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                                                                   EXHIBIT 4.4

      THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE
      HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
      AMENDED (THE "ACT"), OR ANY STATE SECURITIES OR BLUE SKY LAWS AND MAY
      NOT BE OFFERED, SOLD, TRANSFERRED, HYPOTHECATED OR OTHERWISE ASSIGNED
      EXCEPT (1) PURSUANT TO A REGISTRATION STATEMENT WITH RESPECT TO SUCH
      SECURITIES WHICH IS EFFECTIVE UNDER THE ACT OR (2) PURSUANT TO AN
      AVAILABLE EXEMPTION FROM REGISTRATION UNDER THE ACT RELATING TO THE
      DISPOSITION OF SECURITIES AND (3) IN ACCORDANCE WITH APPLICABLE STATE
      SECURITIES AND BLUE SKY LAWS.

                                   WARRANT
              WARRANT TO PURCHASE 323,500 SHARES OF COMMON STOCK
                                      OF
                      SONUS COMMUNICATION HOLDINGS, INC.
                       DATE OF ISSUANCE: MARCH 29, 2000

THIS CERTIFIES that, for value received, Ferris, Baker Watts, Incorporated, a
________________ corporation, or its assigns ("Warrant Holder") is entitled to
purchase, subject to the provisions of this Warrant, from SONUS COMMUNICATION
HOLDINGS, INC., a Delaware corporation (the "Company"), at the price per share
set forth in Section 8 hereof, the number of shares of the Company's common
stock, $.0001 par value per share (the "Common Stock"), set forth in Section 7
hereof. This Warrant is referred to herein as the "Warrant" and the shares of
Common Stock issuable pursuant to the terms hereof are sometimes referred to
herein as "Warrant Shares".

      Section 10.    Exercise of Warrant. To exercise this Warrant in whole or
in part, WARRANT HOLDER shall deliver to the Company at its principal office,
(a) a written notice, in substantially the form of the exercise notice
attached hereto (the "Exercise Notice"), of the WARRANT HOLDER's election to
exercise this Warrant, which notice shall specify the number of shares of
Common Stock to be purchased, (b) a check in the amount of the aggregate
exercise price for the Warrant Shares being purchased, and (c) this Warrant.
The Company shall as promptly as practicable, and in any event within twenty
(20) days after delivery to the Company of (i) the Exercise Notice, (ii) the
check mentioned above, and (iii) this Warrant, execute and deliver or cause to
be executed and delivered, in accordance with such notice, a certificate or
certificates representing the aggregate number of shares of Common Stock
specified in such notice, provided the Warrants specified in such notice have
vested on or prior to the date such notice is delivered. If WARRANT HOLDER
elects to purchase, at any time, less than the number of shares of Common
Stock then purchasable under the terms of this Warrant, the Company shall
issue to WARRANT HOLDER a new Warrant exercisable into the number of remaining
shares of Common Stock purchasable under this Warrant. Each certificate
representing Warrant Shares shall bear the legend or legends required by
applicable securities laws as well as such other legend(s) the Company
requires to be included on certificates for its Common Stock. The Company
shall pay all expenses, taxes and other charges payable in connection with the
preparation, issuance and delivery of such stock certificates issued in the

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name of Warrant Holder. If stock certificates are issued in a name other than
Warrant Holder, Warrant Holder shall pay any additional expenses. This Warrant
will expire at 5:00 EST on March 28, 2005 (the "Expiration Date").

      Section 11.    Reservation of Shares. The Company shall at all times
reserve and keep available out of its authorized but unissued shares of Common
Stock, solely for the purpose of effecting the exercise of this Warrant, such
number of its shares of Common Stock as shall from time to time be sufficient
to effect the exercise of this Warrant; and if at any time the number of
authorized but unissued shares of Common Stock shall not be sufficient to
effect the exercise of this Warrant, the Company will take all appropriate
corporate action as may, in the opinion of its counsel, be necessary to
increase its authorized but unissued shares of Common Stock to such number of
shares as shall be sufficient for such purpose.

      Section 12.    Fractional Shares. This Warrant may be exercised only for
a whole number of shares of Common Stock, and no fractional shares or scrip
representing fractional shares shall be issuable upon the exercise of this
Warrant.

  Transfer of Warrant and Warrant Shares. WARRANT HOLDER may sell, pledge,
hypothecate, or otherwise transfer this Warrant, in whole or in part, only if
such sale, pledge, hypothecation, or transfer is made in compliance with the
Act or pursuant to an available exemption from registration under the Act
relating to the disposition of securities, and is made in accordance with
applicable State securities laws.

  Loss of Warrant. Upon receipt by the Company of evidence satisfactory to it
of the loss, theft, or destruction of this Warrant, and of indemnification
satisfactory to it, or upon surrender and cancellation of this Warrant, if
mutilated, the Company will execute and deliver a new Warrant of like tenor.

  Rights of WARRANT HOLDER. No provision of this Warrant shall be construed as
conferring upon WARRANT HOLDER the right to vote, consent, receive dividends
or receive notice other than as expressly provided herein. Prior to exercise,
no provision hereof, in the absence of affirmative action by WARRANT HOLDER to
exercise this Warrant, and no enumeration herein of the rights or privileges
of WARRANT HOLDER, shall give rise to any liability of WARRANT HOLDER for the
purchase price of any Warrant Shares or as a stockholder of the Company,
whether such liability is asserted by the Company or by creditors of the
Company.

  Number of Warrant Shares. This Warrant shall be exercisable for up to
323,500 shares of the Company's Common Stock, as adjusted in accordance with
this Agreement.

  Exercise Price; Redemption; Adjustment of Warrants.

         Determination of Exercise Price. The per share purchase price (the
"Exercise Price") for each of the Warrant Shares purchasable under this
Warrant shall be equal to Two Dollars ($2.00).

         (c)    Adjustments for Stock Dividends, Distributions and
Subdivisions. If the Company at any time or from time to time after the
original issue date shall declare or pay any dividend or distribution on the
Common Stock payable in Common Stock, or effect a subdivision of the
outstanding shares of Common Stock into a greater number of shares of Common
Stock (by reclassification or otherwise than by payment of a dividend in
Common Stock), then the number of shares of Common Stock into which this
Warrant is exercisable shall be increased to an amount which is equal to the
product of (i) the number of shares of Common Stock for which this Warrant is
exercisable immediately prior to the stock dividend, distribution or
subdivision, as the case may be, and (ii) a fraction, the numerator of which
is equal to the number of shares of

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Common Stock issued and outstanding after giving effect to such stock
dividend, distribution or subdivision, and the denominator of which is the
number of shares of Common Stock issued and outstanding prior to such stock
dividend, distribution or subdivision. If the outstanding shares of Common
Stock shall be divided or increased because of a stock dividend or
distribution, by stock split or otherwise, into a greater number of shares of
Common Stock, the Exercise Price in effect immediately prior to such dividend,
distribution or division shall, concurrently with the effectiveness of such
division, dividend or distribution, be proportionately decreased.

      (d)    Adjustments for Combinations or Consolidation of Common Stock. If
the outstanding shares of Common Stock shall be combined or consolidated, by
reclassification, reverse stock split or otherwise, into a lesser number of
shares of Common Stock, then the number of shares of Common Stock into which
this Warrant is exercisable shall be decreased to an amount which is equal to
the product of (i) the number of shares of Common Stock for which this Warrant
is exercisable immediately prior to combination or consolidation, as the case
may be, and (ii) a fraction, the numerator of which is equal to the number of
shares of Common Stock issued and outstanding after giving effect to such
combination or consolidation, and the denominator of which is the number of
shares of Common Stock issued and outstanding prior to such combination or
consolidation. If the outstanding shares of Common Stock shall be combined or
consolidated, by reclassification, reverse stock split or otherwise, into a
lesser number of shares of Common Stock, the Exercise Price in effect
immediately prior to such combination or consolidation shall, concurrently
with the effectiveness of such combination or consolidation, be
proportionately increased.

