Recitals

Escrow and Indemnification Agreement

by Captaris Inc.
April 14th, 1999

                                                                    EXHIBIT 10.3
 
                      ESCROW AND INDEMNIFICATION AGREEMENT

     This ESCROW AND INDEMNIFICATION AGREEMENT (this "Agreement") is made and
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entered into as of April  14, 1999, among AVT Corporation, a Washington
corporation ("Parent"), Sanjeev Manaley (the "Securityholder Agent"), as agent
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for the stockholders of MediaTel Corporation, a Delaware corporation (the
"Company"), and ChaseMellon Shareholder Services, LLC, as escrow agent (the
"Escrow Agent").
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                                    RECITALS

     A.  Pursuant to an Agreement and Plan of Merger, dated as of April 13, 1999
(the "Merger Agreement") among Parent, Goldengate Acquisition Corp., a Delaware
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corporation and a wholly owned subsidiary of Parent ("Merger Sub"), the Company,
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and certain significant stockholders of the Company, the parties thereto intend
to effect the merger of Merger Sub with and into the Company (the "Merger").
                                                                   ------   

     B.  Under the terms of the Merger Agreement, a portion of the shares of
Parent Common Stock, par value $.01 per share, to be issued to the holders of
the Company's capital stock in the Merger are to be deposited in an escrow
account with the Escrow Agent.  The shares of Parent Common Stock so deposited
will remain subject to any indemnification claims Parent may have under Section
1(b) of this Agreement and Article VII of the Merger Agreement, until released
by the Escrow Agent pursuant to the terms hereof.

     C.  Pursuant to Article VII of the Merger Agreement, a copy of which is
attached hereto as Exhibit A, the Securityholder Agent has been duly appointed
by the Stockholders.

     D.  The execution and delivery of this Agreement by the parties hereto is a
condition precedent to the obligations of the parties to the Merger Agreement.

     E.  Capitalized terms used herein and not otherwise defined shall have the
meaning set forth in the Merger Agreement.  In the event of any conflict between
the terms of this Agreement (other than those terms herein that affect the
rights, indemnifications, duties or obligations of the Escrow Agent which shall
be governed exclusively by the terms of this Agreement), the terms of the Merger
Agreement shall prevail.

                                   AGREEMENT

     NOW, THEREFORE, in consideration of the mutual covenants and agreements set
forth herein, the parties hereto agree as follows:

1.   Delivery of Shares; Indemnification

     (a) At the Effective Time, certificates representing ten percent (10%) of
the shares of Parent Common Stock issuable to each Stockholder under Section
1.6(a) of the Merger 

                                      -1-

 
Agreement (the "Escrow Shares") shall be deposited in escrow with the Escrow
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Agent, to be held and administered in accordance with the terms and conditions
of this Agreement. The number of Escrow Shares deposited in escrow by each
stockholder will be calculated by aggregating all shares of Parent Common Stock
to be issued to such Stockholder under Section 1.6(a) of the Merger Agreement
and multiplying that number by ten percent (10%). Fractional shares of Parent
Common Stock will not be deposited in escrow. Instead, the number of shares to
be deposited by each Stockholder in escrow will be rounded down to the nearest
whole number of shares.

     (b) Subject to Section 7.5 of the Merger Agreement, Parent shall be
entitled pursuant to Section 7.2 of the Merger Agreement to recover from the
Escrow Shares the full dollar amount of any Losses that may be incurred by any
Indemnitee directly or indirectly as a result of (a) any inaccuracy or breach of
a representation or warranty of the Company or a Significant Stockholder
contained in Article II of the Merger Agreement, or (b) the nonperformance by
the Company or a Significant Stockholder (whether partial or total) of any
covenants or agreements made in the Merger Agreement or any agreement entered
into pursuant thereto which was due to be performed at or before Closing.

     (c) The indemnification period with respect to the Escrow Shares shall
begin as of the Effective Time and shall continue until the earlier of (i) April
14, 2000 or (ii) the date on which Parent's independent accountants issue an
audit report for Parent and its consolidated subsidiaries for the year ended
December 31, 1999 (the "Escrow Period").  During the Escrow Period, Parent may
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make claims from the Escrow Shares on behalf of any Indemnitee for any Loss in
accordance with Section 1(b) hereof and Article VII of the Merger Agreement
(each, a "Claim").  Notwithstanding the foregoing, if any Claim Notice is filed
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during the Escrow Period, any representation or warranty relating to such claim
shall survive until the time when it is resolved in accordance with this
Agreement; and provided further that this Agreement shall not be deemed to
reduce the survival period provided in the Merger Agreement of any
representation and warranty.

