<PAGE>

                                                                   EXHIBIT 10.50
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CROSS-CORPORATE CONTINUING GUARANTY

BORROWERS:         VERSO TECHNOLOGIES, INC.
                   NACT TELECOMMUNICATIONS, INC.
                   TELEMATE.NET SOFTWARE, INC.

GUARANTORS:        VERSO TECHNOLOGIES, INC.
                   NACT TELECOMMUNICATIONS, INC.
                   TELEMATE.NET SOFTWARE, INC.
DATE:              DECEMBER 14, 2001

THIS CROSS-CORPORATE CONTINUING GUARANTY is executed by the above-named
guarantors (jointly and severally, the "Guarantor"), as of the above date, in
favor of SILICON VALLEY BANK ("Silicon"), whose address is 3003 Tasman Drive,
Santa Clara, California 95054, with respect to the Indebtedness of each and all
of the above-named borrowers (jointly and severally, the "Borrower").

   1. CONTINUING GUARANTY. Guarantor hereby unconditionally guarantees and
promises to pay on demand to Silicon in lawful money of the United States, and
to perform for the benefit of Silicon, all of the Borrower's present and future
Indebtedness (as defined below) to Silicon.

   2. "INDEBTEDNESS." As used in this Guaranty, the term "Indebtedness" is used
in its most comprehensive sense and shall mean and include, without limitation:
(a) any and all debts, duties, obligations, liabilities, representations,
warranties and guaranties of Borrower or any one or more of them, heretofore,
now, or hereafter made, incurred, or created, whether directly to Silicon or
acquired by Silicon by assignment or otherwise, or held by Silicon on behalf of
others, however arising, whether voluntary or involuntary, due or not due,
absolute or contingent, liquidated or unliquidated, certain or uncertain,
determined or undetermined, monetary or nonmonetary, written or oral, and
whether Borrower may be liable individually or jointly with others, and
regardless of whether recovery thereon may be or hereafter become barred by any
statute of limitations, discharged or uncollectible in any bankruptcy,
insolvency or other proceeding, or otherwise unenforceable; and (b) any and all
amendments, modifications, renewals and extensions of any or all of the
foregoing, including, without limitation, amendments, modifications, renewals
and extensions which are evidenced by any new or additional instrument, document
or agreement; and (c) any and all attorneys' fees, court costs, and collection
charges incurred in endeavoring to collect or enforce any of the foregoing
against Borrower, Guarantor, or any other person liable thereon (whether or not
suit be brought) and any other expenses of, for or incidental to collection
thereof.

   3. WAIVERS. Guarantor hereby waives: (a) presentment for payment, notice of
dishonor, demand, protest, and notice thereof as to any instrument, and all
other notices and demands to which Guarantor might be entitled, including,
without limitation, notice of all of the following: the acceptance hereof; the
creation, existence, or acquisition of any Indebtedness; the amount of the
Indebtedness from time to time outstanding; any foreclosure sale or other
disposition of any property which secures any or all of the Indebtedness or
which secures the obligations of any other guarantor of any or all of the
Indebtedness; any adverse change in Borrower's financial position; any other
fact which might increase Guarantor's risk; any default, partial payment or
non-payment of all or any part of the Indebtedness; the occurrence of any other
Event of Default (as hereinafter defined); any and all agreements and
arrangements between Silicon and Borrower and any changes, modifications, or
extensions thereof, and any revocation, modification or release of any guaranty
of any or all of the Indebtedness by any person (including without limitation
any other person signing this Guaranty); (b) any right to require Silicon to
institute suit against, or to exhaust its rights and remedies against, Borrower
or any other person, or to proceed against any property of any kind which
secures all or any part of the Indebtedness, or to exercise any right of offset
or other right with respect to any reserves, credits or deposit accounts held by
or maintained with Silicon or any indebtedness of Silicon to Borrower, or to
exercise any other right or power, or pursue any other remedy Silicon may have;
(c) any defense arising by reason of any disability or other defense of Borrower
or any other guarantor or any endorser, co-maker or other person, or by reason
of the cessation from any cause whatsoever of any liability of Borrower or any
other guarantor or any endorser, co-maker or other person, with respect to all
or any part of the Indebtedness, or by reason of any act or omission of Silicon
or others which directly or indirectly results in the discharge or release of
Borrower or any other guarantor or any other person or any Indebtedness or any
security therefor, whether by operation of law or otherwise; (d) any defense
arising by reason of any failure of Silicon to obtain, perfect, maintain or keep
in force any security interest in, or lien or encumbrance upon, any property of
Borrower or any other person; (e) any defense based upon any failure of Silicon
to give Guarantor notice of any sale or other disposition of any property
securing any or all of the Indebtedness, or any defects in any such notice that
may be given, or any failure of Silicon to comply with any provision of
applicable law in enforcing any security interest in or lien upon any property
securing any or all of the Indebtedness including, but not limited to, any
failure by Silicon to dispose of any property securing any or all of the
Indebtedness in a commercially reasonable manner; (f) any defense based upon or
arising out of any bankruptcy, insolvency, reorganization, arrangement,
readjustment of debt, liquidation or dissolution proceeding commenced by