      (e)    Adjustment for Mergers or Reorganization, etc. In case of any
consolidation or merger of the Company with or into another corporation or the
conveyance of all or substantially all of the assets of the Company to another
corporation, this Warrant shall be exercisable into the number of shares of
stock or other securities or property to which a holder of the number of
shares of Common Stock of the Company deliverable upon exercise of this
Warrant would have been entitled upon such consolidation, merger or
conveyance.

      (f)    No Impairment. The Company will not, through any reorganization,
transfer of assets, consolidation, merger, dissolution, issue or sale of
securities or any other voluntary action, avoid or seek to avoid the
observance or performance of any of the terms to be observed or performed
hereunder by the Company, but will at all times in good faith assist in the
carrying out of all the provisions of this Section 8 and in the taking of all
such action as may be necessary or appropriate in order to protect the
exercise rights of the holder of this Warrant against impairment.

      (g)         Issue Taxes.  The Company shall pay any and all issue and
other taxes that may be payable in respect of any issue or delivery of shares
of Common Stock on exercise of this Warrant to the Warrant Holder, in whole or
in part.

      (h)         Cashless Exercise. WARRANT HOLDER shall have the right to
pay all or a portion of the Exercise Price by making a "Cashless Exercise",
(in a written request similar in form to Exhibit B attached) in which case the
portion of the Exercise Price to be so paid shall be paid by reducing the
number of Warrant Shares otherwise issuable pursuant to this Warrant in
accordance with the formula set forth below so that the number of Warrant
Shares to be issued to WARRANT HOLDER as a result of a Cashless Exercise shall
therefore be:

         (Fair Market Value Per Share - Exercise Price per Warrant Share    X
the number of Warrant
         Fair Market Value Per Share
Shares otherwise

issuable

Within ten (10) days of receipt of an election to exercise this Warrant
specifying a Cashless Exercise, the Company shall provide to Warrant Holder in
writing its determination of the fair

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market value per share of Common Stock. "Fair Market Value" means the average
closing price of a share of Common Stock for the five (5) consecutive trading
days preceding such date on the principal national securities exchange
(including the Nasdaq National Market and Small Cap Market) on which the
shares of Common Stock are listed or admitted to trading or, if not listed or
admitted to trading on any national securities exchange (including the Nasdaq
National Market or Small Cap Market), the average of the closing prices during
such 5-day period in the over-the-counter market as furnished by Nasdaq.

      (i)    Fractional Shares. No fractional share shall be issued upon the
exercise, in whole or in part, of this Warrant. If any exercise in whole or in
part of this Warrant would result in the issuance of a fraction of a share of
Common Stock, the Company shall, in lieu of issuing any fractional share, pay
the holder otherwise entitled to such fraction a sum in cash equal to the fair
market value of such fraction on the date of exercise (as determined in good
faith by the Board of Directors of the Company).

      Section 9.      Reclassification or Reorganization. In case of any
reclassification, capital reorganization or other change of outstanding shares
of Common Stock of the Company (other than a change in par value, or from par
value to no par value, or from no par value to par value, or as a result of an
issuance of Common Stock by way of dividend or other distribution or of a
subdivision or combination), the Company shall cause effective provision to be
made so that WARRANT HOLDER shall have the right thereafter by exercising this
Warrant, to purchase the kind and amount of shares of stock and other
securities and property receivable upon such reclassification, capital
reorganization or other change, by a holder of the number of shares of Common
Stock which might have been purchased upon exercise of this Warrant
immediately prior to such reclassification or change. Any such provision shall
include provision for adjustments which shall be as nearly equivalent as may
be practicable to the adjustments provided for in this Warrant. The foregoing
provisions of this Section 9 shall similarly apply to successive
reclassifications, capital reorganizations and changes of shares of Common
Stock

      Section 10.      Piggy Back Registration Rights.

               a)      Definitions.  As used herein the following defined
terms shall have the following respective meanings:

                       (i)     "Common Stock" has the meaning set forth in the
Recitals.

                       (ii)    "Holder(s)" means the holder(s) of Warrants or
Warrant Shares.

                       (ii)    "Indemnified Party" has the meaning set forth
in Section 10(f)(iii).

                       (iii)   "Indemnifying Party" has the meaning set forth
in Section 10(f)(iii).

                       (iv)    The terms "register," "registered" and
"registration" refer to a registration effected by preparing and filing a
registration statement in compliance with the Securities Act.

                       (v)     "Prospectus" means a preliminary and definitive
prospectus and all amendments and supplements thereto.

                       (vi)    "SEC" means the Securities and Exchange
Commission.

                       (vii)   "Securities Act" means the Securities Act of
1933, as amended.

               b.  Piggy Back Registration.

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                          (i) If the Company shall hereafter determine to
register any of its securities, either for its own account or the account of a
security holder or holders, in a registration statement covering the sale of
Common Stock to the general public pursuant to a public offering (except with
respect to any registration filed on Form S-8, Form S-4 or any successor forms
thereto or forms analogous therewith and except for the registration statement
on Form SB-2 filed December 7, 1999), the Company will: (A) give to each
Holder written notice thereof (the "Filing Notice") at least 30 days before
filing; provided, however, in the case of a registration statement on Form
SB-1, the Company shall be required to give each Holder written notice of the
proposed filing thereof promptly after a decision to make such filing has been
made and in no event less than ten business days prior to filing; and (B) use
its best efforts to include in such registration (and any related
qualification under blue sky laws) and in any underwriting involved therein,
the Warrant Shares specified in a written request or requests by the Holders,
made within 15 days after delivery of the Filing Notice, or, in the case of a
registration statement on Form SB-1, within seven business days after receipt
of the Filing Notice, by any Holder(s), except to the extent limited by the
other terms of this Section 10.

                          (ii) The right of any Holder to registration
pursuant to this Section 10 shall be conditioned upon such Holder's
participation in the underwriting (if an underwriting is pursued). All Holders
proposing to distribute their securities through such underwriting shall
(together with the Company) enter into an underwriting agreement in customary
form with the underwriter or underwriters selected for such underwriting by
the Company, which shall contain standard lock-up provisions which will be
negotiated with the lead underwriter in writing. Notwithstanding any other
provision of this Section, if the underwriter determines that marketing
factors require a limitation of the number of securities to be underwritten,
the Company shall so advise all Holders of Warrant Shares which would
otherwise be registered and underwritten pursuant hereto, and the Company
shall include in such registration first the number of securities requested to
be sold by the Company together with the number of securities requested to be
sold by the security holders exercising demand registration rights with
respect to such registration, if any, and the number of securities requested
to be sold by security holders exercising registration rights superior to the
registration rights of the Holders, then the number of Shares requested to be
included in the registration which, in the opinion of such underwriter, can be
sold, pro rata among all Holders thereof and all other shareholders of the
Company that have other contractual rights with respect to the registration of
securities held by such shareholders (the "Other Holders") in proportion, as
nearly as practicable, to the respective amounts of securities held by such
Holders and Other Holders at the time of filing the registration statement,
with further proportional allocations among the Holders and Other Holders if
any such Holder or Other Holder has requested less than all such Shares it is
entitled to register

                c.        Demand Registration.

                          (i)  Subject to the terms and conditions of this
Warrant, Holders of not less than fifty one percent (51%) of the aggregate
number of Warrant Shares issuable upon exercise of this Warrant (and all other
Warrants issued upon transfer of this Warrant) may request, by delivering to
the Company written notice making such request and signed by such Holders (the
"Demand Notice"), that the Company file a registration statement under the
Securities Act on an appropriate form covering the Warrant Shares requested to
be included in such registration in accordance with the terms of this Section
10(c).

                          (ii) Within 20 days after receipt of a Demand Notice
determined to be sufficient by the Company, the Company shall send a written
notice (the "Company Demand Notice") to all Holders other than Holders having
signed the Demand Notice (the "Other

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Holders") inquiring whether such Holders wish their Warrant Shares to be
registered in such registration. The Company shall use its best efforts to
file, as soon as practicable following the date of the Company Demand Notice,
a registration statement covering the Warrant Shares specified in the Demand
Notice and in written responses delivered to the Company by the Other Holders,
which written responses must be delivered within 20 days after receipt by the
Other Holder(s) of the Company Notice. The Company shall furnish each Holder
and Other Holder desiring to sell its Warrant Shares such number of
Prospectuses as may be reasonably requested.

