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                    ADVANCED SWITCHING COMMUNICATIONS, INC.
                            STOCKHOLDERS' AGREEMENT



     THIS STOCKHOLDERS' AGREEMENT (this "Agreement") is made as of the
_____ day of August, 1998, by (i) ADVANCED SWITCHING COMMUNICATIONS, INC.
(hereinafter referred to as the "Corporation"), a corporation duly organized,
validly existing and in good standing under the laws of the State of Delaware,
and (ii) MOSTAFA INVESTMENTS LIMITED PARTNERSHIP, a Virginia limited
partnership [hereinafter sometimes referred to as "MILP"].


                            R  E  C  I  T  A  L  S:


     WHEREAS, the Corporation has authorized capital stock consisting of, among
other shares, Fourteen Million One Hundred Thousand (14,100,000) shares of
Common Stock, with a par value of one half a cent ($.005) per share;

     WHEREAS, MILP is the legal and beneficial owner of Four Million
(4,000,000) shares of Common Stock (collectively, "Shares");

     WHEREAS, the parties hereto believe that it is in the best interests of
the Corporation and of the stockholders of the Corporation to make provision
for future dispositions of its shares of stock in certain instances, including
MILP's Shares, and certain other matters;

     WHEREAS, the parties hereto desire to set forth in writing their
understandings and agreements.

     NOW, THEREFORE, in consideration of the foregoing, of the mutual promises
hereinafter set forth and of other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the parties hereto, intending
to be legally bound, hereby agree as follows:

                    ARTICLE I. PURCHASE OF SHARES UPON DEATH

     1.01. TRANSFER OF SHARES. In the event of the death of Asghar Mostafa
("Mostafa"), all (but not less than all) of the Shares owned by MILP as of the
date of his death shall be sold and transferred to the Corporation as
hereinafter provided in this Article I. For purposes of this Article I, MILP is
conclusively deemed and considered to own all Shares of stock owned by it, its
administrators and personal and legal representatives.



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     1.02. Settlement. At settlement on a purchase of the Shares under this
Article I, the general partner of MLFP shall deliver to the Corporation the
Shares owned by MILP as of the date of his death, and, upon delivery of the
Shares, the Corporation shall be obligated to pay the general partner of MILP
the greater of the following two amounts: (i) the proceeds of any life insurance
policy (policies), owned by the Corporation on which (a) Mostafa is the named
insured and (b) the Corporation is the applicant, owner and beneficiary, and
which policy (policies) were purchased for the purpose of using the proceeds
thereof to purchase the Shares of MILP upon his death, rather than to reimburse
the Corporation for the loss of the services to be provided to it by Mostafa,
such policy referred to in this Article I as the "Life Insurance Policy", or
(ii) the appraised value of the Shares as determined pursuant to Article III
hereof. In the event the Life Insurance Policy proceeds are the greater of the
two amounts, then at settlement, the Corporation shall deliver to the general
partner of MILP a good check in the amount of the proceeds of the Life Insurance
Policy. In the event that the appraised value of the Shares shall be the greater
of such two (2) amounts, at settlement the Corporation shall execute and deliver
to the general partner of MILP a negotiable promissory note in substantially the
same form as the promissory note attached hereto as Exhibit A and made a part
hereof, representing the difference between the proceeds of the Life Insurance
Policy and the appraised value, constituting the unpaid portion of the purchase
price.