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or against Borrower or any other guarantor or any endorser, co-maker or other
person, including, without limitation, any discharge of, or bar against
collecting, any of the Indebtedness (including, without limitation, any interest
thereon), in or as a result of any such proceeding; and (g) the benefit of any
and all statutes of limitation with respect to any action based upon, arising
out of or related to this Guaranty. Until all of the Indebtedness has been paid,
performed, and discharged in full, nothing shall discharge or satisfy the
liability of Guarantor hereunder except the full performance and payment of all
of the Indebtedness. If any claim is ever made upon Silicon for repayment or
recovery of any amount or amounts received by Silicon in payment of or on
account of any of the Indebtedness, because of any claim that any such payment
constituted a preferential transfer or fraudulent conveyance, or for any other
reason whatsoever, and Silicon repays all or part of said amount by reason of
any judgment, decree or order of any court or administrative body having
jurisdiction over Silicon or any of its property, or by reason of any settlement
or compromise of any such claim effected by Silicon with any such claimant
(including, without limitation, the Borrower), then and in any such event,
Guarantor agrees that any such judgment, decree, order, settlement and
compromise shall be binding upon Guarantor, notwithstanding any revocation or
release of this Guaranty or the cancellation of any note or other instrument
evidencing any of the Indebtedness, or any release of any of the Indebtedness,
and the Guarantor shall be and remain liable to Silicon under this Guaranty for
the amount so repaid or recovered, to the same extent as if such amount had
never originally been received by Silicon, and the provisions of this sentence
shall survive, and continue in effect, notwithstanding any revocation or release
of this Guaranty. Until all of the Indebtedness has been irrevocably paid and
performed in full, Guarantor hereby expressly and unconditionally waives all
rights of subrogation, reimbursement and indemnity of every kind against
Borrower, and all rights of recourse to any assets or property of Borrower, and
all rights to any collateral or security held for the payment and performance of
any Indebtedness, including (but not limited to) any of the foregoing rights
which Guarantor may have under any present or future document or agreement with
any Borrower or other person, and including (but not limited to) any of the
foregoing rights which Guarantor may have under any equitable doctrine of
subrogation, implied contract, or unjust enrichment, or any other equitable or
legal doctrine. Neither Silicon, nor any of its directors, officers, employees,
agents, attorneys or any other person affiliated with or representing Silicon
shall be liable for any claims, demands, losses or damages, of any kind
whatsoever, made, claimed, incurred or suffered by Guarantor or any other party
through the ordinary negligence of Silicon, or any of its directors, officers,
employees, agents, attorneys or any other person affiliated with or representing
Silicon.

