PROMISSORY NOTE
                                 ---------------

$200,000                                                     April 20, 2000
                                                             Passaic, New Jersey

FOR  VALUE  RECEIVED,  the  undersigned  RARE  TELEPHONY,   INC.  (f/k/a  WASHOE
TECHNOLOGY CORPORATION) AND CASH BACK REBATES LD.COM, INC. a Nevada and Delaware
corporation,  respectively  ("Maker"),  promise  to  pay  to  the  order  of VDC
Communications,  Inc.,  a  Delaware  corporation  ("Holder"),  which  term shall
include any subsequent holder of this Note, at 75 Holly Hill Lane, Greenwich, CT
06830 (or at such other place as Holder  shall  designate  in writing) in lawful
money of the  United  States of  America,  the  aggregate  principal  sum of Two
Hundred  Thousand  Dollars  ($200,000),  with interest  thereon at the rate (the
"Interest Rate") described below.

         1.   Interest Rate.  The Interest Rate shall be  zero  percent (0%) per
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              annum.

         2.   Outstanding  Principal Balance. All references to the "Outstanding
              -------------------------------
              Principal  Balance" shall mean the amount of Two Hundred  Thousand
              Dollars ($200,000), less any principal repaid.

         3.   Payments.  This note shall be payable in full on October  20, 2000
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              (the  "Maturity  Date")  when  the  entire  Outstanding  Principal
              Balance,  and any  accrued but unpaid  interest,  shall be due and
              payable.

         4.   Application  of  Payments.  All  payments  on this  Note  shall be
              --------------------------
              applied first to the payment of accrued and unpaid  interest,  and
              then to the reduction of the Outstanding Principal Balance.

         5.   Prepayment  Right.  Maker  shall  have the  right to prepay at any
              ------------------
              time, in whole or in part, the  Outstanding  Principal  Balance of
              this Note, without premium or penalty.

         6.   Accelerated Maturity. Notwithstanding anything in this Note to the
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              contrary  and  irrespective  of  the  Maturity  Date,  the  entire
              Outstanding  Principal  Balance and accrued  interest shall become
              immediately  due and  payable  upon the  earliest  to occur of the
              following (the "Accelerated  Maturity Date"):  (a) the sale of all
              or  substantially  all of the  assets of the  Maker or the  common
              stock of the Maker to a third  party;  or (b) the  issuance of the
              securities of Maker on the public market.

         7.   Modifications. From time to time, without affecting the obligation
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              of Maker to pay the  Outstanding  Principal  Balance or to observe
              the covenants of Maker contained herein, and without giving notice
              to or obtaining the consent of Maker, Holder may, at the option of
              Holder,  extend the time for payment of the Outstanding  Principal

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              Balance  or any  part  thereof,  reduce  the  payments  hereunder,
              release any person liable hereunder, accept a renewal or extension
              of this Note,  join in any extension or  subordination  agreement,
              release any security given herefor,  take or release security,  or
              agree in writing  with Maker to modify  the  Interest  Rate or any
              other provision of this Note.

         8.   Events  of  Default.  Time  is of the  essence  hereof.  Upon  the
              --------------------
              occurrence  of  any  of  the  following  events  (the  "Events  of
              Default"), payment of the entire Outstanding Principal Balance and
              accrued  interest of this Note shall, at the option of the Holder,
              be accelerated  and shall be immediately  due and payable  without
              notice or demand:

              (a)  Failure of Maker to pay the Outstanding Principal Balance and
                   accrued  interest  in  full  on  the  Maturity  Date  or  the
                   Accelerated Maturity Date; or
              (b)  All or the  majority  of the value of the  assets of Maker is
                   seized or  levied  upon by writ of  attachment,  garnishment,
                   execution  or  otherwise,  and  such  seizure  or levy is not
                   released within thirty (30) calendar days thereafter; or
              (c)  Maker  executes a general  assignment  for the benefit of its
                   creditors,  convenes  any meeting of its  creditors,  becomes
                   insolvent,  admits in writings its insolvency or inability to
                   pay its debts, or is unable to pay or is generally not paying
                   its debts as they become due; or
              (d)  A receiver,  trustee, custodian or agent is appointed to take
                   possession  of all  or any  substantial  portion  of  Maker's
                   assets; or
              (e)  Any case or  proceeding  is  voluntarily  commenced  by Maker
                   under any  provision  of the federal  Bankruptcy  Code or any
                   other federal or state law relating to debtor rehabilitation,
                   insolvency, bankruptcy, liquidation or reorganization, or any
                   such case or proceeding is  involuntarily  commenced  against
                   Maker and not  dismissed  within  thirty (30)  calendar  days
                   thereafter; or
              (f)  Any  representation  made by Maker in this  Note or in any of
                   the other documents delivered in connection therewith,  shall
                   have been untrue or incorrect  in any  material  respect when
                   made.

