Movatterモバイル変換

Internet Engineering Task Force (IETF)                   R. Atarius, Ed.Request for Comments: 8465                                September 2018Category: InformationalISSN: 2070-1721Using the Mobile Equipment Identity (MEID) URN as an Instance IDAbstract   This document specifies how the Uniform Resource Name (URN) namespace   reserved for the Third Generation Partnership Project 2 (3GPP2)   identities and its Namespace Specific String (NSS) for the Mobile   Equipment Identity (MEID) can be used as an Instance ID.  The purpose   of this Instance ID 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 candidates for any level of Internet   Standard; seeSection 2 of RFC 7841.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttps://www.rfc-editor.org/info/rfc8465.Copyright Notice   Copyright (c) 2018 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 78 and the IETF Trust's Legal   Provisions Relating to IETF Documents   (https://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.Atarius                       Informational                     [Page 1]

RFC 8465               MEID URN as an Instance ID         September 2018Table of Contents1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .22.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .33.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .34.  3GPP2 Use Cases . . . . . . . . . . . . . . . . . . . . . . .45.  User Agent Client Procedures  . . . . . . . . . . . . . . . .56.  User Agent Server Procedures  . . . . . . . . . . . . . . . .57.  3GPP/3GPP2 SIP Registrar Procedures . . . . . . . . . . . . .58.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .69.  Security Considerations . . . . . . . . . . . . . . . . . . .610. References  . . . . . . . . . . . . . . . . . . . . . . . . .710.1.  Normative References . . . . . . . . . . . . . . . . . .710.2.  Informative References . . . . . . . . . . . . . . . . .8   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .8   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .81.  Introduction   This document specifies how the Uniform Resource Name (URN) namespace   reserved for Third Generation Partnership Project 2 (3GPP2)   identities and its Namespace Specific String (NSS) for the Mobile   Equipment Identity (MEID) as specified inRFC 8464 [10] can be used   as an Instance ID as specified inRFC 5626 [4] and also as used byRFC 5627 [5].RFC 5626 [4] specifies the "+sip.instance" Contact header field   parameter that contains a URN as specified inRFC 8141 [6].  The   Instance ID uniquely identifies a specific User Agent (UA) instance.   This Instance ID is used as specified inRFC 5626 [4] so that the   Session Initiation Protocol (SIP) registrar (as specified inRFC 3261   [2]) can recognize that the contacts from multiple registrations   correspond to the same UA.  The Instance ID is also used as specified   byRFC 5627 [5] 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 [4] requires that a UA SHOULD create a Universally Unique   Identifier (UUID) URN as specified inRFC 4122 [9] as its Instance ID   but allow for the possibility to use other URN schemes.RFC 5626 [4] states:      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.Atarius                       Informational                     [Page 2]

RFC 8465               MEID URN as an Instance ID         September 2018   This specification meets this requirement by specifying how the 3GPP2   MEID URN is used in the "+sip.instance" Contact header field   parameter for outbound behavior andRFC 8464 [10] specifies how the   3GPP2 MEID URN is constructed.   The 3GPP2 MEID URN is a URN for the MEID a globally unique identifier   that identifies mobile devices used in the 3GPP2 networks.  The MEID   allocation is managed by the 3GPP2 to ensure that the MEID values are   globally unique.  Details of the formatting of the MEID as a URN are   specified inRFC 8464 [10] and the definition of the MEID is   contained in 3GPP2 S.R0048-A [13].2.  Terminology   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and   "OPTIONAL" in this document are to be interpreted as described inBCP 14 [1] [7] when, and only when, they appear in all capitals, as   shown here.3.  Background   Mobile communication has been rapidly improved from low-bit-rate   circuit-switched systems to the higher-data-rate packet-switched   system.  The packet-switched system has added the mobile capability   of Internet Protocol (IP) connectivity; thereby, the IP Multimedia   Subsystem (IMS) have made SIP-based calls and IP multimedia sessions   from mobile devices possible.   3GPP2 defines High Rate Packet Data (HRPD) with high data rates, and   it dispenses with the 1x Circuit Switched (1xCS) infrastructure.   This means that with HRPD networks, voice calls will need to be   conducted using IP and IMS.  However, SIP-based IMS networks will   take a great many years from the time of writing to transition to the   use of all IP; mobile devices will need to operate in both IP/SIP/IMS   mode and circuit-switched mode.  This means that calls and sessions   will need to be handed over between IP/SIP/IMS mode and circuit-   switched mode mid-call or mid-session.  To achieve this, the mobile   device needs to simultaneously communicate via both the IP/SIP/IMS   domain and the circuit-switched domain.   To meet this need, 3GPP2 has specified how to maintain voice-session   continuity between the IP/SIP/IMS domain and the circuit-switched   domain in 3GPP2 S.X0042-A [14].   In order for the mobile device to access SIP/IMS voice service via   the circuit-switched domain, 3GPP2 has specified that a Mobile   Switching Center (MSC) server will control mobile voice call setupAtarius                       Informational                     [Page 3]

