<PAGE>   1
                                                                    EXHIBIT 10.1
                                                                  CONFORMED COPY


                         REGISTRATION RIGHTS AGREEMENT

         REGISTRATION RIGHTS AGREEMENT, dated as of March 31, 2000 between
FastComm Communications Corporation, a Virginia corporation (the "Company"),
and CTI Telecom, Inc. (formerly Cronus Technology, Inc.) (the "Holder").

         1.      Introduction.  Pursuant to an Agreement and Plan of
Reorganization dated as of March 27, 2000 among the Company, Cronus Technology,
Inc., Cronus Communications Inc, and certain Principal Stockholders of Cronus
Technology, Inc. (the "Seller") (the "Agreement"), the Board of Directors of
the Company has authorized the grant of certain registration rights to the
Holder on the terms and conditions set forth herein.

         2.      Registration under the Securities Act.  The Holder shall have
the registration rights specified below:

                 2.1      Primary Registration.  The Company will use best
efforts to affect the registration under the Securities Act of the Registrable
Shares within 45 days after the Company has filed its Annual Report on form
10-K for the Company's year 2000 fiscal year.  In that regard, the Company
will:

                          (a)     prepare and file with the Commission a
registration statement on any form that the Company is eligible to use, such
form to be selected by the Company after consultation with counsel, with
respect to such Registrable Securities and use best efforts to cause such
registration statement to become effective as soon as practicable.  If, for any
reason, such registration statement is not filed with the Commission on or
before September 30, 2000, the Holder shall have the right to demand
registration of his Registrable Securities.  Upon receipt of such demand, the
Company shall, as promptly as practicable prepare and file with the Commission
a registration statement sufficient to permit the public offering of the
Registrable Securities and will use best efforts through it's officers,
directors, auditors, and counsel, in all matters necessary or advisable, to
cause such registration statement to become effective as promptly as
practicable; provided, however, the Company shall only be obligated to file one
such registration for the Registrable Securities;

                          (b)     prepare and file with the Commission such
amendments and supplements to such registration statement and the prospectus
used in connection therewith as may be necessary to keep such registration
statement effective and to comply with the provisions of the Securities Act
with respect to the disposition of all Registrable Securities and other
securities covered by such registration statement until the earlier of such
time as all of such Registrable Securities and securities have been disposed of
in accordance with the intended methods of disposition by the Holder thereof
set forth in such registration statement or the expiration of one hundred and
eighty (180) days after such registration statement becomes effective; and will
furnish, within a reasonable time prior to filing, to the Holder's
Representative prior to the filing thereof a copy of any amendment or
supplement to such registration statement or prospectus and shall not file any
such amendment or supplement to which the Holder's Representative shall have
reasonably objected on the

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grounds that such amendment or supplement does not comply in all material
respects with the requirements of the Securities Act or of the rules or
regulations thereunder;

                          (c)     furnish to the Holder's Representative of
such Registrable Securities a copy of each such amendment and supplement
thereto (in each case including all exhibits), and such documents, if any,
incorporated by reference in such registration statement or prospectus, and
such other documents, as the Holder's Representatives may reasonably request;

                          (d)     use best efforts to register or qualify all
Registrable Securities and other securities covered by such registration
statement under such other securities or blue sky laws of the States of the
United States as the Holder shall reasonably request, to keep such registration
or qualification in effect for so long as such registration statement remains
in effect, and do any and all other acts and things which may be necessary or
advisable to enable the Holder to consummate the disposition in such
jurisdictions of his Registrable Securities offered by such registration
statement, except that the Company shall not for any such purpose be required
to qualify generally to do business as a foreign corporation in any
jurisdiction wherein it would not but for the requirements of this subsection
(d) be obligated to be so qualified, or to subject itself to taxation in any
such jurisdiction, or to consent general service of process in any such
jurisdiction;

                          In addition, the Company shall not be required to
qualify the Registrable Shares or any portion thereof in any jurisdiction where
the Registrable Shares do not meet the requirements of such jurisdiction.

