THIS  PROMISSORY  NOTE  SUPERCEDES  AND RENDERS NULL AND VOID:  (1) A PROMISSORY
NOTE,  DATED MAY 12, 1999,  IN THE  PRINCIPAL  AMOUNT OF $300,000 MADE BY WASHOE
TECHNOLOGY  CORPORATION WITH NETWORK CONSULTING GROUP, INC. AS HOLDER; AND (2) A
PROMISSORY  NOTE,  DATED JUNE 14, 2000, IN THE PRINCIPAL AMOUNT OF $100,000 MADE
BY RARE TELEPHONY,  INC., A NEVADA  CORPORATION WITH NETWORK  CONSULTING  GROUP,
INC. AS HOLDER.

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

$100,000                                                  June 23, 2000
                                                          Greenwich, Connecticut

FOR VALUE  RECEIVED,  RARE  TELEPHONY,  INC. A DELAWARE  CORPORATION  ("Maker"),
promises  to pay to the order of  NETWORK  CONSULTING  GROUP,  INC. a New Jersey
Corporation  ("Holder"),  which term shall include any subsequent holder of this
Note,  at 101 Route 46 East,  Pine  Brook,  NJ 07058 (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 One Hundred Thousand Dollars ($100,000),
with interest thereon at the rate (the "Interest Rate") described below.

         1.   Interest  Rate.  The Interest Rate shall be eight percent (8%) per
              ---------------
              annum.  Interest  shall be  computed at the  Interest  Rate on the
              basis of the actual number of days which the Outstanding Principal
              Balance  (as  defined  herein)  is  outstanding  divided  by three
              hundred sixty (360),  which shall,  for the purposes of this Note,
              be considered one (1) year.

         2.   Outstanding  Principal Balance. All references to the "Outstanding
              -------------------------------
              Principal  Balance" shall mean the amount of One Hundred  Thousand
              Dollars ($100,000), less any principal repaid.

         3.   Installment  Payments.  This Note  shall be  payable in thirty six
              ----------------------
              (36) equal installments ("Installments") of principal and interest
              in the amount of $3,133.64,  which  installments shall commence on
              December 1, 2000 and  continue  thereafter  on the 1st day of each
              successive  calendar  month until  November 1, 2003 (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 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") after June  23, 2000:

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<PAGE>

              (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
              (provided,  however, that this provision shall not take  effect or
              be  applicable  if the  sale of all or  substantially  all  of the
              assets  of the  Maker or the  common  stock of the  Maker  is to a
              subsidiary,  controlling  corporation or affiliate of the  Maker);
              or (b) the  issuance  of the  securities  of Maker on the   Public
              Market.

         7.   Modifications. From time to time, without affecting the obligation
              --------------
              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
              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 any Installment within ten (10)
                         days after the due date thereof; or
                  (b)    Failure  of  Maker  to pay  the  Outstanding  Principal
                         Balance  and accrued  interest in full on the  Maturity
                         Date or the Accelerated Maturity Date; or
                  (c)    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)  days
                         thereafter; or
                  (d)    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
                  (e)    A receiver, trustee, custodian or agent is appointed to
                         take  possession of all or any  substantial  portion of
                         Maker's assets; or
                  (f)    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) days thereafter; or
                  (g)    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  (a)  fails  to  pay  any
              --------------
              Installment  within ten (10) days after the due  date thereof,  or
              (b)  fails  to pay  the  Outstanding  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)  the then

                                       2
<PAGE>

              applicable  Interest  Rate plus five  percent  (5%),  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.

         10.  Governing Law. Maker, and each endorser and cosigner of this Note,
              --------------
              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.  This Note is 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 this Note.  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  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


                                       3
<PAGE>

              the  Outstanding  Principal  Balance due hereunder and  not to the
              payment of interest or, if necessary, rebated to Maker.

         13.  Guaranty.  (intentionally deleted)
              ---------

         14.  Purpose of Loan.  Maker  certifies that the loan evidenced by this
              ----------------
              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, incurred to
                  collect  this  Note  if  this  Note  is  not  paid  when  due,
                  including,  but not limited to,  attorneys'  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

                                       4
<PAGE>

                  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 to 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.

              (j) THIS  NOTE  SUPERSEDES  AND  RENDERS  NULL  AND  VOID:  (1)  A
                  PROMISSORY  NOTE,  DATED MAY 12, 1999, IN THE PRINCIPAL AMOUNT
                  OF $300,000 MADE BY WASHOE TECHNOLOGY CORPORATION WITH NETWORK
                  CONSULTING GROUP, INC. AS HOLDER (THE "FIRST NOTE"); AND (2) A
                  PROMISSORY  NOTE, DATED JUNE 14, 2000, IN THE PRINCIPAL AMOUNT
                  OF $100,000 MADE BY RARE TELEPHONY, INC., A NEVADA CORPORATION
                  WITH  NETWORK  CONSULTING  GROUP,  INC. AS HOLDER (THE "SECOND
                  NOTE"). For good and valuable  consideration,  the receipt and
                  sufficiency  of which are hereby  acknowledged,  Holder hereby
                  forever  releases,  discharges,  and agrees to hold  harmless,
                  Maker and its  predecessors,  successors,  and affiliates from
                  any and all  claims,  demands,  or actions  arising  out of or
                  related to the First Note or the Second Note.

              (k) This Note may be signed by the  undersigned  in  counterparts.
                  This  Note may also be  executed  and  delivered  by Holder by
                  facsimile  signature.  This  Note  may  not  be  executed  and
                  delivered by Maker by facsimile signature.

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

Accepted by "Holder"                        "Maker"

Network Consulting Group, Inc.                       Rare Telephony, Inc.

By /s/ Peter J. Salzano                              By /s/ Frederick A. Moran
  -----------------------                              -------------------------
   Peter J. Salzano, President                          Frederick A. Moran, CEO

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