RFC 3665 (rfc3665) - Page 2 of 94

Session Initiation Protocol (SIP) Basic Call Flow Examples

RFC 3665              SIP Basic Call Flow Examples         December 2003


Table of Contents

   1.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  2
       1.1.  General Assumptions. . . . . . . . . . . . . . . . . . .  3
       1.2.  Legend for Message Flows . . . . . . . . . . . . . . . .  3
       1.3.  SIP Protocol Assumptions . . . . . . . . . . . . . . . .  4
   2.  SIP Registration . . . . . . . . . . . . . . . . . . . . . . .  4
       2.1.  Successful New Registration. . . . . . . . . . . . . . .  5
       2.2.  Update of Contact List . . . . . . . . . . . . . . . . .  7
       2.3.  Request for Current Contact List . . . . . . . . . . . .  8
       2.4.  Cancellation of Registration . . . . . . . . . . . . . .  9
       2.5.  Unsuccessful Registration. . . . . . . . . . . . . . . . 10
   3.  SIP Session Establishment. . . . . . . . . . . . . . . . . . . 12
       3.1.  Successful Session Establishment . . . . . . . . . . . . 12
       3.2.  Session Establishment Through Two Proxies. . . . . . . . 15
       3.3.  Session with Multiple Proxy Authentication . . . . . . . 26
       3.4.  Successful Session with Proxy Failure. . . . . . . . . . 37
       3.5.  Session Through a SIP ALG. . . . . . . . . . . . . . . . 46
       3.6.  Session via Redirect and Proxy Servers with SDP in ACK . 54
       3.7.  Session with re-INVITE (IP Address Change) . . . . . . . 61
       3.8.  Unsuccessful No Answer . . . . . . . . . . . . . . . . . 67
       3.9.  Unsuccessful Busy. . . . . . . . . . . . . . . . . . . . 75
       3.10. Unsuccessful No Response from User Agent . . . . . . . . 80
       3.11. Unsuccessful Temporarily Unavailable . . . . . . . . . . 85
   4.  Security Considerations. . . . . . . . . . . . . . . . . . . . 91
   5.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 91
       5.1.  Normative References . . . . . . . . . . . . . . . . . . 91
       5.2.  Informative References . . . . . . . . . . . . . . . . . 91
   6.  Intellectual Property Statement. . . . . . . . . . . . . . . . 91
   7.  Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . 92
   8.  Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 93
   9.  Full Copyright Statement . . . . . . . . . . . . . . . . . . . 94

1.  Overview

   The call flows shown in this document were developed in the design of
   a SIP IP communications network.  They represent an example minimum
   set of functionality.

   It is the hope of the authors that this document will be useful for
   SIP implementers, designers, and protocol researchers alike and will
   help further the goal of a standard implementation of RFC 3261 [1].
   These flows represent carefully checked and working group reviewed
   scenarios of the most basic examples as a companion to the
   specifications.






Johnston, et al.         Best Current Practice