Document:

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                                                                     EXHIBIT 4.6

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE "ACT"), OR APPLICABLE STATE SECURITIES LAWS, AND MAY NOT BE SOLD,
TRANSFERRED, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF SUCH REGISTRATION OR
RECEIPT BY THE COMPANY OF AN OPINION OF COUNSEL (WHICH COUNSEL SHALL BE
REASONABLY ACCEPTABLE TO THE COMPANY) IN THE FORM, SUBSTANCE AND SCOPE
REASONABLY SATISFACTORY TO THE COMPANY THAT THIS NOTE MAY BE SOLD, TRANSFERRED,
HYPOTHECATED OR OTHERWISE DISPOSED OF, UNDER AN EXEMPTION FROM REGISTRATION
UNDER THE ACT AND SUCH STATE SECURITIES LAWS.

                                 PROMISSORY NOTE

$100,000.00                                                         July 2, 2002

     For value received, the undersigned, VERTEL CORPORATION, a California
corporation ("Maker"), hereby unconditionally promises to pay to the order of
SDS MERCHANT FUND, L.P. ("Holder"), at such place as Holder may designate, the
principal sum of ONE HUNDRED THOUSAND DOLLARS ($100,000.00) on the Maturity Date
(as such term is hereinafter defined), together with interest on the unpaid
principal amount of this Note, beginning as of the date hereof, before or after
maturity or judgment, at the rate of ten percent (10%) per annum, which rate
shall be computed monthly on the basis of a three hundred sixty (360) day year
and for actual days elapsed.

     1. Payments. The outstanding principal balance of this Note plus all unpaid
accrued interest shall be due and payable in lawful money of the United States
and in immediately available funds on the "Maturity Date" where "Maturity Date"
shall mean the earliest of (i) January 31, 2003, (ii) the date on which the Note
becomes immediately due and payable pursuant to Section 4 hereof and (iii) the
consummation of the Proposed Financing (as defined below). Should there be any
withholding or similar amounts payable in respect of any amount payable under
this Note, the amount payable to the Holder shall be grossed up by an amount so
that the actual amount received by the Holder shall be equal to a net amount as
if no withholding was applicable. Amounts payable to the Holder hereunder shall
be to the Holder at such place and/or account as the Holder may designate.

     2. Principal Payments. At the Maturity Date, the outstanding principal
amount of this Note plus all accrued and unpaid interest herein shall be due and
payable in cash or, if the Maturity Date occurs as a result of the Proposed
Financing, then such amount shall be automatically converted into debt or equity
securities which may be issued in connection with a possible private placement
by the Maker of its debt or equity securities to certain institutional investors
completed at or prior to the Maturity Date (the "Proposed Financing"). Upon the
conversion of this Note, the outstanding principal amount of this Note, together
with accrued interest hereon, shall be deemed to be part of the consideration
for the Holder's interest in the new debt or equity securities on the

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Maturity Date. Simultaneously with such conversion into debt or equity
securities, the Holder shall surrender for cancellation the originally signed
version of this Note to Maker marked "CANCELED" across the face of each page.

     3. Interest. Upon the occurrence of an Event of Default (as hereinafter
defined), interest shall accrue on the unpaid principal amount of this Note, and
any other amounts payable hereunder which has not been paid when such amount is
payable (including accrued interest); interest shall accrue on such amount, both
before and after judgment, until paid in full, at a rate of twenty percent
(20%), calculated as aforesaid. In no event shall the amount of interest charged
on this Note exceed the maximum amount permitted by applicable law.

     4. Events of Default. The occurrence at any time of any one or more of the
following events (each an "Event of Default") shall constitute an "Event of
Default" under this Note: (a) the Maker's failure to pay principal of or
interest or any other amount when due under this Note when such amount is
payable hereunder; (b) the failure of the Maker to perform in any material
respect its agreements and the obligations, or a breach of any of Maker's
representations and warranties made in this Note; or (c) the commencement of any
proceeding under any provision of the Bankruptcy Code of the United States, as
now in existence or hereafter amended, or of any other proceeding under any
federal or state law, now existing or hereafter in effect, relating to
bankruptcy, reorganization, insolvency, liquidation or otherwise, for the relief
of debtors or readjustment of indebtedness, by or against the Maker, or the
Maker making an assignment for the benefit of creditors.

     5. Effect of Default. Upon the occurrence of an Event of Default, the
entire outstanding principal amount of this Note, together with accrued interest
thereon, and any other amount payable under this Note shall, at the option of
the Holder (in the Holder's sole and absolute discretion), be immediately due
and payable, without presentment, demand, protest or notice, all of which are
hereby expressly unconditionally and irrevocably waived by the Maker. The
failure of the Holder to exercise such option shall not constitute a waiver of
the right to exercise the same in the event of any subsequent Event of Default.

     6. Representations and Warranties. In order to induce the Holder to extend
the credit to the Maker represented by this Note, the Maker hereby represents
and warrants to the Holder as follows: (a) the Maker has the legal capacity to
create, deliver and perform this Note; (b) this Note constitutes the valid and
binding obligation of the Maker enforceable against the Maker in accordance with
its terms; and (c) the execution, delivery and performance of this Note does not
violate any material agreement, order, rule or judgment to which the Maker is a
party or by which any of the Maker's properties or assets are bound.

     7. Confession of Judgment. Maker irrevocably authorizes and empowers any
attorney to appear for the Maker at any time after the occurrence of an Event of
Default in any action, suit or other proceeding brought against the Maker on
this Note by the Holder, and in that action, suit or other proceeding to confess
or enter judgment against the Maker for the entire unpaid principal of

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this Note, all accrued interest and all other amounts payable due under this
Note, and all interest accrued on those amounts, until actual payment is made to
Holder of the full amount due.

     8. Transfer. Subject to the limitations set forth on the legend on this
Note, this Note may not be transferred, sold, pledged, hypothecated or otherwise
granted as security by the Holder except that the Holder may transfer this Note
to an affiliate of the Holder. The obligations of the Maker hereunder may not be
assigned. This Note shall inure to the benefit of the transferees, successors
and assigns of the Holder of this Note.

     9. Replacement. Upon receipt of a duly executed, notarized and unsecured
written statement from the Holder with respect to the loss, theft or destruction
of this Note (or any replacement hereof), and without requiring an indemnity
bond or other security, or, in the case of a mutilation of this Note, upon
surrender and cancellation of such Note, the Maker shall issue a new Note, of
like tenor and amount, in lieu of such lost, stolen, destroyed or mutilated
Note.

     10. Enforcement Expenses. The Maker agrees to pay on demand all costs and
expenses (including and without limitation, attorneys fees and expenses and
court costs) incurred by the Holder in connection with the enforcement of this
Note or the protection of the rights of the Holder hereunder.