   4. CONSENTS. Guarantor hereby consents and agrees that, without notice to or
by Guarantor and without affecting or impairing in any way the obligations or
liability of Guarantor hereunder, Silicon may, from time to time before or after
revocation of this Guaranty, do any one or more of the following in Silicon's
sole and absolute discretion: (a) accelerate, accept partial payments of,
compromise or settle, renew, extend the time for the payment, discharge, or
performance of, refuse to enforce, and release all or any parties to, any or all
of the Indebtedness; (b) grant any other indulgence to Borrower or any other
person in respect of any or all of the Indebtedness or any other matter; (c)
accept, release, waive, surrender, enforce, exchange, modify, impair, or extend
the time for the performance, discharge, or payment of, any and all property of
any kind securing any or all of the Indebtedness or any guaranty of any or all
of the Indebtedness, or on which Silicon at any time may have a lien, or refuse
to enforce its rights or make any compromise or settlement or agreement therefor
in respect of any or all of such property; (d) substitute or add, or take any
action or omit to take any action which results in the release of, any one or
more endorsers or guarantors of all or any part of the Indebtedness, including,
without limitation, one or more parties to this Guaranty, regardless of any
destruction or impairment of any right of contribution or other right of
Guarantor; (e) amend, alter or change in any respect whatsoever any term or
provision relating to any or all of the Indebtedness, including the rate of
interest thereon; (f) apply any sums received from Borrower, any other
guarantor, endorser, or co-signer, or from the disposition of any collateral or
security, to any indebtedness whatsoever owing from such person or secured by
such collateral or security, in such manner and order as Silicon determines in
its sole discretion, and regardless of whether such indebtedness is part of the
Indebtedness, is secured, or is due and payable; (g) apply any sums received
from Guarantor or from the disposition of any collateral or security securing
the obligations of Guarantor, to any of the Indebtedness in such manner and
order as Silicon determines in its sole discretion, regardless of whether or not
such Indebtedness is secured or is due and payable. Guarantor consents and
agrees that Silicon shall be under no obligation to marshal any assets in favor
of Guarantor, or against or in payment of any or all of the Indebtedness.
Guarantor further consents and agrees that Silicon shall have no duties or
responsibilities whatsoever with respect to any property securing any or all of
the Indebtedness. Without limiting the generality of the foregoing, Silicon
shall have no obligation to monitor, verify, audit, examine, or obtain or
maintain any insurance with respect to, any property securing any or all of the
Indebtedness.

   5. NO COMMITMENT. Guarantor acknowledges and agrees that acceptance by
Silicon of this Guaranty shall not constitute a commitment of any kind by
Silicon to extend such credit or other financial accommodation to Borrower or to
permit Borrower to incur Indebtedness to Silicon.

   6. EXERCISE OF RIGHTS AND REMEDIES; FORECLOSURE OF TRUST DEEDS. Guarantor
hereby waives all rights of subrogation, reimbursement, indemnification, and
contribution and any other rights and defenses that are or may become available
to the Guarantor or other surety by reason of California Civil Code Sections
2787 to 2855, inclusive. The Guarantor waives all rights and defenses that the
Guarantor may have because the Borrower's Indebtedness is secured by real
property. This means, among other things: (1) Silicon may collect from the
Guarantor without first foreclosing on any real or personal property collateral
pledged by the Borrower, and (2) If Silicon forecloses on any real property
collateral pledged by the Borrower: (A) The amount of the Indebtedness may be
reduced only by the price for which that collateral is sold at the foreclosure
sale, even if the collateral is worth more than the sale price, and (B) Silicon
may collect from the Guarantor even if Silicon, by foreclosing on the real
property collateral, has destroyed any right the Guarantor may have to collect
from the Borrower. This is an unconditional and irrevocable waiver of any rights
and


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defenses the Guarantor may have because the Borrower's Indebtedness is secured
by real property. These rights and defenses include, but are not limited to, any
rights or defenses based upon Section 580a, 580b, 580d, or 726 of the Code of
Civil Procedure. The Guarantor waives all rights and defenses arising out of an
election of remedies by Silicon, even though that election of remedies, such as
a nonjudicial foreclosure with respect to security for a guaranteed obligation,
has destroyed the Guarantor's rights of subrogation and reimbursement against
the principal by the operation of Section 580d of the Code of Civil Procedure or
otherwise.