         9.   Default Rate. In the event that Maker fails to pay the Outstanding
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              Principal Balance and all accrued interest in full on the Maturity
              Date  or the  Accelerated  Maturity  Date,  the  amount  past  due
              (including any acceleration of the Outstanding Principal Balance),
              and unpaid  shall  bear  interest  at an annual  rate equal to the
              lesser of (i) fifteen  percent  (15%),  or (ii) the maximum amount
              permitted by law (the "Default  Rate"),  computed from the date on
              which said amount was due and payable until paid.  The charging or
              collecting  of interest at the Default Rate shall not limit any of
              Holder's other rights or remedies under this Note.

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         10.  Governing Law. Maker, and each endorser and cosigner of this Note,
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              acknowledges  and agrees that this Note is made and is intended to
              be  paid  and  performed  in the  State  of  New  Jersey  and  the
              provisions hereof will be construed in accordance with the laws of
              the State of New Jersey and,  to the extent  that  federal law may
              preempt the  applicability of state laws,  federal law. Maker, and
              each  endorser and  cosigner of this Note further  agree that upon
              the  occurrence of an Event of Default,  this Note may be enforced
              in any court of competent jurisdiction in the State of New Jersey,
              and they do  hereby  submit  to the  jurisdiction  of such  courts
              regardless of their residence.

         11.  Remedies  Cumulative:  Waiver.  The remedies of Holder as provided
              ------------------------------
              herein shall be  cumulative  and  concurrent,  and  may be pursued
              singularly,  successively or  together,  in the sole discretion of
              Holder,  and may be exercised  as often as occasion therefor shall
              arise.  No act of omission   or  commission  of Holder,  including
              specifically  any  failure   to  exercise  any  right,  remedy  or
              recourse,  shall be deemed to  be a waiver or release of the same;
              such  waiver or release  to  be  affected  only  through a written
              document   executed  by  Holder  and   then  only  to  the  extent
              specifically recited therein.  Without  limiting the generality of
              the preceding sentence,  acceptance by  Holder of any payment with
              knowledge of the occurrence of an Event  of Default by Maker shall
              not be deemed a waiver of such Event of  Default,  and  acceptance
              by Holder of any  payment in an amount  less  than the amount then
              due  hereunder  shall be an  acceptance on  account only and shall
              not in any way  affect  the  existence  of  an  Event  of  Default
              hereunder.  A waiver or release  with  reference to any  one event
              shall not be construed as continuing, as a bar to, or as a  waiver
              or release of, any subsequent  right,  remedy or recourse as  to a
              subsequent event.

         12.  No Usury  Intended.  All agreements  between  Maker and Holder are
              -------------------
              expressly  limited  so that in no contingency or event whatsoever,
              whether  by reason of: error of fact or law;  payment,  prepayment
              or  advancement of the proceeds  hereof;  acceleration of maturity
              of  the Outstanding  Principal  Balance,  or otherwise,  shall the
              amount  paid or  agreed to be paid to Holder  hereof  for the use,
              forbearance  or  retention of the money to be advanced  hereunder,
              including any  charges  collected or made in  connection  with the
              indebtedness   evidenced  by this  Note  which may be  treated  as
              interest  under  applicable  law, if any, exceed the maximum legal
              limit  (if  any such  limit is  applicable)  under  United  States
              federal  law or state law (to the extent not  preempted by federal
              law, if  any), now or hereafter  governing the interest payable in
              connection   with  such  agreements.  If,  from any  circumstances
              whatsoever,  fulfillment  of  any  provision  hereof  at the  time
              performance  of   such  provision   shall  be  due  shall  involve
              transcending  the  limit of validity  (if any)  prescribed  by law
              which a court   of  competent  jurisdiction  may  deem  applicable
              hereto,  then  ipso facto, the obligation to be fulfilled shall be
              reduced  to   the  limit  of  such  validity,   and  if  from  any

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<PAGE>

              circumstances,   Holder  shall ever  receive as interest an amount
              which would exceed  the maximum  legal limit (if any such limit is
              applicable),  such  amount which would be excessive interest shall
              be applied to the  reduction of the Outstanding  Principal Balance
              due  hereunder  and   not  to  the  payment  of  interest  or,  if
              necessary,  rebated  to Maker.  This provision shall control every
              other  provision of all agreements between Maker and Holder.

         13.  Guaranty.  The  payment  of this Note is  guaranteed  by  Guaranty
              ---------
              Agreements  of even date  executed by Peter J. Salzano and Network
              Consulting  Group, Inc. Peter J. Salzano's  Guaranty  Agreement is
              secured by a security  agreement  and certain  property  described
              therein.  Network  Consulting Group,  Inc.'s Guaranty Agreement is
              secured by two security  agreements and certain property described
              therein.

         14.  Purpose of Loan.  Maker  certifies that the loan evidenced by this
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              Note is obtained for business or commercial  purposes and that the
              proceeds   thereof  shall  not  be  used  for  personal,   family,
              household, or agricultural purposes.

