Dispatch Working Group A. Allen, Ed. Internet-Draft Research in Motion (RIM) Intended status: Informational January 11, 2011 Expires: July 15, 2011 Using the International Mobile station Equipment Identity(IMEI)URN as an Instance ID draft-allen-dispatch-imei-urn-as-instanceid-02 Abstract This specification defines how the Uniform Resource Name namespace reserved for GSMA (Global Sstandard for Mobiles Association) identities and its sub namespace for the IMEI (International Mobile station Equipment Identity) can be used as an instance-id as specified in RFC 5626 [1] and also as used by RFC 5627 [2]. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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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 Allen Expires July 15, 2011 [Page 1] Internet-Draft Using IMEI URN as an Instance ID January 2011 described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Background . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. User Agent Client Procedures . . . . . . . . . . . . . . . . . 5 5. Security considerations . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative references . . . . . . . . . . . . . . . . . . . 6 7.2. Informative references . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 7 Allen Expires July 15, 2011 [Page 2] Internet-Draft Using IMEI URN as an Instance ID January 2011 1. Introduction This specification defines how the Uniform Resource Name namespace reserved for GSMA identities and its sub namespace for the IMEI (International Mobile station Equipment Identity) as defined in draft-montemurro-gsma-imei-urn-06 [3] can be used as an instance-id as specified in RFC 5626 [1] and also as used by RFC 5627 [2]. RFC 5626 [1] defines the "+sip.instance" Contact header field parameter which contains a URN as per RFC 2141 [4] defined as an instance-id that uniquely identifies a specific UA instance. This instance-id is used as defined in RFC 5626 [1] so that registrar can recognize that the contacts from multiple registrations correspond to the same UA. The instance-ID is also used as defined by RFC 5627 [2] 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 [1] defines that a UA SHOULD create a Universally Unique Identifier (UUID) URN as defined in RFC 4122 [6] as its instance-id but allows for the possibility of other URN schemes to be used. If a URN scheme other than UUID is used, the UA MUST only use URNs for which an RFC (from the IETF stream) defines how the specific URN needs to be constructed and used in the "+sip.instance" Contact header field parameter for outbound behavior. This specification meets this requirement by specifying how the GSMA IEMEI URN is used in the "+sip.instance" Contact header field parameter for outbound behavior and draft-montemurro-gsma-imei-urn-06 [3] defines how the GSMA IMEI URN is constructed The GSMA IMEI is an identifier for a namespace for the IMEI a globally unique identifier that identifies Mobile Equipment used in Global System for Mobile (GSM), Universal Mobile Telecommunications System (UMTS) and 3GPP LTE (Long Term Evolution)networks. The IMEI allocation is managed by the GSMA to ensure that the IMEI values are globally unique. Details of the formatting of the IMEI as a URN are defined in draft-montemurro-gsma-imei-urn-06 [3] and the definition of the IMEI is contained in 3GPP TS 23.003 [7]. Further details about the GSMA role in allocating the IMEI and the IMEI allocation guidelines can be found in GSMA PRD DG.06 [8] 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [5]. Allen Expires July 15, 2011 [Page 3] Internet-Draft Using IMEI URN as an Instance ID January 2011 3. Background GSM and UMTS capable mobile devices represent 90% of the mobile devices in use worldwide. GSM and UMTS mobile devices each have an IMEI allocated which uniquely identifies the mobile device from all other GSM/UMTS mobile devices deployed. Amongst other things in some regulatory jurisdictions the IMEI is used to identify a stolen mobile is being used and help to identify the subscription that is using it and to prevent its use. Whilst GSM was originally a circuit switched system enhancements such as GPRS (General Packet Radio Service) and UMTS have added IP data capabilities which along with the definition of the IP Multimedia Subsystem (IMS) has made SIP based calls and IP multimedia sessions from mobile devices possible. The latest enhancment known as LTE will introduce even higher data rates and dispenses with the circuit switched domain completely meaning that with LTE voice calls will need to be conducted using IP and IMS. However, the transition to all IP, SIP based IMS networks worldwide will take a great many years and mobile devices being mobile will need to operate in both IP/SIP/IMS mode and circuit switched mode. In fact calls and sessions will need to be handed over between IP/ SIP/IMS mode and circuit switched mode during a call. Also as many existing GSM and UMTS radio access networks are unable to support IP/ SIP/IMS based voice services in a commercially acceptable manner some sessions may have some media types