A Session Initiation Protocol (SIP) Extension for the Identification of Services
RFC 6050

Internet Engineering Task Force (IETF)                          K. Drage
Request for Comments: 6050                                Alcatel-Lucent
Category: Informational                                    November 2010
ISSN: 2070-1721

             A Session Initiation Protocol (SIP) Extension
                   for the Identification of Services

Abstract

   This document describes private extensions to the Session Initiation
   Protocol (SIP) that enable a network of trusted SIP servers to assert
   the service of authenticated users.  The use of these extensions is
   only applicable inside an administrative domain with previously
   agreed-upon policies for generation, transport, and usage of such
   information.  This document does NOT offer a general service
   identification model suitable for use between different trust domains
   or for use in the Internet at large.

   The document also defines a URN to identify both services and User
   Agent (UA) applications.  This URN can be used within the SIP header
   fields defined in this document to identify services, and also within
   the framework defined for caller preferences and callee capabilities
   to identify usage of both services and applications between end UAs.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see 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/rfc6050.

Drage                         Informational                     [Page 1]
RFC 6050               SIP Service Identification          November 2010

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Applicability Statement  . . . . . . . . . . . . . . . . . . .  5
   3.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  6
   4.  Syntax of the Header Fields  . . . . . . . . . . . . . . . . .  6
     4.1.  The P-Asserted-Service Header  . . . . . . . . . . . . . .  6
     4.2.  The P-Preferred-Service Header . . . . . . . . . . . . . .  7
     4.3.  Service and Application Definition . . . . . . . . . . . .  8
     4.4.  Registration Template  . . . . . . . . . . . . . . . . . .  8
   5.  Usage of the P-Preferred-Service and P-Asserted-Service
       Header Fields  . . . . . . . . . . . . . . . . . . . . . . . . 10
     5.1.  Usage of the P-Preferred-Service and
           P-Asserted-Service Header Fields in Requests . . . . . . . 10
       5.1.1.  Procedures at User Agent Clients (UAC) . . . . . . . . 10
       5.1.2.  Procedures at Intermediate Proxies . . . . . . . . . . 11
       5.1.3.  Procedures at User Agent Servers . . . . . . . . . . . 12
     5.2.  Usage of the P-Preferred-Service and
           P-Asserted-Service Header Fields in Responses  . . . . . . 12
   6.  Examples of Usage  . . . . . . . . . . . . . . . . . . . . . . 12
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 15
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 16
     8.1.  P-Asserted-Service and P-Preferred-Service Header
           Fields . . . . . . . . . . . . . . . . . . . . . . . . . . 16
     8.2.  Definition of Service-ID Values  . . . . . . . . . . . . . 16
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 17
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 18

Drage                         Informational                     [Page 2]
RFC 6050               SIP Service Identification          November 2010

1.  Introduction