FIRST AMENDMENT TO INTERNET PROTOCOL TELEPHONE SERVICE PARTICIPATION AND PROMOTION AGREEMENT

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                                                                   EXHIBIT 10.45

                               FIRST AMENDMENT TO
              INTERNET PROTOCOL TELEPHONE SERVICE PARTICIPATION AND
                               PROMOTION AGREEMENT


         This First Amendment is made as of the 31st day of March, 2000, between
and Priceline Long Distance, LLC ("Priceline"), with offices at 000 Xxxxxxxxxxx
Xxxxxx, Xxxxxxx, Xxxxxxxxxxx 00000, and Net2Phone, Inc. ("Net2Phone") with
offices at 000 Xxxx Xxxxxx, Xxxxxxxxxx, Xxx Xxxxxx 00000.

         WHEREAS, the Priceline and Net2Phone entered into a Internet Protocol
Telephone Service Participation and Promotion Agreement dated March 31, 2000
(the "Participation Agreement"); and

         WHEREAS, the parties now desire to memoralize their mutual
understanding to amend the Participation Agreement as set forth herein.

         NOW THEREFORE, in consideration of the mutual covenants and agreements
contained herein, the parties hereto agree as follows:

         1.       The Participation Agreement is hereby amended by deleting
                  Schedule 5.4 thereto and replacing it in its entirety with
                  Replacement Schedule 5.4 attached hereto as Exhibit A.

         2.       Priceline acknowledges receipt of the [****] required under
                  Replacement Schedule 5.4 to be paid on the Soft Launch Date.

         In all other respects the terms the Participation Agreement shall
remain unchanged.

         IN WITNESS WHEREOF, the parties hereto have duly executed this First
Amendment as of the day and year first above written.



PRICELINE LONG DISTANCE, LLC                NET2PHONE, INC.



By:/s/ Xxx Xxxxxxx                          By:/s/ Xxxx Xxxxxx
       Name:    Xxx Xxxxxxx                        Name:   Xxxx Xxxxxx
       Title:   President                          Title:  Chief Executive
                                                           Officer
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         EXHIBIT A


         REPLACEMENT SCHEDULE 5.4 TELECOM DCS PREFERRED PROVIDER STATUS
         COMPENSATION



                  As consideration for Net2Phone Preferred Provider Status in
the Telecom DCS in accordance with this Agreement, Net2Phone shall pay to
Priceline [****], payable in the following manner;

         (i)      [****] on the Soft Launch Date of the Telecom DCS;

         (ii)     [****] on each of the 90th, 180th and 279th day following the
                  Soft Launch Date.

         (iii)    [****] on the first anniversary of the Soft Launch Date;

         (iv)     [****] on each of the 90th, 180th and 270th day following the
                  Soft Launch Date;

         (v)      [****] on the second anniversary of the Soft Launch Date; and

         (vi)     [****] on each of the 90th, 180th and 270th day following the
                  second anniversary of the Soft Launch Date.


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