     (d) At the termination of the Escrow Period, Parent and the Securityholder
Agent shall jointly notify the Escrow Agent that the Escrow Period has
terminated and supply the Escrow Agent with a Schedule (as defined in Section
2(b) hereof), updated as of the last day of the Escrow Period, setting forth the
aggregate number of Escrow Shares to be released from Escrow (the "Released
                                                                   --------
Shares") and the aggregate number of Escrow Shares subject to a claim for
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reimbursement brought on behalf of any Indemnitee pending determination of
whether such claim is an indemnifiable Claim pursuant to Section 7.2 of the
Merger Agreement.  The Released Shares shall be returned by the Escrow Agent to
the Record Holders (as defined in Section 2(b) hereof) pro rata in the same
proportions and to the addresses indicated on such updated Schedule within 10
days of the Escrow Agent's receipt of the Schedule.  Upon the final
determination of any pending indemnification Claims, the Escrow Shares being
held pending such determination shall be distributed by the Escrow 

                                      -2-

 
Agent upon receipt and in accordance with the terms of the relevant notice or
memorandum stipulated in Section 4 hereof.

     (e) For purposes of this Agreement and Article VII of the Merger Agreement,
the satisfaction of any Losses owed under Section 1(b) of this Agreement and
Article VII of the Merger Agreement shall be made by delivery by the Escrow
Agent to Parent of that number of Escrow Shares calculated by dividing the
dollar amount of any Losses by the Parent Common Stock Price, which is $24.8766.

     (f) The Escrow Agent will hold the Escrow Shares in accordance with the
terms and conditions of this Agreement.  All obligations of the Escrow Agent
hereunder shall terminate upon final delivery of all Escrow Shares to the
appropriate party or parties in accordance with the instructions from the
Securityholder Agent and Parent, who shall act in accordance with this
Agreement.  This Agreement shall terminate upon final delivery of all Escrow
Shares in accordance with the preceding sentence.

2.   Administration

     (a) The Escrow Agent shall accept, hold and safeguard the Escrow Shares
during the term of the Escrow Period and shall administer, hold and dispose of
such shares only in accordance with the terms of this Agreement and as
instructed in writing by Parent and the Securityholder Agent, as applicable, in
accordance with this Agreement and Article VII of the Merger Agreement.

     (b) At the Effective Time, the Securityholder Agent shall supply Parent and
the Escrow Agent with a schedule (the "Schedule") of the Stockholders of record
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as of the Effective Time (the "Record Holders"), reflecting each such Record
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Holder's pro rata interest in the Escrow Shares, and reflecting also the mailing
address of each Record Holder.  Parent shall keep such information current based
on information supplied in writing by the Securityholder Agent or by any Record
Holder in accordance with the notice provisions of this Agreement.  Parent shall
advise the Escrow Agent in writing of changes to the Schedule, and Parent shall
make the Schedule, as it may be updated from time to time, available for
inspection by any Record Holder upon his or her reasonable request.  The Escrow
Agent shall be fully protected, and shall incur no liability, in relying on the
latest version of the Schedule provided to it in accordance herewith.

     (c) Notwithstanding the escrow of the Escrow Shares, dividends or other
distributions declared and paid on such shares shall continue to be paid by
Parent to the Stockholders and all voting rights with respect to such shares
shall inure to the benefit of and be enjoyed by the Record Holders; provided,
however, that in the event that any Escrow Shares are delivered to Parent in
satisfaction of any Losses pursuant to Article VII, the Record Holders shall
forfeit to Parent any dividends or other distributions associated with such
Escrow Shares.  Any securities received by the Escrow Agent in respect of any
Escrow Shares held in escrow as a result of any stock split or combination of
shares of Parent 

                                      -3-

 
Common Stock, payment of a stock dividend or other stock distribution in or on
shares of Parent Common Stock, or change of shares of Parent Common Stock into
any other securities pursuant to or as part of a merger, consolidation,
acquisition of property or stock, separation, reorganization, or liquidation of
Parent, or otherwise, shall be held by the Escrow Agent as, and shall be
included within the definition of, Escrow Shares, as the case may be. Any voting
notices, proxies, ballots, etc. with respect to the Escrow Shares received by
the Escrow Agent shall be forwarded to the Record Holders and the Escrow Shares
shall be voted by the Record Holders thereof.

