Network Working GroupInternet Engineering Task Force (IETF) M. Montemurro, Ed.Internet-DraftRequest for Comments: 7254 A. AllenIntended status:Category: Informational BlackberryExpires: August 30, 2014ISSN: 2070-1721 D. McDonald Eircom P. Gosden GSM AssociationFebruary 26,May 2014 A Uniform Resource Name Namespace for the Global System for MobilecommunicationsCommunications Association (GSMA) and the International Mobile station Equipment Identity (IMEI)draft-montemurro-gsma-imei-urn-20Abstract This specificationspecifiesdefines a Uniform Resource Name (URN) namespace for theGSMA (GlobalGlobal System for Mobilecommunications Association)Communications Association (GSMA) and a Namespace Specific String (NSS) for theIMEI (InternationalInternational Mobile station EquipmentIdentity), andIdentity (IMEI), as well as an associated parameter for theIMEISV (InternationalInternational Mobile station Equipment Identity and Software Versionnumber).number (IMEISV). The IMEI and IMEISV were introduced as part of the specification forGlobal System for Mobile communications (GSM)the GSM and are also now incorporated by the 3rd Generation Partnership Project (3GPP) as part of the 3GPP specification for GSM,theUniversal Mobile Telecommunications System(UMTS)(UMTS), and 3GPPLTE (LongLong TermEvolution).Evolution (LTE) networks. The IMEI and IMEISV are used to uniquely identify Mobile Equipment within these systems and are managed by the GSMA. URNs from this namespace almost always containPersonally Identifying Informationpersonally identifiable information and need to be treated accordingly. Status ofthisThis Memo ThisInternet-Draftdocument issubmitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documentsnot an Internet Standards Track specification; it is published for informational purposes. This document is a product of the Internet Engineering Task Force (IETF).Note that other groups may also distribute working documents as Internet-Drafts. The listIt represents the consensus ofcurrent Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents validthe 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 amaximumcandidate for any level ofsix monthsInternet 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 beupdated, replaced, or obsoleted by other documentsobtained atany time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on August 30, 2014.http://www.rfc-editor.org/info/rfc7254. 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 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. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Table of Contents 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 4....................................................3 2. Terminology. . . . . . . . . . . . . . . . . . . . . . . . . 5.....................................................4 3. Namespace Registration Template. . . . . . . . . . . . . . . 5.................................4 4. Specification. . . . . . . . . . . . . . . . . . . . . . . . 9...................................................8 4.1. IMEI Parameters. . . . . . . . . . . . . . . . . . . . . 9............................................8 4.2. IMEI Format. . . . . . . . . . . . . . . . . . . . . . . 10................................................9 4.2.1. Type Allocation Code (TAC). . . . . . . . . . . . . . 10..........................9 4.2.2. Serial Number (SNR). . . . . . . . . . . . . . . . . 10.................................9 4.2.3. Spare. . . . . . . . . . . . . . . . . . . . . . . . 10..............................................10 4.2.4. Binary Encoding. . . . . . . . . . . . . . . . . . . 10....................................10 4.3. IMEISV Format. . . . . . . . . . . . . . . . . . . . . . 11.............................................10 4.3.1. Type Allocation Code (TAC). . . . . . . . . . . . . . 11.........................10 4.3.2. Serial Number (SNR). . . . . . . . . . . . . . . . . 11................................11 4.3.3. Software Version Number (SVN). . . . . . . . . . . . 11......................11 4.3.4. Binary Encoding. . . . . . . . . . . . . . . . . . . 11....................................11 5. Communityconsiderations . . . . . . . . . . . . . . . . . . . 12Considerations .......................................11 6. Namespaceconsiderations . . . . . . . . . . . . . . . . . . . 12Considerations .......................................12 7. IANAconsiderations . . . . . . . . . . . . . . . . . . . . . 13Considerations ............................................12 8. Security andprivacy considerations . . . . . . . . . . . . . 13Privacy Considerations ............................12 9. Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . 14...............................................14 10. References. . . . . . . . . . . . . . . . . . . . . . . . . . 14....................................................14 10.1. Normativereferences . . . . . . . . . . . . . . . . . . . 14References .....................................14 10.2. Informativereferences . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15References ...................................15 1. Introduction This specificationspecifiesdefines a Uniform Resource Name (URN) namespace for theGSMA (GSM Association)Global System for Mobile Communications Association (GSMA) and aNSSNamespace Specific String (NSS) for theIMEI (InternationalInternational Mobile station EquipmentIdentity), andIdentity (IMEI), as well as an associated parameter for theSoftware Version number from the IMEISV (InternationalInternational Mobile station Equipment Identity and Software Versionnumber)number (IMEISV) as per the namespace registration requirement found in RFC 3406 [1]. TheNID (Namespace Identifier)Namespace Identifier (NID) 'gsma' is for identities used in GSM,UMTSUniversal Mobile Telecommunications System (UMTS), andLTELong Term Evolution (LTE) networks. The IMEI and the IMEISV are managed by the GSMA, so this NID is managed by the GSMA.WhilstWhile this specification currentlyspecifiesdefines only theIMEI'imei' NSS under the 'gsma' NID, additional NSS under the 'gsma' NID may be specified in the future by theGSMAGSMA, using the procedure for URN NSS changes and additions (currently through the publication of future Informational RFCs approved by IETFconensus).consensus). The IMEI is 15 decimal digits long and includes a Type Allocation Code (TAC) of 8 decimal digits and a Serial Number (SNR) of 6 decimal digits plus a Spare decimal digit. The TAC identifies the type of the Mobile Equipment and is chosen from a range of values allocated to the Mobile Equipment manufacturer in order to uniquely identify the model of the Mobile Equipment. The SNR is an individual serial number that uniquely identifies each Mobile Equipment device within the TAC. The Spare digit is used as acheckCheck digit to validate the IMEI and is always set to the value 0 when transmitted by the Mobile Equipment. The IMEISV is 16 decimal digits long and includes the TAC andSNRSNR, same as for theIMEIIMEI, but also includes a 2 decimal digit Software Version Number(SVN)(SVN), which is allocated by the Mobile Equipment manufacturer to identify the software version of the Mobile Equipment. The information here is meant to be a concise guide for those wishing to use the IMEI and IMEISV as URNs. Nothing in this document should be construed to override 3GPP Technical Specification (TS) 23.003[2] that[2], which specifies the IMEI and IMEISV. TheGSM Association (GSMA)GSMA is a global trade association representing nearly 800 mobile phone operators across 220 territories and countries of the world. The primary goals of the GSMA are to ensure that mobile phones and wireless services work globally and are easily accessible. Further details about theGSMAGSMA's role in allocating the IMEI and theIMEISV andIMEISV, as well as the IMEI and IMEISV allocationguidelinesguidelines, can be found in GSMA Permanent Reference Document (PRD)TS 06TS.06 [3]. 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 RFC 2119 [4]. 3. Namespace Registration Template Namespace ID: 'gsma'requestedRegistration Information: Registration version number: 1 Registration date: 2014-01-12 Declared registrant of the namespace: Registering organization: Name: GSM Association Address: 1st Floor, Mid City Place, 71 High Holborn, London, England Designated contact person: Name: Paul Gosden Coordinates: pgosden@gsma.com Declaration of syntactic structure: The identifier is expressed in American Standard Code for Information Interchange (ASCII) characters and has a hierarchical structure expressed using theaugmentedAugmented Backus-Naur Form (ABNF) defined in RFC 5234[5][5], as follows: gsma-urn = "urn:" gsma-NID ":" gsma-NSS gsma-NID = "gsma" gsma-NSS = imei-specifier / future-gsma-specifier imei-specifier = "imei:" ( imeival / ext-imei ) [ ";" sw-version-param ] [ ";" imei-version-param ] ext-imei = gsma-defined-nonempty ;GSMA defined and ;IETF consensus ;required sw-version-param = "svn=" software-version imei-version-param = "vers=" imei-version-val software-version = 2DIGIT imei-version-val = DIGIT future-gsma-specifier = future-specifier *( ";" future-param ) future-specifier = gsma-defined-nonempty ;GSMA definedand ;IETF consensus ;requiredfuture-param = par-name [ EQUAL par-value ] par-name = gsma-defined-nonempty par-value = gsma-defined-nonempty EQUAL = "=" gsma-defined-nonempty = 1*gsma-urn-char gsma-urn-char = ALPHA / DIGIT / "-" / "." / "_" / "%" / ":"AAn NSS for the IMEI is defined under the 'gsma' NID. An IMEI is an identifier under the 'gsma' NID that uniquely identifies the mobile devices used in the GSM,UMTSUMTS, and LTE networks. The representation of the IMEI is defined in 3GPP TS 23.003 [2]. To accurately represent an IMEI received in a cellular signaling message (see 3GPP TS 24.008 [6]) as a URN, it is necessary to convert the received binary (Binary Coded Decimal(BCD)(BCD)) encoded bit sequence to a decimal digit string representation. Each field has its representation for humans as a decimal digit string with the most significant digit first. The followingaugmented Backus-Naur Form (ABNF)ABNF includes the set of core rules in RFC 5234[5], and[5]; the core rules are not repeated here. A URN with the 'imei' NSS contains oneimeival,'imeival', and its formal definition is provided by the following ABNF (RFC 5234) [5]: imeival = tac "-" snr "-" spare tac = 8DIGIT snr = 6DIGIT spare = DIGITThe <future-gsma-specifier>,<future-gsma-specifier> and <gsma-defined-nonempty> can comprise any ASCII characters compliant with the above ABNF. The GSMA will take responsibility for theNSS 'imei'.'gsma' namespace, including the 'imei' NSS. Additional NSS may be added for future identifiers needed by theGSMA usingGSMA, at their discretion. Only URNs with theprocedure for URN'imei' NSSchangesare considered to be "GSMA IMEI URNs", andadditions (currently through the publicationuse in IETF protocols of other NSS that might be defined in the futureInformational RFCs approved bywill require IETFconsensus).consensus. Relevant ancillary documentation: See IMEI Allocation and Approval Guidelines (GSMA PRD TS.06) [3] and 3GPP TS 23.003 [2]. Identifier uniqueness considerations: Identifiers under the 'gsma' NID are defined and assigned by the GSMA after ensuring that the URNs to be assigned are unique. Uniqueness is achieved by checking against the IANA registry of previously assigned names. Procedures are in place to ensure that each IMEI is uniquely assigned by the Mobile Equipment manufacturer so that it is guaranteed to uniquely identify that particular MobileEquipment.Equipment device. Procedures are in place to ensure that each IMEISV is uniquely assigned by the Mobile Equipment manufacturer so that it is guaranteed to uniquely identify that particular Mobile Equipment device and the specific software version installed. Identifier persistence considerations: The GSMA is committed to maintaining uniqueness and persistence of all resources identified by assigned URNs. As the NID sought is 'gsma' andGSMA"GSMA" is thelong standinglong-standing acronym for the trade association that represents the mobile phoneoperatorsoperators, the URN should also persist indefinitely (at least as long as there is a need for its use). The assignment process guarantees that names are not reassigned. The binding between the name and its resource is permanent. The TAC and SNR portions of the IMEI andIMEISVsIMEISV are permanently stored in the MobileEquipmentEquipment, so they remain persistent as long as the Mobile Equipment exists. The process for TAC and SNR assignment is documented in GSMA PRDTS 06[3]TS.06 [3], and once assigned, the TAC and SNR valuesonce assignedare notre-assignedreassigned to other MobileEquipment.Equipment devices. The SVN portion of the IMEISV may be modified by software when new versions are installed but should be persistent for the duration of the installation of that specific version of software. Process of identifier assignment: The GSMA will manage the <NSS> (including'imei'),'imei') and<future-gsma- specifier><future-gsma-specifier> identifier resources to maintain uniqueness. The process for IMEI and IMEISV assignment is documented in GSMA PRDTS 06[3]TS.06 [3]. Process for identifier resolution: Since the 'gsma' NSS is not currently globally resolvable, this is not applicable. Rules for Lexical Equivalence: Two GSMA IMEI URNs are equivalent if they have the same 'imeival' value, and the same parameter values in the same sequential order, with the exception that the"vers=0"'vers=0' parameter is to be ignored for the purposes of comparison. All of these comparisons are to becase-insensitive.case insensitive. Any identifier in the 'gsma' NSS can be compared using the normal mechanisms for percent-encoded UTF-8 strings (see RFC 3629 [7]). Conformance with URN Syntax: The string representation of the 'gsma' NID and of theIMEI'imei' NSS is fully compatible with the URNsyntax(seesyntax (see RFC 2141 [8]). ValidationMechanism:mechanism: The IMEI can be validated using the mechanism defined in Annex B of 3GPP TS 23.003 [2]. There is no mechanism defined to validate the SVN field of the IMEISV. Scope: The GSMA URN is global in scope. 