     1.03. Description of Policies. The Corporation hereby agrees that it will
become the applicant, owner and beneficiary of Life Insurance Policies, as
hereinafter defined, under which the insured is Mostafa. The Corporation agrees
to pay premiums on such insurance policies and on any other Life Insurance
Policies purchased by the Corporation and shall give proof of payment of
premiums to MILP whenever MILP shall request such proof. For all purposes of
this Agreement, the term "Life Insurance Policies" shall mean all life insurance
policies under which the insured is Mostafa and the Corporation is the
applicant, owner and beneficiary, which shall be in an amount and issued by an
insurer which is satisfactory to MILP; provided, however, that no such life
insurance policy shall come within the foregoing definition if the Corporation
and Mostafa shall execute a statement acknowledging that such policy is a
"key-man insurance policy" intended to reimburse the Corporation for the loss of
services which would have otherwise been provided were it not for the death of
Mostafa. If a premium on any Life Insurance Policies shall not be paid within
ten (10) days after its due date, the insured shall have the right to pay such
premium and to be promptly reimbursed therefor by the Corporation. Each policy
referred to in this Section 1.03 shall be the sole and absolute property of the
Corporation; provided, however, that the Corporation hereby (i) collaterally
assigns the policy (policies) owned by it to Mostafa who is the named insured as
security only for the performance by the Corporation of the obligations on its
part to be performed under this Article I and (ii) agrees to complete, execute,
have acknowledged and deliver to the issuing life insurance company any form
required by such insurance company in order to effect such collateral
assignment. The parties hereto agree to determine, from time to time, in good
faith, the fair market value of the Shares. In the event that the fair market
value of the Shares exceeds the face amount of the Life Insurance Policies on
the life of Mostafa, the Corporation shall consider the purchase of additional
Life Insurance Policies so that the total



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face amount of all of the Life Insurance Policies on the life of Mostafa is
equal to or exceeds the fair market value of the Shares owned by MILP. In the
event that the Corporation purchases additional insurance on the life of
Mostafa, Mostafa hereby agrees to cooperate fully by performing all the
requirements of the insurer which are necessary conditions precedent to the
issuance of such life insurance policies.

     1.04. PURCHASE OF POLICIES. In the event that MILP shall transfer all of
its Shares other than pursuant to Article I hereof or, in the event that this
Agreement shall terminate, then, in either event, Mostafa shall have the right
to purchase from the Corporation any Life Insurance Policies on which he is the
named insured, by paying to the Corporation an amount equal to the cash value
of such policy (policies), if any, the unearned premiums on such policy
(policies) or One Dollar ($1.00), whichever is greatest.


                     ARTICLE II.  PUT AND CALL RIGHTS UPON
                      PERMANENT DISABILITY OR TERMINATION


     2.01. PURCHASE OF SHARES UPON PERMANENT DISABILITY OR TERMINATION.  In the
event of the permanent disability or termination of employment of Mostafa for
any reason whatsoever, for a period of one hundred eighty (180) calendar days
after the date of such permanent disability or termination, as the case may
be, MILP shall have the right to cause Company to repurchase all but not less
than all of the Shares then owned by MILP, and (ii) Company shall have the
right to repurchase all but not less than all of the Shares then owned by MILP,
such purchase to be completed within thirty (30) days from the date of
exercise, for a purchase price equal to the value of the Shares, determined as
of the last day of the month preceding the date on which either MILP or
Corporation exercises its rights under this Section 2.01. The purchase shall be
shall be in cash or, if the Corporation and MILP agree, the Corporation may pay
the value with its promissory note in substantially the same form as Exhibit A,
except bearing interest at the annual the prime rate (as set forth at the main
depository bank of the Corporation) plus 1% and amortized over a term of ten
(10) years.

     2.02. EXERCISE OF RIGHTS TO CALL. To exercise its rights hereunder, the
Corporation shall give MILP a written notice of its intent to exercise its
rights ("Call Notice"), which notice shall constitute an unconditional and
irrevocable offer to repurchase the Shares, and which shall contain the
Corporation's determination of the value of the Shares. If MILP does not agree
with the valuation, it shall notify the Corporation that it contests the value
stated in Call Notice within twenty (20) days after the Corporation has given
such Call Notice, and the Shares shall thereupon be appraised as set forth in
Article III below. If MILP fails to notify the Corporation that it contests the
value, such value shall be final, and on or before forty (40) days from the
date on which the Corporation has given such Call Notice, (i) the Corporation
shall pay the value of the Shares to MILP in cash or, if the Corporation and
MILP agree, the Corporation may pay the value with its promissory note in
substantially the same form as Exhibit A, except bearing interest at the annual
the prime rate (as set forth at the main



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depository bank of the Corporation) plus 1% and amortized over a term of ten
(10) years, and (ii) MILP shall give to the Corporation the certificate(s)
representing the Shares, properly endorsed for transfer.

