EXHIBIT 10.30
                                 -------------
                                        

                                   SUBLEASE
                                   --------


THIS SUBLEASE made as of the 20th day of August, 1997 by and between Eisai
Research Institute of Boston, Inc., a Massachusetts corporation (hereinafter
called "Sublessor"), and Vialog Corporation, a Massachusetts corporation
(hereinafter called "Sublessee").

WHEREAS, Sublessor is the tenant under a certain Lease dated as of July 2nd,
1996 (the "Prime Lease") wherein Connecticut General Life Insurance Company on
behalf of its Separate Account R (the "Prime Landlord") is the landlord with
respect to the premises being 2623 rentable square feet of space on the third
(3rd) floor of the building known and numbered as 10 New England Business
Center, Andover, Massachusetts (the "Building") which premises are shown on the
floor plan attached to the Prime Lease (hereinafter referred to as the "Demised
Premises"); and

WHEREAS, the parties desire to enter into a sublease of the Demised Premises
upon the terms, provisions and conditions herein contained.

NOW, THEREFORE, it is agreed as follows:

1.   Sublessor does hereby lease and demise to Sublessee the Demised Premises
     together with all the rights and benefits of the Sublessor under the Prime
     Lease.

2.   Sublessee shall pay to Sublessor Annual Base Rent in the amount of Forty-
     Nine Thousand Eight Hundred Thirty-Seven and No/100 Dollars ($49,837.00)
     per annum (Nineteen and No/100 Dollars [$19.00] per square foot of Rentable
     Floor Area of the Demised Premises).

     Said Annual Base Rent shall be paid in equal monthly installments, payable
     in advance on the first day of each and every month, or prorated for any
     partial month, commencing on the Commencement Date (as hereinafter
     defined).

3.   The term of this Sublease shall commence on September 1, 1997 (the
     "Commencement Date") and shall expire on May 31, 1999, unless sooner
     terminated as herein provided.

4.   The Sublessee hereby agrees to perform each and every obligation on the
     part of the Sublessor contained in the Prime Lease, insofar as the same
     relates to the Demised Premises. Sublessee shall deliver to Sublessor
     certificates of insurance listing Sublessor as an additional insured at the
     time Sublessor is required under the Prime Lease to deliver policies or
     certificates of insurance to Prime Landlord.

5.   The Sublessee agrees to do nothing that would violate any term, provision
     and condition of said Prime Lease.

 
6.   In the event of any default hereunder by the Sublessee, or in the event of
     any default under said Prime Lease caused by the act or omission of said
     Sublessee and, if any of such defaults shall continue for a period of
     fifteen (15) days or more (or such shorter period, but not less than five
     [5] days, as shall remain before the expiration of the cure period provided
     under the Prime Lease), after written notice from the Sublessor to the
     Sublessee designating the nature of the default complained of; or , in the
     event of any bankruptcy or insolvency of the Sublessee, or the commencement
     of any proceeding by the Sublessee under any such bankruptcy or insolvency
     law, State or Federal, now or hereinafter enacted; or, in the event of any
     involuntary proceeding brought against the Sublessee under any such
     bankruptcy or insolvency laws, if such proceeding is not dismissed within
     forty-five (45) days of its filings; or, in the event that the Sublessee
     shall make an assignment for the benefit of creditors by way of trust
     mortgage or otherwise, or if any attachment shall be made of this leasehold
     by mesne process which shall not be discharged within thirty (30) days
     after written notice from Sublessor to the Sublessee, then and in any such
     case, the Sublessor may terminate this sublease by giving notice of
     termination to the Sublessee and this sublease shall thereupon determine on
     the third day after the date of such notice and the Sublessee covenants to
     indemnify and hold harmless the Sublessor from and against all loss of rent
     or other payments which the Sublessor may incur by reason of such
     termination including reasonable attorney's fees, from time to time upon
     demand of the Sublessor.

     During the term hereof said Sublessee shall maintain the Subleased Premises
     and at the expiration or prior termination of said term, yield the same up
     in good repair, order and condition in all respects, reasonable wear and
     use, damage by fire and casualty only excepted.

     Sublessee shall have responsibility to maintain the heating, ventilation,
     air-conditioning, plumbing and electrical systems serving the Demised
     Premises to the same extent as the Sublessor is required to so maintain the
     same under the Prime Lease.

     Sublessee agrees that all of its goods and effects are on the Demised
     Premises at its sole risk and expense and the Sublessor shall not be liable
     for any loss of such goods or effects for any reason whatsoever.

7.   If said Prime Lease shall terminate for any reason whatsoever, this
     Sublease shall terminate without liability on the part of the Prime
     Landlord or Sublessor. Sublessor agrees not to enter into a voluntary
     termination of said Prime Lease.

