GUARANTY AGREEMENT
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     THIS GUARANTY AGREEMENT ("Guaranty Agreement")  is made  and  entered  into
this 4th day of May, 2000 by Network  Consulting Group, Inc.  ("Guarantor"),  in
favor of VDC Communications, Inc. ("Lender").

                                   WITNESSETH:
                                   -----------

     WHEREAS,   concurrently  herewith,  Rare  Telephony,   Inc.  (f/k/a  Washoe
Technology  Corporation) and Cash Back Rebates LD.com,  Inc. Nevada and Delaware
corporations respectively ("Borrower"),  have executed a certain Promissory Note
in favor of Lender  in the  stated  principal  amount  of One  Hundred  Thousand
Dollars ($100,000) (the "Note"); and

     WHEREAS,  to  induce  Lender  to lend  the  One  Hundred  Thousand  Dollars
($100,000) to Borrower, Guarantor has agreed to guarantee the Note;

     NOW,  THEREFORE,  in  consideration  of the premises and for other good and
valuable  consideration,  the  receipt  and  sufficiency  of  which  are  hereby
acknowledged, the parties hereby covenant and agree as follows:

     1.  Guarantor irrevocably and  unconditionally,  fully guarantees to Lender
the full and  prompt  payment  of the  indebtedness  evidenced  by the Note (the
"Indebtedness") at the times and according to the terms expressed.

     Guarantor  agrees that if all or any part of the  Indebtedness  is not paid
according to the tenor thereof,  Guarantor shall, upon demand of Lender, pay the
Indebtedness  in like manner as if the  Indebtedness  constituted the direct and
primary  obligation of Guarantor as provided for herein.  Guarantor's  liability
hereunder shall be IN THE FULL AMOUNT of the Indebtedness.

     2.  This Guaranty Agreement is  irrevocable  and shall remain in full force
and effect  continuously from the date hereof to and until the date on which the
Indebtedness  is  paid  in  full,   whereupon  this  Guaranty   Agreement  shall
automatically terminate ("Termination Date").

     3.  Guarantor grants to Lender, in Lender's  sole and  absolute  discretion
and without  notice to Guarantor,  the power and authority to deal in any lawful
manner  with the  Indebtedness  and,  without  limiting  the  generality  of the
foregoing, the power and authority from time to time:

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         (a) To change, amend or modify the Note or any other documents relating
thereto in a non-material way (collectively, the "Loan Documents");

         (b) To discharge or release any person liable under the Loan Documents;

         (c) To take and  hold  security  for the  payment  of the  Indebtedness
and/or  the  performance  of the other  obligations  guaranteed  herein,  and to
exchange, enforce, subordinate, waive or release any such security;

         (d) To foreclose any security for the  Indebtedness,  and to direct the
order or manner of sale of any such  security  as  Lender in  Lender's  sole and
absolute discretion may determine;

         (e) To grant any  extensions  of time,  renewals or other  indulgences,
forbearance,  waivers or releases to Borrower or any other  person  liable under
the Loan Documents.

         (f) To accept  or  make  compositions  or other  alignments  or file or
refrain  from filing a claim in any  bankruptcy  proceedings  of Borrower or any
other person liable under the Loan Documents;

         (g) To credit  payments on the  Indebtedness in such manner and in such
order of  priority  as  Lender  may  determine  in  lender's  sole and  absolute
discretion; and

         (h) To otherwise  deal with  Borrower or any other  guarantor or person
related to the  Indebtedness or any security as Lender may determine in Lender's
sole and absolute discretion.

     Without limiting the generality of the foregoing,  Guarantor WAIVES any and
all rights,  benefits and defenses  under law which may provide that a surety is
exonerated if a creditor, without the consent of the surety, alters the original
obligation  of the  principal  in any  respect,  or if the  creditor  in any way
imperils or suspends the creditor's rights against the principal.

     The liability of Guarantor shall not be terminated,  affected,  impaired or
reduced in any way by any action taken by Lender under the foregoing  provisions
or any other provision  hereof or by any delay,  failure or refusal of Lender to
exercise  any right or remedy  Lender  may have  against  Borrower  or any other
person,  including other  guarantors,  if any, liable for all or any part of the
Indebtedness hereby guaranteed.

     4.  If at any time all or any  part of any  payment  made by  Guarantor  or
received  by  Lender  from  Guarantor  under or with  respect  to this  Guaranty
Agreement  is avoided or  recovered  directly  or  indirectly  from  Lender as a

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preference,  fraudulent  transfer,  or otherwise,  then Guarantor's  obligations
hereunder shall, to the extent of the payment avoided or recovered, be deemed to
have  continued in  existence,  notwithstanding  such  previous  payment made by
Guarantor or receipt of payment by Lender, and Guarantor's obligations hereunder
shall continue to be effective or be reinstated,  as the case may be, as to such
payment,  all as though such previous  payment by Guarantor had never been made,
irrespective of the payment in full of the Indebtedness.