     2.03. EXERCISE OF RIGHTS TO PUT. To exercise its rights hereunder, MILP
shall give the Corporation a written notice of its intent to exercise its
rights hereunder ("Put Notice") to that effect, which notice shall constitute
an unconditional and irrevocable offer to sell the Shares to the Corporation.
Within sixty (60) days after receiving the Put Notice, the Corporation shall
notify MILP in writing of its determination of the value of the Shares. If MILP
does not agree with the valuation, it shall notify the Corporation that it
contests the value stated in response to the Put Notice within twenty (20) days
after the Corporation has given such response, and the Shares shall thereupon
be appraised as set forth in Article III below. If MILP does not notify the
Corporation that it contests the value as determined by the Corporation, then
within twenty (20) days after receiving such response, such value shall be
final, and on or before forty (40) days from the date on which the Corporation
has sent MILP the notice of determination of value, (i) the Corporation shall
pay the value of the Shares to MILP, in cash or, if the Corporation and MILP
agree, the Corporation may pay the value with its promissory note in
substantially the same form as Exhibit A, except bearing interest at the annual
the prime rate plus 1% (as set forth at the main depository bank of the
Corporation) and amortized over a term of ten (10) years, and (ii) MILP shall
upon receipt of such payment give to the Corporation the certificate(s)
representing the Shares, properly endorsed for transfer.

            ARTICLE III.   VALUATION OF THE SHARES

     3.01.  DETERMINATION OF VALUE. Value, for purposes of this Agreement,
shall be determined initially by the Corporation's Board of Directors, who may
but shall not be obligated to seek or rely upon the opinions of financial or
investment advisors. If MILP notifies the Corporation within the time limits
set forth above in Sections 2.02 or 2.03, as the case may be, that it contests
such determination, the Corporation shall appoint an appraiser ("Appraiser"),
acceptable to MILP, who shall determine the value and whose determination shall
be final and binding. The Appraiser (i) shall have the requisite experience and
knowledge to evaluate the Corporation and determine its value and (ii) shall
have no prior professional relationship with either party. The Appraiser shall
determine the value of the Shares, using such procedures as he deems necessary.
The Corporation and MILP shall provide the Appraiser with full access to
financial and other data, all of which the Appraiser shall hold in confidence
to the extent reasonably requested by the Corporation. The Corporation shall
pay the entire cost of the appraisal.

     3.02.  EXERCISE OF RIGHTS TO PUT. The value of the Shares for all purposes
under this Agreement, regardless of who determines it, shall be determined on
the basis at which the entire the Corporation would change hands between a
willing buyer and a willing seller, each having knowledge of all relevant facts
and neither being under any compulsion to buy or sell,

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with a premium attributed to the fact that the Shares represent a control
position in a closely-held company.

     3.03.  Right of Revaluation.  Notwithstanding anything set forth herein,
in the event the Corporation shall purchase the Shares following the Call
Notice under Section 2.02 above, then MILP shall have the right for the
Revaluation Period, as defined below, to again request the Corporation
determine the value. Upon receipt of such notice, the Corporation's Board of
Directors shall determine value, who may but shall not be obligated to seek or
rely upon the opinions of financial or investment advisors. Value shall be as
of the date of the receipt of the request and thereafter the Corporation shall
pay MILP the difference, if any, between the value determined in connection
with the Call Notice and the value determined under this Section 3.03. The
Revaluation Period shall commence with the date of disability or termination,
and shall extend for the same number of months as Mostafa was employed by the
Corporation, but for a minimum of eighteen (18) months. The value determined
under this Section shall be final, and the Corporation shall pay the difference
in the value to MILP in the form of a four (4) equal quarterly payments,
without interest, or upon such other terms as may be agreed upon between the
Corporation the MILP, and MILP shall have no further rights under this
Agreement. Notwithstanding the foregoing, MILP shall have no right to a
revaluation hereunder if Mostafa shall be been terminated, following his
termination "for cause" as defined in that certain Executive Employment
Agreement dated of even date herewith between the Corporation and Mostafa,
("Executive Employment Agreement").

     3.04.  Definition of Permanent Disability.  For purposes of this
Agreement, the term "permanent disability" shall have the same meaning as in
the Executive Employment Agreement.