3.   Issuance of New Stock Certificates

     When Escrow Shares are to be delivered hereunder (other than if delivered
in full to Parent), the Escrow Agent shall deliver the certificate(s) then
evidencing the appropriate number of Escrow Shares to Parent, who shall cause
replacement certificates to be promptly redeposited in escrow hereunder or
delivered to the Record Holders, as the case may be, in accordance with the
terms of this Agreement and the Merger Agreement.

4.   Indemnification and Reimbursement Procedures; Claims Against the Escrow

     4.1  Indemnification Claim Notice

     Parent shall give written notice (the "Claim Notice") of any claim for
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indemnification under Section 1(b) hereof or Article VII of the Merger Agreement
to the Securityholder Agent and the Escrow Agent on or before the last day of
the Escrow Period.  Notwithstanding the foregoing, if such claim relates to the
assertion against any Indemnitee of any Claim by a third party (a "Third Party
                                                                   -----------
Claim"), such notice shall be given within 30 days after the assertion of such
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Third Party Claim; provided, however, that the failure or delay to so notify the
Securityholder Agent shall not relieve the Stockholders of any obligation or
liability that the Stockholders may have to the Indemnitees except to the extent
that the Securityholder Agent demonstrates that its ability to defend or resolve
such Claim is adversely affected thereby.  Any such Claim Notice shall describe
the facts and circumstances on which the asserted Claim for indemnification is
based and shall specify the basis for the determination of the amount which the
Indemnitees intend to recover.  Unless the Claim described in the Claim Notice
is contested by the Securityholder Agent by written notice to Parent and the
Escrow Agent of the amount of the Claim that is contested, given within 30 days
of the receipt by the Securityholder Agent of the Claim Notice, Parent on behalf
of the Indemnitees may recover such undisputed amount of the Claim described in
the Claim Notice from the Stockholders by giving written notice of such Claim to
the Escrow Agent and certifying that the Securityholder Agent has not contested
such Claim in the appropriate time period.  In such event, the Escrow Agent
shall be entitled to rely on any such Claim Notice and distribute the Escrow
Shares held in escrow to Parent with a value (determined as provided in Section
1(e) above) equal to the undisputed amount of the Claim described in the Claim
Notice.

                                      -4-

 
     4.2  Dispute Notice

     If, within 30 days of the receipt by the Securityholder Agent of the Claim
Notice, the Securityholder Agent contests in writing to Parent and the Escrow
Agent that such Losses constitute an indemnifiable Claim pursuant to Section
1(b) hereof or Article VII of the Merger Agreement (the "Dispute Notice"), then
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Parent and the Securityholder Agent, acting in good faith, shall attempt to
reach agreement with respect to such Claim.  If Parent and the Securityholder
Agent should so agree, a memorandum setting forth such agreement shall be
prepared and signed by Parent and the Securityholder Agent.  Such notice shall
be furnished to the Escrow Agent and shall set forth the appropriate number of
Escrow Shares, if any, to be delivered to each party.  The Escrow Agent shall be
entitled to rely on any such memorandum and distribute the Escrow Shares held in
escrow in accordance with the terms thereof.