8.   The Sublessor shall have no obligation to provide any services, utilities
     or the like. All of the same shall be provided by the Prime Landlord as
     provided in the Prime Lease or by the Sublessee. Sublessee shall pay for
     certain services as provided in Paragraph 14 hereof.

9.   It is expressly understood and agreed that the Sublessee may not assign
     this Sublease or sublet all or any portion of the Demised Premises or
     permit any person, firm or corporation to occupy any portion of the Demised
     Premises as licensee or in any other fashion without the prior written
     consent of the Sublessor. Sublessor agrees not to 

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     unreasonably withhold its consent to an assignment of this Sublease or a
     sublease of a portion of the Demised Premises provided that: (a) Sublessee
     is not in default of any obligation hereunder; (b) Sublessor determined in
     its sole discretion that the proposed assignee or sublessee (i) is a first-
     class office establishment and would use the Demised Premises solely for
     the uses permitted under the Prime Lease, and (ii) has a financial standing
     acceptable to Sublessor as evidenced by financial statements in scope and
     substance satisfactory to Sublessor and in conformity with generally
     accepted accounting principles and, if requested by Sublessor, certified by
     a certified public accountant acceptable to Sublessor; and (c) the rent
     charged by Sublessee on a square footage basis shall not be less than the
     Annual Base Rent and additional rent due hereunder, on a square footage
     basis. In the case of an assignment, the proposed assignee must
     specifically assume and agree in writing to be bound by all of the
     obligations of the Sublessee hereunder.

10.  The Sublessee agrees to hold harmless and indemnify the Sublessor of and
     from all damages, costs and expenses and losses which the Sublessor may
     incur under the Prime Lease or for which Sublessor may be liable to Prime
     Landlord by reason of the Sublessee's default hereunder which are the
     subject matter of any indemnity or hold harmless of Sublessor to Prime
     Landlord under the Prime Lease or which would constitute a default on the
     part of the Sublessor under said Prime Lease. The Sublessor agrees to hold
     harmless and indemnify the Sublessee of and from all damages, costs and
     expenses which the Sublessee may incur under the Prime Lease or for which
     Sublessee may be liable to Prime Landlord by reason of Sublessor's default
     hereunder which are the subject matter of any indemnity or hold harmless of
     Sublessor to Prime Landlord under the Prime Lease would constitute a
     default of the Sublessor under the Prime Lease.

11.  The Sublessee shall indemnify and hold harmless the Sublessor from and
     against the claims and demands of all persons on account of injury to
     person, including death and including employees of the said Sublessee or
     damage to property occurring on or in the Demised Premises unless such
     injury or damage shall be due solely to the act of the Sublessor or its
     employees.

12.  Sublessee shall pay for any additional insurance premiums which shall be
     charged to Sublessor by reason of Sublessee's occupancy of the Subleased
     Premises.

13.  The Sublessee agrees that Sublessee has inspected the Demised Premises,
     found the same to be acceptable in all respects, and acknowledges that
     neither of Prime Landlord nor Sublessor shall have any responsibility to
     make repairs or improvements to comply with Sublessor's obligations to
     deliver the Subleased Premises to the Sublessee. Any alterations or
     additions to the Demised Premises shall be at the sole expense of the
     Sublessee and shall require the approval of the Sublessor (and the Prime
     Landlord if required under the terms of the Prime Lease). By acceptance of
     this Sublease, Sublessor agrees that any alterations or additions approved
     by Prime Landlord and Sublessor need not be removed at the termination of
     the Prime Lease or Sublease unless such removal is made a condition of such
     approval. Sublessee has advised Sublessor that it intends to subdivide the
     existing conference room in the Demised Premises to create two individual

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     offices by installing a non-structural partition wall. Subject to
     Sublessor's review and approval of architectural plans therefore, and
     reserving it rights to condition its approval on the subsequent restoration
     of the Demised Premises, the Sublessor acknowledges that it has no
     objection to Sublessee's proposed alterations as aforesaid.

14.  Without limiting the generality of Section 4 of this Sublease, Sublessee
     agrees to pay to the Sublessor the following:
 
     (a)  all charges for electricity as set forth in Section 4.4 of the Prime
          Lease;

     (b)  Tenant's Share of Premises Expenses as set forth in Section 4.2 of the
          Prime Lease, including any Estimated Premises Expense Payments 
          required under Section 4.3 of the Prime Lease.


     All of the foregoing payments shall be made by the Sublessee at the time
     and in the manner required of Sublessor under the Prime Lease.