                          (iii) Anything to the contrary in this Section 10
notwithstanding: (i) the Company is not and shall not be obligated to file any
registration statement (A) until the date which is sixty (60) days after the
date hereof, or (ii) the Company shall not be obligated to file any
registration statement if the Company, in the exercise of its reasonable good
faith judgement, determines that such registration would interfere with any
material financing, acquisition, disposition, corporate reorganization or
other material transaction involving the Company or any of its subsidiaries or
because public disclosure thereof would be required prior to the time such
disclosure might otherwise be required, in which case the Company shall delay
the registration request for only as long as would be required to disclose the
event at issue.

                          (iv)  The Company shall be obligated to prepare and
file no more than one registration statement pursuant to this Section 10(c).

                          (iv)  In the event of an underwritten offering, the
managing underwriter or underwriters of an underwritten public offering
covered by these demand registration rights shall be selected by the Company
and be reasonably acceptable to Holders of a majority of Warrant Shares to be
included in the registration.

                          (v) If any Holder's Warrant Shares are to be
included in any registration statement, such Holder shall furnish to the
Company such information as the Company may reasonably request in writing and
as shall be required in connection with any registration, qualification or
compliance referred to in this Warrant.

                 d. Expenses of Registration. All expenses incurred in
connection with any registration or qualification pursuant to this Agreement,
including, without limitation, all registration, filing and qualification
fees, printing expenses, fees and disbursements of counsel for the Company,
and expenses and fees of any special audits incidental to or required by such
registration, shall be borne by the Company; provided, however, that the
Company shall not be required to pay fees of legal counsel of the Holders, or
underwriters' commissions relating to the Warrant Shares. e. Registration
Procedures. In the case of each registration effected by the Company pursuant
to this Warrant, the Company will keep each Holder participating therein
advised in writing as to the initiation of such registration (and any state
qualifications) and as to the completion thereof. Other than with respect to a
registration statement filed upon exercise of the demand registration rights
set forth in Section 10(c) hereof, the Company may decline to file a
registration statement after giving notice to each Holder, or withdraw any
registration after filing and after such notice, but prior to the
effectiveness thereof, provided that the Company shall promptly notify each
Holder in writing of any such action and provided further that the Company
shall bear all expenses incurred by such Holder or otherwise in connection
with such withdrawn registration. Upon receipt of written notice from the
Company that any registration statement or Prospectus contains an untrue
statement of a material fact or an omission to state a material fact required
to be stated in a registration statement or Prospectus or necessary to make
the statements in a registration statement or Prospectus not misleading, each
Holder shall forthwith discontinue disposition of Warrant Shares until such
Holder has received copies of the

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supplemented or amended Prospectus, or until such Holder is advised in writing
by the Company that the use of the Prospectus may be resumed, and, if so
directed by the Company, such Holder shall deliver to the Company (at the
Company's expense) all copies, other than permanent file copies then in such
Holder's possession, of the Prospectus covering such Warrant Shares current at
the time of receipt of such notice.

                 f.  Indemnification.

                          (i)  The Company will indemnify each Holder of
Warrant Shares included in the registration, each of the Holder's officers,
directors, partners and employees, and each person controlling such Holder,
with respect to such registration or qualification effected pursuant to this
Warrant, against all claims, losses, damages, and liabilities (or actions in
respect thereto) arising out of or based on any untrue statement (or alleged
untrue statement) of a material fact contained in any Prospectus, registration
statement or other document incident to any such registration or
qualification, or based on any omission (or alleged omission) to state therein
a material fact required to be stated therein or necessary to make the
statements therein not misleading (each a "Misstatement") or any violation by
the Company of any rule or regulation promulgated pursuant to any Federal,
state or common law rule or regulation including, without limitation, the
Securities Act, applicable to the Company and relating to action or inaction
required of the Company in connection with any such registration,
qualification or compliance and will reimburse each such Holder, each of the
Holder's officers, directors, partners and employees, and each person
controlling such Holder, for any legal and any other reasonable expenses
incurred in connection with investigating or defending any such claim, loss,
damage, liability or action, including reasonable attorneys' fees and
expenses; provided, however, that the Company will not be liable in any such
case to the extent that any such claim, loss, damage or liability arises out
of or is based on any untrue statement or omission based upon and in
conformity with written information furnished to the Company by such Holder.
Such indemnity shall be effective notwithstanding any investigation made by or
on behalf of any Holder or any such officer, director, partner, employee, or
controlling person and shall survive any transfer by the same of the Shares.
The foregoing notwithstanding, the Company shall not be liable to the extent
that any such claim, loss, damage or liability arises out of or is based upon
a Misstatement or alleged Misstatement made in any Prospectus if (i) such
Holder failed to send or deliver a copy of the Prospectus with or prior to the
delivery of written confirmation of the sale of Shares giving rise to such
claim, loss, damage or liability and (ii) the Prospectus would have corrected
such Misstatement. In addition, the Company shall not be liable to the extent
that any such claim, loss, damage or liability arises out of or is based upon
a Misstatement or alleged Misstatement in a Prospectus, (i) if such
Misstatement or alleged Misstatement is corrected in an amendment or
supplement to such Prospectus and (ii) having previously been furnished by or
on behalf of the Company with copies of the Prospectus as so amended or
supplemented, such Holder thereafter fails to deliver such Prospectus as so
amended or supplemented prior to or concurrently with the sale to the person
who purchased Shares from such Holder and who is asserting such claim, loss,
damage or liability.

                          (ii)  Each Holder will, if Shares held by or
issuable to such Holder are included in the securities as to which such
registration or qualification is being effected, indemnify the Company, each
of its directors, officers and employees, each person who controls the
Company, and each other such Holder, each of such other Holder's officers,
directors, partners and employees, and each person controlling such other
Holder, against all claims, losses, damages and liabilities (or actions in
respect thereto) arising out of or based on any untrue statement (or alleged
untrue statement) of a material fact contained in any such registration
statement, Prospectus or other

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document, or any omission (or alleged omission) to state therein a material
fact required to be stated therein or necessary to make the statements therein
not misleading, and will reimburse the Company, such Holders, such directors,
officers, partners, employees or persons for any legal or any other reasonable
expenses incurred in connection with investigating or defending any such
claim, loss, damage, liability or action, including reasonable attorneys' fees
and expenses, in each case to the extent, but only to the extent, that such
untrue statement (or alleged untrue statement) or omission (or alleged
omission) is made in such registration statement, Prospectus or other document
in reliance upon and in conformity with written information furnished to the
Company by such Holder. Notwithstanding the foregoing, the liability of any
such Holder shall not exceed an amount equal to the proceeds realized by each
such Holder of Shares sold as contemplated herein. Such indemnity shall be
effective notwithstanding any investigation made by or on behalf of the
Company, any such director, officer, partner, employee, or controlling person
and shall survive the transfer of such securities by such Holder.

                          (iii) Each party entitled to indemnification under
this Section 10 (the "Indemnified Party") shall give notice to the party
required to provide indemnification (the "Indemnifying Party") promptly after
such Indemnified Party has actual knowledge of any claim as to which indemnity
may be sought. Unless in the reasonable judgment of the Indemnified Party a
conflict of interest may exist between the Indemnifying Party and the
Indemnified Party, the Indemnifying Party shall be permitted to assume the
defense of any such claim or any litigation resulting therefrom; provided,
however, that in any event counsel for the Indemnifying Party or Indemnified
Party who shall conduct the defense of such claim or litigation as provided
above shall be approved by the other Party (which approval shall not be
unreasonably withheld), and such other Party may participate in such defense
at such Party's expense; provided, further, that the failure of any
Indemnified Party to give notice as provided herein shall not relieve the
Indemnifying Party of its obligations under this Paragraph 6 unless such
failure shall have had a material adverse effect on the Indemnifying Party's
ability to defend such claim.