     If the Securityholder Agent disputes a Claim described in a notice from
Parent given pursuant to Section 4.1 hereof, or the amount that the Indemnitees
are claiming on account of such Claim (the "Contested Amount"), and the
Securityholder Agent and Parent are unable to resolve any such dispute within 45
days after delivery of the Dispute Notice, then the matter shall be settled by
binding arbitration in Seattle, Washington.  All claims shall be settled by
three arbitrators in accordance with the Commercial Arbitration Rules then in
effect of the American Arbitration Association (the "AAA Rules").  The
Securityholder Agent and Parent shall each designate one arbitrator within 15
days after the termination of such 45-day period.  The Securityholder Agent and
Parent shall cause such designated arbitrators mutually to agree upon and
designate a third arbitrator; provided, however, that (i) failing such agreement
within 70 days of delivery of the Dispute Notice, the third arbitrator shall be
appointed in accordance with the AAA Rules and (ii) if either the Securityholder
Agent or Parent fails to timely designate an arbitrator, the dispute shall be
resolved by the one arbitrator timely designated.  All of the fees and expenses
of the three arbitrators initially shall be paid by Parent; provided, however,
that if Parent is the prevailing party in the arbitration, such fees and
expenses shall be treated as a "Loss" for purposes of Section 1(b) hereof and
Article VII of the Merger Agreement, and Parent shall be entitled to recover the
amount of such fees and expenses from the Escrow Shares in accordance with the
provisions of this Agreement.  For purposes of this Agreement, the prevailing
party shall be that party in whose favor final judgment is rendered or who
substantially prevails, if both parties are awarded judgment.  The
Securityholder Agent and Parent shall cause the arbitrators to decide the matter
to be arbitrated pursuant hereto within 30 days after the appointment of the
last arbitrator.  The arbitrators' decision shall relate solely to whether the
Indemnitees are entitled to receive the Contested Amount (or a portion thereof)
pursuant to the applicable terms of the Merger Agreement and this Agreement.
The final decision of the majority of the arbitrators shall be furnished to the
Securityholder Agent, Parent and the Escrow Agent in writing and shall
constitute the conclusive determination of the issue in question binding upon
the Securityholder Agent, Parent and the Escrow Agent.  Such decision may be
used in a court of law only for the purpose of seeking enforcement of the
arbitrators' decision.

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     4.3  Third-Party Claims

     (a) The Securityholder Agent shall have the right, upon written notice
given to Parent and the Escrow Agent within 30 days after receipt of the Claim
Notice relating to a Third Party Claim, to undertake the defense or handling of
such Third Party Claim.  The Securityholder Agent shall select counsel
reasonably acceptable to Parent in connection with conducting the defense or
handling of such Third Party Claim, and the Securityholder Agent shall defend or
handle the same in consultation with Parent and shall keep Parent timely
apprised of the status of such Third Party Claim.  The Securityholder Agent
shall not, without the prior written consent of Parent, agree to a settlement of
any Third Party Claim, unless (i) the settlement provides an unconditional
release and discharge of the Indemnitees and the Indemnitees are reasonably
satisfied with such discharge and release and (ii) Parent has not reasonably
objected to any such settlement on the ground that the circumstances surrounding
the settlement could result in an adverse impact on the business, operations,
assets, liabilities (absolute, accrued, contingent or otherwise), condition
(financial or otherwise) or prospects of Parent.  Parent shall be entitled to
participate in the defense or handling of such Third Party Claim with its own
counsel and at its own expense.

     Notwithstanding the foregoing paragraph, Parent shall have the right to
retain control of the defense of any Third Party Claim which involves potential
Losses in excess of the value of the Escrow Fund remaining in the Escrow
Account, or which could reasonably be expected to materially affect Parent's on-
going operations.  In such event, the Securityholder Agent shall have the right
to be present at the negotiation, defense and settlement of such action or
claim.

     (b) If the Securityholder Agent, within 30 days after receipt of a Claim
Notice relating to a Third Party Claim (or, if earlier, by the tenth day
preceding the day on which an answer or other pleading must be served in order
to prevent judgment by default in favor of the person asserting such claim),
does not elect to defend against such claim, Parent may, at the Stockholder's
expense (through the submission of such expenses as Losses to be indemnified
from the Escrow Fund), select counsel in connection with conducting the defense
or handling of such Third Party Claim and defend or handle such Third Party
Claim in such manner as it may deem appropriate, provided, however, that Parent
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shall keep the Securityholder Agent timely apprised of the status of such Third
Party Claim and shall not settle such Third Party Claim without the prior
written consent of the Securityholder Agent, which consent shall not be
unreasonably withheld.  If the Parent defends or handles such Third Party Claim,
the Securityholder Agent shall cooperate with the Parent and shall be entitled
to participate in the defense or handling of such Third Party Claim with its own
counsel and at its own expense.

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     4.4  Fractional Shares

     To the extent it is necessary to satisfy a Claim or a Third Party Claim by
delivering to Parent a fractional Escrow Share, the Escrow Agent shall round
such fractional Escrow Share to the nearest whole share, with one half of such
Escrow Share being rounded downward.