                          (e)     upon request, furnish to the Holder of
Registrable Securities a signed counterpart, addressed to the Holder, an
opinion of counsel for the Company, dated the effective date of such
registration statement covering such items that are customarily covered in the
opinion of issuer's counsel delivered to underwriters in underwritten public
offerings of securities;

                          (f)     provide and cause to be maintained a transfer
agent and registrar for all Registrable Securities covered by such registration
statement from and after a date not later than the effective date of such
registration statement;

                          (g)     use best efforts to list all Registrable
Securities covered by such registration statement on each securities exchange
on which any of the Company's Common Stock is then listed or, if the Common
Stock is not then quoted on NASDAQ or listed on any national securities
exchange, use its best efforts to have such Company's Common Stock covered by
such registration statement quoted by NASDAQ or, at the option of the Company,
listed on a national securities exchange; and

                          (h)     Expenses.  Except as otherwise required by
applicable law, the Company shall pay all Registration Expenses in connection
with the registration of the Registrable Securities pursuant to Section 2.1.

                          (i)     Penalty.  If the Company has not filed the
Registration Statement referenced in this Section 2.1 within the time period
specified above and such non-filing was not caused by force majeure, then the
Company will pay to the Holder's Representative a penalty of $100,000.





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                 2.2 Piggy-Back Registration.

                          (a)     Right to Include Registrable Shares.  If the
Company at any time proposes to register any of its securities under the
Securities Act (other than a registration on Form S-4, S-8, or any successor or
similar forms and other than pursuant to Section 2.1), for sale to the public
whether on its own account or on account of the other holders or both, it will
each such time give prompt written notice to the Holder's Representative of its
intention to do so and of the Holder's rights under this Section 2.2.  Upon the
written request of the Holder made within thirty (30) days after the receipt of
the notice (which request shall specify the Registrable Shares intended to be
disposed of by the Holder and the intended method of disposition thereof), the
Company will use its best efforts to effect the registration under the
Securities Act of all Registrable Shares which the Company has been so
requested to register by the Holder, to the extent requisite to permit the
disposition (in accordance with the intended methods thereof as aforesaid) of
the Registrable Shares so to be registered, by inclusion of such Registrable
Shares in the registration statement and, in the case of an underwritten
offering, the underwriting which covers the securities which the Company
proposes to register; provided, however, that if, at any time after giving
written notice or its intention to register any securities and prior to the
effective date of the registration statement filed in connection with such
registration, the Company shall determine for any reason either not to register
or to delay registration of such securities, the Company may, at its election,
give written notice of such determination to the Holder's Representative and,
upon the giving of such notice, (i) in the case of a determination not to
register, shall be relieved of its obligation to register any Registrable
Shares in connection with such registration (but shall pay all Registration
Expenses in connection therewith), and (ii) in the case of a determination to
delay registering, shall be permitted to delay registering such other
securities.  No registration effected under this Section 2.2 shall relieve the
Company of its obligation to effect the Primary Registration under Section 2.1.
The Holder's participation in any such piggyback registration shall not require
that he or she pay any portion of the Registration Expenses incurred by the
Company but such Holder shall pay the proportional amount of all underwriting
discounts and commissions applicable to Registrable Shares sold by it and fees
and disbursements of any legal counsel or accountants retained by such Holder.

                          (b)     Priority in Piggy-Back Registrations.  If (i)
a registration pursuant to this Section 2.2 involves an underwritten offering
of the securities so being registered to be distributed (on a firm commitment
basis) by or through one or more underwriters of recognized standing under
underwriting terms appropriate for such a transaction, and (ii) the managing
underwriter of such underwritten offering shall inform the Company and the
Holder's Representative (if any Registrable Shares held by the Holder have been
requested to be included in such underwritten offering) by letter of its belief
that the distribution of all or a specified number of the Registrable Shares
requested to be included concurrently with the securities being distributed by
such underwriters would interfere with the successful marketing of the
securities being distributed by such underwriters (such writing to state the
basis of such belief and the approximate number of the Registrable Shares
requested to be included which may be distributed without such effect), then
the Company may, upon written notice to the Holder's Representative, reduce (if
and to the extent stated by such managing underwriter to be necessary to
eliminate such effect) the number of the Registrable Shares, if any, requested
to be included so that the resultant aggregate number of the Registrable Shares
requested to be included that will be included in such registration shall be
equal to the number of shares stated in such managing underwriter's letter;
provided, however, that the priority in such registration shall be subject to
the following restriction.  The parties who received Common Stock of the
Company are divided into two classes: (1) former creditors, and (ii) former
stockholders of the Seller.  See Attachment 1 hereto.  To the extent that there
is a limit on the number of shares that can be registered, such shares shall be
registered in