     11. Waiver; Amendment. Failure by the Holder to insist upon the strict
performance by the Maker of any terms and provisions herein shall not be deemed
to be a waiver of any terms and provisions herein, and the Holder shall retain
the right thereafter to insist upon strict performance by the Maker of any and
all terms and provisions of this Note. This Note may not be amended, modified or
waived, except by an instrument in writing executed by the Holder.

     12. Governing Law. This Note shall be governed by and construed in
accordance with the laws of the State of New York (without regard to principles
of conflicts of law provisions). This Note shall not be interpreted or construed
with any presumption against the party that caused this Note to be drafted.

     13. JURISDICTION. THE MAKER HEREBY CONSENTS TO THE JURISDICTION OF THE
COURTS OF THE STATE OF NEW YORK LOCATED IN NEW YORK COUNTY AND THE FEDERAL
DISTRICT COURT FOR THE SOUTHERN DISTRICT OF NEW YORK WITH RESPECT TO ANY ACTION,
SUIT OR OTHER PROCEEDING TO ENFORCE THIS NOTE OR OTHERWISE RELATING TO THIS
NOTE. THE MAKER HEREBY UNCONDITIONALLY AND IRREVOCABLY WAIVES ANY RIGHT TO
CHALLENGE THE JURISDICTION OF SUCH COURTS, TO ASSERT THAT VENUE IN SUCH COURTS
IS IMPROPER OR THAT VENUE IN SUCH COURTS CONSTITUTE AN INCONVENIENT FORUM. THE
MAKER FURTHER UNCONDITIONALLY AND IRREVOCABLY WAIVES ANY RIGHT THAT THE MAKER
MAY HAVE TO A TRIAL BY JURY IN ANY SUCH ACTION, SUIT OR PROCEEDING.

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     14. Headings. The section headings in this Note are included herein for
purposes of convenience of reference only and shall not constitute a part of
this Note for any other purpose.

     IN WITNESS WHEREOF, the Maker has duly executed this Note as of the date
first above written.

                                     VERTEL CORPORATION

                                     By: _________________________________
                                         Name:
                                         Title:

                                       4<PAGE>
                                                                     Exhibit 4.7

                          REGISTRATION RIGHTS AGREEMENT
                          -----------------------------

     This Registration Rights Agreement (this "Agreement") is made and entered
into as of July 2, 2002, between Vertel Corporation, a California corporation
(the "Company"), and the purchaser listed on Schedule A hereto (the
"Purchaser").

     This Agreement is being entered into pursuant to the Convertible Note
Purchase Agreement, dated as of the date hereof between the Company and the
Purchaser (the "Purchase Agreement").

     The Company and the Purchaser hereby agree as follows:

1.   Definitions.
     -----------

     Capitalized terms used and not otherwise defined herein shall have the
meanings given such terms in the Purchase Agreement. As used in this Agreement,
the following terms shall have the following meanings:

     "Advice" shall have meaning set forth in Section 3(m).

     "Affiliate" means, with respect to any Person, any other Person that
directly or indirectly controls or is controlled by or under common control with
such Person. For the purposes of this definition, "control," when used with
respect to any Person, means the possession, direct or indirect, of the power to
direct or cause the direction of the management and policies of such Person,
whether through the ownership of voting securities, by contract or otherwise;
and the terms of "affiliated," "controlling" and "controlled" have meanings
correlative to the foregoing.

     "Board" shall have meaning set forth in Section 3(n).

     "Business Day" means any day except Saturday, Sunday and any day which
shall be a legal holiday or a day on which banking institutions in the state of
New York generally are authorized or required by law or other government actions
to close.

     "Closing Date" means the date of the closing of the purchase and sale of
the Notes and Warrant Shares pursuant to the Purchase Agreement.

     "Commission" means the Securities and Exchange Commission.

     "Common Stock" means the Company's Common Stock, par value $0.01 per share.

     "Effectiveness Date" means with respect to the Registration Statement the
earlier of the 90th day following the Closing Date and the date which is within
five (5) days of the date on which the Commission informs the Company that the
Commission (i) will not review the Registration Statement or (ii) that the
Company may request the acceleration of the effectiveness of the Registration
Statement and the Company makes such request.

<PAGE>

     "Effectiveness Period" shall have the meaning set forth in Section 2.

     "Event" shall have the meaning set forth in Section 7(e).

     "Event Date" shall have the meaning set forth in Section 7(e).

     "Exchange Act" means the Securities Exchange Act of 1934, as amended.

     "Filing Date" means the 10th day following the Closing Date.

     "Holder" or "Holders" means the holder or holders, as the case may be, from
time to time of Registrable Securities.

     "Indemnified Party" shall have the meaning set forth in Section 5(c).

     "Indemnifying Party" shall have the meaning set forth in Section 5(c).

     "Losses" shall have the meaning set forth in Section 5(a).

     "Person" means an individual or a corporation, partnership, trust,
incorporated or unincorporated association, joint venture, limited liability
company, joint stock company, government (or an agency or political subdivision
thereof) or other entity of any kind.

     "Proceeding" means an action, claim, suit, investigation or proceeding
(including, without limitation, an investigation or partial proceeding, such as
a deposition), whether commenced or threatened.

     "Prospectus" means the prospectus included in the Registration Statement
(including, without limitation, a prospectus that includes any information
previously omitted from a prospectus filed as part of an effective registration
statement in reliance upon Rule 430A promulgated under the Securities Act), as
amended or supplemented by any prospectus supplement, with respect to the terms
of the offering of any portion of the Registrable Securities covered by the
Registration Statement, and all other amendments and supplements to the
Prospectus, including post-effective amendments, and all material incorporated
by reference in such Prospectus.

     "Registrable Securities" means 34,000,000 shares of Common Stock issuable
upon conversion of the Notes and the shares of Common Stock issuable upon
exercise of the Warrants and upon the filing of the Charter Amendment with the
Secretary of State of the State of California, shall also include a number of
shares of Common Stock, when aggregated with the initial 34,000,000 shares of
Common Stock registered, equals at least 200% of the maximum number of shares of
Common Stock which would be issuable upon conversion of the Notes and any
interest accrued and outstanding thereon and upon exercise of the Warrants,
assuming such conversion and exercise occurred on the Closing Date or the Filing
Date, whichever date would result in the greater number of Registrable
Securities. Such registered shares of Common Stock shall be allocated among the
Holders pro rata based on the total number of Registrable Securities

                                      -2-

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issued or issuable as of each date that a Registration Statement, as amended,
relating to the resale of the Registrable Securities is declared effective by
the Commission. Notwithstanding anything herein contained to the contrary, if
the actual number of shares of Common Stock issuable upon conversion of the
Notes and upon exercise of the Warrants exceeds 200% of the number of shares of
Common Stock issuable upon conversion of the Notes and upon exercise of the
Warrants based upon a computation as at the Closing Date or the Filing Date, the
term "Registrable Securities" shall be deemed to include such additional shares
of Common Stock.