5.   Provisions Regarding the Escrow Agent

     5.1  Liability of the Escrow Agent

     The duties of the Escrow Agent hereunder are purely ministerial in nature.
In performing any duties under this Agreement, the Escrow Agent shall not be
liable to any party for any losses, claims, damages, liabilities or expenses,
except for gross negligence or willful misconduct on the part of the Escrow
Agent.  The Escrow Agent shall be fully protected in relying on and shall not
incur any liability for any action taken, suffered or omitted in reliance on any
instrument, including any written statement or affidavit provided for in this
Agreement that the Escrow Agent shall in good faith believe to be genuine, nor
will the Escrow Agent be liable or responsible for forgeries, fraud,
impersonations, or determining the scope of any representative authority,
provided that the Escrow Agent believed that the forgeries, fraud, or
impersonations of others were genuine and acted without gross negligence or
willful misconduct.  In addition, the Escrow Agent may consult with legal
counsel in connection with the Escrow Agent's duties under this Agreement and
shall be fully protected in any act taken, suffered, or omitted by it in
accordance with the advice of counsel; provided that the Escrow Agent exercised
reasonable care in the selection of such counsel.  The Escrow Agent is not
responsible for determining and verifying the authority of any person acting or
purporting to act on behalf of any party to this Agreement.  The Escrow Agent
shall have the right to perform any of its duties hereunder through agents,
custodians or nominees.

     5.2  Fees and Expenses

     It is understood that the fees, expenses and usual charges agreed on for
services of the Escrow Agent shall be considered compensation for ordinary
services as contemplated by this Agreement.  In the event that the conditions of
this Agreement are not promptly fulfilled, or if the parties request a
substantial modification of its terms, or if any controversy arises, or if the
Escrow Agent is made a party to, or intervenes in, any litigation pertaining to
this escrow or its subject matter, the Escrow Agent shall be reasonably
compensated for such extraordinary services and shall be reimbursed for all
costs, attorneys' fees, including allocated costs of in-house counsel, and
expenses occasioned by such default, delay, controversy, litigation or other
event, and the Escrow Agent shall have the right to retain all documents and/or
other things of value at any time held by the Escrow Agent in this escrow until
such compensation, fees, costs, and expenses are paid.  All fees, costs and
expenses of the Escrow Agent shall be borne by Parent.

                                      -7-

 
     5.3  Controversies

     If any controversy arises between the parties to this Agreement, or with
any other party, concerning the subject matter of this Agreement, its terms or
conditions, the Escrow Agent will not be required to determine the controversy
or to take any action regarding it.  The Escrow Agent may hold all documents and
funds and may wait for settlement of any such controversy by agreement by the
parties as provided by Section 4.  In such event, the Escrow Agent will not be
liable, as a result thereof, to any person or entity for any losses, damages or
otherwise.  The Escrow Agent is authorized to deposit with the arbitrator all
documents and funds held in escrow, except all costs, expenses, charges, and
reasonable attorneys' fees incurred by the Escrow Agent or Escrow Shares equal
to such value.  Upon initiating such action, the Escrow Agent shall be fully
released and discharged of and from all obligations and liability imposed by the
terms of this Agreement.

     In addition, in the event of any dispute between the parties to this Escrow
Agreement, or between any of them and any other person, resulting in adverse
claims or demands being made upon any of the Escrow Shares, or in the event that
the Escrow Agent, in good faith, is in doubt as to what action it should take
hereunder, the Escrow Agent may, at its option, file a suit as interpleader in a
court of appropriate jurisdiction, or refuse to comply with any claims or
demands on it, or refuse to take any other action hereunder, so long as such
dispute shall continue or such doubt shall exist.  The Escrow Agent shall be
entitled to continue to refrain from acting until (i) the rights of all parties
have been fully and finally adjudicated by a court of appropriate jurisdiction
or (ii) all differences and doubt shall have been resolved by agreement among
all of the interested persons, and the Escrow Agent shall have been notified
thereof in writing signed by all such persons.  The rights of the Escrow Agent
under this Section are cumulative of all other rights which it may have by law
or otherwise.

     5.4  Indemnification of the Escrow Agent

     Parent shall indemnify the Escrow Agent for, and hold it harmless against,
any loss, liability, claim, cost, settlement, judgment, damage, fines, penalty,
demand or expense, including attorney's fees, arising out of or in connection
with its execution of this Agreement or its performance of its duties under this
Agreement, including the costs and expenses of defending itself against any such
loss, liability, claim or expense in connection herewith, unless such loss,
liability, claim, cost, settlement, judgment, damage, fines, penalty, demand or
expense shall have been determined by a court of competent jurisdiction to be a
result of the Escrow Agent's gross negligence or intentional misconduct.
Anything in this Agreement to the contrary notwithstanding, in no event shall
the Escrow Agent be liable for special, punitive, indirect, incidental or
consequential loss or damage of any kind whatsoever (including but not limited
to lost profits), even if the Escrow Agent has been advised of the likelihood of
such damages and regardless of the form of action.  Any liability of the Escrow
Agent will be limited to the amount of fees paid by Parent.  The obligations of
Parent under this section and Section 5.2 hereof shall survive termination of
this Agreement and the resignation or substitution of the Escrow Agent.

