Internet Engineering Task Force (IETF) M. Barnes
Request for Comments: 7044 Polycom
Obsoletes: 4244 F. Audet
Category: Standards Track Skype
ISSN: 2070-1721 S. Schubert
NTT
J. van Elburg
Detecon International Gmbh
C. Holmberg
Ericsson
February 2014
An Extension to the Session Initiation Protocol (SIP) for
Request History Information
Abstract
This document defines a standard mechanism for capturing the history
information associated with a Session Initiation Protocol (SIP)
request. This capability enables many enhanced services by providing
the information as to how and why a SIP request arrives at a specific
application or user. This document defines an optional SIP header
field, History-Info, for capturing the history information in
requests. The document also defines SIP header field parameters for
the History-Info and Contact header fields to tag the method by which
the target of a request is determined. In addition, this
specification defines a value for the Privacy header field that
directs the anonymization of values in the History-Info header field.
This document obsoletes RFC 4244.
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/rfc7044.
Barnes, et al. Standards Track [Page 1]RFC 7044 History-Info February 2014Copyright Notice
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Barnes, et al. Standards Track [Page 2]RFC 7044 History-Info February 2014Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions and Terminology . . . . . . . . . . . . . . . . . 4
3. Background . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5. History-Info Header Field Protocol Structure . . . . . . . . 7
5.1. History-Info Header Field Example Scenario . . . . . . . 10
6. User Agent Handling of the History-Info Header Field . . . . 12
6.1. User Agent Client (UAC) Behavior . . . . . . . . . . . . 12
6.2. User Agent Server (UAS) Behavior . . . . . . . . . . . . 12
6.3. Back-to-Back User Agent (B2BUA) Behavior . . . . . . . . 12
7. Proxy/Intermediary Handling of History-Info Header Fields . . 13
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