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the following order of priority: (i) stockholder-creditors of the Seller, and
(ii) non-creditor, stockholder of the Seller.

                          (c)     Expiration of Piggy-Back Rights.  The Company
shall not be obligated to include Registrable Shares in any registration
statement pursuant to this Section 2.2 that will become effective during a
period when the Holder thereof is eligible to sell such Registrable Shares
pursuant to the Commission's Rule 144.

                          (d)     Lack of Information.  The Company shall not
be required to register or cause the registration of the Registrable Shares or
any portion thereof pursuant to this Section 2.2 hereof if the Holder shall not
promptly supply the Company with any information about the Holder or his
Registrable Shares which the Company may reasonably and timely request in
written form in order to permit the preparation, filing and effectiveness of a
registration statement in accordance with the Securities Act and any rules and
regulations promulgated by the Commission thereunder.

                 2.3      Registration Procedures.  If and whenever the Company
is required to use best efforts to effect the registration of any Registrable
Shares under the Securities Act as provided in Sections 2.1 and 2.2 the Company
shall, as expeditiously as possible:

                          (i)     prepare and (within sixty (60) days after the
end of the period within which requests for registration may be given to the
Company or in any event as soon thereafter as possible) file with the
Commission the requisite registration statement to effect such registration and
thereafter use best efforts to cause such registration statement to become and
remain effective; provided, however, that the Company may discontinue any
registration of its securities which are not Registrable Shares (and, under the
circumstances specified in Section 2.2(a), its securities which are Registrable
Shares) at any time prior to the effective date of the registration statement
relating thereto;

                          (ii)    prepare and file with the Commission such
amendments and supplements to such registration statement and the prospectus
used in connection therewith as may be necessary to keep such registration
statement effective and to comply with the provisions of the Securities Act
with respect to the disposition of all Registrable Shares covered by such
registration statement until the earlier of such time as all of such securities
have been disposed of in accordance with the intended methods of disposition by
the Holder thereof set forth in such registration statement or (a) in the case
of a registration pursuant to Section 2.1, the period of time specified in
Section 2.1, or (b) in the case of a registration pursuant to Section 2.2, the
expiration of one hundred eighty (180) days after such registration statement
becomes effective;

                          (iii)            furnish to the Holder's
Representative of the Registrable Shares covered by such registration statement
and each underwriter, if any, of the securities being sold by such seller such
number of conformed copies of such registration statement and of each such
amendment and supplement thereto (in each case including all exhibits), such
number of copies of the prospectus contained in such registration statement
(including each preliminary prospectus and any summary prospectus) and any
other prospectus filed under Rule 424 under the Securities Act, in conformity
with the requirements of the Securities Act, and such other documents, as the
Holder and underwriter, if any, may reasonably request in order to facilitate
the public sale or other disposition of the Registrable Shares owned by such
seller;





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                          (iv)    use best efforts to register or qualify all
Registrable Shares and other securities covered by such registration statement
under such other securities laws or blue sky laws of such jurisdiction the
Holder and any underwriter of the securities being sold by such underwriter and
the Holder shall reasonably request, to keep such registration statement in
effect, and take any other action which may be reasonably necessary or
advisable to enable the Holder and underwriter to consummate the disposition in
such jurisdictions of the securities owned by such seller, except that the
Company shall not for any such purpose be required to qualify generally to do
business as a foreign corporation in any jurisdiction wherein it would not but
for the requirements of this subdivision (iv) be obligated to be so qualified,
to subject itself to taxation in any such jurisdiction or to consent to general
service of process in any such jurisdiction;