                                      -8-

 
     5.5  Resignation of the Escrow Agent

     The Escrow Agent may resign at any time upon giving at least 30 days'
written notice to the parties; provided, however that no such resignation shall
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become effective until the appointment of a successor escrow agent, which shall
be accomplished as follows:  Parent and the Securityholder Agent shall use their
best efforts to mutually agree on a successor escrow agent within 30 days after
receiving such notice.  If Parent and the Securityholder Agent fail to agree on
a successor escrow agent within such time, the Escrow Agent shall have the right
to appoint a successor escrow agent authorized to do business in the State of
Washington, which successor escrow agent shall be reasonably acceptable to
Parent and the Securityholder Agent.  The successor escrow agent shall execute
and deliver an instrument accepting such appointment and it shall, without
further acts, be vested with all the estates, properties, rights, powers and
duties of the predecessor escrow agent as if originally named as escrow agent.
Upon the effective appointment of a successor escrow agent, the Escrow Agent
shall be discharged from any further duties and liability under this Agreement.
If a successor escrow agent is not appointed within the above time frames by
either Parent, the Securityholder Agent or the Escrow Agent, then the Escrow
Agent shall, upon delivery of all records to Parent, be discharged from any
further duties and liability under this Agreement.

6.   Representations and Warranties

     Each of the parties hereto represents and warrants with respect to itself
only as follows:  (i) that it has full power and authority to execute, deliver
and perform its obligations under this Agreement; (ii) that all action on the
part of such party necessary for the due authorization, execution, delivery and
performance of this Agreement, the consummation of the transactions contemplated
hereby, and the performance of each party's obligations hereunder has been
taken; (iii) that this Agreement has been duly authorized, executed and
delivered by such party; and (iv) that this Agreement is a legal, valid and
binding obligation of such party, enforceable against such party in accordance
with its terms.

7.   Amendments

     This Agreement may not be amended except by an instrument signed by Parent,
the Escrow Agent and the Securityholder Agent.  No such amendment shall be
effective to alter or enlarge the Escrow Agent's duties, rights, discretion and
obligations hereunder without its prior consent.

8.   Notices

     Any notice or request required or permitted to be given hereunder must be
in writing given by personal delivery, overnight courier, certified or
registered mail or facsimile, addressed as respectively set forth below or to
such other address as any party has previously designated by such a notice.  The
effective date of any notice or request is (a) three days from the date it is
sent so long as it is in fact received within five days if sent by certified or

                                      -9-

 
registered mail, (b) the date of delivery if personally delivered or delivered
by overnight courier, or (c) when sent by facsimile with receipt confirmed.

     Notices to the parties hereto shall be sent as follows:

     To Parent:

          AVT Corporation
          11410 N.E. 122nd Way
          Kirkland, Washington  98034
          Attn: Roger A. Fukai, Executive Vice President

     with a copy to:

          Perkins Coie
          1201 Third Avenue, 40th Floor
          Seattle, Washington  98101-3099
          Fax:  (206) 583-8500
          Attention:  Linda Schoemaker

     To the Securityholder Agent:

          Wilson Sonsini Goodrich & Rosati, P.C.
          for Sanjeev Malaney, Client
          650 Page Mill Road
          Palo Alto, California 94304
          Attention:  Michael J. Danaher, Esq.
          Telephone No.:  (650) 493-9300
          Facsimile No.:  (650) 493-6811

          with a copy to:

          Wilson Sonsini Goodrich & Rosati, P.C.
          650 Page Mill Road
          Palo Alto, California 94304
          Attention:  Michael J. Danaher, Esq.
          Telephone No.:  (650) 493-9300
          Facsimile No.:  (650) 493-6811

     To the Escrow Agent:

          ChaseMellon Shareholder Services LLC
          Corporate Trust Division
          P.O. Box 21927
          Seattle, WA  98111