                          (iv)  The Indemnified Party shall make no settlement
of any claim or litigation which would give rise to liability on the part of
the Indemnifying Party under any indemnity contained in this Section without
the written consent of the Indemnifying Party, which consent shall not be
unreasonably withheld or delayed, and no Indemnifying Party shall make any
settlement of any such claim or litigation without the consent of the
Indemnified Party, which consent shall not be unreasonably withheld or
delayed. If a firm offer is made to settle a claim or litigation defended by
the Indemnified Party and the Indemnified Party notifies the Indemnifying
Party in writing that the Indemnified Party desires to accept and agree to
such offer, but the Indemnifying Party elects not to accept or agree to such
offer within ten days after receipt of written notice from the Indemnified
Party of the terms of such offer, then, in such event, the Indemnified Party
shall continue to contest or defend such claim or litigation and, if such
claim or litigation is within the scope of the Indemnifying Party's indemnity
contained in this Section, the Indemnified Party shall be indemnified pursuant
to the terms hereof. If a firm offer is made to settle a claim or litigation
defended by the Indemnifying Party and the Indemnifying Party notifies the
Indemnified Party in writing that the Indemnifying Party desires to accept and
agree to such offer, but the Indemnified Party elects not to accept or agree
to such offer within ten days after receipt of written notice from the
Indemnifying Party of the terms of such offer, then, in such event, the
Indemnified Party may continue to contest or defend such claim or litigation
and, in such event, the total maximum liability of the Indemnifying Party to
indemnify or otherwise reimburse the Indemnified Party in accordance with this
Agreement with respect to such claim or litigation shall be limited to

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and shall not exceed the amount of such settlement offer, plus reasonable
out-of-pocket costs and expenses (including reasonable fees and disbursements
of counsel) to the date of notice that the Indemnifying Party desired to
accept such settlement offer.

                          (v)  The indemnification payments required pursuant
to this Section 10 for expenses of the investigation or defense of a claim or
lawsuit shall be made from time to time during the course of the investigation
or defense, as the case may be, upon submission of reasonably sufficient
documentation that any such expenses have been incurred.

                 g. Information by Holder. The Holder or Holders of Warrant
Shares included in any registration shall furnish to the Company such written
information regarding such Holder or Holders and the distribution proposed by
such Holder or Holders as the Company may reasonably request in writing and as
shall be required in connection with any registration or qualification
referred to in this Agreement. The Company agrees to include in any such
registration statement all information concerning the Holders and their
distribution which the Holders shall reasonably request.

                 h. Termination. The registration rights granted pursuant to
this Section 10 shall terminate with respect to any Holder on the date on
which the Holder may sell such Holder's Warrant Shares pursuant to Rule 144
under the Securities Act or, with respect to any such Holder, on the date on
which such Holder's Warrant Shares have been registered pursuant to a
registration statement filed with the SEC and which has become effective.

      Section 11.   Representations and Warranties of the Company. The Company
hereby represents and warrants to Warrant Holder as follows as of the date
hereof:

                 a. Organization, Good Standing and Qualification. The Company
is a corporation duly organized, validly existing and in good standing under
the laws of the State of Delaware, and has all requisite power and authority
to carry on its business as now conducted. The Company is duly qualified to
transact business, and is in good standing, in each U.S. jurisdiction in which
the failure to so qualify would have a material adverse effect on its
business.

                 b.  Capitalization. The authorized capital of the Company
consists of 100,000,000 shares of common stock and, on the date hereof,
7,098,071 shares of Common Stock are issued and outstanding.

                 c.  Authorization. All action on the part of the Company
necessary for the authorization, execution and delivery of this Agreement, the
performance of all obligations of the Company hereunder and the authorization,
issuance and delivery of the Warrants, to the extent that the foregoing
requires performance on or prior to the Closing, has been taken or will be
taken on or prior to the Closing, and the Company has all requisite power and
authority to enter into this Agreement.

      Section 12.    Representations and Warranties of Warrant Holder. Warrant
Holder hereby represents and warrants to the Company as follows as of the date
hereof:

                 a.  Organization; Good Standing; Power and Authority; Binding
Obligation. Warrant Holder has full power and authority to enter into this
Agreement, and, if Warrant Holder is a corporation (i) such Warrant Holder is
a corporation duly organized, validly existing and in good standing under the
laws of the jurisdiction of its incorporation, and has all requisite power and
authority to carry on its business as now conducted, and (ii) all action on
the part of WARRANT HOLDER necessary for the authorization, execution and
delivery

                                                                            46

<PAGE>   10

of this Agreement, the performance of all obligations of WARRANT HOLDER
hereunder has been taken, and WARRANT HOLDER has all requisite power and
authority to enter into this Agreement. This Agreement has been duly executed
and delivered by Warrant Holder and, assuming due authorization, execution and
delivery by the Company, constitutes Warrant Holder's valid and legally
binding obligation enforceable against WARRANT HOLDER in accordance with its
terms, subject to the effect of any applicable bankruptcy, reorganization,
insolvency (including, without limitation, all laws relating to fraudulent
transfers), moratorium or similar laws affecting creditors' rights generally,
subject, as to enforceability, to the effect of general principles of equity
(regardless of whether such enforceability is considered in a proceeding in
equity or at law) and subject to the effect of applicable securities laws as
to rights of indemnification.

                 b. Purchase Entirely for Own Account, Etc.. The Warrants and
shares of Common Stock underlying the Warrants (the "Warrant Shares") to be
purchased by Warrant Holder hereunder will be acquired for investment for
Warrant Holder's own account, not as a nominee or agent, and not with a view
to the resale or distribution of any part thereof. Warrant Holder has no
present intention of selling, granting any participation in, or otherwise
distributing the Warrants or the Warrant Shares. Warrant Holder does not have
any contract, undertaking, agreement or arrangement with any person to sell,
transfer or grant participations to any person with respect to the Warrants or
the Warrant Shares. WARRANT HOLDER has not construed the contents of this
Agreement, or any additional agreement with respect to the proposed investment
in the Warrants or any prior or subsequent communications from the Company, or
any of its officers, employees or representatives, as investment, tax or legal
advice or as information necessarily applicable to such Warrant Holder's
particular financial situation. WARRANT HOLDER has consulted its own financial
advisor, tax advisor, legal counsel and accountant, as necessary or desirable,
as to matters concerning his investment in the Warrants and Warrant Shares.

                 c. Disclosure. Warrant Holder has received or reviewed all
the information which such Warrant Holder has requested for the purposes of
determining the merits of the Warrants as an investment. Warrant Holder has
read and understands the Risk Factors attached to this Warrant as Exhibit A.
Warrant Holder has had an opportunity to ask questions and receive answers
from the Company regarding Sonus, the Company and their respective business,
operations and financial condition and the terms and conditions of this
Warrant, and answers have been provided to Warrant Holder's full satisfaction.
Warrant Holder has fully reviewed all corporate and governance documents of
the Company and such other documents, which Warrant Holder feels is necessary
or appropriate prior to purchase of the Warrant, understands all relevant
terms and has asked all questions and received answers thereto to Warrant
Holder's full satisfaction. If deemed necessary by Warrant Holder, Warrant
Holder has consulted with a professional advisor who has provided Warrant
Holder with advice concerning terms. WARRANT HOLDER ACKNOWLEDGES AND AGREES
THAT THE PURCHASE OF THE WARRANTS AND WARRANT SHARES INVOLVES A HIGH DEGREE OF
RISK, INCLUDING, WITHOUT LIMITATION, THOSE SET FORTH ON EXHIBIT A, AND MAY
RESULT IN A LOSS OF THE ENTIRE AMOUNT INVESTED. WARRANT HOLDER FURTHER
ACKNOWLEDGES AND AGREES THAT THERE IS ONLY A LIMITED PUBLIC MARKET FOR THE
WARRANT SHARES OF THE COMPANY. THERE IS NO ASSURANCE THAT THE COMPANY'S
OPERATIONS WILL RESULT IN REVENUES OR BE PROFITABLE OR THAT A MORE LIQUID
PUBLIC MARKET FOR THE WARRANT SHARES WILL DEVELOP AT ANY TIME.