     5.  To the fullest  extent permitted by law,  Guarantor  hereby  WAIVES the
following rights, defenses and benefits:

         a. The defense of the statute of limitations in any action hereunder or
in any action for the collection of the  Indebtedness  or the performance of any
other obligation hereby guaranteed;

         b. Any  defense  that may arise by reason  of the  incapacity,  lack of
authority,  death or disability of any other person or persons or the failure of
Lender  to file or  enforce  a claim  against  the  estate  (in  administration,
bankruptcy or any other proceeding) of any other person or persons

         c. Except as  otherwise  provided  herein,  diligence  and all demands,
presentment for payment,  notice of nonpayment,  protest,  notice of protest and
all other notices of any kind, including, without limiting the generality of the
foregoing,  notice  of the  existence,  creation  or  incurring  of  any  new or
additional  obligation  or of any action or  nonaction  on the part of Borrower,
Lender,  any  endorser or creditor of Borrower or of Guarantor or on the part of
any other person  whomsoever  under this or any other  instrument  in connection
with  any  Indebtedness  or  evidence  of  Indebtedness  held  by  Lender  or in
connection with the Indebtedness hereby guaranteed;

         d. Any duty or obligation on Lender's part to perfect,  protect, retain
or enforce any security for the payment of the  Indebtedness  or the performance
of any of the other obligations guaranteed herein;

         e. Any duty on the part of Lender to  disclose to  Guarantor  any facts
Lender may now or hereafter  know about  Borrower,  regardless of whether Lender
has reason to believe  that any such facts  materially  increase the risk beyond
that which Guarantor  intends to assume or has reason to believe that such facts
are unknown to Guarantor or has a reasonable  opportunity  to  communicate  such
facts to  Guarantor,  it being  understood  and agreed that  Guarantor  is fully
responsible  for  being and  keeping  informed  of the  financial  condition  of
Borrower and of any and all circumstances bearing on the risk that liability may
be incurred by Guarantor hereunder; and

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         f. Any and all rights,  benefits  and defenses  under law  available to
guarantors or sureties, including without limitations, any such rights, benefits
or defenses which would otherwise  require Lender to proceed against Borrower or
any other person,  or to proceed  against or exhaust any security held by Lender
at any time,  or to first apply any security of Borrower to the discharge of the
Indebtedness,  or to pursue any other remedy in Lender's power before proceeding
against Guarantor hereunder.

     6.  Guarantor agrees  that  Guarantor  shall have no right of  subrogation,
reimbursement, exoneration, contribution, indemnity, or similar right as against
Borrower  which would  result in  Guarantor  being deemed a creditor of Borrower
under the Federal Bankruptcy Code or any other law or for any other purpose; and
Guarantor  further  WAIVES any and all rights,  benefits and defenses under law,
which may provide that a surety is entitled to the benefit of every security for
the performance of the principal obligation held by the creditor.

     7.  With or without notice to  Guarantor  and without  affecting in any way
Guarantor's  obligation or liability  hereunder for payment of the Indebtedness,
Lender, in Lender's sole and absolute  discretion,  at any time and from time to
time, and in such manner and upon such terms as Lender deems fit, may:

     a.  Apply any or all payments or recoveries from Borrower or from all other
guarantors  or  endorsers  under  any  other  instrument  or  realized  from any
security,  in such  manner  and order of  priority  as lender may  determine  in
Lender's  sole and  absolute  discretion,  to any  Indebtedness  of  Borrower to
Lender,  whether or not such  Indebtedness is guaranteed  hereby or is otherwise
secured or is due at the time of such application; or

     b.  Refund to Borrower any payment received by Lender upon the Indebtedness
hereby guaranteed.

     8.  All rights, powers and remedies of Lender hereunder shall be cumulative
and not alternative and such rights, powers and remedies shall be in addition to
all  rights,  powers  and  remedies  given to lender  under  the Loan  Documents
(including any other guarantees of the Indebtedness) or otherwise by law.

     9.  The liability of Guarantor  under this Guaranty  Agreement  shall be an
absolute,  direct,  immediate and unconditional  guarantee of payment and not of
collection.  The  Indebtedness  of  Guarantor  hereunder is  independent  of the
Indebtedness  of  Borrower  and  is  not  conditioned  on  contingent  upon  the
genuineness,   validity,  regularity  or  enforceability  of  any  of  the  Loan
Documents.  In the event of any default hereunder,  a separate action or actions
may be brought and  prosecuted  against  Guarantor,  whether or not  Borrower is
joined  therein or a separate  action or actions are brought  against  Borrower.