     "Registration Statement" means the registration statements and any
additional registration statements contemplated by Section 2, including (in each
case) the Prospectus, amendments and supplements to such registration statement
or Prospectus, including pre- and post-effective amendments, all exhibits
thereto, and all material incorporated by reference in such registration
statement.

     "Rule 144" means Rule 144 promulgated by the Commission pursuant to the
Securities Act, as such Rule may be amended from time to time, or any similar
rule or regulation hereafter adopted by the Commission having substantially the
same effect as such Rule.

     "Rule 158" means Rule 158 promulgated by the Commission pursuant to the
Securities Act, as such Rule may be amended from time to time, or any similar
rule or regulation hereafter adopted by the Commission having substantially the
same effect as such Rule.

     "Rule 415" means Rule 415 promulgated by the Commission pursuant to the
Securities Act, as such Rule may be amended from time to time, or any similar
rule or regulation hereafter adopted by the Commission having substantially the
same effect as such Rule.

     "Securities Act" means the Securities Act of 1933, as amended.

     "Special Counsel" means any special counsel to the Holders, for which the
Holders will be reimbursed by the Company pursuant to Section 4.

2.   Shelf Registration.
     ------------------

     On or prior to the Filing Date the Company shall prepare and file with the
Commission a "shelf" Registration Statement covering 34,000,000 shares of Common
Stock for an offering to be made on a continuous basis pursuant to Rule 415.
Additionally, within five (5) Business Days of the filing of the Charter
Amendment with the Secretary of State of the State of California increasing the
Company's number of authorized shares of Common Stock, the Company shall file an
additional "shelf" Registration Statement covering such number of shares of
Common Stock, when aggregated with the initial 34,000,000 shares of Common Stock
previously registered, equals at least 200% of the maximum number of shares of
Common Stock which would be issuable upon conversion of the Notes and any
interest accrued and outstanding thereon and upon exercise of the Warrants,
assuming such conversion and exercise occurred on the Closing Date or the filing
date of such additional Registration Statement, whichever date would result in
the greater number of shares being registered. The Company shall use its best
efforts to cause such additional Registration Statement to be declared effective
by the Commission as soon as possible, but in no event later than ninety (90)
days after filing. The

                                      -3-

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Registration Statement shall be on Form S-3 (except if the Company is not then
eligible to register for resale the Registrable Securities on Form S-3, in which
case such registration shall be on another appropriate form in accordance
herewith). The Company shall (i) not permit any securities other than the
Registrable Securities to be included in the Registration Statement and (ii) use
its best efforts to cause the Registration Statement to be declared effective
under the Securities Act as promptly as possible after the filing thereof, but
in any event prior to the Effectiveness Date, and to keep such Registration
Statement continuously effective under the Securities Act until such date as is
the earlier of (x) the date when all Registrable Securities covered by such
Registration Statement have been sold or (y) the date on which the Registrable
Securities may be sold without any restriction pursuant to Rule 144 as
determined by the counsel to the Company pursuant to a written opinion letter,
addressed to the Company's transfer agent to such effect (the "Effectiveness
Period"). At any time after the filing of the Registration Statement required to
be filed within five (5) Business Days of the filing of the Charter Amendment,
if an additional Registration Statement is required to be filed because the
actual number of shares of Common Stock into which the Notes are convertible and
the Warrants are exercisable exceeds the number of shares of Common Stock
initially registered on the Registration Statement in respect of the Conversion
Shares and the Warrant Shares based upon the computation on the Closing Date or
filing date of such additional Registration Statement, whichever date would
result in the greater number of shares being registered, the Company shall have
forty-five (45) Business Days to file such additional Registration Statement,
and the Company shall use its best efforts to cause such additional Registration
Statement to be declared effective by the Commission as soon as possible, but in
no event later than ninety (90) days after filing.

3.   Registration Procedures.
     -----------------------

     In connection with the Company's registration obligations hereunder, the
Company shall:

     (a) Prepare and file with the Commission on or prior to the Filing Date, a
Registration Statement on Form S-3 (or if the Company is not then eligible to
register for resale the Registrable Securities on Form S-3 such registration
shall be on another appropriate form in accordance herewith) in accordance with
the method or methods of distribution thereof as specified by the Holders
(except if otherwise directed by the Holders), and cause the Registration
Statement to become effective and remain effective as provided herein; provided,
however, that not less than five (5) Business Days prior to the filing of the
Registration Statement or any related Prospectus or any amendment or supplement
thereto (including any document that would be incorporated therein by
reference), the Company shall (i) furnish to the Holders and any Special
Counsel, copies of all such documents proposed to be filed, which documents
(other than those incorporated by reference) will be subject to the review of
such Holders and such Special Counsel, and (ii) cause its officers and
directors, counsel and independent certified public accountants to respond to
such inquiries as shall be necessary, in the reasonable opinion of counsel to
such Holders, to conduct a reasonable investigation within the meaning of the
Securities Act. The Company shall not file the Registration Statement or any
such Prospectus or any amendments or supplements thereto to which the Holders of
a majority of the Registrable Securities or any Special Counsel shall reasonably
object in writing within three (3) Business Days of their receipt thereof.

                                      -4-

<PAGE>

     (b) (i) Prepare and file with the Commission such amendments, including
post-effective amendments, to the Registration Statement as may be necessary to
keep the Registration Statement continuously effective as to the applicable
Registrable Securities for the Effectiveness Period and prepare and file with
the Commission such additional Registration Statements in order to register for
resale under the Securities Act all of the Registrable Securities; (ii) cause
the related Prospectus to be amended or supplemented by any required Prospectus
supplement, and as so supplemented or amended to be filed pursuant to Rule 424
(or any similar provisions then in force) promulgated under the Securities Act;
(iii) respond as promptly as possible to any comments received from the
Commission with respect to the Registration Statement or any amendment thereto
and as promptly as possible provide the Holders true and complete copies of all
correspondence from and to the Commission relating to the Registration
Statement; and (iv) comply in all material respects with the provisions of the
Securities Act and the Exchange Act with respect to the disposition of all
Registrable Securities covered by the Registration Statement during the
applicable period in accordance with the intended methods of disposition by the
Holders thereof set forth in the Registration Statement as so amended or in such
Prospectus as so supplemented.