                                                                            47

<PAGE>   11

                 d. Accredited Investor. Warrant Holder is an accredited
investor as defined in Rule 501(a) of Regulation D promulgated under the 1933
Act. The information provided by Warrant Holder on the Statement of Accredited
Investor, attached hereto as Exhibit B, is true, correct and complete in all
respects. Warrant Holder is capable of bearing the economic risk of an
investment in the Warrants, including the possible loss of Warrant Holder's
entire investment. Warrant Holder has such knowledge and experience in
financial or business matters that it is capable of evaluating the merits and
risks of an investment in the Warrant offered hereby. If other than an
individual, Warrant Holder has not been organized solely for the purpose of
acquiring the Warrants.

                 e. Restricted Securities. Warrant Holder understands that the
Warrants received hereunder, as well as the Warrant Shares, are "restricted
securities" as defined in the Securities Act, and that under federal and state
securities laws the Shares and Warrant Shares may be resold without
registration under the Securities Act only in certain limited circumstances.
Warrant Holder is familiar with Rule 144 promulgated by the Securities and
Exchange Commission (the "Commission") under the Securities Act, and
understands the resale limitations imposed thereby and by the Securities Act
generally. Warrant Holder also acknowledges that the Warrants and Warrant
Shares are subject to significant restrictions on transfer, pledge or
hypothecation.

                 f. Legends. It is understood that certificates or other
evidence of the Warrants and Warrant Shares may bear the following legend, as
well as any legend required by the laws of any state:

                 "THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE
                 SECURITIES ACT OF 1933. THEY MAY NOT BE SOLD, OFFERED FOR
                 SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF A
                 REGISTRATION STATEMENT IN EFFECT WITH RESPECT TO THE
                 SECURITIES UNDER SUCH ACT OR AN OPINION OF COUNSEL
                 SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT
                 REQUIRED PURSUANT TO A VALID EXEMPTION THEREFROM UNDER THE
                 SECURITIES ACT OF 1933."

                 g. Consents and Approvals; No Conflict. (i) The execution and
delivery of this Agreement by WARRANT HOLDER does not, and the performance of
this Agreement by WARRANT HOLDER will not, require any consent, approval,
authorization or other action by, or filing with or notification to, any
governmental or regulatory authority.

                          (ii) The execution, delivery and performance of this
Agreement by WARRANT HOLDER does not (A) in the case of any Warrant Holder
that is not an individual, conflict with or violate the charter or by-laws,
partnership or other governing documents of such Warrant Holder, or (B)
conflict with or violate any law, rule, regulation, order, writ, judgment,
injunction, decree, determination or award applicable to WARRANT HOLDER.

      Section 13.    Miscellaneous.

                 (a) Successors and Assigns. The terms and conditions of this
Agreement shall inure to the benefit of, and be binding upon, the respective
successors and assigns of the parties, except to the extent otherwise provided
herein. Nothing in this Agreement, express or implied, is intended to confer
upon any party, other than the parties hereto or their respective successors
and assigns, any rights, remedies, obligations or liabilities under or by
reason of this Agreement, except as expressly provided in this Agreement.

                                                                            48
<PAGE>   12

                 (b)  Governing Law.  This Agreement shall be governed by and
construed in accordance with the laws of the State of Delaware, without regard
to the principles of conflict of laws thereof.

                 (c)  Counterparts; Delivery by Facsimile. This Agreement may
be executed in one or more counterparts, each of which shall be deemed an
original, but all of which together shall constitute one and the same
instrument. Delivery of this Agreement may be effected by facsimile.

                 (d)  Titles and Subtitles. The titles and subtitles used in
this Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

                 (e)  Notices. Unless otherwise provided, any notice required
or permitted hereunder shall be given by personal service upon the party to be
notified, by nationwide overnight delivery service or upon deposit with the
United States Post Office, by certified mail, return receipt requested and:

                          i.  if to the Company, addressed to SONUS
COMMUNICATION HOLDINGS, INC., 1600 Wilson Blvd., Suite 1008, Arlington,
Virginia 22209, Attention: W. Todd Coffin, with a copy to Cecil E. Martin,
III, Esquire, McGuire, Woods Battle & Booth LLP, Seven Saint Paul Street,
Suite 1000, Baltimore, Maryland 21202- 1626, or at such other address as the
Company may designate by notice to Warrant Holder in accordance with the
provisions of this Section; and

                          ii.  if to WARRANT HOLDER, at the address indicated
on the signature pages hereof, or at such other addresses as Warrant Holder
may designate by notice to the Company in accordance with the provisions of
this Section.

                 (f)  Amendments and Waivers. Any term of this Agreement may
be amended and the observance of any term of this Agreement may be waived
(either generally or in a particular instance and either prospectively or
retroactively), only with the written consent of the Company and Warrant
Holder.

                 (g)  Entire Agreement. This Agreement and the Subscription
Agreement (including the exhibits and schedules hereto) constitute the entire
agreement among the parties hereto with respect to the subject matter hereof
and thereof and supersede all prior agreements, understandings, negotiations
and discussions, whether oral or written, of the parties hereto.

                                                                            49

<PAGE>   13

      IN WITNESS WHEREOF, the undersigned hereby sets his hand and seal this
29th day of March, 2000.

                              SONUS COMMUNICATION HOLDINGS, INC.

                              By: /s/ Richard D. Rose
                                  ------------------------------------
                              Name: Richard D. Rose
                              Title:  Chief Financial Officer

                              FERRIS, BAKER WATTS, INCORPORATED

                              By:
                                  ------------------------------------
                              Name:

                              Title:

                              Address:
                                      --------------------------

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

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

                               EXERCISE NOTICE

Dated: _____________________

      The undersigned hereby irrevocably elects to exercise his, her or its
right to purchase _________ shares of the common stock, $.0001 par value per
share (the "Common Stock"), of SONUS COMMUNICATION HOLDINGS, INC., a Delaware
corporation (the "Company"), such right being pursuant to a Warrant issued
March 29, 2000, and as issued to the undersigned by the Company, and remits
herewith the sum of $______ in payment for same in accordance with the
Exercise Price specified in Section 8 of said Warrant.
               15           ASSIGNMENT FORM

Dated: _____________________

      For value received ____________________ hereby sells, assigns and
      transfers unto

      Name: ____________________________________________
                       (Please typewrite or print block letters)

      Address:
               ____________________________________________

               ____________________________________________

    and appoints:  ____________________________________________

                   ____________________________________________

Attorney to transfer the said Warrant on the books of SONUS COMMUNICATION
HOLDINGS, INC. with full power of substitution in the premises.

                                     Signature: ______________________________

                                                                            50
<PAGE>   14

                            CASHLESS EXERCISE FORM

To:      Sonus Communication Holdings, Inc

The undersigned hereby irrevocably elects a cashless exercise of the right of
purchase represented by the attached Warrant with respect to
__________________ Warrant Shares, as provided for in Section 8 (h) thereof.

Please issue a certificate or certificates for such shares of Common Stock
issuable pursuant hereto in the name of the Warrant Holder as also shown
below. Please pay in cash any fractional share that results from such
calculation.

Note:    The signature below should correspond exactly with the name shown on
page one of the Warrant as Warrant Holder.

Date:                                         Name:
     -----------------------------------           ----------------------------
                                                      (Please print name)

Social Security Number or
Other tax identification number:

----------------------------------------              -------------------------
                                                      Signature

                                                                            51
<PAGE>   15

                                  EXHIBIT A
                                 RISK FACTORS

         The risk factors included in the Form SB-2/A filed with the
Securities and Exchange Commission on March 22, 2000 are incorporated by
reference into this warrant.

                                  EXHIBIT B
                       STATEMENT OF ACCREDITED INVESTOR

To:      SONUS COMMUNICATION HOLDINGS, INC. (the "Company")

Ladies and Gentlemen:

         The undersigned hereby refers to the Warrants executed and delivered
to the Company by the undersigned as of the date herewith. In connection with
the issuance of the Warrants, the undersigned hereby represents and warrants
that such individual or entity meets at least one of the tests listed on the
attached Addendum I for an "accredited investor" (as such term is defined
under Regulation D promulgated pursuant to the Securities Act of 1933, as
amended). Dated:                        ,  2000

                                       Very truly yours,

                                       FERRIS, BAKER WATTS, INCORPORATED

                                       -----------------------------------
                                       Authorized Signature
                                       Name:
                                       Title:

                                                                            52
<PAGE>   16
                                  ADDENDUM I

         NOTE: "Accredited Investors" are accorded special status under the
federal securities laws. Individuals who hold certain positions with an issuer
or its affiliates, or who have certain minimum individual income or certain
minimum net worth (each as described below) may qualify as Accredited
Investors. Partnerships, corporations or other entities may qualify as
Accredited Investors if they fulfill certain financial and other standards, or
if all of their equity owners have incomes and/or net worth which qualify them
individually as Accredited Investors, and trusts may qualify as Accredited
Investors if they meet certain financial and other tests (as described below).