RFC 8465               MEID URN as an Instance ID         September 2018   over the circuit-switched radio access while establishing the   corresponding voice session in the core network using SIP/IMS.  The   specified MSC server operates either via an IMS Media Gateway Control   Function (MGCF) or directly if it is enhanced by SIP interface.  To   enable this, the mobile device MUST be identified in both the 1xCS   and IP/SIP/IMS domains.  The only mobile device identifier that is   transportable using 1xCS signaling is the MEID; therefore, the   Instance ID included by the MGCF or the MSC server and the Instance   ID directly included by the mobile device both need to be based on   the MEID.   Additionally in order to meet the above requirements, the same MEID   that is obtained from the circuit-switched signaling by the MSC   server needs to be obtainable from SIP signaling so that it can be   determined that both the SIP signaling and circuit-switched signaling   originate from the same mobile device.4.  3GPP2 Use Cases   1.  The mobile device includes its MEID in the SIP REGISTER request       so that the SIP registrar can perform a check of the Equipment       Identity Register (EIR) to verify if this mobile device is       allowed or barred from accessing the network for non-emergency       services (e.g., because it has been stolen).  If the mobile       device is not allowed to access the network for non-emergency       services, the SIP registrar can reject the registration.  Thus, a       barred mobile device is prevented from accessing the network for       non-emergency services.   2.  The mobile device includes its MEID in SIP INVITE requests used       to establish emergency sessions.  This is so that the Public       Safety Answering Point (PSAP) can obtain the MEID of the mobile       device for identification purposes if required by regulations.   3.  The inclusion by the mobile device of its MEID in SIP INVITE       requests used to establish emergency sessions is also used in the       cases of unauthenticated emergency sessions to enable the network       to identify the mobile device.  This is especially important if       the unauthenticated emergency session is handed over from the       packet-switched domain to the circuit-switched domain.  In this       scenario, the MEID is the only identifier that is common to both       domains.  The Emergency Access Transfer Function (EATF), which       coordinates the call transfer between the domains, can thus use       the MEID to identify that the circuit-switched call is from the       same mobile device that was in the emergency session in the       packet-switched domain.Atarius                       Informational                     [Page 4]

