Using the International Mobile station Equipment Identity (IMEI) Uniform Resource Name (URN) as an Instance ID
RFC 7255

Internet Engineering Task Force (IETF)                     A. Allen, Ed.
Request for Comments: 7255                                    Blackberry
Category: Informational                                         May 2014
ISSN: 2070-1721

    Using the International Mobile station Equipment Identity (IMEI)
             Uniform Resource Name (URN) as an Instance ID

Abstract

   This specification defines how the Uniform Resource Name (URN)
   reserved for the Global System for Mobile Communications Association
   (GSMA) identities and its sub-namespace for the International Mobile
   station Equipment Identity (IMEI) can be used as an instance-id.  Its
   purpose is to fulfill the requirements for defining how a specific
   URN needs to be constructed and used in the '+sip.instance' Contact
   header field parameter for outbound behavior.

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/rfc7255.

Allen                         Informational                     [Page 1]
RFC 7255            Using IMEI URN as an Instance ID            May 2014

Copyright Notice

   Copyright (c) 2014 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
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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................2
   2. Terminology .....................................................3
   3. Background ......................................................3
   4. 3GPP Use Cases ..................................................5
   5. User Agent Client Procedures ....................................5
   6. User Agent Server Procedures ....................................6
   7. 3GPP SIP Registrar Procedures ...................................6
   8. Security Considerations .........................................7
   9. Acknowledgements ................................................7
   10. References .....................................................8
      10.1. Normative References ......................................8
      10.2. Informative References ....................................8

1.  Introduction

   This specification defines how the Uniform Resource Name (URN)
   reserved for the Global System for Mobile Communications Association
   (GSMA) identities and its sub-namespace for the International Mobile
   station Equipment Identity (IMEI) as specified in RFC 7254 [1] can be
   used as an instance-id as specified in RFC 5626 [2] and also as used
   by RFC 5627 [3].

   RFC 5626 [2] specifies the '+sip.instance' Contact header field
   parameter that contains a URN as specified in RFC 2141 [4].  The
   instance-id uniquely identifies a specific User Agent (UA) instance.
   This instance-id is used as specified in RFC 5626 [2] so that the
   Session Initiation Protocol (SIP) registrar (as specified in RFC 3261
   [9]) can recognize that the contacts from multiple registrations
   correspond to the same UA.  The instance-id is also used as specified

Allen                         Informational                     [Page 2]
RFC 7255            Using IMEI URN as an Instance ID            May 2014

   by RFC 5627 [3] to create Globally Routable User Agent URIs (GRUUs)
   that can be used to uniquely address a UA when multiple UAs are
   registered with the same Address of Record (AoR).

   RFC 5626 [2] requires that a UA SHOULD create a Universally Unique
   Identifier (UUID) URN as specified in RFC 4122 [6] as its instance-id
   but allows for the possibility to use other URN schemes.  Per
   RFC 5626, "If a URN scheme other than UUID is used, the UA MUST only