     (c) Notify the Holders of Registrable Securities to be sold and any Special
Counsel as promptly as possible (and, in the case of (i)(A) below, not less than
five (5) days prior to such filing) and (if requested by any such Person)
confirm such notice in writing no later than one (1) Business Day following the
day (i)(A) when a Prospectus or any Prospectus supplement or post-effective
amendment to the Registration Statement is proposed to be filed; (B) when the
Commission notifies the Company whether there will be a "review" of such
Registration Statement and whenever the Commission comments in writing on such
Registration Statement and (C) with respect to the Registration Statement or any
post-effective amendment, when the same has become effective; (ii) of any
request by the Commission or any other Federal or state governmental authority
for amendments or supplements to the Registration Statement or Prospectus or for
additional information; (iii) of the issuance by the Commission of any stop
order suspending the effectiveness of the Registration Statement covering any or
all of the Registrable Securities or the initiation of any Proceedings for that
purpose; (iv) if at any time any of the representations and warranties of the
Company contained in any agreement contemplated hereby ceases to be true and
correct in all material respects; (v) of the receipt by the Company of any
notification with respect to the suspension of the qualification or exemption
from qualification of any of the Registrable Securities for sale in any
jurisdiction, or the initiation or threatening of any Proceeding for such
purpose; and (vi) of the occurrence of any event that makes any statement made
in the Registration Statement or Prospectus or any document incorporated or
deemed to be incorporated therein by reference untrue in any material respect or
that requires any revisions to the Registration Statement, Prospectus or other
documents so that, in the case of the Registration Statement or the Prospectus,
as the case may be, it will not contain any untrue statement of a material fact
or omit to state any material fact required to be stated therein or necessary to
make the statements therein, in the light of the circumstances under which they
were made, not misleading.

     (d) Use its best efforts to avoid the issuance of, or, if issued, obtain
the withdrawal of, (i) any order suspending the effectiveness of the
Registration Statement or (ii) any

                                      -5-

<PAGE>

suspension of the qualification (or exemption from qualification) of any of the
Registrable Securities for sale in any jurisdiction, at the earliest practicable
moment.

     (e) If requested by the Holders of a majority in interest of the
Registrable Securities, (i) promptly incorporate in a Prospectus supplement or
post-effective amendment to the Registration Statement such information as the
Company reasonably agrees should be included therein and (ii) make all required
filings of such Prospectus supplement or such post-effective amendment as soon
as practicable after the Company has received notification of the matters to be
incorporated in such Prospectus supplement or post-effective amendment.

     (f) Furnish to each Holder and any Special Counsel, without charge, at
least one conformed copy of each Registration Statement and each amendment
thereto, including financial statements and schedules, all documents
incorporated or deemed to be incorporated therein by reference, and all exhibits
to the extent requested by such Person (including those previously furnished or
incorporated by reference) promptly after the filing of such documents with the
Commission.

     (g) Promptly deliver to each Holder and any Special Counsel, without
charge, as many copies of the Prospectus or Prospectuses (including each form of
prospectus) and each amendment or supplement thereto as such Persons may
reasonably request; and the Company hereby consents to the use of such
Prospectus and each amendment or supplement thereto by each of the selling
Holders in connection with the offering and sale of the Registrable Securities
covered by such Prospectus and any amendment or supplement thereto.

     (h) Prior to any public offering of Registrable Securities, use its best
efforts to register or qualify or cooperate with the selling Holders and any
Special Counsel in connection with the registration or qualification (or
exemption from such registration or qualification) of such Registrable
Securities for offer and sale under the securities or Blue Sky laws of such
jurisdictions within the United States as any Holder requests in writing, to
keep each such registration or qualification (or exemption therefrom) effective
during the Effectiveness Period and to do any and all other acts or things
necessary or advisable to enable the disposition in such jurisdictions of the
Registrable Securities covered by a Registration Statement; provided, however,
that the Company shall not be required to qualify generally to do business in
any jurisdiction where it is not then so qualified or to take any action that
would subject it to general service of process in any such jurisdiction where it
is not then so subject or subject the Company to any material tax in any such
jurisdiction where it is not then so subject.

     (i) Cooperate with the Holders to facilitate the timely preparation and
delivery of certificates representing Registrable Securities to be sold pursuant
to a Registration Statement, which certificates shall be free of all restrictive
legends, and to enable such Registrable Securities to be in such denominations
and registered in such names as any Holder may request at least two (2) Business
Days prior to any sale of Registrable Securities.

     (j) Upon the occurrence of any event contemplated by Section 3(c)(vi), as
promptly as possible, prepare a supplement or amendment, including a
post-effective amendment, to the Registration Statement or a supplement to the
related Prospectus or any document incorporated or deemed to be incorporated
therein by reference, and file any other

                                      -6-

<PAGE>

required document so that, as thereafter delivered, neither the Registration
Statement nor such Prospectus will contain 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, in the light of the circumstances under which
they were made, not misleading.

     (k) Use its best efforts to cause all Registrable Securities relating to
such Registration Statement to be listed on The Nasdaq SmallCap Market, The
Nasdaq National Market, OTC Bulletin Board and any other securities exchange,
quotation system or market, if any, on which similar securities issued by the
Company are then listed as and when required pursuant to the Purchase Agreement.

     (l) Comply in all material respects with all applicable rules and
regulations of the Commission and make generally available to its security
holders earning statements satisfying the provisions of Section 11(a) of the
Securities Act and Rule 158 not later than 45 days after the end of any 12-month
period (or 90 days after the end of any 12-month period if such period is a
fiscal year) commencing on the first day of the first fiscal quarter of the
Company after the effective date of the Registration Statement, which statement
shall conform to the requirements of Rule 158.

     (m) The Company may require each selling Holder to furnish to the Company
information regarding such Holder and the distribution of such Registrable
Securities as is required by law to be disclosed in the Registration Statement,
and the Company may exclude from such registration the Registrable Securities of
any such Holder who unreasonably fails to furnish such information within a
reasonable time after receiving such request.

     If the Registration Statement refers to any Holder by name or otherwise as
the holder of any securities of the Company, then such Holder shall have the
right to require (if such reference to such Holder by name or otherwise is not
required by the Securities Act or any similar federal statute then in force) the
deletion of the reference to such Holder in any amendment or supplement to the
Registration Statement filed or prepared subsequent to the time that such
reference ceases to be required.

     Each Holder covenants and agrees that (i) it will not sell any Registrable
Securities under the Registration Statement until it has received copies of the
Prospectus as then amended or supplemented as contemplated in Section 3(g) and
notice from the Company that such Registration Statement and any post-effective
amendments thereto have become effective as contemplated by Section 3(c) and
(ii) it and its officers, directors or Affiliates, if any, will comply with the
prospectus delivery requirements of the Securities Act as applicable to them in
connection with sales of Registrable Securities pursuant to the Registration
Statement.

     Each Holder agrees by its acquisition of such Registrable Securities that,
upon receipt of a notice from the Company of the occurrence of any event of the
kind described in Section 3(c)(ii), 3(c)(iii), 3(c)(iv), 3(c)(v) or 3(c)(vi),
such Holder will forthwith discontinue disposition of such Registrable
Securities under the Registration Statement until such Holder's receipt of the
copies of the supplemented Prospectus and/or amended Registration Statement
contemplated by Section 3(j), or until it is advised in writing (the "Advice")
by the Company that the use of the applicable Prospectus may be resumed, and, in
either case, has received copies of

                                      -7-

<PAGE>

any additional or supplemental filings that are incorporated or deemed to be
incorporated by reference in such Prospectus or Registration Statement.

