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Session Initiation Protocol (SIP) Extension Header Field for Registering Non-Adjacent Contacts (RFC3327)

IP.com Disclosure Number: IPCOM000010531D
Original Publication Date: 2002-Dec-01
Included in the Prior Art Database: 2002-Dec-13
Document File: 18 page(s) / 37K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D. Willis: AUTHOR [+2]

Abstract

The REGISTER function is used in a Session Initiation Protocol (SIP) system primarily to associate a temporary contact address with an address-of-record. This contact is generally in the form of a Uniform Resource Identifier (URI), such as Contact: and is generally dynamic and associated with the IP address or hostname of the SIP User Agent (UA). The problem is that network topology may have one or more SIP proxies between the UA and the registrar, such that any request traveling from the user's home network to the registered UA must traverse these proxies. The REGISTER method does not give us a mechanism to discover and record this sequence of proxies in the registrar for future use. This document defines an extension header field, "Path" which provides such a mechanism.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 8% of the total text.

Network Working Group                                          D. Willis

Request for Comments: 3327                              dynamicsoft Inc.

Category: Standards Track                                   B. Hoeneisen

                                                                  Switch

                                                           December 2002

        Session Initiation Protocol (SIP) Extension Header Field

                 for Registering Non-Adjacent Contacts

Status of this Memo

   This document specifies an Internet standards track protocol for the

   Internet community, and requests discussion and suggestions for

   improvements.  Please refer to the current edition of the "Internet

   Official Protocol Standards" (STD 1) for the standardization state

   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   The REGISTER function is used in a Session Initiation Protocol (SIP)

   system primarily to associate a temporary contact address with an

   address-of-record.  This contact is generally in the form of a

   Uniform Resource Identifier (URI), such as Contact:

   <sip:alice@pc33.atlanta.com> and is generally dynamic and associated

   with the IP address or hostname of the SIP User Agent (UA).  The

   problem is that network topology may have one or more SIP proxies

   between the UA and the registrar, such that any request traveling

   from the user's home network to the registered UA must traverse these

   proxies.  The REGISTER method does not give us a mechanism to

   discover and record this sequence of proxies in the registrar for

   future use.  This document defines an extension header field, "Path"

   which provides such a mechanism.

Willis & Hoeneisen          Standards Track                     [Page 1]

RFC 3327          Path Extension Header Field for SIP      December 2002

Table of Contents

   1.    Background . . . . . . . . . . . . . . . . . . . . . . . . .  2

   2.    Terminology  . . . . . . . . . . . . . . . . . . . . . . . .  3

   3.    Applicability Statement  . . . . . . . . . . . . . . . . . .  3

   4.    Path Header Field Definition and Syntax  . . . . . . . . . .  3

   5.    Usage of Path Header Field . . . . . . . . . . . . . . . . .  5

   5.1   Procedures at the UA . . . . . . . . . . . . . . . . . . . .  5

   5.2   Procedures at Intermediate Proxies . . . . . . . . . . . . .  5

   5.3   Procedures at the Registrar  . . . . . . . . . . . . . . . .  6

   5.4   Procedures at the Home Proxy . . . . . . . . . . . . . . . .  6

   5.5   Examples of Usage  . . . . . . . ...