                          (v)     notify each seller of Registrable Shares
covered by such registration statement and the Holder, at any time when a
prospectus relating thereto is required to be delivered under the Securities
Act, upon the Company's discovery that, or upon the happening of any event as a
result of which, the prospectus included in such registration statement, as
then in effect, includes an untrue statement of a material fact or omits to
state any material fact required to be stated therein or necessary to make the
statements therein not misleading in the light of the circumstances under which
they were made, and at the request of any such seller or the Holder promptly
prepare and furnish to such seller or the Holder and each underwriter, if any,
a reasonable number of copies of a supplement to or an amendment of such
prospectus as may be necessary so that, as thereafter delivered to the
purchasers of such securities, such prospectus shall not include an untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary to make the statements therein not misleading in
the light of the circumstances under which they were made; and

                 The Holder  agrees that, upon receipt of any notice from the
Company of the occurrence of any event of the kind described in subdivision (v)
of this Section 2.3, the Holder  will forthwith discontinue his disposition of
Registrable Shares until the Holder's receipt of the copies of the supplemented
or amended prospectus contemplated by subdivision (v) of this Section 2.3 and,
if so directed by the Company (at the Company's expense) all copies, other than
permanent file copies, then in the Holder's possession of the prospectus
relating to such Registrable Shares current at the time of receipt of such
notice.  In the event the Company shall give any such notice, the period
mentioned in paragraph (ii) of this Section 2.3 shall be extended by the length
of the period from and including the date when each seller of any Registrable
Shares covered by such registration statement shall have received such notice
to the date on which each such seller has received the copies of the
supplemented or amended prospectus contemplated by paragraph (v) of this
Section 2.3.

                 2.4      Underwritten Offerings.

                          (a)     Underwritten Piggy-Back Offerings.  The
Holder of Registrable Shares to be distributed by underwriters in a
registration pursuant to Section 2.2 shall be parties to the underwriting
agreement between the Company and such underwriters and may require that any or
all of the conditions precedent to the obligations of such underwriters under
such underwriting agreement also be conditions precedent to the obligations of
the Holder of Registrable Shares.  The Holder agrees to make such
representations or warranties to or agreements with the Company or the
underwriters as are customarily given to the underwriters and any other
representation required by law.





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                          (b)     Holdback Agreements.  Holder agrees, if so
required by the managing underwriter, not to effect any public sale or
distribution of any securities of the Company during the seven days prior to
and the one hundred eighty (180) days (or such longer period as the managing
underwriter may reasonably require for all holdback agreements entered into
with holders of Common Stock) after any underwritten registration pursuant to
Section 2.2 has become effective (the "Holdback"), except as part of such
underwritten registration, whether or not such Holder participates in such
registration; provided however, that if a Holder does not participate in a
registration, such Holder shall not be subject to the Holdback beyond the
expiration of this Agreement, unless agreed to in writing.

                 2.5      Preparation; Reasonable Investigation.
Notwithstanding Section 2.1 hereof and despite a Request, the Company shall not
be required to file any registration statement, or if filed cause any
registration statement to become effective, if at the time the Holder makes a
Request, or during the period after filing but before effectiveness, the
Company is engaged in negotiations to acquire the stock or assets of any
business entity which would be required to make any public announcement
thereof; provided, however, no such delay occasioned under this Section shall
exceed ninety (90) days.  If, however, the Company shall take any action with
respect to the acquisition of the stock or assets of any business entity which
would require the Company to amend any prospectus included in a registration
statement which became effective under the provisions of Section 2.1 hereof by
including therein financial statements which conform to the requirements of
Regulation S-X promulgated by the Commission, the Holder agrees to suspend the
offering or sale of the Registrable Shares or any portion thereof for a period
not to exceed 90 days so that the Company may prepare such financial
statements, provided that the Company uses best efforts to prepare such
financial statements as promptly as possible and provided further that the
ninety (90) day period referred to in the first sentence of this Section shall
be extended for a period equivalent to the delay.