     (n) If (i) there is material non-public information regarding the Company
which the Company's Board of Directors (the "Board") reasonably determines not
to be in the Company's best interest to disclose and which the Company is not
otherwise required to disclose, or (ii) there is a significant business
opportunity (including, but not limited to, the acquisition or disposition of
assets (other than in the ordinary course of business) or any merger,
consolidation, tender offer or other similar transaction) available to the
Company which the Board reasonably determines not to be in the Company's best
interest to disclose, then the Company may postpone or suspend filing or
effectiveness of a registration statement for a period not to exceed 20
consecutive days, provided that the Company may not postpone or suspend its
obligation under this Section 3(n) for more than 45 days in the aggregate during
any 12 month period; provided, however, that no such postponement or suspension
shall be permitted for consecutive 20 day periods, arising out of the same set
of facts, circumstances or transactions.

4.   Registration Expenses.
     ---------------------

     All fees and expenses incident to the performance of or compliance with
this Agreement by the Company, except as and to the extent specified in Section
4, shall be borne by the Company whether or not the Registration Statement is
filed or becomes effective and whether or not any Registrable Securities are
sold pursuant to the Registration Statement. The fees and expenses referred to
in the foregoing sentence shall include, without limitation, (i) all
registration and filing fees (including, without limitation, fees and expenses
(A) with respect to filings required to be made with the The Nasdaq SmallCap
Market, The Nasdaq National Market and each other securities exchange or market
on which Registrable Securities are required hereunder to be listed, (B) with
respect to filings required to be made with the National Association of
Securities Dealers, Inc. and the NASD Regulation, Inc. and (C) in compliance
with state securities or Blue Sky laws (including, without limitation, fees and
disbursements of counsel for the Holders in connection with Blue Sky
qualifications of the Registrable Securities and determination of the
eligibility of the Registrable Securities for investment under the laws of such
jurisdictions as the Holders of a majority of Registrable Securities may
designate)), (ii) printing expenses (including, without limitation, expenses of
printing certificates for Registrable Securities and of printing prospectuses if
the printing of prospectuses is requested by the holders of a majority of the
Registrable Securities included in the Registration Statement), (iii) messenger,
telephone and delivery expenses, (iv) fees and disbursements of counsel for the
Company and Special Counsel for the Holders, in the case of the Special Counsel,
to a maximum amount of $5,000, (v) Securities Act liability insurance, if the
Company so desires such insurance, and (vi) fees and expenses of all other
Persons retained by the Company in connection with the consummation of the
transactions contemplated by this Agreement, including, without limitation, he
Company's independent public accountants (including the expenses of any comfort
letters or costs associated with the delivery by independent public accountants
of a comfort letter or comfort letters). In addition, the Company shall be
responsible for all of its internal expenses incurred in connection with the
consummation of the transactions contemplated by this Agreement (including,
without limitation, all salaries and expenses of its officers and employees
performing legal or accounting duties), the expense of any annual audit, the
fees and expenses

                                      -8-

<PAGE>

incurred in connection with the listing of the Registrable Securities on any
securities exchange as required hereunder.

5.   Indemnification.
     ---------------

     (a) Indemnification by the Company. The Company shall, notwithstanding any
termination of this Agreement, indemnify and hold harmless each Holder, the
officers, directors, agents, brokers (including brokers who offer and sell
Registrable Securities as principal as a result of a pledge or any failure to
perform under a margin call of Common Stock), investment advisors and employees
of each of them, each Person who controls any such Holder (within the meaning of
Section 15 of the Securities Act or Section 20 of the Exchange Act) and the
officers, directors, agents and employees of each such controlling Person, to
the fullest extent permitted by applicable law, from and against any and all
losses, claims, damages, liabilities, costs (including, without limitation,
costs of preparation and attorneys' fees) and expenses (collectively, "Losses"),
as incurred, arising out of or relating to any untrue or alleged untrue
statement of a material fact contained in the Registration Statement, any
Prospectus or any form of prospectus or in any amendment or supplement thereto
or in any preliminary prospectus, or arising out of or relating to any omission
or alleged omission of a material fact required to be stated therein or
necessary to make the statements therein (in the case of any Prospectus or form
of prospectus or supplement thereto, in the light of the circumstances under
which they were made) not misleading, except to the extent, but only to the
extent, that such untrue statements or omissions are based solely upon
information regarding such Holder or such other Indemnified Party furnished in
writing to the Company by such Holder expressly for use therein, which
information was reasonably relied on by the Company for use therein or to the
extent that such information relates to such Holder or such Holder's proposed
method of distribution of Registrable Securities and was reviewed and expressly
approved in writing by such Holder expressly for use in the Registration
Statement, such Prospectus or such form of Prospectus or in any amendment or
supplement thereto. The Company shall notify the Holders promptly of the
institution, threat or assertion of any Proceeding of which the Company is aware
in connection with the transactions contemplated by this Agreement.

     (b) Indemnification by Holders. Each Holder shall, severally and not
jointly, indemnify and hold harmless the Company, the directors, officers,
agents and employees, each Person who controls the Company (within the meaning
of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the
directors, officers, agents or employees of such controlling Persons, to the
fullest extent permitted by applicable law, from and against all Losses (as
determined by a court of competent jurisdiction in a final judgment not subject
to appeal or review), as incurred, arising solely out of or based solely upon
any untrue statement of a material fact contained in the Registration Statement,
any Prospectus, or any form of prospectus, or arising solely out of or based
solely upon any omission of a material fact required to be stated therein or
necessary to make the statements therein (in the case of any Prospectus or form
of prospectus or supplement thereto, in the light of the circumstances under
which they were made) not misleading, to the extent, but only to the extent,
that such untrue statement or omission is contained in any information so
furnished in writing by such Holder or other Indemnified Party to the Company
specifically for inclusion in the Registration Statement or such Prospectus and
that such information was reasonably relied upon by the Company for use in the
Registration Statement, such Prospectus or such form of prospectus or to the
extent that such information

                                      -9-

<PAGE>

relates to such Holder or such Holder's proposed method of distribution of
Registrable Securities and was reviewed and expressly approved in writing by
such Holder expressly for use in the Registration Statement, such Prospectus or
such form of Prospectus.