                                      -10-

 
          Fax:  (206) 292-3196
          Attention:  Joseph Campbell, Assistant Vice President

          For Courier Deliveries:

          Corporate Trust Division
          14th Floor
          999 Third Avenue
          Seattle, WA 98104

9.   Severability

     If any term or other provision of this Agreement is invalid, illegal or
incapable of being enforced by any rule of law, or public policy, all other
conditions and provisions of this Agreement shall nevertheless remain in full
force and effect so long as the economic or legal substance of the transactions
contemplated hereby is not affected in any manner adverse to any party.  Upon
such determination that any term or other provision is invalid, illegal or
incapable of being enforced, the parties hereto shall negotiate in good faith to
modify this Agreement so as to effect the original intent of the parties as
closely as possible in a mutually acceptable manner in order that the
transactions contemplated hereby be consummated as originally contemplated to
the fullest extent possible.

10.  Entire Agreement

     This Agreement, the Merger Agreement and each of the agreements,
certificates, instruments and documents to be executed or delivered pursuant to
the terms of the Merger Agreement constitute the entire agreement among the
parties with respect to the subject matter hereof and thereof and supersede all
prior agreements and undertakings, both written and oral, among the parties, or
any of them, with respect to the subject matter hereof and thereof.

11.  Parties in Interest

     This Agreement shall be binding upon and inure solely to the benefit of
each party hereto, and nothing in this Agreement, express or implied, is
intended to or shall confer upon any other person any right, benefit or remedy
of any nature whatsoever under or by reason of this Agreement.

12.  Governing Law

     This Agreement shall be governed by, and construed in accordance with, the
laws of the State of Washington applicable to contracts executed in and to be
performed in that State; provided, however, that all provisions regarding the
rights, duties and obligations of the Escrow Agent shall be governed by and
construed in accordance with the laws of the State of New York applicable to
contracts made and to be performed entirely within such State.

                                      -11-

 
13.  Headings

     The descriptive headings contained in this Agreement are included for
convenience of reference only and shall not affect in any way the meaning or
interpretation of this Agreement.

14.  Assignment

     This Agreement shall not be assigned by operation of law or otherwise,
without the prior written consent of the other parties; provided, however, that
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Parent may assign all or any of its rights and obligations hereunder to any of
its affiliates.

15.  Specific Performance

     Each of the parties acknowledges and agrees that the other parties hereto
would be damaged irreparably in the event any of the provisions of this
Agreement are not performed in accordance with their specific terms or otherwise
are breached.  Accordingly, each of the parties hereto agrees the other parties
hereto will be entitled to an injunction to prevent breaches of the provisions
of this Agreement and to enforce specifically this Agreement and the terms and
provisions of this Agreement (including the indemnification provisions hereof)
in any competent court having jurisdiction over the parties, in addition to any
other remedy to which they might be entitled at law or in equity.

16.  Further Assurances

     Each party will, at the reasonable request of any other party hereto, from
time to time execute and deliver such other assignments, transfers, conveyances,
and other instruments and documents and do and perform such other acts and
things as may be reasonably necessary or desirable for effecting complete
consummation of this Agreement and the transactions contemplated hereby.

17.  Counterparts; Electronic Signatures

     This Agreement may be executed and delivered in one or more counterparts,
and by the different parties hereto in separate counterparts, each of which when
executed and delivered will be deemed to be an original but all of which taken
together will constitute one and the same agreement.  To expedite the process of
entering into this Agreement, the parties acknowledge that Transmitted Copies of
this Agreement will be equivalent to original documents until such time as
original documents are completely executed and delivered.  "Transmitted Copies"
                                                            ------------------ 
will mean copies that are reproduced or transmitted via photocopy, facsimile, or
other process of complete and accurate reproduction and transmission.

                                      -12-

 
     IN WITNESS WHEREOF, the parties have executed this Agreement on the date
first written above.

                              AVT CORPORATION

                              By: /s/ Richard J. LaPorte
                                  ----------------------
                                  Its:  Chairman and CEO


                              SECURITYHOLDER AGENT

                                        /s/ Sanjeev Malaney
                              --------------------------------------
                                             Sanjeev Malaney

                              CHASEMELLON SHAREHOLDER 
                              SERVICES LLC

                              By: /s/ Joseph Campbell
                                  -------------------
                                  Its:  Assistant Vice President

                                      -13-