         The Company shall furnish the Holder's Representative with a printer's
proof of Part I of any registration statement sufficiently in advance of its
filing with the Commission to provide the Holder and it's counsel with a
reasonable opportunity for review and comment, which proof shall not be
materially different in content from Part I of the registration statement as
filed.  In addition, the Company shall furnish to the Holder's Representative,
within reasonable time prior to the filing thereof, a copy of any registration
statement as filed with the Commission and any amendments thereto, including if
requested, copies of any exhibits and consents filed therewith and of any
exhibits incorporated therein by reference, and shall not circulate any
preliminary prospectus until five (5) days after a copy of the same has been
furnished to the Holder's Representative.  In addition, the Company shall
furnish the Holder's Representative as many copies of any prospectuses (and of
any preliminary, amended or supplemented prospectuses) in connection with such
registration as the Holder's Representative may reasonably request.

         3.      Definitions.  As used herein, unless the context otherwise
requires, the following terms have the following respective meanings:

                 (a)      Agreement: As defined in Section 1 of this Agreement.

                 (b)      Closing Date: As defined in Section 1 (c) of the
Agreement.

                 (c)      Commission: The Securities and Exchange Commission or
any other Federal agency at the time administering the Securities Act.




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                 (d)      Common Stock: The common stock, .01 par value, of the
Company.

                 (e)      Company: As defined in the introductory paragraph of
this Agreement.

                 (f)      Holder: As defined in the introductory paragraph to
this Agreement.  "Holders" shall mean all of the former stockholders of Seller
listed on Attachment 1.

                 (g)      Holder's Representative shall mean William J. Dawson.

                 (h)      Person: A corporation, an association, a partnership,
an organization, business, an individual, a governmental or political
subdivision thereof or a governmental agency.

                 (i)      Registrable Shares or Registrable Securities: (a) Any
shares of Common Stock received by Holder pursuant to the Agreement, and (b)
any additional shares of Common Stock receivable or received by the Holder upon
the payment of stock dividends thereon and (c) any securities issued or
issuable with respect to the Common Stock referred to in the foregoing
subdivision by way of stock dividend or stock split or in connection with a
combination of shares, recapitalization, merger, consolidation or other
reorganization or otherwise, excepting any of the aforementioned shares which,
in the opinion of Sokolow, Dunaud, Mercadier & Carreras, LLP (or if such firm
is not counsel to the Company, counsel to the Holder), may at the time of
proposed sale or registration be sold pursuant to Rule 144(k) of the Securities
Act or any exemption to the same effect which permits such shares to be freely
sold.  Any particular Registrable Shares shall cease to be Registrable Shares
when (i) a registration statement with respect to the sale of such securities
shall have become effective under the Securities Act and such securities shall
have been disposed of in accordance with such registration statement, (ii) they
may be distributed to the public pursuant to Rule 144 (or any successor
provision) under the Securities Act, or (iii) three years shall have expired
since the Closing Date.

                 (j)      Registration Expenses: All expenses incident to the
Company's performance of or compliance with Section 2, including, without
limitation, all registration, filing Securities and Exchange commission and
National Association of Securities Dealers, Inc. fees, all fees and expenses of
complying with securities or blue sky laws, all word processing, duplicating
and printing expenses, messenger and delivery expenses, internal expenses, the
fees and disbursement of counsel for the Company and of its independent public
accountants any fees and disbursements of underwriters customarily paid by
issuers of securities, but excluding underwriting discounts and commissions and
fees and disbursements of legal counsel and accountants, if any, retained by
the Holders.

                 (k)      Request:  The act of the Holder or Holder's
Representative to either demand or request registration by the Company of
either all or any portion thereof of it's Registrable Shares.

                 (l)      Securities Act: The Securities Act of 1933, as
amended, or any similar Federal statute, and the rules and regulations of the
Commission thereunder, all as of the same shall be in effect at the time.
References to a particular section of the Securities Act of 1933 shall include
a reference to the comparable section, if any, of any such similar Federal
statute.





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         4.      Covenants and Representations of the Company.