   7. ACCELERATION. Notwithstanding the terms of all or any part of the
Indebtedness, the obligations of the Guarantor hereunder to pay and perform all
of the Indebtedness shall, at the option of Silicon, immediately become due and
payable, without notice, and without regard to the expressed maturity of any of
the Indebtedness, in the event: (a) Guarantor shall fail to pay or perform when
due any of its obligations under this Guaranty; or (b) any default or event of
default occurs under any present or future loan agreement or other instrument,
document, or agreement between Silicon and Borrower or between Silicon and
Guarantor. The foregoing are referred to in this Guaranty as "Events of
Default".

   8. INDEMNITY. Guarantor hereby agrees to indemnify Silicon and hold Silicon
harmless from and against any and all claims, debts, liabilities, demands,
obligations, actions, causes of action, penalties, costs and expenses (including
without limitation attorneys' fees), of every nature, character and description,
which Silicon may sustain or incur based upon or arising out of any of the
Indebtedness, any actual or alleged failure to collect and pay over any
withholding or other tax relating to Borrower or its employees, any relationship
or agreement between Silicon and Borrower, any actual or alleged failure of
Silicon to comply with any writ of attachment or other legal process relating to
Borrower or any of its property, or any other matter, cause or thing whatsoever
occurred, done, omitted or suffered to be done by Silicon relating in any way to
Borrower or the Indebtedness (except any such amounts sustained or incurred as
the result of the gross negligence or willful misconduct of Silicon or any of
its directors, officers, employees, agents, attorneys, or any other person
affiliated with or representing Silicon). Notwithstanding any provision in this
Guaranty to the contrary, the indemnity agreement set forth in this Section
shall survive any termination or revocation of this Guaranty and shall for all
purposes continue in full force and effect.

   9. SUBORDINATION. Any and all rights of Guarantor under any and all debts,
liabilities and obligations owing from Borrower to Guarantor, including any
security for and guaranties of any such obligations, whether now existing or
hereafter arising, are hereby subordinated in right of payment to the prior
payment in full of all of the Indebtedness. No payment in respect of any such
subordinated obligations shall at any time be made to or accepted by Guarantor
if at the time of such payment any Indebtedness is outstanding. If any Event of
Default has occurred, Borrower and any assignee, trustee in bankruptcy,
receiver, or any other person having custody or control over any or all of
Borrower's property are hereby authorized and directed to pay to Silicon the
entire unpaid balance of the Indebtedness before making any payments whatsoever
to Guarantor, whether as a creditor, shareholder, or otherwise; and insofar as
may be necessary for that purpose, Guarantor hereby assigns and transfers to
Silicon all rights to any and all debts, liabilities and obligations owing from
Borrower to Guarantor, including any security for and guaranties of any such
obligations, whether now existing or hereafter arising, including, without
limitation, any payments, dividends or distributions out of the business or
assets of Borrower. Any amounts received by Guarantor in violation of the
foregoing provisions shall be received and held as trustee for the benefit of
Silicon and shall forthwith be paid over to Silicon to be applied to the
Indebtedness in such order and sequence as Silicon shall in its sole discretion
determine, without limiting or affecting any other right or remedy which Silicon
may have hereunder or otherwise and without otherwise affecting the liability of
Guarantor hereunder. Guarantor hereby expressly waives any right to set-off or
assert any counterclaim against Borrower.

   10. REVOCATION. This is a Continuing Guaranty relating to all of the
Indebtedness, including Indebtedness arising under successive transactions which
from time to time continue the Indebtedness or renew it after it has been
satisfied. The obligations of Guarantor hereunder may be terminated only as to
future transactions and only by giving 90 days' advance written notice thereof
to Silicon at its address above by registered first-class U.S. mail, postage
prepaid, return receipt requested. No such revocation shall be effective until
90 days following the date of actual receipt thereof by Silicon. Notwithstanding
such revocation, this Guaranty and all consents, waivers and other provisions
hereof shall continue in full force and effect as to any and all Indebtedness
which is outstanding on the effective date of revocation and all extensions,
renewals and modifications of said Indebtedness (including, without limitation,
amendments, extensions, renewals and modifications which are evidenced by new or
additional instruments, documents or agreements executed after revocation), and
all interest thereon, then and thereafter accruing, and all attorneys' fees,
court costs and collection charges theretofore and thereafter incurred in
endeavoring to collect or enforce any of the foregoing against Borrower,
Guarantor or any other person liable thereon (whether or not suit be brought)
and any other expenses of, for or incidental to collection thereof.