     (c) Conduct of Indemnification Proceedings. If any Proceeding shall be
brought or asserted against any Person entitled to indemnity hereunder (an
"Indemnified Party"), such Indemnified Party promptly shall notify the Person
from whom indemnity is sought (the "Indemnifying Party) in writing, and the
Indemnifying Party shall assume the defense thereof, including the employment of
counsel reasonably satisfactory to the Indemnified Party and the payment of all
fees and expenses incurred in connection with defense thereof; provided, that
the failure of any Indemnified Party to give such notice shall not relieve the
Indemnifying Party of its obligations or liabilities pursuant to this Agreement,
except (and only) to the extent that it shall be finally determined by a court
of competent jurisdiction (which determination is not subject to appeal or
further review) that such failure shall have proximately and materially
adversely prejudiced the Indemnifying Party.

     An Indemnified Party shall have the right to employ separate counsel in any
such Proceeding and to participate in the defense thereof, but the fees and
expenses of such counsel shall be at the expense of such Indemnified Party or
Parties unless: (1) the Indemnifying Party has agreed in writing to pay such
fees and expenses; or (2) the Indemnifying Party shall have failed promptly to
assume the defense of such Proceeding and to employ counsel reasonably
satisfactory to such Indemnified Party in any such Proceeding; or (3) the named
parties to any such Proceeding (including any impleaded parties) include both
such Indemnified Party and the Indemnifying Party, and such Indemnified Party
shall have been advised by counsel (which shall be reasonably acceptable to the
Indemnifying Party) that a conflict of interest is likely to exist if the same
counsel were to represent such Indemnified Party and the Indemnifying Party (in
which case, if such Indemnified Party notifies the Indemnifying Party in writing
that it elects to employ separate counsel at the expense of the Indemnifying
Party, the Indemnifying Party shall not have the right to assume the defense
thereof and such counsel shall be at the expense of the Indemnifying Party). The
Indemnifying Party shall not be liable for any settlement of any such Proceeding
effected without its written consent, which consent shall not be unreasonably
withheld or delayed. No Indemnifying Party shall, without the prior written
consent of the Indemnified Party, effect any settlement of any pending
Proceeding in respect of which any Indemnified Party is a party, unless such
settlement includes an unconditional release of such Indemnified Party from all
liability on claims that are the subject matter of such Proceeding.

     All fees and expenses of the Indemnified Party (including reasonable fees
and expenses to the extent incurred in connection with investigating or
preparing to defend such Proceeding in a manner not inconsistent with this
Section) shall be paid to the Indemnified Party, as incurred, within ten (10)
Business Days of written notice thereof to the Indemnifying Party (regardless of
whether it is ultimately determined that an Indemnified Party is not entitled to
indemnification hereunder; provided, that the Indemnifying Party may require
such Indemnified Party to undertake to reimburse all such fees and expenses to
the extent it is finally judicially determined that such Indemnified Party is
not entitled to indemnification hereunder).

     (d) Contribution. If a claim for indemnification under Section 5(a) or 5(b)
is unavailable to an Indemnified Party because of a failure or refusal of a
governmental authority to

                                      -10-

<PAGE>

enforce such indemnification in accordance with its terms (by reason of public
policy or otherwise), then each Indemnifying Party, in lieu of indemnifying such
Indemnified Party, shall contribute to the amount paid or payable by such
Indemnified Party as a result of such Losses, in such proportion as is
appropriate to reflect the relative fault of the Indemnifying Party and
Indemnified Party in connection with the actions, statements or omissions that
resulted in such Losses as well as any other relevant equitable considerations.
The relative fault of such Indemnifying Party and Indemnified Party shall be
determined by reference to, among other things, whether any action in question,
including any untrue or alleged untrue statement of a material fact or omission
or alleged omission of a material fact, has been taken or made by, or relates to
information supplied by, such Indemnifying, Party or Indemnified Party, and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such action, statement or omission. The amount paid or
payable by a party as a result of any Losses shall be deemed to include, subject
to the limitations set forth in Section 5(c), any reasonable attorneys' or other
reasonable fees or expenses incurred by such party in connection with any
Proceeding to the extent such party would have been indemnified for such fees or
expenses if the indemnification provided for in this Section was available to
such party in accordance with its terms.

     The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 5(d) were determined by pro rata
allocation or by any other method of allocation that does not take into account
the equitable considerations referred to in the immediately preceding paragraph.
No Person guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the Securities Act) shall be entitled to contribution from any Person
who was not guilty of such fraudulent misrepresentation.

     The indemnity and contribution agreements contained in this Section are in
addition to any liability that the Indemnifying Parties may have to the
Indemnified Parties

6.   Rule 144.
     --------

     As long as any Holder owns Shares, Conversion Shares, Warrants or Warrant
Shares, the Company covenants to timely file (or obtain extensions in respect
thereof and file within the applicable grace period) all reports required to be
filed by the Company after the date hereof pursuant to Section 13(a) or 15(d) of
the Exchange Act and to promptly furnish the Holders with true and complete
copies of all such filings. As long as any Holder owns Shares, Conversion
Shares, Warrants or Warrant Shares, if the Company is not required to file
reports pursuant to Section 13(a) or 15(d) of the Exchange Act, it will prepare
and furnish to the Holders and make publicly available in accordance with Rule
144(c) promulgated under the Securities Act annual and quarterly financial
statements, together with a discussion and analysis of such financial statements
in form and substance substantially similar to those that would otherwise be
required to be included in reports required by Section 13(a) or 15(d) of the
Exchange Act, as well as any other information required thereby, in the time
period that such filings would have been required to have been made under the
Exchange Act. The Company further covenants that it will take such further
action as any Holder may reasonably request, all to the extent required from
time to time to enable such Person to sell Conversion Shares and Warrant Shares
without registration under the Securities Act within the limitation of the
exemptions provided by Rule 144 promulgated under the Securities Act, including
providing any legal opinions relating to such

                                      -11-

<PAGE>

sale pursuant to Rule 144. Upon the request of any Holder, the Company shall
deliver to such Holder a written certification of a duly authorized officer as
to whether it has complied with such requirements.

7.   Miscellaneous.
     -------------

     (a) Remedies. In the event of a breach by the Company or by a Holder, of
any of their obligations under this Agreement, each Holder or the Company, as
the case may be, in addition to being entitled to exercise all rights granted by
law and under this Agreement, including recovery of damages, will be entitled to
specific performance of its rights under this Agreement. The Company and each
Holder agree that monetary damages would not provide adequate compensation for
any losses incurred by reason of a breach by it of any of the provisions of this
Agreement and hereby further agrees that, in the event of any action for
specific performance in respect of such breach, it shall waive the defense that
a remedy at law would be adequate.