RFC 8465               MEID URN as an Instance ID         September 20185.  User Agent Client Procedures   A single mode 3GPP2 User Agent Client (UAC), which uses only 3GPP2   technology to transmit and receive voice or data, has an MEID as   specified in 3GPP2 S.R0048-A [13].  The single mode 3GPP2 UAC that is   registering with a 3GPP2 IMS network includes in the "sip.instance"   media feature tag the 3GPP2 MEID URN according to the syntax   specified inRFC 8464 [10] when performing the registration   procedures specified inRFC 5626 [4] orRFC 5627 [5] (or any other   procedure requiring the inclusion of the "sip.instance" media feature   tag).   A UAC MUST NOT use the 3GPP2 MEID URN as an Instance ID except when   registering with a 3GPP2 IMS network.  When a UAC is operating in IMS   mode, it will obtain the domain of the carrier's IMS network to   register with, from the Universal Integrated Circuit Card (UICC),   preconfiguration, or the network at the time of establishing the   Packet Data Protocol (PDP) context.  These three methods are carrier   specific and are only performed by the carrier IMS networks.  The UAC   will also obtain the address of the IMS edge proxy to send the   REGISTER request containing the MEID using information elements in   the Attach response when it attempts to connect to the carrier's   packet data network.  When registering with a non-3GPP or non-3GPP2   IMS network, a UAC SHOULD use a UUID as an Instance ID as specified   inRFC 5626 [4].   A UAC MUST NOT include the "sip.instance" media feature tag   containing the 3GPP2 MEID URN in the Contact header field of non-   REGISTER requests except when the request is related to an emergency   session.  Regulations can require that the MEID be provided to the   PSAP.  Any future exceptions to this prohibition require an RFC that   addresses how privacy is not violated by such usage.6.  User Agent Server Procedures   A User Agent Server (UAS) MUST NOT include its "sip.instance" media   feature tag containing the 3GPP2 MEID URN in the Contact header field   of responses except when the response is related to an emergency   session.  Regulations can require the MEID to be provided to the   PSAP.  Any future exceptions to this prohibition require an RFC that   addresses how privacy is not violated by such usage.7.  3GPP/3GPP2 SIP Registrar Procedures   In 3GPP/3GPP2 IMS, when the SIP Registrar receives in the Contact   header field a "sip.instance" media feature tag containing the 3GPP2   MEID URN according to the syntax specified inRFC 8464 [10], the SIP   registrar follows the procedures specified inRFC 5626 [4].  The MEIDAtarius                       Informational                     [Page 5]

RFC 8465               MEID URN as an Instance ID         September 2018   URN MAY be validated as described in theRFC 8464 [10].  If the UA   indicates that it supports the extension inRFC 5627 [5] and the SIP   Registrar allocates a GRUU according to the procedures specified inRFC 5627 [5], the Instance ID MUST be obfuscated when creating the   "gr" parameter in order not to reveal the MEID to other UAs when the   public GRUU is included in non-REGISTER requests and responses.  3GPP   TS 24.229 [11] subclause 5.4.7A.2 specifies the mechanism for   obfuscating the MEID when creating the "gr" parameter.8.  IANA Considerations   This document has no IANA actions.9.  Security Considerations   Since MEIDs, like other formats of Instance IDs, can be correlated to   a user, they are personally identifiable information and MUST be   treated as such.  In particular, the "sip.instance" media feature tag   containing the 3GPP2 MEID URN MUST NOT be included in requests or   responses intended to convey any level of anonymity, as this could   violate the user's privacy.RFC 5626 [4] states:      One case where a UA could prefer to omit the "sip.instance" media      feature tag is when it is making an anonymous request or some      other privacy concern requires that the UA not reveal its      identity.   The same concerns apply when using the 3GPP2 MEID URN as an Instance   ID.  Publication of the 3GPP2 MEID URN to networks that the UA is not   attached to or the UA does not have a service relationship with is a   security breach; the "sip.instance" media feature tag MUST NOT be   forwarded by the service provider's network elements when forwarding   requests or responses towards the destination UA.  The 3GPP2 MEID URN   MUST NOT accidentally leak in other contexts, such as and in   particular when application servers subscribe to user registration   state using the event package defined inRFC 3680 [3].  Additionally,   an Instance ID containing the 3GPP2 MEID URN identifies a mobile   device and not a user.  The Instance ID containing the 3GPP2 MEID URN   MUST NOT be used alone as an address for a user or as an   identification credential for a user.  The GRUU mechanism specified   inRFC 5627 [5] provides a means to create URIs that address the user   at a specific device or UA.   Entities that log the Instance ID need to protect them as personally   identifiable information.  Regulations can require carriers to log   SIP MEIDs.Atarius                       Informational                     [Page 6]