         15.  Miscellaneous Provisions.
              -------------------------

              (a)  Maker, and each endorser and cosigner of this Note  expressly
                   grants to Holder the right to  release or to agree not to sue
                   any other person, or to suspend the  right  to  enforce  this
                   Note against  such  other  person or to  otherwise  discharge
                   such  person;  and  Maker,  and each  endorser  and  cosigner
                   agrees  that the  exercise of such rights by Holder will have
                   no  effect on this  liability of any other person,  primarily
                   or  secondarily  liable  hereunder.  Maker, and each endorser
                   and  cosigner of this  Note  waives,  to the  fullest  extent
                   permitted  by  law,  demand   for  payment,  presentment  for
                   payment,  protest,  notice of  protest,  notice of  dishonor,
                   notice of nonpayment,  notice of   acceleration  of maturity,
                   diligence  in  taking  any  action   to  collect  sums  owing
                   hereunder,  any duty or  obligation   of  Holder  to  effect,
                   protect,  perfect,  retain or enforce  any  security  for the
                   payment of this Note or to proceed  against   any  collateral
                   before otherwise enforcing this Note, and the  right to plead
                   as  a  defense  to  the   payment   hereof  any   statute  of
                   limitations.

              (b)  This  Note   and  each  payment  of  principal  and  interest
                   hereunder shall be paid when due without deduction or  setoff
                   of any kind or nature whatsoever.

              (c)  Maker agrees to  reimburse  Holder for all costs,  including,
                   without limitation, reasonable  attorneys' fees (including an
                   allocable portion of  in-house  counsel  fees),  incurred  to
                   collect this  Note  if  this  Note  is  not  paid  when  due,
                   including, but not limited to,  attorneys' fees (including an

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<PAGE>

                   allocable portion  of  in-house  counsel  fees)  incurred  in
                   connection with any bankruptcy  proceedings  instituted by or
                   against Maker (including relief from stay litigation).

              (d)  If any provision  hereof is for any reason and to any extent,
                   invalid or unenforceable,  then neither the  remainder of the
                   document in  which  such  provision  is  contained,  nor  the
                   application of the  provision to other  persons,  entities or
                   circumstances shall be affected thereby, but instead shall be
                   enforceable to the maximum extent permitted by law.

              (e)  This Note shall be a joint and several  obligation  of Maker,
                   and of all  endorsers  and  cosigners  hereof  and  shall  be
                   binding  upon  them and  their  respective  heirs,  personal
                   representatives, successors and assigns.

              (f)  This Note may not be modified or amended orally, but only  by
                   a modification  or amendment in writing signed by Holder  and
                   Maker.

              (g)  When the context and construction so require,  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.

              (h)  The headings of the  paragraphs and sections of this Note are
                   for convenience or reference only, are not to be considered a
                   part hereof and shall not limit or otherwise  affect  any  of
                   the terms hereof.

              (i)  In the event that at any time any  payment received by Holder
                   hereunder shall  be  deemed  by  final  order  of a court  of
                   competent jurisdiction to have been a voidable  preference or
                   fraudulent conveyance under the bankruptcy or insolvency laws
                   of the United States,  or shall otherwise be deemed to be due
                   to any party other than Holder, then, in any such event,  the
                   obligation  to   make   such   payment   shall   survive  any
                   cancellation of this Note and/or return thereof  to Maker and
                   shall not be  discharged  or satisfied by any  prior  payment
                   thereof and/or cancellation of this Note, but shall  remain a
                   valid and binding obligation  enforceable in accordance  with
                   the  terms and  provisions  hereof,  and the  amount of  such
                   payment  shall bear  interest at the  Default  Rate from  the
                   date of such final order until repaid hereunder.

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<PAGE>

         IN WITNESS  WHEREOF Maker has executed this  Promissory  Note as of the
day and year first above written.

                                            "Maker"

                                            Rare Telephony, Inc.  (f/k/a  Washoe
                                            Technology Corporation)

                                            By:      /s/ Thomas J. Vrabel
                                               ---------------------------------
                                                 Thomas J. Vrabel, President


                                            Cash Back Rebates LD.com, Inc.

                                            By:      /s/ Thomas J. Vrabel
                                               ---------------------------------
                                                  Thomas J. Vrabel, President

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<PAGE>

State of New Jersey

County of Passaic

Before me, the undersigned,  personally  appeared Thomas J. Vrabel,  known to me
(or  satisfactorily  proven) to be the person who executed the within instrument
on behalf of Rare Telephony,  Inc.  (f/k/a Washoe  Technology  Corporation)  and
acknowledged  that he executed the same for the purposes therein  contained.  In
witness whereof, I hereunto set my hand.

                                            /s/ Debra Santa Lucia
                                            ------------------------------------
                                            (Notary Public)

                                            Dated:    4/20/00
                                                  ------------------------------


State of New Jersey

County of Passaic

Before me, the undersigned,  personally  appeared Thomas J. Vrabel,  known to me
(or  satisfactorily  proven) to be the person who executed the within instrument
on behalf of Cash Back Rebates LD.com,  Inc. and  acknowledged  that he executed
the same for the purposes therein contained.  In witness whereof, I hereunto set
my hand.

                                            /s/ Debra Santa Lucia
                                            ------------------------------------
                                            (Notary Public)

                                            Dated:    4/20/00
                                            ------------------------------------

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