     (b) No Inconsistent Agreements. Neither the Company nor any of its
subsidiaries has, as of the date hereof entered into and currently in effect,
nor shall the Company or any of its subsidiaries, on or after the date of this
Agreement, enter into any agreement with respect to its securities that is
inconsistent with the rights granted to the Holders in this Agreement or
otherwise conflicts with the provisions hereof. Except as disclosed in Schedule
2.1(c) of the Purchase Agreement, neither the Company nor any of its
subsidiaries has previously entered into any agreement currently in effect
granting any registration rights with respect to any of its securities to any
Person. Without limiting the generality of the foregoing, without the written
consent of the Holders of a majority of the then outstanding Registrable
Securities, the Company shall not grant to any Person the right to request the
Company to register any securities of the Company under the Securities Act
unless the rights so granted are subject in all respects to the prior rights in
full of the Holders set forth herein, and are not otherwise in conflict with the
provisions of this Agreement.

     (c) No Piggyback on Registrations. Neither the Company nor any of its
security holders (other than the Holders in such capacity pursuant hereto or as
disclosed in Schedule 2.1(c) of the Purchase Agreement) may include securities
of the Company in the Registration Statement, and the Company shall not after
the date hereof enter into any agreement providing such right to any of its
securityholders, unless the right so granted is subject in all respects to the
prior rights in full of the Holders set forth herein, and is not otherwise in
conflict with the provisions of this Agreement.

     (d) Piggy-Back Registrations. If at any time when there is not an effective
Registration Statement covering (i) Conversion Shares or (ii) Warrant Shares,
the Company shall determine to prepare and file with the Commission a
registration statement relating to an offering for its own account or the
account of others under the Securities Act of any of its equity securities,
other than on Form S-4 or Form S-8 (each as promulgated under the Securities
Act) or their then equivalents relating to equity securities to be issued solely
in connection with any acquisition of any entity or business or equity
securities issuable in connection with stock option or other employee benefit
plans, the Company shall send to each holder of Registrable Securities written
notice of such determination and, if within thirty (30) days after receipt of
such notice,

                                      -12-

<PAGE>

any such holder shall so request in writing, (which request shall specify the
Registrable Securities intended to be disposed of by the Purchaser), the Company
will cause the registration under the Securities Act of all Registrable
Securities which the Company has been so requested to register by the holder, to
the extent requisite to permit the disposition of the Registrable Securities so
to be registered, provided that if at any time after giving written notice of
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 not to register or to delay registration of such
securities, the Company may, at its election, give written notice of such
determination to such holder and, thereupon, (i) in the case of a determination
not to register, shall be relieved of its obligation to register any Registrable
Securities in connection with such registration (but not from its obligation to
pay expenses in accordance with Section 4 hereof), and (ii) in the case of a
determination to delay registering, shall be permitted to delay registering any
Registrable Securities being registered pursuant to this Section 7(d) for the
same period as the delay in registering such other securities. The Company shall
include in such registration statement all or any part of such Registrable
Securities such holder requests to be registered; provided, however, that the
Company shall not be required to register any Registrable Securities pursuant to
this Section 7(d) that are eligible for sale pursuant to Rule 144(k) of the
Securities Act. In the case of an underwritten public offering, if the managing
underwriter(s) or underwriter(s) should reasonably object to the inclusion of
the Registrable Securities in such registration statement, then if the Company
after consultation with the managing underwriter should reasonably determine
that the inclusion of such Registrable Securities, would materially adversely
affect the offering contemplated in such registration statement, and based on
such determination recommends inclusion in such registration statement of fewer
or none of the Registrable Securities of the Holders, then (x) the number of
Registrable Securities of the Holders included in such registration statement
shall be reduced pro-rata among such Holders (based upon the number of
Registrable Securities requested to be included in the registration), if the
Company after consultation with the underwriter(s) recommends the inclusion of
fewer Registrable Securities, or (y) none of the Registrable Securities of the
Holders shall be included in such registration statement, if the Company after
consultation with the underwriter(s) recommends the inclusion of none of such
Registrable Securities; provided, however, that if Securities are being offered
for the account of other persons or entities as well as the Company, such
reduction shall not represent a greater fraction of the number of Registrable
Securities intended to be offered by the Holders than the fraction of similar
reductions imposed on such other persons or entities (other than the Company).

     (e) Failure to File Registration Statement and Other Events. The Company
and the Purchaser agree that the Holders will suffer damages if the Registration
Statement is not filed on or prior to the Filing Date and not declared effective
by the Commission on or prior to the Effectiveness Date and maintained in the
manner contemplated herein during the Effectiveness Time or if certain other
events occur. The Company and the Holders further agree that it would not be
feasible to ascertain the extent of such damages with precision. Accordingly, if
(A) the Registration Statement is not filed on or prior to the Filing Date, or
is not declared effective by the Commission on or prior to the Effectiveness
Date, or the additional Registration Statement to be filed after the filing of
the Charter Amendment is not filed or declared effective within the time periods
set forth in Section 2 (or in the event an additional Registration Statement is
filed because the actual number of shares of Common Stock into which the Notes
are convertible and the Warrants are exercisable exceeds the number of shares of
Common Stock

                                      -13-

<PAGE>

initially registered is not filed and declared effective with the time periods
set forth in Section 2), or (B) the Company fails to file with the Commission a
request for acceleration in accordance with Rule 12dl-2 promulgated under the
Exchange Act within five (5) Business Days of the date that the Company is
notified (orally or in writing, whichever is earlier) by the Commission that a
Registration Statement will not be "reviewed," or not subject to further review,
or (C) the Registration Statement is filed with and declared effective by the
Commission but thereafter ceases to be effective as to all Registrable
Securities at any time prior to the expiration of the Effectiveness Period,
without being succeeded immediately by a subsequent Registration Statement filed
with and declared effective by the Commission, or (D) trading in the Common
Stock shall be suspended or if the Common Stock is delisted from The Nasdaq
SmallCap Market, The Nasdaq National Market or the OTC Bulletin Board for any
reason for more than three Business Days in the aggregate, or (E) the conversion
rights of the Holders are suspended for any reason, or (F) the Company breaches
in a material respect any covenant or other material term or condition to this
Agreement, the Purchase Agreement (other than a representation or warranty
contained therein) or any other agreement, document, certificate or other
instrument delivered in connection with the transactions contemplated hereby and
thereby, and such breach continues for a period of thirty days after written
notice thereof to the Company, or (G) the Company has breached Section 3(n) (any
such failure or breach being referred to as an "Event," and for purposes of
clauses (A) and (E) the date on which such Event occurs, or for purposes of
clause (B) the date on which such five day period is exceeded, or for purposes
of clause (C) after more than fifteen Business Days, or for purposes of clause
(D) the date on which such three Business Day period is exceeded, or for clause
(F) the date on which such thirty day period is exceeded, being referred to as
"Event Date"), the Company shall pay, at the option of the Holder, an amount in
cash or shares of Common Stock, as liquidated damages to each Holder equal to 1%
for the first calendar month and 2% per calendar month thereafter or portion
thereof of the principal amount of the Notes held by such Holder plus the
principal amount of any Notes that have been converted to the extent any of the
Conversion Shares issued upon such conversion have not been sold from the Event
Date until the applicable Event is cured. Payments to be made pursuant to this
Section 7(e) shall be due and payable immediately upon demand in immediately
available funds. If the Holder elects to be paid in shares of Common Stock, the
number of such shares of Common Stock shall be based on the liquidated damage
amount divided by the Conversion Rate (as defined in the Note).