   11. INDEPENDENT LIABILITY. Guarantor hereby agrees that one or more
successive or concurrent actions may be brought hereon against Guarantor, in the
same action in which Borrower may be sued or in separate actions, as often as
deemed advisable by Silicon. The liability of Guarantor hereunder is exclusive
and independent of any other guaranty of any or all of the Indebtedness whether
executed by Guarantor or by any other guarantor (including, without limitation,
any other persons signing this Guaranty). The liability of Guarantor hereunder
shall not be affected, revoked, impaired, or reduced by any one or more of the
following: (a) the fact that the Indebtedness exceeds the maximum amount of
Guarantor's liability, if any, specified herein or elsewhere (and no agreement
specifying a maximum amount of Guarantor's liability shall be enforceable unless
set forth in a writing signed by Silicon or set forth in this Guaranty); or (b)
any direction as to the application of payment by Borrower or by any other
party; or (c) any other continuing or restrictive guaranty or undertaking or any
limitation on the liability of any other guarantor (whether under this Guaranty
or under any other agreement); or (d) any payment on or reduction of any such
other guaranty or undertaking; or (e) any revocation, amendment, modification or
release of any such other


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guaranty or undertaking; or (f) any dissolution or termination of, or increase,
decrease, or change in membership of any Guarantor which is a partnership.
Guarantor hereby expressly represents that it was not induced to give this
Guaranty by the fact that there are or may be other guarantors either under this
Guaranty or otherwise, and Guarantor agrees that any release of any one or more
of such other guarantors shall not release Guarantor from its obligations
hereunder either in full or to any lesser extent.

   12. FINANCIAL CONDITION OF BORROWER. Guarantor is fully aware of the
financial condition of Borrower and is executing and delivering this Guaranty at
Borrower's request and based solely upon its own independent investigation of
all matters pertinent hereto, and Guarantor is not relying in any manner upon
any representation or statement of Silicon with respect thereto. Guarantor
represents and warrants that it is in a position to obtain, and Guarantor hereby
assumes full responsibility for obtaining, any additional information concerning
Borrower's financial condition and any other matter pertinent hereto as
Guarantor may desire, and Guarantor is not relying upon or expecting Silicon to
furnish to him any information now or hereafter in Silicon's possession
concerning the same or any other matter.

   13. REPRESENTATIONS AND WARRANTIES. Guarantor hereby represents and warrants
that (i) it is in Guarantor's direct interest to assist Borrower in procuring
credit, because Borrower is an affiliate of Guarantor, furnishes goods or
services to Guarantor, purchases or acquires goods or services from Guarantor,
and/or otherwise has a direct or indirect corporate or business relationship
with Guarantor, (ii) this Guaranty has been duly and validly authorized,
executed and delivered and constitutes the valid and binding obligation of
Guarantor, enforceable in accordance with its terms, and (iii) the execution and
delivery of this Guaranty does not violate or constitute a default under (with
or without the giving of notice, the passage of time, or both) any order,
judgment, decree, instrument or agreement to which Guarantor is a party or by
which it or its assets are affected or bound.