15.  Sublessee shall pay to Sublessor a security deposit of Eight Thousand Three
     Hundred Six and 16/100 Dollars ($8,306.16) (the "Deposit") which Deposit
     shall be held by Sublessor without interest as security for the faithful
     performance by Sublessee of all of the terms of this Sublease by Sublessee
     to be observed and performed.  If Sublessee defaults and said default is
     not cured within any applicable cure period under any of the terms of this
     Sublease, Sublessor may, at its option and without prejudice to any other
     remedy, apply all or any portion of the Deposit to the loss suffered by
     Sublessor as a result of such default and Sublessee shall forthwith upon
     demand restore the Deposit to the original sum deposited.  If Sublessee
     elects to so apply all or any portion of the Deposit as aforesaid, it shall
     notify Sublessee of such application within a reasonable period of time
     thereafter.  Should Sublessee comply with all of the terms of this
     Sublease, the Deposit will be returned to Sublessee at the end of the term
     of this Sublease.

16.  Sublessor and Sublessee each represent to the other that no broker was
     involved in the transaction reflected by this Sublease except Trammel Crow
     Company, and each of Sublessor and Sublessee agree to indemnify the other
     party against any loss resulting from breach of this representation.
     Sublessor shall be responsible for the commission to be paid to Trammel
     Crow Company in connection with this Sublease in the amount of Six Thousand
     Five Hundred and Fifty-Seven and 50/100 Dollars ($6,557.50).

17.  This Sublease is subject and subordinate to the Prime Lease.  Whenever any
     obligation on the part of Sublessor under this Sublease is, in fact, an
     obligation to be performed by the Prime Landlord under the Prime Lease,
     Sublessor's liability herein shall be to use reasonable efforts to obtain
     performance by such party.  If, notwithstanding Sublessor's reasonable
     efforts, such party shall fail to perform any of its obligations as
     aforesaid, Sublessee may, in Sublessor's name but at Sublessee's expense,
     seek to enforce such party's obligations.  Sublessor agrees to use
     reasonable efforts to arrange for Sublessee's name to be added by Prime
     Landlord to the Tenant directory in the Main Lobby of the 

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     Building and at the entranceway door to the Demised Premises. Any
     reasonable costs associated therewith shall be borne by Sublessor.

18.  No oral agreement or prior written matter shall have any force or effect.
     Sublessee agrees that it is not relying on any representations or
     agreements other than those contained in this Sublease.  This Sublease
     shall not be modified or cancelled except by a writing executed by
     Sublessor and Sublessee.

19.  All notices required or permitted hereunder shall be given to the parties
     in the manner provided in the Prime Lease addressed as follows:

     if addressed to Sublessor:

          Eisai Research Institute of Boston, Inc.
          One Corporate Drive
          Andover, MA 01810
          Attn:  President

     with a copy to:

          Yutaka Ishizaka, Director
          Lampert-Ishizaka Associates
          79 Miller Avenue
          Tarrytown, NY 10591

     further with a copy to:

          Jonathan L. Moll, Esq.
          Jeffrey L. Musman, Esq.
          Goldstein & Manello, P.C.
          265 Franklin Street
          Boston, MA 02110

     if addressed to Sublessee:

          Vialog Corporation
          10 New England Business Center, Suite 302
          Andover, MA 01810 until the
          Commencement Date and, thereafter, at
          the Demised Premises

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     with a copy to:

          Jeffrey L. Donaldson, Esq.
          Mirick, O'Connell, DeMallie & Lougee
          1700 Bank of Boston Tower
          Worcester, MA 01608

     Sublessor and Sublessee agree promptly to deliver a copy to the other of
     any notice, demand, request consent or approval from such party to Prime
     Landlord or received from Prime Landlord.

20.  Sublessee, subject to the terms and provisions of the Sublease and on
     payment of the rent and observing, keeping and performing all of the terms
     and provisions of this Sublease on its part to be observed, kept and
     performed, shall lawfully, peaceably and quietly have, hold, occupy and
     enjoy the Demised Premises during the term hereof without hindrance or
     ejection by any persons lawfully claiming under Sublessor.

21.  Sublessor represents to Sublessee to its knowledge that:

     (a)  the Prime Lease is, as of the date hereof, in full force and effect;
          and

     (b)  no event of default has occurred under the Prime Lease and no event
          has occurred and is continuing which would constitute an event of
          default but for the requirement of the giving of notice and/or the
          expiration of the period of time to cure.

22.  This Sublease shall be governed by and construed in accordance with the
     laws of The Commonwealth of Massachusetts.

23.  This Sublease and the obligations of the parties herewith are expressly
     conditioned upon Sublessor's obtaining prior written consent hereto by
     Prime Landlord.  Sublessee shall promptly deliver to Sublessor any
     information reasonably requested by Prime Landlord in connection with its
     approval of this Sublease.

     It is expressly understood and agreed that no shareholder, officer or
     director of the Sublessor shall ever be personally or individually liable
     for the obligation of the Sublessor hereunder.

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EXECUTED under seal the day and year first above written.