RFC 8465               MEID URN as an Instance ID         September 2018   In order to protect the "sip.instance" media feature tag containing   the 3GPP2 MEID URN from being tampered with, those REGISTER requests   containing the 3GPP2 MEID URN MUST be sent using a security mechanism   such as Transport Layer Security (TLS) as specified inRFC 8446 [8]   or any other security mechanism that provides equivalent levels of   protection such as hop-by-hop security based upon IP Security   (IPsec).10.  References10.1.  Normative References   [1]  Bradner, S., "Key words for use in RFCs to Indicate Requirement        Levels",BCP 14,RFC 2119, DOI 10.17487/RFC2119, March 1997,        <https://www.rfc-editor.org/info/rfc2119>.   [2]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,        Peterson, J., Sparks, R., Handley, M., and E.  Schooler, "SIP:        Session Initiation Protocol",RFC 3261, DOI 10.17487/RFC3261,        June 2002, <https://www.rfc-editor.org/info/rfc3261>.   [3]  Rosenberg, J., "A Session Initiation Protocol (SIP) Event        Package for Registrations",RFC 3680, DOI 10.17487/RFC3680,        March 2004, <https://www.rfc-editor.org/info/rfc3680>.   [4]  Jennings, C., Ed., Mahy, R., Ed., and F. Audet, Ed., "Managing        Client-Initiated Connections in the Session Initiation Protocol        (SIP)",RFC 5626, DOI 10.17487/RFC5626, October 2009,        <https://www.rfc-editor.org/info/rfc5626>.   [5]  Rosenberg, J., "Obtaining and Using Globally Routable User Agent        URIs (GRUUs) in the Session Initiation Protocol (SIP)",RFC 5627, DOI 10.17487/RFC5627, October 2009,        <https://www.rfc-editor.org/info/rfc5627>.   [6]  Saint-Andre, P. and J. Klensin, "Uniform Resource Names (URNs)",RFC 8141, DOI 10.17487/RFC8141, April 2017,        <https://www.rfc-editor.org/info/rfc8141>.   [7]  Leiba, B., "Ambiguity of Uppercase vs Lowercase inRFC 2119 Key        Words",BCP 14,RFC 8174, DOI 10.17487/RFC8174, May 2017,        <https://www.rfc-editor.org/info/rfc8174>.   [8]  Rescorla, E., "The Transport Layer Security (TLS) Protocol        Version 1.3",RFC 8446, DOI 10.17487/RFC8446, August 2018,        <https://www.rfc-editor.org/info/rfc8446>.Atarius                       Informational                     [Page 7]

RFC 8465               MEID URN as an Instance ID         September 2018   [9]  Leach, P., Mealling, M., and R. Salz, "A Universally Unique        IDentifier (UUID) URN Namespace",RFC 4122,        DOI 10.17487/RFC4122, July 2005,        <https://www.rfc-editor.org/info/rfc4122>.   [10] Atarius, R., "A URN Namespace for Device Identity and Mobile        Equipment Identity (MEID)",RFC 8464, DOI 10.17487/RFC8464,        September 2018, <https://www.rfc-editor.org/info/rfc8464>.   [11] 3GPP, "IP multimedia call control protocol based on Session        Initiation Protocol (SIP) and Session Description Protocol        (SDP); Stage 3", 3GPP 24.229, Version 10.13.0, Release 10,        September 2013,        <ftp://ftp.3gpp.org/Specs/archive/24_series/24.229/>.10.2.  Informative References   [12] Allen, A., Ed., "Using the International Mobile station        Equipment Identity (IMEI) Uniform Resource Name (URN) as an        Instance ID",RFC 7255, DOI 10.17487/RFC7255, May 2014,        <https://www.rfc-editor.org/info/rfc7255>.   [13] 3GPP2, "3G Mobile Equipment Identifier (MEID) - Stage 1, Version        4.0", Stage 1, Version 4.0, 3GPP2 S.R0048-A, June 2005.   [14] 3GPP2, "Voice Call Continuity between IMS and Circuit Switched        Systems - Version 1.0", Version 1.0, 3GPP2 S.X0042-A 1.0, August        2008, <https://www.3gpp2.org/Public_html/Specs/X.S0042-A_v1.0_080904.pdf>.Acknowledgments   This document draws heavily onRFC 8464 [10] and also on the style   and structure used inRFC 7255 [12].   The author thanks Andrew Allen for the detailed comments.Author's Address   Roozbeh Atarius (editor)   Email: ratarius@motorola.comAtarius                       Informational                     [Page 8]