Internet Engineering Task Force (IETF) R. Sparks
Request for Comments: 6026 Tekelec
Updates: 3261 T. Zourzouvillys
Category: Standards Track Skype
ISSN: 2070-1721 September 2010
Correct Transaction Handling for 2xx Responses
to Session Initiation Protocol (SIP) INVITE Requests
Abstract
This document normatively updates RFC 3261, the Session Initiation
Protocol (SIP), to address an error in the specified handling of
success (2xx class) responses to INVITE requests. Elements following
RFC 3261 exactly will misidentify retransmissions of the request as a
new, unassociated request. The correction involves modifying the
INVITE transaction state machines. The correction also changes the
way responses that cannot be matched to an existing transaction are
handled to address a security risk.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6026.
Sparks & Zourzouvillys Standards Track [Page 1]RFC 6026 Correct Handling for SIP 2xx Responses September 2010Copyright Notice
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Table of Contents
1. Introduction ....................................................3
2. Conventions and Definitions .....................................3
3. Reason for Change ...............................................3
4. Summary of Change ...............................................4
5. Consequences if Not Implemented .................................4
6. The Change ......................................................4
7. Change Details ..................................................5
7.1. Server Transaction Impacts .................................5
7.2. Client Transaction Impacts .................................9
7.3. Proxy Considerations ......................................10
8. Exact Changes to RFC 3261 ......................................11
8.1. Page 85 ...................................................11
8.2. Page 107 ..................................................11
8.3. Page 114 ..................................................11
8.4. Pages 126 through 128 .....................................12
8.5. Pages 134 to 135 ..........................................15
8.6. Page 136 ..................................................15
8.7. Page 137 ..................................................17
8.8. Page 141 ..................................................17
8.9. Page 144 ..................................................18
8.10. Page 146 .................................................18
8.11. Page 265 .................................................18
9. IANA Considerations ............................................18
10. Security Considerations .......................................19
11. Acknowledgments ...............................................20
12. Normative References ..........................................20
Sparks & Zourzouvillys Standards Track [Page 2]RFC 6026 Correct Handling for SIP 2xx Responses September 20101. Introduction
This document describes an essential correction to the Session
Initiation Protocol (SIP), defined in [RFC3261]. The change
addresses an error in the handling of 2xx class responses to INVITE
requests that leads to retransmissions of the INVITE being treated as
datatracker.ietf.org