   14. COSTS; INTEREST. Whether or not suit be instituted, Guarantor agrees to
reimburse Silicon on demand for all reasonable attorneys' fees and all other
reasonable costs and expenses incurred by Silicon in enforcing this Guaranty, or
arising out of or relating in any way to this Guaranty, or in enforcing any of
the Indebtedness against Borrower, Guarantor, or any other person, or in
connection with any property of any kind securing all or any part of the
Indebtedness. Without limiting the generality of the foregoing, and in addition
thereto, Guarantor shall reimburse Silicon on demand for all reasonable
attorneys' fees and costs Silicon incurs in any way relating to Guarantor,
Borrower or the Indebtedness, in order to: obtain legal advice; enforce or seek
to enforce any of its rights; commence, intervene in, respond to, or defend any
action or proceeding; file, prosecute or defend any claim or cause of action in
any action or proceeding (including, without limitation, any probate claim,
bankruptcy claim, third-party claim, secured creditor claim, reclamation
complaint, and complaint for relief from any stay under the Bankruptcy Code or
otherwise); protect, obtain possession of, sell, lease, dispose of or otherwise
enforce any security interest in or lien on any property of any kind securing
any or all of the Indebtedness; or represent Silicon in any litigation with
respect to Borrower's or Guarantor's affairs. In the event either Silicon or
Guarantor files any lawsuit against the other predicated on a breach of this
Guaranty, the prevailing party in such action shall be entitled to recover its
attorneys' fees and costs of suit from the non-prevailing party. All sums due
under this Guaranty shall bear interest from the date due until the date paid at
the highest rate charged with respect to any of the Indebtedness.

   15. NOTICES. Any notice which a party shall be required or shall desire to
give to the other hereunder (except for notice of revocation, which shall be
governed by Section 10 of this Guaranty) shall be given by personal delivery or
by telecopier or by depositing the same in the United States mail, first class
postage pre-paid, addressed to Silicon at its address set forth in the heading
of this Guaranty and to Guarantor at its address provided by Guarantor to
Silicon in writing, and such notices shall be deemed duly given on the date of
personal delivery or one day after the date telecopied or 3 business days after
the date of mailing as aforesaid. Silicon and Guarantor may change their address
for purposes of receiving notices hereunder by giving written notice thereof to
the other party in accordance herewith. Guarantor shall give Silicon immediate
written notice of any change in its address.

   16. CLAIMS. Guarantor agrees that any claim or cause of action by Guarantor
against Silicon, or any of Silicon's directors, officers, employees, agents,
accountants or attorneys, based upon, arising from, or relating to this
Guaranty, or any other present or future agreement between Silicon and Guarantor
or between Silicon and Borrower, or any other transaction contemplated hereby or
thereby or relating hereto or thereto, or any other matter, cause or thing
whatsoever, whether or not relating hereto or thereto, occurred, done, omitted
or suffered to be done by Silicon, or by Silicon's directors, officers,
employees, agents, accountants or attorneys, whether sounding in contract or in
tort or otherwise, shall be barred unless asserted by Guarantor by the
commencement of an action or proceeding in a court of competent jurisdiction
within Santa Clara County, California, by the filing of a complaint within one
year after the first act, occurrence or omission upon which such claim or cause
of action, or any part thereof, is based and service of a summons and complaint
on an officer of Silicon or any other person authorized to accept service of
process on behalf of Silicon, within 30 days thereafter. Guarantor agrees that
such one year period is a reasonable and sufficient time for Guarantor to
investigate and act upon any such claim or cause of action. The one year period
provided herein shall not be waived, tolled, or extended except by a specific
written agreement of Silicon. This provision shall survive any termination of
this Guaranty or any other agreement.

   17. CONSTRUCTION; SEVERABILITY. The term "Guarantor" as used herein shall be
deemed to refer to all and any one or more such persons and their obligations
hereunder shall be joint and several. As used in this Guaranty, the term
"property" is used in its most comprehensive sense and shall mean all property
of every kind and nature whatsoever, including, without limitation, real
property, personal property, mixed property, tangible property and intangible
property. If any provision of this Guaranty or the application thereof to any
party or circumstance is held invalid, void, inoperative or unenforceable, the
remainder of this Guaranty and the application of such provision to other
parties or circumstances shall not be affected thereby, the provisions of this
Guaranty being severable in any such instance.