                 (a)      From the date of this Agreement, the Company shall
not, without the prior written consent of the holders of at least a majority of
the outstanding Registrable Securities held by the Holders, enter into any
agreement with any holder or prospective holder of any securities of the
Company which gives such holder or prospective holder rights that are superior
to, or which adversely affect, the rights granted under this Agreement;
provided however, that the foregoing covenant shall be null and void upon the
earlier of (i) the Registration of the Registrable Shares pursuant to Section
2.1; (ii) the Registration of the Registrable Shares pursuant to Section 2.2;
(iii) the availability for resale of the Registrable Shares pursuant to Rule
144, or other applicable rule.

                 (b)      The Company hereby represents and warrants that there
are no other registration rights which it has previously granted which are
superior to those stated herein, except as set forth in Attachment 2 hereof.

         5.      Rule 144.  The Company shall timely request and/or file the
reports required to be filed by it under the Securities Exchange Act of 1934
(including but not limited to the reports under Sections 13 and 15(d) of the
Exchange Act referred to in subparagraph (c)(1) of Rule 144 adopted by the
Commission under the Securities Act) and the rules and regulations adopted by
the Commission thereunder and will take such further action as any Holder of
Registrable Shares may reasonably request, all to the extent required from time
to time to enable such Holder to sell Registrable Shares without registration
under the Securities Act within the limitation of the exemptions provided by
(a) Rule 144 under the Securities Act, as such Rule may be amended from time to
time, or (b) any similar rule or regulation hereafter adopted by the
Commission.  Upon the request of the Holder, the Company will deliver to such
Holder a written statement as to whether it has complied with such
requirements.

         6.      Amendments and Waivers.  This Agreement may be amended only by
written instrument signed by the parties hereto.

         7.      Nominees for Beneficial Owners.  In the event that any
Registrable Shares are held by a nominee for the beneficial owner thereof, the
beneficial owner thereof may, at his election, be treated as the Holder of such
Registrable Shares for purposes of any request or other action by any Holder or
the Holders pursuant to this Agreement.  If the beneficial owner of any
Registrable Shares so elects, the Company may require assurance reasonably
satisfactory to it of such owner's beneficial ownership of such Registrable
Shares.

         8.      Notices.  Any notice or other communication required or
permitted to be given hereunder shall be deemed to have been given if
delivered, or five (5) days after mailing by certified or registered mail,
return receipt requested, first class postage prepaid, or one business day
after the time dispatched by telecopy; in every case addressed as follows:


<TABLE>
         <S>     <C>                               <C>
         (a)     If to the Company:                FastComm Communications Corporation
                                                   45472 Holiday Drive
                                                   Sterling, Virginia  20166
</TABLE>





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<TABLE>
         <S>     <C>                               <C>
         (b)     If to the Holder or the
                 Holder's Representative:          William J. Dawson
                                                   4001 Prentice Lane
                                                   Austin, Texas 78746

         (c)     With Copies to:                   Robert B. Webb, III
                                                   Reed Smith Hazel & Thomas LLP
                                                   8251 Greensboro Drive - Suite 1100
                                                   Suite 1100
                                                   McLean, Virginia 22102
</TABLE>

    (which shall not constitute notice to Holder or Holder's Representative)

or at such address as the party addressed may from time to time designate in
writing to the other parties in like manner.  Any communication dispatched by
telecopy shall be confirmed by letter.

         9.      Indemnification.  The Company and the Holder agree to
indemnify each other on the terms and conditions set forth below:

                 (a)      Indemnification by the Company.  The Company will
indemnify and hold harmless the Holder and each underwriter (as defined in the
Securities Act) employed by the Holder (including any broker or dealer through
whom the shares may be sold) and each person, if any, who controls the Holder
or any such underwriter within the meaning of the Securities Act from and
against any and all losses, claims, damages, expenses or liabilities, joint or
several, to which they or any of them may become subject under the Securities
Act or under any other statute or at common law or otherwise, including the
Blue Sky laws of the various jurisdictions, and, except as hereinafter
provided, will reimburse the Holder and each of the underwriters and each such
controlling person, if any, for any legal or other expenses reasonably incurred
by them or any of them in connection with investigating or defending any
actions whether or not resulting in any liability, insofar as such losses,
claims, damages, expenses, liabilities or actions arise out of or are based
upon any untrue statement of a material fact, or omission to state a material
fact required to be stated therein or necessary in order to make the statements
therein not misleading, contained in any registration statement, preliminary or
amended prospectus or any prospectus (or any registration statement or
prospectus as from time to time amended or supplemented by the Company) which
the Company  shall file pursuant to either Sections 2.1 or 2.2 hereof, unless
such untrue statement or omission was made in such registration statement,
preliminary or amended preliminary prospectus or prospectus (or any
registration statement or prospectus as from time to time amended or
supplemented by the Company) in reliance upon and in conformity with
information furnished in writing to the Company by the Holder or any
underwriter employed by the Holder and arising out of any violations by the
Company of any rule or regulation promulgated under the Securities Act
applicable to the Company in connection with such registration.  Promptly after
receipt by the Holder or any underwriter or any person controlling the Holder
or such underwriter of notice of the commencement of any action (but in no
event later than ten (10) days prior to the time any notice of appearance or
any response thereto is required) in respect of which indemnity may be sought
against the Company, the Holder or such underwriter, as the case may be, shall
notify the Company in writing of the commencement thereof, and, subject to the
provisions hereinafter stated, the Company shall assume the defense of such
action (including the employment of counsel) insofar as such action shall
relate to any alleged liability in respect of which indemnity may be sought
against the Company.  The Holder or any underwriter or any such controlling





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person shall have the right to employ separate counsel in any such action and
to participate in the defense thereof, but the fees and expenses of such
counsel shall not be at the expense of the Company unless the employment of
such counsel has been specifically authorized by it.  The Company shall not be
liable to indemnify any person, as required by this Section, for any settlement
of any such action effected without its consent, nor shall it be liable to
indemnify any person unless it shall be notified of the commencement of any
action within the time limits and as set forth above.

                 (b)      Indemnification by the Holder.  The Holder will
indemnify and hold harmless the Company, each of its directors and officers who
have signed the registration statement and each person, if any, who controls
the Company with the meaning of Section 15 of the Securities Act from and
against any and all losses, claims, damages, expenses or liabilities, joint or
several, to which they or any of them may become subject under the Securities
Act or under any other statute or at common law or otherwise, including the
Blue Sky laws of the various jurisdictions, and except as hereinafter provided,
will reimburse the Company and each such director, officer or controlling
person for any legal or other expenses reasonably incurred by them or any of
them in connection with investigating or defending any actions whether or not
resulting in any liability, insofar as such losses, claims, damages, expenses,
liabilities or actions arise out of or are based upon any untrue statement of
material fact, or an omission to state therein a material fact required to be
stated therein or necessary in order to make the statements therein not
misleading, contained in any registration statement, any preliminary or amended
preliminary prospectus or in any prospectus (or the registration statement or
prospectus as from time to time amended or supplemented) which the Company
shall file pursuant to Sections 2.1 or 2.2 hereof, but only insofar as any such
statement or omission was made in reliance upon and in conformity with
information furnished in writing to the Company by the Holder or any
underwriter employed by the Holder.  Promptly after receipt of notice of the
commencement of any action in respect of which indemnity may be sought against
the Holder (but in no event later than ten (10) days prior to the time any
notice of appearance or any response thereto is required) the Company shall
notify the Holder in writing of the commencement thereof, and the Holder shall,
subject to the provisions hereinafter stated, assume the defense of such action
(including the employment of counsel) insofar as such action shall relate to
any alleged liability in respect of which indemnity may be sought against the
Holder.  The Company and each director, officer or controlling person shall
have the right to employ separate counsel in any such action and to participate
in the defense thereof, but the fees and expenses of such counsel shall not be
at the expense of the Holder unless the employment of such counsel has been
specifically authorized by him.  The Holder shall not be liable to indemnify
any person, as required by this Section, for any settlement of any such action
effected without the Holder's consent, nor shall he be liable to indemnify any
person unless he shall be notified of the commencement of any action within the
time limits and as set forth above.