         You may qualify as an Accredited Investor under Regulation D
promulgated under the Securities Act of 1933 (the "Securities Act") if you
meet any of the following tests:

FOR INDIVIDUALS ONLY

         1.    You are a director or an executive officer of SONUS
COMMUNICATION HOLDINGS, INC. An "executive officer" is the president, any vice
president in charge of a principal business unit, division or function (such
as sales, administration or finance), any other officer who performs a policy
making function or any other person who performs similar policy making
functions for SONUS COMMUNICATION HOLDINGS, INC.

                                      OR

         2.    You had individual income (exclusive of any income attributable
to your spouse) of more than $200,000 in 1998 and 1999 and reasonably expect
to have an individual income in excess of $200,000 in 2000, or your spouse and
you had a joint income in excess of $300,000 in 1998 and 1999, and you
reasonably expect to have a joint income in excess of $300,000 in 2000. For
purposes hereof, income means adjusted gross income, as reported for federal
income tax purposes, increased by the following amounts: (i) the amount of any
tax exempt interest income under Section 103 of the Internal Revenue Code (the
"Code") received, (ii) the amount of losses claimed as a limited partner in a
limited partnership as reported on Schedule E of Form 1040, (iii) any
deduction claimed for depletion under Section 611 of the Code or (iv) any
amount by which income has been reduced in arriving at adjusted gross income
pursuant to the provisions of Section 1202 of the Code. In determining
personal income, however, unrealized capital gains should not be included.

                                      OR

         3.    You have an individual net worth, or your spouse and you have a
combined net worth, in excess of $1,000,000. For purposes of this statement,
"net worth" means the excess of total assets at fair market value, including
home, home furnishings and automobiles, over total liabilities.

FOR TRUSTS ONLY

         4.    The Trust has total assets in excess of $5,000,000, was not
formed for the specific purpose of acquiring securities of SONUS COMMUNICATION
HOLDINGS, INC., and the purchase of such securities is directed by a person
with such knowledge and experience in financial and business matters that he
is capable of evaluating the risks and merits of the prospective investment in
such securities.

FOR CORPORATIONS, PARTNERSHIPS OR OTHER PURCHASING ENTITIES

         5.    Any corporation, partnership, limited liability company or
limited liability partnership not formed for the specific purpose of acquiring
securities of SONUS COMMUNICATION HOLDINGS, INC., with total assets in excess
of $5,000,000.

                                      OR

         6.    All equity owners of the purchasing entity are Accredited
               Investors.

                                                                            53<PAGE>   1

                                                                     EXHIBIT 4.5

                        REGISTRATION RIGHTS AGREEMENT

       This REGISTRATION RIGHTS AGREEMENT (this "Agreement"), is dated as of
________________ __, 200__, by and between SONUS COMMUNICATION HOLDINGS, INC.,
a Delaware corporation (the "COMPANY"), the Principal Stockholders (within the
meaning of the Merger Agreement defined below), and the stockholders of Empire
One Telecommunications, Inc., a New York corporation, who agree to be bound by
this Agreement listed on Schedule A attached hereto and incorporated by
reference herein (each a "STOCKHOLDER" and collectively, the "STOCKHOLDERS").

       WHEREAS, pursuant to the terms of that certain Merger Agreement of even
date herewith by and between the Company, EOT Acquisition Corporation, a
Delaware corporation ("Acquisition"), Empire One Telecommunications, Inc., a
New York corporation ("Empire One"), the Stockholder and certain other
stockholders of Empire One (the "MERGER AGREEMENT"), the Stockholder will
receive, pursuant to the conditions of the Merger Agreement, _________ shares
of the Company's Common Stock, par value $.0001 per share (the "COMMON STOCK")
upon the consummation of the merger of Empire One into Acquisition (the
"Merger"); and

       WHEREAS, in order to induce the Stockholder to enter into the Merger
Agreement and/or vote for the Merger contemplated thereby, the Company desires
to grant registration rights to the Stockholder for the shares of Common Stock
to be received in the Merger in accordance with the terms and conditions
hereof;

       NOW, THEREFORE, in consideration of the mutual promises and covenants
contained herein, the parties hereto agree as follows:

       1. DEFINITIONS. As used herein the following defined terms shall have
the following respective meanings:

              (a) "CAPITAL STOCK" means the Company's Common Stock and any
       other class of common stock created by the Company in the future.

              (b) "COMMON STOCK" has the meaning set forth in the Recitals.

              (c) "HOLDERS" means any person or entity to whom shares of
       Capital Stock were issued pursuant to the Merger Agreement and which
       agrees to be bound by this Agreement.

                                                                            54
<PAGE>   2

              (d) "INDEMNIFIED PARTY" has the meaning set forth in
       subparagraph.

              (e) "INDEMNIFYING PARTY" has the meaning set forth in
       subparagraph.

              (f) The terms "REGISTER," "REGISTERED" and "REGISTRATION" refer
       to a registration effected by preparing and filing a registration
       statement in compliance with the Securities Act.

              (g) "REGISTRABLE SECURITIES" means all shares of Capital Stock
       of the Company issued pursuant to the Merger Agreement.

              (h) "SEC" means the Securities and Exchange Commission.

              (i) "SECURITIES ACT" means the Securities Act of 1933, as
       amended.

       2. RESERVED.

       3. COMPANY REGISTRATION.

              (a) If the Company, at any time after the completion of the next
       registration of Capital Stock under the Securities Act to occur
       following the date hereof, shall determine to register any of its
       securities, either for its own account or the account of a security
       holder or holders, in a registration statement covering the sale of
       Capital Stock to the general public pursuant to an underwritten public
       offering (except with respect to any registration filed on Form S-8,
       Form S-4 or any successor forms thereto), the Company will: (i) give to
       each Holder written notice thereof at least 45 days before filing;
       provided, however, in the case of a Registration Statement on Form S-3,
       the Company shall be required to give each Holder written notice of the
       proposed filing thereof promptly after a decision to make such filing
       has been made and in no event less than ten business days prior to
       filing; and (ii) use its best efforts to include in such registration
       (and any related qualification under blue sky laws) and in any
       underwriting involved therein, all the Registrable Securities specified
       in a written request or requests, made within 15 days after receipt of
       such written notice from the Company, or, in the case of a Registration
       Statement on Form S-3, within seven business days after receipt of such
       written notice, by any Holder or Holders, except as set forth in
       subparagraph 3(b) below. The notice referred to in this subparagraph
       shall include a list of the jurisdictions in which the Company intends
       to attempt to qualify such securities under the applicable blue sky or
       other state securities laws.