                        ARTICLE IV. GENERAL PROVISIONS

     4.01.  Transfer Legend Notice.  The certificate representing the Shares
will bear a legend indicating (i) that the Shares have not been registered
under the Securities Act of 1933 or the securities laws of any jurisdiction,
and may not be sold or offered for sale in the absence of such registration or
an exemption therefrom, and (ii) that any Transfer of the Shares is subject to
this Agreement, and will not be recognized by Company unless made in compliance
with this Agreement.


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     4.02.     Notices.  Any and all notices, requests or other communications
provided for herein shall be given in writing and sent by hand delivery or by
registered or certified mail, return receipt requested, with first-class
postage prepaid; and such notices shall be addressed: (i) if to the
Corporation, to the principal office of the Corporation; and (ii) if to MILP,
to the address of MILP as reflected in the records of the Corporation, unless
notice of a change of address is furnished to all parties in the manner provided
in this Section 4.02. Any notice which is required to be made within a stated
period of time shall be considered timely if delivered or mailed before
midnight of the last day of such period.

     4.03.     Invalid or Unenforceable Provisions.    The invalidity or
unenforceability of any particular provision of this Agreement shall not
affect the other provisions whereof, and this Agreement shall be construed in
all respects as if such invalid or unenforceable provision were omitted.

     4.04.     Delivery of Shares and Documents.  Upon the closing of any
purchase of any Shares pursuant to this Agreement, the seller shall deliver to
the purchaser the following: The certificate or certificates representing the
Shares being sold, duly endorsed for transfer and bearing such documentary
stamps, if any, as are necessary, and such assignments, certificates of
authority, tax releases, consents to transfer, instruments and evidences of
title of the seller and of its compliance with this Agreement as may be
reasonably required by the purchaser (or by counsel for the purchaser).

     4.05.      Changes: Waiver.    No change or modification of this Agreement
shall be valid unless the same is in writing and signed by both the parties
hereto. The failure of any party at any time to insist upon strict performance
of any condition, promise, agreement or understanding set forth herein shall not
be construed as a waiver or relinquishment of the right to insist upon strict
performance of the same or any other condition, promise, agreement or
understanding at a future time.

     4.06.      Entire Agreement.   This Agreement sets forth all of the
promises, agreements, conditions, understandings, warranties and representations
among the parties hereto with respect to the Shares owned by MILP and any other
matters set forth herein, and there are no promises, agreements, conditions,
understandings, warranties or representations, oral or written, express or
implied, among them with respect to such shares or such other matters except as
set forth herein. This Agreement is, and is intended by the parties to be, an
integration of any and all prior agreements or understandings, oral or written,
with respect to the Shares.

     4.07.     Governing Law. This Agreement shall be construed and enforced in
accordance with the laws of the Commonwealth of Virginia.

     4.08.     Headings. The headings, subheadings and other captions in this
Agreement are for convenience and reference only and shall not be used in
interpreting, construing or


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enforcing any of the provisions of this Agreement.

     4.09.  Term of Agreement.  This Agreement shall be effective as of the
date first hereinabove set forth and shall terminate at such time as MILP shall
sell all of its Shares in the Corporation.

     4.09   Benefit and Burden.  This Agreement shall inure to the benefit of,
and shall be binding upon, the parties hereto and their legatees, distributees,
estates, executors, administrators, personal representatives, successors and
assigns, and other legal representatives.

     4.10   Days Defined.  Whenever any notice or action needs to be taken
under this Agreement within a specified number of days, such reference shall
measured in calendar days.

     IN WITNESS WHEREOF, the Corporation has caused this Agreement to be
executed by its duly authorized officers and its corporate seal to be affixed
hereto, and MILP has executed this Agreement by its general partner, all as of
the day and year first above written.

ATTEST:                                         CORPORATION:

                                                ADVANCED SWITCHING
COMMUNICATIONS,                                  INC., a Delaware corporation

/s/ Ronald S. Westernik                         By /s/ Ronald S. Westernik
-------------------------------                 -------------------------------
Ronald S. Westernik                             Ronald S. Westernik, COO
Secretary
[Corporate Seal]


WITNESS:                                        MOSTAFA INVESTMENTS LIMITED
                                                 PARTNERSHIP, a Virginia limited
                                                 partnership

/s/ Jhoti Ranade                                by /s/ Asghar D. Mostafa  [SEAL]
-------------------------------                 --------------------------------
                                                Asghar D. Mostafa, General
                                                 Partner

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