INTERNET DRAFT                                             Masataka Ohta
draft-ohta-notasip-00.txt                  Tokyo Institute of Technology
                                                          Kenji Fujikawa
                                                        Kyoto University
                                                            1 April 1998



          Nothing Other Than a Simple Internet Phone (NOTASIP)



Status of this Memo

   This document is an Internet-Draft.  Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
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   (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu
   (US West Coast).



Abstract

   This memo describes a simple protocol for Internet phone without QoS.

   It is assumed that the operating system support a connected UDP
   socket.



1. Caller Initiate the Call

   The caller host somehow (through SDP URL, for example) find the
   callee's IP address, UDP port number (with appropriate default) and
   desired encoding.

   The caller host opens a connected UDP socket and start sending



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   properly encoded UDP packets of voice.


2. Callee Accept the Call

   The callee host receiving a UDP packet from someone opens a connected
   UDP socket and start ringing the phone to notify the existence of a
   call to the callee person.  The ringing tone should also be send to
   the caller.

   Or, if the port is already connected to someone else, ICMP unreach
   port error packet is returned, which makes the caller host generate a
   busy signal to the caller person.


3. Connection Established

   If the callee person hangs up a headset, the voice of the callee is
   sent to the caller and the call is established.


4. Interoperation with PSTN

   Interoperation with PSTN is performed through dial tone.  The exact
   protocol is service provider dependent and MUST NOT be standardized.


5. Error Conditions

   If the connected UDP socket can not be created or the socket
   generates some error, the call terminate.

   If there is no packets received for 42 seconds, the call terminates.


6. Security Considerations

   The protocol is as secure as UDP.

Authors' Addresses

   Masataka Ohta
   Computer Center
   Tokyo Institute of Technology
   2-12-1, O-okayama, Meguro-ku, Tokyo 152, JAPAN

   Phone: +81-3-5734-3299
   Fax: +81-3-5734-3415



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INTERNET DRAFT                   NOTASIP                      March 1998


   EMail: mohta@necom830.hpcl.titech.ac.jp


   Kenji Fujikawa
   Department of Information Science
   Kyoto University
   Yoshidahonmachi, Sakyo Ku, Kyoto City, 606-01, JAPAN

   Phone : +81-75-753-5387
   Fax: +81-75-751-0482
   Email : magician@kuis.kyoto-u.ac.jp









































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