              (b) The right of any Holder to registration pursuant to this
       Paragraph 3 shall be conditioned upon such Holder's participation in
       the underwriting to the extent provided herein. All Holders proposing
       to distribute their securities through such underwriting shall
       (together with the Company) enter into an underwriting agreement in
       customary form with the underwriter or underwriters selected for such
       underwriting by the Company, and may, at their option, require that any
       or all the representations and warranties by, and the covenants and
       other agreements on the part of, the Company to and for the benefit of
       such underwriter shall also be made to and for the benefit of such
       Holders. Such Holders shall not be required to make any representations
       or warranties to or agreements with the Company or the underwriter
       other than those relating to such Holders, their Registrable Securities
       and their intended methods of distribution and information about such
       Holders provided by such

                                                                            55

<PAGE>   3

       Holders for use in the registration statement. Upon the written request
       of the managing underwriter of any underwritten offering of the
       Company's securities, a Holder of Registrable Securities shall not
       sell, make any short sale of, loan, grant any option for the purchase
       of, or otherwise dispose of any Registrable Securities (other than
       those included in such registration) without the prior written consent
       of such managing underwriter for a period (not to exceed 30 days before
       the effective date and 75 days thereafter) that such managing
       underwriter reasonably determines is necessary in order to effect the
       underwritten public offering. Notwithstanding any other provision of
       this Paragraph 3, if the underwriter determines that marketing factors
       require a limitation of the number of shares to be underwritten, the
       Company shall so advise all Holders of Registrable Securities which
       would otherwise be registered and underwritten pursuant hereto, and the
       Company shall include in such registration first the number of shares
       requested to be sold by the Company together with the number of shares
       requested to be sold by the persons and entities exercising demand
       registration rights with respect to such registration, if any, then the
       number of shares of Registrable Securities requested to be included in
       the registration which, in the opinion of such underwriter, can be
       sold, pro rata among all Holders thereof and all other shareholders of
       the Company that have contractual rights with respect to the
       registration of shares of Capital Stock held by such shareholders (the
       "Other Holders") in proportion, as nearly as practicable, to the
       respective amounts of Registrable Securities held by such Holders and
       Other Holders at the time of filing the registration statement, with
       further proportional allocations among the Holders and Other Holders if
       any such Holder or Other Holder has requested less than all such
       Registrable Securities it is entitled to register.

       4. EXPENSES OF REGISTRATION. All expenses incurred in connection with
       any registration or qualification pursuant to this Agreement,
       including, without limitation, all registration, filing and
       qualification fees, printing expenses, fees and disbursements of
       counsel for the Company, and expenses and fees of any special audits
       incidental to or required by such registration, shall be borne by the
       Company; provided, however, that the Company shall not be required to
       pay fees of legal counsel of the Holders, or underwriters' discounts or
       commissions relating to Registrable Securities (such underwriters'
       fees, discounts or commissions to be borne by the Holders, on a pro
       rata basis, based on the number of shares of Registrable Securities
       sold by each of them).

       5. REGISTRATION PROCEDURES. In the case of each registration effected
       by the Company pursuant to this Agreement, the Company will keep each
       Holder participating therein advised in writing as to the initiation of
       such registration (and any state qualifications) and as to the
       completion thereof. The Company may decline to file a Registration
       Statement after giving notice to each Holder, or withdraw any
       registration after filing and after such notice, but prior to the
       effectiveness thereof, provided that the Company shall promptly notify
       each Holder in writing of any such action and provided further that the
       Company shall bear all expenses incurred by such Holder or otherwise in
       connection with such withdrawn registration. Upon receipt of written
       notice from the Company that a registration statement or prospectus
       contains a Misstatement (as defined below), each Holder of Registrable
       Securities shall forthwith discontinue disposition of Registrable
       Securities until such Holder has received copies of the supplemented or
       amended prospectus, or until such Holder is advised in writing by the
       Company that the use of the prospectus may be resumed, and, if so
       directed by the Company, such

                                                                            56

<PAGE>   4

       Holder shall deliver to the Company (at the Company's expense) all
       copies, other than permanent file copies then in such Holder's
       possession, of the prospectus covering such Registrable Securities
       current at the time of receipt of such notice.

       6. INDEMNIFICATION.

              (a) The Company will indemnify each Holder of Registrable
       Securities, each of the Holder's officers, directors, partners and
       employees, and each person controlling such Holder, with respect to
       such registration or qualification effected pursuant to this Agreement
       and in which Registrable Securities of the Holders are included,
       against all claims, losses, damages, and liabilities (or actions in
       respect thereto) arising out of or based on any untrue statement (or
       alleged untrue statement) of a material fact contained in any
       prospectus, registration statement or other document incident to any
       such registration or qualification, or based on any omission (or
       alleged omission) to state therein a material fact required to be
       stated therein or necessary to make the statements therein not
       misleading, or any violation by the Company of any rule or regulation
       promulgated pursuant to any Federal, state or common law rule or
       regulation including, without limitation, the Securities Act,
       applicable to the Company and relating to action or inaction required
       of the Company in connection with any such registration, qualification
       or compliance and will reimburse each such Holder, each of the Holder's
       officers, directors, partners and employees, and each person
       controlling such Holder, for any legal and any other reasonable
       expenses incurred in connection with investigating or defending any
       such claim, loss, damage, liability or action, including reasonable
       attorneys' fees and expenses; provided, however, that the Company will
       not be liable in any such case to the extent that any such claim, loss,
       damage or liability arises out of or is based on any untrue statement
       or omission based upon and in conformity with written information
       furnished to the Company by such Holder. Such indemnity shall be
       effective notwithstanding any investigation made by or on behalf of any
       Holder or any such officer, director, partner, employee, or controlling
       person and shall survive any transfer by the same of the Registrable
       Securities. The foregoing notwithstanding, the Company shall not be
       liable to the extent that any such claim, loss, damage or liability
       arises out of or is based upon an untrue statement of a material fact
       or an omission to state a material fact required to be stated in a
       registration statement or prospectus or necessary to make the
       statements in a registration statement, prospectus or preliminary
       prospectus not misleading (a "Misstatement") or alleged Misstatement
       made in any preliminary prospectus if (i) such Holder failed to send or
       deliver a copy of the Prospectus with or prior to the delivery of
       written confirmation of the sale of Registrable Securities giving rise
       to such claim, loss, damage or liability and (ii) the prospectus would
       have corrected such Misstatement. In addition, the Company shall not be
       liable to the extent that any such claim, loss, damage or liability
       arises out of or is based upon a Misstatement or alleged Misstatement
       in a prospectus, (i) if such Misstatement or alleged Misstatement is
       corrected in an amendment or supplement to such prospectus and (ii)
       having previously been furnished by or on behalf of the Company with
       copies of the prospectus as so amended or supplemented, such Holder
       thereafter fails to deliver such prospectus as so amended or
       supplemented prior to or concurrently with the sale to the person who
       purchased a Registrable Security from such Holder and who is asserting
       such claim, loss, damage or liability.

              (b) Each Holder will, if Registrable Securities held by or
       issuable to such Holder are included in the securities as to which such

                                                                            57
<PAGE>   5

       registration or qualification is being effected, indemnify the Company,
       each of its directors, officers and employees, each person who controls
       the Company, and each other such Holder, each of such other Holder's
       officers, directors, partners and employees, and each person
       controlling such other Holder, against all claims, losses, damages and
       liabilities (or actions in respect thereto) arising out of or based on
       any untrue statement (or alleged untrue statement) of a material fact
       contained in any such registration statement, prospectus or other
       document, or any omission (or alleged omission) to state therein a
       material fact required to be stated therein or necessary to make the
       statements therein not misleading, and will reimburse the Company, such
       Holders, such directors, officers, partners, employees or persons for
       any legal or any other reasonable expenses incurred in connection with
       investigating or defending any such claim, loss, damage, liability or
       action, including reasonable attorneys' fees and expenses, in each case
       to the extent, but only to the extent, that such untrue statement (or
       alleged untrue statement) or omission (or alleged omission) is made in
       such registration statement, prospectus or other document in reliance
       upon and in conformity with written information furnished to the
       Company by such Holder. Notwithstanding the foregoing, the liability of
       any such Holder shall not exceed an amount equal to the proceeds
       realized by each such Holder of Registrable Securities sold as
       contemplated herein. Such indemnity shall be effective notwithstanding
       any investigation made by or on behalf of the Company, any such
       director, officer, partner, employee, or controlling person and shall
       survive the transfer of such securities by such Holder.

              (c) Each party entitled to indemnification under this Paragraph
       6 (the "Indemnified Party") shall give notice to the party required to
       provide indemnification (the "Indemnifying Party") promptly after such
       Indemnified Party has actual knowledge of any claim as to which
       indemnity may be sought. Unless in the reasonable judgment of the
       Indemnified Party a conflict of interest may exist between the
       Indemnifying Party and the Indemnified Party, the Indemnifying Party
       shall be permitted to assume the defense of any such claim or any
       litigation resulting therefrom; provided, however, that in any event
       counsel for the Indemnifying Party or Indemnified Party who shall
       conduct the defense of such claim or litigation as provided above shall
       be approved by the other Party (which approval shall not be
       unreasonably withheld), and such other Party may participate in such
       defense at such Party's expense; provided, further, that the failure of
       any Indemnified Party to give notice as provided herein shall not
       relieve the Indemnifying Party of its obligations under this Paragraph
       6 unless such failure shall have had a material adverse effect on the
       Indemnifying Party's ability to defend such claim.