delivered via IP/IMS simultaneously with voice media delivered via circuit switched with the same mobile device simultaneously attached via both the IP/SIP/ IMS domain and the circuit switched domain. To meet this need 3GPP has specified how to maintain session continuity between the IP/SIP/ IMS domain and the circuit switched domain in 3GPP TS 24.237 [9] and how to access IMS hosted services via both the IP/SIP/IMS domain and the circuit switched domain in 3GPP TS 24.292 [10]. In order for the the mobile device to access SIP/IMS services via the circuit switched domain 3GPP has defined a MSC (Mobile Switching Center) server enhanced for ICS which controls mobile voice call setup over the circuit switched radio access while establishing the corresponding voice session in the core network using SIP/IMS. To enable this the MSC server enhanced for ICS (IMS centralized services) performs SIP registration on behalf of the mobile device which may simultaneously also be directly registered with the IP/SIP/ IMS domain. The SIP/IMS network needs to be able to identify that both of these SIP registrations are from the same UA instance and also correctly handle sessions establishment requests addressed using GRUUs as defined in RFC 5627 [2] when the mobile device is attached using the circuit switched domain. The only mobile device identifier that is transportable using GSM/UMTS/LTE signaling is the IMEI therefore the instance-id used by the MSC server enhanced for ICS when registering on behalf of the mobile device and the instance-id Allen Expires July 15, 2011 [Page 4] Internet-Draft Using IMEI URN as an Instance ID January 2011 when the mobile device registers directly needs to be based on the IMEI. Additionally in order to meet the regulatory requirements to use the IMEI to identify a stolen mobile is being used and help to identify the subscription that is using it and to prevent its use the same IMEI that is obtained from the circuit switched signaling needs to be obtainable from SIP signaling. 3GPP TS 24.237 [9] and 3GPP TS 24.292 [10] already define the use of the URN namespace for the GSMA and IMEI as defined in draft-montemurro-gsma-imei-urn-06 [3] as the instance-id used by mobile devices and the MSC server enhanced for ICS for SIP/IMS registrations for these reasons. 4. User Agent Client Procedures A UAC that has an IMEI as defined in 3GPP TS 23.003 [7] SHALL include in the "sip.instance" media feature tag the GSMA IMEI URN according to the syntax defined in draft-montemurro-gsma-imei-urn-06 [3] when performing the registration procedures defined in RFC 5626 [1] or RFC 5627 [2] or any other procedure requiring including the "sip.instance" media feature tag. The UAC must provide lexically equivalent URNs in each registration [1]. Hence, any optional or variable components of the URN (e.g., the "vers" and "svn" parameters) must be presented with the same values and in the same order in every registration as in the first registration. 5. Security considerations In order to protect from tampering the REGISTER requests containing the GSMA IMEI URN SHOULD be sent using a security mechanism such as TLS [11] (or other security mechanism that provides equivalent levels of protection). 6. Acknowledgements The author would like to thank Paul Kyzivat and Dale Worley for reviewing this draft and providing their comments. 7. References Allen Expires July 15, 2011 [Page 5] Internet-Draft Using IMEI URN as an Instance ID January 2011 7.1. Normative references [1] Jennings, C., Mahy, R., and F. Audet, "Managing Client- Initiated Connections in the Session Initiation Protocol (SIP)", RFC 5626, October 2009. [2] Rosenberg, J., "Obtaining and Using Globally Routable User Agent URIs (GRUUs) in the Session Initiation Protocol (SIP)", RFC 5627, October 2009. [3] Montemurro, M., "A Uniform Resource Name Namespace For The GSM Association (GSMA) and the International Mobile station Equipment Identity(IMEI), work in progress", Internet Draft draft-montemurro-gsma-imei-urn-06, January 2011. [4] Moats, R., "URN Syntax", RFC 2141, May 1997. [5] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. 7.2. Informative references [6] Leach, P., Mealling, M., and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005. [7] 3GPP, "TS 23.003: Numbering, addressing and identification (Release 8)", 3GPP 23.003, September 2008, . [8] GSMA Association, "IMEI Allocation and Approval Guidelines", PRD DG.06 version 3.6, February 2008, . [9] 3GPP, "TS 24.237: Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 (Release 8)", 3GPP 24.237, March 2009, . [10] 3GPP, "TS 24.292: IP Multimedia (IM) Core Network (CN) subsystem Centralized Services (ICS); Stage 3 (Release 8)", 3GPP 24.292, March 2009, . [11] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", RFC 2246, January 1999. Allen Expires July 15, 2011 [Page 6] Internet-Draft Using IMEI URN as an Instance ID January 2011 Author's Address Andrew Allen (editor) Research in Motion (RIM) 2550 West Golf Road Rolling Meadows, Illinois 60008 USA Phone: unlisted Fax: unlisted Email: aallen@rim.com Allen Expires July 15, 2011 [Page 7]