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   18. GENERAL PROVISIONS. Silicon shall have the right to seek recourse against
Guarantor to the full extent provided for herein and in any other instrument or
agreement evidencing obligations of Guarantor to Silicon, and against Borrower
to the full extent of the Indebtedness. No election in one form of action or
proceeding, or against any party, or on any obligation, shall constitute a
waiver of Silicon's right to proceed in any other form of action or proceeding
or against any other party. The failure of Silicon to enforce any of the
provisions of this Guaranty at any time or for any period of time shall not be
construed to be a waiver of any such provision or the right thereafter to
enforce the same. All remedies hereunder shall be cumulative and shall be in
addition to all rights, powers and remedies given to Silicon by law or under any
other instrument or agreement. Time is of the essence in the performance by
Guarantor of each and every obligation under this Guaranty. Silicon shall have
no obligation to inquire into the power or authority of Borrower or any of its
officers, directors, employees, or agents acting or purporting to act on its
behalf, and any Indebtedness made or created in reliance upon the professed
exercise of any such power or authority shall be included in the Indebtedness
guaranteed hereby. This Guaranty is the entire and only agreement between
Guarantor and Silicon with respect to the guaranty of the Indebtedness of
Borrower by Guarantor, and all representations, warranties, agreements, or
undertakings heretofore or contemporaneously made, which are not set forth
herein, are superseded hereby. No course of dealings between the parties, no
usage of the trade, and no parol or extrinsic evidence of any nature shall be
used or be relevant to supplement or explain or modify any term or provision of
this Guaranty. There are no conditions to the full effectiveness of this
Guaranty. The terms and provisions hereof may not be waived, altered, modified,
or amended except in a writing executed by Guarantor and a duly authorized
officer of Silicon. All rights, benefits and privileges hereunder shall inure to
the benefit of and be enforceable by Silicon and its successors and assigns and
shall be binding upon Guarantor and its successors and assigns. Section headings
are used herein for convenience only. Guarantor acknowledges that the same may
not describe completely the subject matter of the applicable Section, and the
same shall not be used in any manner to construe, limit, define or interpret any
term or provision hereof.

   19. GOVERNING LAW; VENUE AND JURISDICTION. This instrument and all acts and
transactions pursuant or relating hereto and all rights and obligations of the
parties hereto shall be governed, construed, and interpreted in accordance with
the internal laws of the State of California. In order to induce Silicon to
accept this Guaranty, and as a material part of the consideration therefor,
Guarantor (i) agrees that all actions or proceedings relating directly or
indirectly hereto shall, at the option of Silicon, be litigated in courts
located within Santa Clara County, California, (ii) consents to the jurisdiction
of any such court and consents to the service of process in any such action or
proceeding by personal delivery or any other method permitted by law; and (iii)
waives any and all rights Guarantor may have to transfer or change the venue of
any such action or proceeding.

   20. RECEIPT OF COPY. Guarantor acknowledges receipt of a copy of this
Guaranty.

   21. MUTUAL WAIVER OF RIGHT TO JURY TRIAL. SILICON AND GUARANTOR HEREBY WAIVE
THE RIGHT TO TRIAL BY JURY IN ANY ACTION, CLAIM, LAWSUIT OR PROCEEDING BASED
UPON, ARISING OUT OF, OR IN ANY WAY RELATING TO: (i) THIS GUARANTEE OR ANY
SUPPLEMENT OR AMENDMENT THERETO; OR (II) ANY OTHER PRESENT OR FUTURE INSTRUMENT
OR AGREEMENT BETWEEN SILICON AND GUARANTOR ; OR (III) ANY BREACH, CONDUCT, ACTS
OR OMISSIONS OF SILICON OR GUARANTOR OR ANY OF THEIR RESPECTIVE DIRECTORS,
OFFICERS, EMPLOYEES, AGENTS, ATTORNEYS OR ANY OTHER PERSON AFFILIATED WITH OR
REPRESENTING SILICON OR GUARANTOR; IN EACH OF THE FOREGOING CASES, WHETHER
SOUNDING IN CONTRACT OR TORT OR OTHERWISE.

Guarantor Signature:

   Verso Technologies, Inc.



   By /s/ Juliet M. Reising
     -----------------------------------
   Title Chief Financial Officer
        ------------------------------


Guarantor Signature:

   NACT Telecommunications, Inc.



   By /s/ Juliet M. Reising
     -----------------------------------
   Title Vice President
        ------------------------------


Guarantor Signature:

   Telemate.net Software, Inc.



   By /s/ Juliet M. Reising
     -----------------------------------
   Title Vice President
        ------------------------------




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