                                     EISAI RESEARCH INSTITUTE   
                                      OF BOSTON, INC.           
                                                                
                                                                
                                     By:/S/                     
                                        -----------------------------------
                                                                
                                     VIALOG CORPORATION         
                                                                
                                                                
                                     By:/S/ Glenn D. Bolduc     
                                        -----------------------------------
                                        President & CEO          



                                    CONSENT
                                    -------
                                        
                                         
The undersigned, Connecticut General Life Insurance Company, on behalf of its
Separate Account R, being the landlord under the Prime Lease above referenced,
hereby grants its consent to this Sublease, subject to the following terms,
conditions, provisions and agreements:


(1)  Neither the Sublease, nor this consent thereto, shall:

     (a)  Release or discharge Sublessor from any liability, whether past,
          present or future, under the Prime Lease.

     (b)  Be construed to modify, waive or affect any of the terms, covenants,
          conditions, provisions or agreements of the Prime Lease, or any of our
          rights thereunder, or to enlarge or increase our obligations
          thereunder.

     (c)  Be construed as a consent by us to any further subletting by either
          Sublessor or Sublessee or to any assignment by the Sublessee of the
          Sublease, whether or not the Sublease purports to permit the same and,
          without limiting the generality of the foregoing, both Sublessor and
          the Sublessee agree that the Sublessee has no right whatsoever to
          assign, mortgage or encumber the Sublease; nor to sublet any portion
          of the Demised Premises or permit any portion of the Demised Premises
          to be used or occupied by any other party; in connection therewith,
          both Sublessor and the Sublessee agree that an assignment by operation
          of law or a transfer of control of Sublessee (including, but not
          limited to, transfer of the controlling interest of the stock of
          Sublessee, if Sublessee is a corporation) shall be deemed to a
          prohibited assignment hereunder.

(2)  In the event of Sublessor's default under the provisions of the Prime
     Lease, the rent due from the Sublessee under the Sublease shall be deemed
     assigned to us; and we shall have the right, under such default, at any
     time, at our option, to give notice of such assignment

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     to the Sublessee. *We shall credit Sublessor with any rent received by us
     under such assignment but the acceptance of any payment on account of rent
     from the Sublessee as the result of any such default shall in no manner
     whatsoever be deemed an attornment by the Sublessee to us **in the absence
     of a specific written agreement signed by us to such an effect, or serve to
     release Sublessor from any liability under the terms, covenants,
     conditions, provisions or agreements under the Prime Lease.

(3)  Sublessor and Sublessee agree and acknowledge that our consent herein shall
     not create nor be deemed to be the basis of creating any covenant,
     representation, or warranty, express or implied, on our part with respect
     to the terms of the Sublease, Sublessee's use and enjoyment of the Demised
     Premises, or any other matter arising out of or in connection with the
     Sublease.

(4)  This consent is not assignable; nor shall this consent be a consent to any
     amendment, or modification of the Sublease, without our prior written
     consent.

(5)  Notwithstanding the provisions of the Prime Lease to the contrary, the
     undersigned (i) waives its rights under Section 6.1.6 of the Prime Lease to
     terminate the Prime Lease and (ii) agrees that any amounts received by
     Sublessor from Sublessee in excess of Annual Base Rent and additional rent
     under the Prime Lease need only by paid by Sublessor to Prime Landlord at
     the end of each lease year of the Term of the Prime Lease.

(6)  To the undersigned's knowledge the Prime Lease is, as of the date hereof,
     in full force and effect and no event of default has occurred under the
     Prime Lease and no event has occurred and is continuing which would
     constitute an event of default but for the requirement of the giving of
     notice and/or the expiration of the period of time to cure.

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(7)  Sublessee has advised Sublessor and Prime Landlord that it intends to
     subdivide the existing conference room in the Demised Premises to create
     two (2) individual offices by installing a nonstructural partition wall.
     Subject to Prime Landlord's review and approval of architectural plans,
     therefore, and reserving its rights to condition its approval on the
     subsequent restoration of the Demised Premises, the Prime Landlord
     acknowledges that it has no objection to Sublessee's proposed alteration,
     as aforesaid.

                                    CONNECTICUT GENERAL LIFE            
                                     INSURANCE COMPANY                  
                                    on behalf of its Separate Account R 
                                                                        
                                                                        
                                                                        
                                    By:  CIGNA Investments, Inc.        
                                                                        
                                                                        
                                    By:/S/ James H. Rogers              
                                       ----------------------------------------
                                       James H. Rogers                  
                                       Managing Director                 


*Upon such notice and until further notice, Sublessee shall pay all rent and
other amounts owing hereunder directly to us as instructed in such notice.

**or our recognition of Sublessee as the successor to Sublessor as tenant under
the Prime Lease.

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