     (f) Amendments and Waivers. The provisions of this Agreement, including the
provisions of this sentence, may not be amended, modified or supplemented, and
waivers or consents to departures from the provisions hereof may not be given,
unless the same shall be in writing and signed by the Company and each of the
Holders. Notwithstanding the foregoing, a waiver or consent to depart from the
provisions hereof with respect to a matter that relates exclusively to the
rights of Holders and that does not directly or indirectly affect the rights of
other Holders may be given by Holders of at least a majority of the Registrable
Securities to which such waiver or consent relates; provided, however, that the
provisions of this sentence may not be amended, modified, or supplemented except
in accordance with the provisions of the immediately preceding sentence.

     (g) Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be in writing and shall be
deemed given and effective on the earlier of (i) the date of transmission, if
such notice or communication is

                                      -14-

<PAGE>

delivered via facsimile at the facsimile telephone number specified for notice
prior to 5:00 p.m., New York City time, on a Business Day, (ii) the Business Day
after the date of transmission, if such notice or communication is delivered via
facsimile at the facsimile telephone number specified for notice later than 5:00
p.m., New York City time, on any date and earlier than 11:59 p.m., New York City
time, on such date, (iii) the Business Day following the date of mailing, if
sent by nationally recognized overnight courier service or (iv) actual receipt
by the party to whom such notice is required to be given. The addresses for such
communications shall be with respect to each Holder at its address set forth
under its name on Schedule 1 attached hereto, or with respect to the Company,
addressed to:

                                    Vertel Corporation
                                    21300 Victory Boulevard
                                    Suite 700
                                    Woodland Hills, California 91367
                                    Attention: Chief Financial Officer
                                    Telecopier:  (818) 598-0104
                                    Telephone:  (818) 227-1400

or to such other address or addresses or facsimile number or numbers as any such
party may most recently have designated in writing to the other parties hereto
by such notice. Copies of notices to the Company shall be sent to Perkins Coie
LLP, 1620 26th Street, Sixth Floor, Santa Monica, California 90404, Attention:
David J. Katz, Esq., Facsimile No.: (310) 843-1254.

     (h) Successors and Assigns. This Agreement shall be binding upon and inure
to the benefit of the parties and their successors and permitted assigns and
shall inure to the benefit of each Holder and its successors and assigns. The
Company may not assign this Agreement or any of its rights or obligations
hereunder without the prior written consent of each Holder. Each Purchaser may
assign its rights hereunder in the manner and to the Persons as permitted under
the Purchase Agreement.

     (i) Assignment of Registration Rights. The rights of each Holder hereunder,
including the right to have the Company register for resale Registrable
Securities in accordance with the terms of this Agreement, shall be
automatically assignable by each Holder to any Affiliate of such Holder or any
other Holder or Affiliate of any other Holder of all or a portion of the Notes
or the Registrable Securities if: (i) the Holder agrees in writing with the
transferee or assignee to assign such rights, and a copy of such agreement is
furnished to the Company within a reasonable time after such assignment, (ii)
the Company is, within a reasonable time after such transfer or assignment,
furnished with written notice of (a) the name and address of such transferee or
assignee, and (b) the securities with respect to which such registration rights
are being transferred or assigned, (iii) following such transfer or assignment
the further disposition of such securities by the transferee or assignees is
restricted under the Securities Act and applicable state securities laws, (iv)
at or before the time the Company receives the written notice contemplated by
clause (ii) of this Section, the transferee or assignee agrees in writing with
the Company to be bound by all of the provisions of this Agreement, (v) such
transfer shall have been made in accordance with the applicable requirements of
the Purchase Agreement, and (vi) at least 100,000 shares of Registrable
Securities (appropriately adjusted for any stock dividend, split or combination
of the Common Stock) are being transferred to such transferee or assignee

                                      -15-

<PAGE>

in connection with such assignment of rights. In addition, each Holder shall
have the right to assign its rights hereunder to any other Person with the prior
written consent of the Company, which consent shall not be unreasonably
withheld. The rights to assignment shall apply to the Holders (and to
subsequent) successors and assigns.

     (j) Counterparts. This Agreement may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original
and, all of which taken together shall constitute one and the same Agreement. In
the event that any signature is delivered by facsimile transmission, such
signature shall create a valid binding obligation of the party executing (or on
whose behalf such signature is executed) the same with the same force and effect
as if such facsimile signature were the original thereof.

     (k) Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of New York, without regard to principles
of conflicts of law thereof.

     (l) Cumulative Remedies. The remedies provided herein are cumulative and
not exclusive of any remedies provided by law.

     (m) Severability. If any term, provision, covenant or restriction of this
Agreement is held to be invalid, illegal, void or unenforceable in any respect,
the remainder of the terms, provisions, covenants and restrictions set forth
herein shall remain in full force and effect and shall in no way be affected,
impaired or invalidated, and the parties hereto shall use their reasonable
efforts to find and employ an alternative means to achieve the same or
substantially the same result as that contemplated by such term, provision,
covenant or restriction. It is hereby stipulated and declared to be the
intention of the parties that they would have executed the remaining terms,
provisions, covenants and restrictions without including any of such that may be
hereafter declared invalid, illegal, void or unenforceable.

     (n) Headings. The headings herein are for convenience only, do not
constitute a part of this Agreement and shall not be deemed to limit or affect
any of the provisions hereof.

     (o) Shares Held by the Company and its Affiliates. Whenever the consent or
approval of Holders of a specified percentage of Registrable Securities is
required hereunder, Registrable Securities held by the Company or its Affiliates
(other than any Holder or transferees or successors or assigns thereof if such
Holder is deemed to be an Affiliate solely by reason of its holdings of such
Registrable Securities) shall not be counted in determining whether such consent
or approval was given by the Holders of such required percentage.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                                      -16-

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Registration Rights
Agreement to be duly executed by their respective authorized persons as of the
date first indicated above.

                                    VERTEL CORPORATION

                                    By:_____________________________________
                                        Name:
                                        Title:

                                    SDS MERCHANT FUND, L.P.

                                    By:_____________________________________
                                        Name:  Steve Derby
                                        Title: Managing Member

                                      -17-

<PAGE>

                                   Schedule I
                                   ----------

SDS Merchant Fund, L.P.
c/o SDS Capital Partners, LLC
53 Forest Avenue, Second Floor
Old Greenwich, CT 06870
Telephone No.: (203) 967-5850
Facsimile No.: (203) 967-5851
Attention: Steve Derby

                                      -18-

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