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Lender may enforce  Lender's rights under the Guaranty  Agreement  without first
exercising  any other  remedy or right that Lender may have or seeking to obtain
payment or  performance  from  Borrower,  any other person  (including any other
guarantor)  or from any  collateral  which  Lender may hold as security  for the
Indebtedness.  Lender  may  maintain  successive  actions  for  other  defaults.
Lender's  rights  hereunder  shall not be  exhausted  by the  exercise of any of
Lender's rights or remedies or by any such action or by any number of successive
actions.  Guarantor  WAIVES any and all rights,  benefits and defenses under law
which may  generally  provide  that a  guarantor  or surety is not liable if for
certain  reasons there is no liability  upon the part of the principal or if the
principal  ceases to  become  liable or which  may  generally  provide  that the
Indebtedness  of a guarantor  or surety  must not be larger nor more  burdensome
than that of the principal.

     10. Notwithstanding  the fact that Borrower may be a corporation,  a  joint
venture or a  partnership,  Lender is not to be concerned to see or inquire into
the powers of Borrower,  its  directors,  officers,  joint  ventures,  partners,
associates  or other  agents  acting or  purporting  to act on its  behalf,  and
Guarantor  expressly  waives any  defense to the  enforcement  of this  Guaranty
Agreement to the effect that the transaction  between  Borrower and Lender is in
excess  of the  powers  of the  Borrower,  or  shall  be in any  way  irregular,
defective or informal.  Guarantor's liability hereunder shall not be affected by
changes in the name of the entity or the constituent members of the entity which
constitutes Borrower.

     11. It is expressly  understood that the obligations of Guarantor hereunder
are an additional and cumulative benefit given to Lender for Lender's security.

     12. No action based on this Guaranty  Agreement  shall be instituted  until
written demand for payment or performance,  as  appropriate,  has been made upon
Guarantor (a) upon delivery of such demand in person to Guarantor, or (b) on the
next business day following  deposit of an envelope  containing such demand with
an overnight  courier  service (such as United  Parcel  Service) for delivery to
Guarantor at the address set forth next to Guarantor's  signature hereon, or (c)
on the second  business day  following  deposit of an envelope  containing  such
demand  in  the  United   States  mail,   postage   prepaid,   certified   mail,
return-receipt  requested,  addressed to Guarantor as described above. Guarantor
may change  Guarantor's  address for such notices by giving notice of the change
of address to Lender in the manner provided herein. All payments hereunder shall
be made in lawful  money of the  United  States of  America.  No delay in making
demand on Guarantor for satisfaction of Guarantor's  liabilities hereunder shall
prejudice Lender's right to enforce such satisfaction.

     13. Guarantor  shall pay  to Lender,  upon written  demand,  all reasonable
attorneys'  fees (including an allocable  portion of in-house  counsel fees) and
all costs and other  expenses  which Lender  expends or incurs in enforcing this

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Guaranty  Agreement against  Guarantor whether or not suit is filed,  including,
without  limitation,  all  reasonable  attorneys'  fees  (including an allocable
portion of in-house  counsel  fees),  costs and  expenses  incurred by Lender in
connection with any insolvency, bankruptcy, reorganization, arrangement or other
similar proceedings  involving Borrower or Guarantor which in any way affect the
exercise  by Lender of Lender's  rights and  remedies  hereunder.  Until paid to
Lender, such attorneys' fees (including an allocable portion of in-house counsel
fees),  costs and expenses  shall bear  interest at the highest rate of interest
allowable by law.

     14. Should  any  one or  more  provisions  of this  Guaranty  Agreement  be
determined to be illegal or  unenforceable,  all other  provisions  nevertheless
shall be effective.

     15. No provision of this  Guaranty  Agreement or right of Lender  hereunder
can  be  waived  nor  shall  Guarantor  be  released  from  any  of  Guarantor's
obligations  hereunder  except by a writing duly  executed by Lender,  or unless
this Guaranty  Agreement  terminates  pursuant to its terms as set forth herein.
This Guaranty Agreement may not be modified, amended, revised, changed or varied
in any way whatsoever  except by the express terms of a writing duly executed by
Lender and Guarantor.