         10.     Miscellaneous.

                 (a)      Assignment.  This Agreement and the rights, interests
and obligations hereunder shall be binding upon and inure to the benefit of and
be enforceable by the parties hereto and their respective successors and
assigns.  In addition, and whether or not any express assignment shall have
been made, the provisions of this Agreement which are for the benefit of the
parties hereto other than the Company shall also be for the benefit of and
enforceable by any subsequent Holder of any Registrable Shares.  Any assignment
pursuant hereto by either party shall be consented in writing, and any such
written consent shall not be unreasonably withheld by either party.





                                       10
<PAGE>   11
                 (b)      No Third-Party Beneficiaries.  Except for the
provisions of Section 9(a) and (b) this Agreement is for the sole benefit of
the parties hereto and their respective successors and permitted assigns and
nothing herein expressed or implied shall give or be construed to give to any
Person, other than the parties hereto and such successors and assigns, any
legal or equitable rights hereunder, except to the extent otherwise provided in
this Agreement.

                 (c)      Descriptive Headings.  The descriptive headings of
the several sections and paragraphs of this Agreement are inserted for
reference only and shall not limit or otherwise affect the meaning hereof.

                 (d)      Waivers.  No failure or delay of any party in
exercising any power or right hereunder shall operate as a waiver thereof, nor
shall any single or partial exercise of any such right or power, or any
abandonment or discontinuance of steps to enforce such a right or power,
preclude any other or further exercise thereof or the exercise of any other
right or power.  The rights and remedies of the parties hereunder are
cumulative and are not exclusive of any rights or remedies which the parties
would otherwise have.  No waiver of any provision of this Agreement or consent
to any departure by the Company therefrom shall in any event be effective
unless the same shall be effected in accordance with this Section 10(d), and
then such waiver or consent shall be effective only in the specific instance
and for the purpose for which given.  No notice or demand on the Company in any
case shall entitle the Company to any other or further notice or demand in
similar or other circumstances.  Neither this Agreement nor any provision
hereof may be waived, amended or modified except pursuant to prior written
consent of the Holders.

                 (e)      Governing Law.  This Agreement shall be construed and
enforced in accordance with, and the rights of the parties shall be governed
by, the laws of the Commonwealth of Virginia without reference to the
principles of conflicts of laws.

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

                 (g)      Entire Agreement.  This Agreement embodies the entire
agreement and understanding between the Company and each other party hereto and
supersedes all prior agreements and understandings related to the subject
matter hereof.

                 (h)      Severability.  In the event that any one or more of
the provisions contained herein, or the application thereof in any
circumstance, is held invalid, illegal or unenforceable in any respect for any
reason, the validity, legality and enforceability of any such provision in
every other respect and of the remaining provisions held invalid, illegal or
unenforceable shall substantially impair the benefits of the remaining
provisions hereof.



         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed and delivered as of the date first above written.





                                       11
<PAGE>   12
<TABLE>
<S>                    <C>
                         THE COMPANY:

                         FASTCOMM COMMUNICATIONS CORPORATION

                                 /s/ Peter C. Madsen
                         -------------------------------------
                         Name: Peter C. Madsen
                         Title: President


                         THE HOLDER:

                         CTI TELECOM, INC.

                                 /s/ Dhru Desai
                         -------------------------------------
                         Name: Dhru Desai
                         Title: President


                         HOLDER'S REPRESENTATIVE

                                 /s/ William J. Dawson
                         -------------------------------------
                         William J. Dawson
</TABLE>





                                       12
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                                  ATTACHMENT 1


CREDITOR-STOCKHOLDERS

1.       WILLIAM J. DAWSON
2.       J.A. SUNKEL
3.       WILLIAM F. FERGUSON
4.       GEORGE CHEN



NON-CREDITOR STOCKHOLDERS:





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<PAGE>   14





                                  ATTACHMENT 2



1.       REGISTRATION RIGHTS GRANTED TO KAUFMAN BROS. LLP




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