              (d) The Indemnified Party shall make no settlement of any claim
       or litigation which would give rise to liability on the part of the
       Indemnifying Party under any indemnity contained in this Paragraph 6
       without the written consent of the Indemnifying Party, which consent
       shall not be unreasonably withheld or delayed, and no Indemnifying
       Party shall make any settlement of any such claim or litigation without
       the consent of the Indemnified Party, which consent shall not be
       unreasonably withheld or delayed. If a firm offer is made to settle a
       claim or litigation defended by the Indemnified Party and the
       Indemnified Party notifies the Indemnifying Party in writing that the
       Indemnified Party desires to accept and agree to such offer, but the
       Indemnifying Party elects not to accept or agree to such offer within
       ten days after receipt of written notice from the Indemnified Party of
       the terms of such offer, then, in such event, the Indemnified Party
       shall continue to contest or defend such claim or litigation and, if
       such claim or litigation is within the scope of the

                                                                            58

<PAGE>   6

       Indemnifying Party's indemnity contained in this Paragraph 6, the
       Indemnified Party shall be indemnified pursuant to the terms hereof. If
       a firm offer is made to settle a claim or litigation defended by the
       Indemnifying Party and the Indemnifying Party notifies the Indemnified
       Party in writing that the Indemnifying Party desires to accept and
       agree to such offer, but the Indemnified Party elects not to accept or
       agree to such offer within ten days after receipt of written notice
       from the Indemnifying Party of the terms of such offer, then, in such
       event, the Indemnified Party may continue to contest or defend such
       claim or litigation and, in such event, the total maximum liability of
       the Indemnifying Party to indemnify or otherwise reimburse the
       Indemnified Party in accordance with this Agreement with respect to
       such claim or litigation shall be limited to and shall not exceed the
       amount of such settlement offer, plus reasonable out-of-pocket costs
       and expenses (including reasonable fees and disbursements of counsel)
       to the date of notice that the Indemnifying Party desired to accept
       such settlement offer.

              (e) The indemnification payments required pursuant to this
       Paragraph 6 for expenses of the investigation or defense of a claim or
       lawsuit shall be made from time to time during the course of the
       investigation or defense, as the case may be, upon submission of
       reasonably sufficient documentation that any such expenses have been
       incurred.

       7. INFORMATION BY HOLDER. The Holder or Holders of Registrable
       Securities included in any registration shall furnish to the Company
       such written information regarding such Holder or Holders and the
       distribution proposed by such Holder or Holders as the Company may
       reasonably request in writing and as shall be required in connection
       with any registration or qualification referred to in this Agreement.
       The Company agrees to include in any such registration statement all
       information concerning the Holders and their distribution which the
       Holders shall reasonably request.

       8. CHANGES; WAIVER; ASSIGNMENT. The terms and provisions of this
       Agreement may not be modified, amended or assigned, except that they
       may be modified, amended or assigned with the written consent of (i)
       the Company and (ii) the Holders of a majority of the Registrable
       Securities outstanding. None of the terms and provisions of this
       Agreement may be waived except in writing by the person so waiving.

       9. GOVERNING LAW. This Agreement shall be governed by and construed in
       accordance with the domestic laws of the State of Delaware, without
       giving effect to any choice of law or conflict of law provision or rule
       (whether of the State of Delaware or any other jurisdiction) that would
       cause the application of the laws of any jurisdiction other than the
       State of Delaware.

       10. NOTICE. All notices, requests and other communications hereunder
       must be in writing and will be deemed to have been duly given only if
       delivered personally against written receipt or by facsimile
       transmission or mailed by prepaid first class certified mail, return
       receipt requested, or delivered by a nationally recognized overnight
       courier service prepaid, to the parties at the following addresses or
       facsimile numbers: If to the Company, to:

                       Sonus Communication Holdings, Inc.
                       1600 Wilson Boulevard, Suite 1008
                       Arlington, Virginia 22209
                       Attention: Rick D. Rose
                       Telecopier: 703-527-8865

                       with a copy to:
                                                                            59

<PAGE>   7
                       Cecil E. Martin, III, Esquire
                       McGuire, Woods, Battle & Boothe LLP
                       7 St. Paul Street, Suite 1000
                       Baltimore, Maryland 21202
                       Telecopier:  410-659-4535

       If to the Holders, to the address listed as the most recent address of
       such Holders on the books and records of Empire One Telecommunications,
       Inc.

                       with a copy to:

                       David E. Bronston, Esquire
                       Wolf, Block, Schorr and Solis-Cohen LLP
                       250 Park Avenue
                       New York, New York 10177
                       Telecopier: 212-986-0604

       All such notices, requests and other communications will (i) if
       delivered personally to the address as provided in this Section, be
       deemed given upon delivery, (ii) if delivered by facsimile transmission
       to the facsimile number as provided for in this Section, be deemed
       given upon receipt, (iii) if delivered by mail in the manner described
       above to the address as provided in this Section, be deemed given on
       the earlier of the fourth Business Day following mailing or upon
       receipt and (iv) if delivered by overnight courier to the address as
       provided for in this Section, be deemed given on the earlier of the
       first Business Day following the date sent by such overnight courier or
       upon receipt (in each case regardless of whether such notice, request
       or other communication is received by any other Person to whom a copy
       of such notice is to be delivered pursuant to this Section). Any party
       from time to time may change its address, facsimile number or other
       information for the purpose of notices to that party by giving notice
       specifying such change to the other parties hereto.

       11. TERMINATION. This Agreement shall terminate with respect to any
       Holder on the date on which the Holder may sell all of such Holder's
       Registrable Securities pursuant to Rule 144 under the Securities Act
       within any 90 day period or, with respect to any such Holder, on the
       date on which all of such Holder's Registrable Securities have been
       registered pursuant to a registration statement filed with the
       Commission and which has become effective.

       12. Arbitration.

              (a) Any controversy or claim arising out of or relating to this
       Agreement, or the breach thereof, shall be settled by arbitration in
       accordance with the Commercial Arbitration Rules of the American
       Arbitration Association by an arbitration panel consisting of three
       persons, one selected by Sonus, one selected by the Principal
       Stockholders and the third selected by mutual agreement of the first
       two arbitrators selected, and judgement upon the award rendered by the
       arbitrators may be entered in any court having jurisdiction thereof.

              (b) The arbitration shall be held in Washington, D.C. if brought
       by Target or any of the Principal Stockholders and in New York City if
       brought by Acquisition or Sonus.

              (c) All fees, costs and expenses (including reasonable
       attorneys' fees and expenses) incurred by a party that prevails on any
       issue in any arbitration commenced hereunder or in any judicial
       proceeding seeking to enforce this Agreement to arbitrate disputes or
       seeking to enforce any order or award of any arbitration hereunder
       shall be assessed against the party or parties that do not prevail on
       such issue or issues.

       14. COUNTERPARTS. This Agreement may be executed in counterparts, each
       of which shall be deemed an original and which together shall
       constitute a single agreement. This Agreement may be delivered by
       facsimile.

       15. HEADINGS. The headings of the Paragraphs of this Agreement are
       inserted for convenience only and shall not be deemed to constitute a
       part hereof.

       16. SEVERABILITY. If any provision or any portion of any provision of
       this Agreement shall be held to be void or unenforceable, the remaining
       portions of this Agreement shall continue in full force and effect.

       IN WITNESS WHEREOF, the undersigned have caused this Agreement to be
duly executed by their authorized officers as of the day and year first above
written.

                                         SONUS COMMUNICATION HOLDINGS, INC.

                                         By:  /s/  W. Todd Coffin
                                            ------------------------------------
                                             Name:   W. Todd Coffin
                                             Title:  CEO

                                         [NAME OF HOLDER]

                                         By:
                                            ------------------------------------
                                             Name:
                                             Title:

                                                                            60

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