     16. When the context and  construction  so requires,  all words used in the
singular  herein  shall be  deemed  to have  been  used in the  plural,  and the
masculine  shall  include  the  feminine  and neuter,  and vice versa.  The word
"person"  as  used  herein  shall  include  any   individual,   company,   firm,
association,  partnership,  corporation, trust or other legal entity of any kind
whatsoever.  The word  "Borrower"  as used herein  includes  Borrower  acting on
behalf of itself or any estate created by the  commencement  of a case under the
Federal Bankruptcy Code or any other insolvency,  bankruptcy,  reorganization or
liquidation  proceeding,  or by any trustee under the Federal  Bankruptcy  Code,
liquidator,  sequestrator,  and receiver of Borrower and Borrower's  property or
similar  person duly  appointed  pursuant to any laws  generally  governing  any
insolvency,  bankruptcy,  reorganization,   liquidation,  receivership  or  like
proceeding.  If more than one person  has  signed  this  Guaranty  Agreement  as
Guarantor,  it shall be the joint and several  obligation  of each of them.  The
words "Loan  Documents" as used herein  include any  modifications,  extensions,
renewals,  or  replacements  thereof.  All  references to statutes  herein shall
include any modifications, amendments, substitutions or replacements thereof.

     17. In the event that all or any part of the  Indebtedness  is  assigned by
Lender,  this Guaranty  Agreement shall  automatically be assigned  therewith in
whole or in part, as applicable, without the need of any express assignment and,
when so assigned,  Guarantor shall be bound as above to the assignee(s)  without
in any manner  affecting  Guarantor's  liability  hereunder  for any part of the
Indebtedness retained by Lender.

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     18. Guarantor  agrees,  within  seven (7) calendar  days after request from
Lender, to deliver to Lender a statement certifying that this Guaranty Agreement
is in full force and effect, and that no defense of offset exists to Guarantor's
obligations under the Guaranty Agreement (or stating any facts to the contrary).

     19. This  Guaranty  Agreement  shall  inure to the benefit of and  bind the
heirs, legal representatives, administrators, executors, successors, and assigns
of Lender and of Guarantor.

     20. Guarantor hereby agrees that:

         a. The execution  and delivery to Lender of this Guaranty  Agreement of
the  accrual  of a claim  hereunder  in favor of Lender  shall be deemed to have
caused an event to occur in the State of New Jersey,  bringing  Guarantor within
the jurisdiction of the state and federal courts in the State of New Jersey, and
Guarantor further hereby agrees to and, as a separate and independent  covenant,
does hereby submit to the  jurisdiction  of the state and federal  courts in the
State of New Jersey; and

         b. This  Guaranty  Agreement is made in the State of New Jersey and the
provisions hereof shall be construed and enforced in accordance with the laws of
the State of New Jersey  (irrespective  of its  conflicts of laws rules) and, to
the extent that federal law may preempt the applicability of state laws, federal
law.

     21. Except as provided in any other written agreement at any time hereafter
in force between Lender and Guarantor,  this Guaranty Agreement shall constitute
the entire agreement of Guarantor with Lender with respect to the subject matter
hereof and no representation, understanding, promise or condition concerning the
subject matter hereof shall be binding upon Lender unless expressed herein.

     THE UNDERSIGNED GUARANTOR ACKNOWLEDGES THAT IT WAS AFFORDED THE OPPORTUNITY
TO READ THIS DOCUMENT  CAREFULLY AND TO REVIEW IT WITH AN ATTORNEY OF ITS CHOICE
BEFORE  SIGNING  IT. THE  UNDERSIGNED  GUARANTOR  ACKNOWLEDGES  HAVING  READ AND
UNDERSTOOD THE MEANING AND EFFECT OF THIS DOCUMENT, INCLUDING BUT NOT LIMITED TO
ALL WAIVERS CONTAINED HEREIN, BEFORE SIGNING IT.

     IN WITNESS WHEREOF, the parties have executed this Guaranty Agreement as of
the day and year first above written.

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ATTEST:                                     "GUARANTOR"

                                            NETWORK CONSULTING GROUP, INC.
/s/ Debra A. Santa Lucia
------------------------
Signature                                   By:      /s/ Peter J. Salzano
                                               ---------------------------------
                                                     Peter J. Salzano
                                                     President

Debra A. Santa Lucia                        Address:
--------------------
Print Name                                  74 Jesse Court
                                            Montville, NJ  07045


ATTEST:                                     "LENDER"

                                            VDC COMMUNICATIONS, INC.

/s/ Louis D. Frost                          By:      /s/ Frederick A. Moran
------------------------                       ---------------------------------
Signature                                            Frederick A. Moran
                                                     Chief Executive Officer

Louis D. Frost                              Address:
------------------------                    75 Holly Hill Lane
Print Name                                  Greenwich, CT  06830



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