UpdatedPROPOSED STANDARDIETF stream

RFC 3327: Session Initiation Protocol (SIP) Extension Header Field for Registering Non-Adjacent Contacts

Still current, but amended. Parts of this document are changed or extended by RFC 5626. Read both.

In plain English — editorial summary, not part of the RFC

The REGISTER function is used in a SIP system primarily to associate a temporary contact address with an address-of-record. This contact is generally in the form of a URI, such as Contact: <sip:alice@pc33.atlanta.com> and is generally dynamic and associated with the IP address or hostname of the SIP UA. The problem is that network topology may have one or more SIP proxies between the UA and the registrar, such that any request travelling 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

Document record

Document ID: RFC3327
Published: December 2002
Authors: D. Willis; B. Hoeneisen
Status: PROPOSED STANDARD
Stream: IETF
Area: rai
Pages: 17
Also known as: —

Updated by:: RFC 5626

Topics

Referenced by

One later RFC formally updates or obsoletes part of this document.

RFC 5626Managing Client-Initiated Connections in the Session Initiation Protocol (SIP)Current
October 2009

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The document record above — title, authors, date, status, stream, area, relationships, DOI and errata — is imported verbatim from the public RFC Editor index. The “in plain English” section is editorial: written by The metasystema editorial team, not part of the RFC. Where the two differ, the RFC text governs.

Last checked against the RFC Editor index on 23 August 2026. RFCs are never revised after publication; changes are issued as new documents.

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