIT A is complete. If there is
                  no such list on EXHIBIT A, the Employee represents that the
                  Employee has no rights in any such Inventions and Other
                  Intellectual Property, discoveries, concepts or ideas or
                  improvements thereof or know-how related thereto.

SECTION 7.        GENERAL PROVISIONS.

         7.1      BINDING EFFECT. This Agreement shall be binding upon and inure
                  to the benefit of the parties hereto and their respective
                  heirs, personal representatives, successors, and assigns.

         7.2      COUNTERPARTS. This Agreement may be executed simultaneously in
                  any number of counterparts, each of which shall be deemed an
                  original but all of which together shall constitute one and
                  the same instrument.

         7.3      PRESUMPTION. This Agreement or any section thereof shall not
                  be construed against any party due to the fact that this
                  Agreement or any section hereof was drafted by such party.

         7.4      GOVERNING LAW. This Agreement, and all transactions
                  contemplated hereby, shall be governed by, construed, and
                  enforced in accordance with the laws of the Commonwealth of
                  Massachusetts, without reference to the conflict of laws
                  provisions thereof.

         7.5      SEVERABILITY. If any term, provision, clause, article,
                  condition or other portion of this Agreement is determined to
                  be invalid, void, or unenforceable by a court of competent
                  jurisdiction, the same will be deemed amended or deleted to
                  the extent necessary to make it enforceable, and it will not
                  affect any other term, provision, clause, article, condition,
                  or other portion hereof, and the remainder of this Agreement
                  will remain in full force and effect.

         7.6      NO CONFLICT. The Employee warrants and represents to the
                  Company that the Employee is not now under any obligation of a
                  contractual or other nature to any person, firm, corporation,
                  or university which is inconsistent

                                       5

<PAGE>

                  or in conflict with this Agreement or any provision hereof, or
                  which would prevent, limit or impair in any way the execution
                  of this Agreement or the performance by the Employee's
                  obligations hereunder, and the Employee will indemnify and
                  hold harmless the Company, its directors, officers and
                  employees against and in respect of all liability, loss,
                  damage, expense, or deficiency resulting from any
                  misrepresentation, or breach of any warranty or agreement made
                  by Employee in connection with Employee's employment
                  hereunder.

         7.7      NOTICES. All notices or other communications required or
                  permitted by this Agreement to be given or made by one party
                  to the other shall be made or given in writing and delivered
                  either in person, by overnight delivery, by certified mail or
                  registered mail, postage prepaid, return receipt requested or
                  by telex or facsimile to the Company at the address specified
                  below, or to the Employee at the address maintained in the
                  Company's records, which Employee agrees to keep up to date.
                  Such notice will be effective upon delivery or transmission in
                  such a manner. Proof of delivery or transmission in such a
                  manner shall constitute proof of receipt.

                           iBasis, Inc.
                           ATTN: Ms. Tamah Rosker
                           20 Second Avenue
                           Burlington, MA 01803
                           FAX:  (781) 505-7330

         7.8      SURVIVAL OF OBLIGATIONS. Sections 3, 4, 5, and 6 of this
                  Agreement, including the Employee's obligations to the Company
                  regarding Confidential and Proprietary Information and the
                  Employee's covenant not to compete with the Company as set for
                  the herein, shall survive the term and termination of this
                  Agreement.

         7.9      ENTIRE AGREEMENT. This Agreement sets forth the entire
                  agreement of the parties hereto in respect of the subject
                  matter contained herein and supersedes all prior agreements,
                  promises, covenants, arrangements, communications,
                  representations or warranties, whether oral or written, by any
                  officer, employee or representative of any party hereto in
                  respect of such subject matter. Any prior agreement of the
                  parties hereto in respect of the subject matter contained
                  herein is hereby terminated and canceled.

         7.10     AGREEMENT READ. UNDERSTOOD AND FAIR. Employee has carefully
                  read and considered all provisions of this Agreement and
                  agrees that all of the restrictions set forth are fair and
                  reasonable and are reasonably required for the protection of
                  the interests of Company.

         7.11     WAIVER. None of the provisions of this Agreement shall be
                  deemed to be waived by any act or acquiescence on the part of
                  the company or its agents. No waiver of any provision of this
                  Agreement shall constitute a waiver of any other provision.
                  The failure of the Company to enforce a provision of this
                  Agreement shall not be deemed a waiver of that provision.

         7.12     PROOF OF LEGAL AUTHORITY. Under federal immigration laws, the
                  Company is required to verify each new employee's identity and
                  legal authority to work in the United States. Therefore, the
                  Employee's employment pursuant to this Agreement is contingent
                  upon the Employee submitting the legally required proof of the
                  Employee's identity and authorization to work in the United
                  States. Not later than the Employee's third day of employment,
                  the Employee will provide the required identification.

         7.13     Except as provided above in Paragraph 5.5 and except for
                  claims arising out of the Workers Compensation Act, either
                  party may require that all disputes or injuries arising out of
                  the employment relationship between the Employee and the
                  Company, including but not limited to claims for breach of
                  contract; wrongful termination; age, sex, race or other
                  unlawful discrimination or harassment; defamation; violation
                  of public policy; and any dispute over the validity of, breach
                  or rescission of this Agreement, shall be settled by an
                  arbitration in accordance with the commercial arbitration
                  rules of the American Arbitration Association before a one (1)
                  person panel. The English language shall be used throughout
                  the arbitral proceeding. The arbitration shall take place in
                  Boston, Massachusetts, U.S.A. The cost of the arbitration,
                  including the fees and expenses of the arbitrator(s), shall be
                  shared equally by the Parties unless that award provides
                  otherwise. Any decision or order of the arbitrator shall be
                  binding upon the parties hereto. Judgment upon any award so

                                       6

<PAGE>

                  rendered may be entered in any court having jurisdiction.
                  Except as provided above in PARAGRAPH 5.5 above, the Employee
                  and the Company agree that arbitration is the sole and
                  exclusive remedy, and each party waives the right to a jury
                  trial and to seek legal relief in any other forum. This
                  provision however, shall not prohibit the Employee or the
                  Company from obtaining injunctive relief pending arbitration.

         I UNDERSTAND THAT THIS AGREEMENT AFFECTS MY RIGHTS TO INVENTIONS I MAKE
DURING MY EMPLOYMENT, AND RESTRICTS MY RIGHTS TO DISCLOSE OR USE THE COMPANY'S
CONFIDENTIAL INFORMATION OR TO COMPETE WITH THE COMPANY DURING OR SUBSEQUENT TO
MY EMPLOYMENT.

         I HAVE READ THIS AGREEMENT CAREFULLY AND UNDERSTAND ITS TERMS. I HAVE
COMPLETELY FILLED OUT EXHIBIT A TO THIS AGREEMENT.

Dated: SEPT. 20, 2001.

                                       /s/ Richard G. Tennant
                                       Signature

                                       Richard G. Tennant
                                       Name of Employee

                                       ---------------------------------

                                       ---------------------------------

                                       ---------------------------------
                                       Address

ACCEPTED AND AGREED:

iBASIS, INC.

By:      /S/ T. ROSKER
   -----------------------------------------
          Signature

         T. ROSKER
   -----------------------------------------
           Print

Title:   VP HR
      --------------------------------------

                                       7

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00035-of-00352.parquet"}]]