4. Specification 4.1. IMEI Parameters The optional 'vers' parameter and the 'ext-imei' field in the ABNF are included for extensibility of theIMEI NSS,'imei' NSS -- forexampleexample, if the IMEI format is extended in the future (such as with additional digits or using hex digits). In thiscasecase, the 'vers' parameter would contain anon zeronon-zero value and the 'ext-imei' would be further defined to represent the syntax of the extended IMEI format. A value of the 'vers' parameter equal to 0 or the absence of the 'vers' parameter means the URN format is compliant with the format specified here. Any change to the formatspecified hereof the 'imei' NSS requires the use of the procedure for URN NSS changes and additions (currently through the publication ofafuture Informational RFCs approved by IETF consensus). Thereason whyuse of the 'vers' parameter was chosen for extensibility instead of defining a new NSS(e.g.(e.g., 'imei2')is thatbecause it is likely that many applications will only need to perform string compares of the 'imeival'.SoSo, even if the format or length of the 'imeival' changes in the future, such applications should continue to work without having to be updated to understand a new NSS.draft-allen-dispatch-imei-urn-as-instanceid-13RFC 7255 [10] specifies how the GSMA IMEI URN can be used as an instance ID as specified in RFC 5626 [11]. Any future value of the 'vers' parameter other thanequal to 00, or the definition of additional parameters that are intended to be used as part of an instanceIDID, will require an update todraft-allen-dispatch-imei-urn-as-instanceid-13RFC 7255 [10]. For example: urn:gsma:imei:90420156-025763-0;vers=0 The IMEISV is an identifier that uniquely identifies mobile devices and their associated software versions used in the GSM,UMTSUMTS, and LTE networks. The representation of the IMEISV is defined in 3GPP TS 23.003 [2]. To represent theIMEISVIMEISV, the URN parameter 'svn' is appended to the GSMA IMEI URN and set equal to the decimal string representation of the two software version number (svn) digits in theIMEISVIMEISV, and thespareSpare digit in the IMEIimeival'imeival' is set to zero. For example: urn:gsma:imei:90420156-025763-0;svn=42 4.2. IMEI Format 4.2.1. Type Allocation Code (TAC) The TAC is an 8 decimal digit value. The TAC identifies the type of the Mobile Equipment and is chosen from a range of values allocated to the Mobile Equipment manufacturer in order to uniquely identify the model of the Mobile Equipment. 4.2.2. Serial Number (SNR) The SNR is a 6 decimal digit value. The SNR is an individual serial number that uniquely identifies each Mobile Equipment device within the TAC. 4.2.3. Spare The Spare is a single decimal digit. When the IMEI is stored on the Mobile Equipment and networkequipmentequipment, it contains a value that is used as a CheckDigitdigit and is intended to avoid manual reportingerrors, (e.g.errors (e.g., when customers register stolen mobiles at the operator's customer care desk) and also to help guard against the possibility of incorrect entries being provisioned in the network equipment. The Spare is always set to zero when transmitted by the MobileEquipment,Equipment (including when in the IMEI URN format). Annex B of 3GPP TS 23.003 [2] specifies a mechanism for computing the actualcheckCheck digit in order to validate the TAC and SNR. 4.2.4. Binary Encoding When included in a cellular signalingmessagemessage, the IMEI format is 15 decimal digits encoded in 8octetsoctets, using BCD as defined in 3GPP TS 24.008 [6]. Figure 1 is an abstract representation of aBCD encodedBCD-encoded IMEI stored in memory (the actual storage format in memory is implementation specific). In Figure11, the most significant digit of the TAC is coded in the least significant bits of octet 1. The most significant digit of the SNR is coded in the least significant bits of octet 5. The Spare digit is coded in the least significant bits of octet 8. When included in an identity element in a cellular signalingmessagemessage, the most significant digit of the TAC is included in digit 1 of the identity element in Figure 10.5.4 of 3GPP TS 24.008 [6]. 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Decimal Digits +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | | | S| | T | S | p| | A | N | a| | C | R | r| | | | e| +--+-----+-----+-----+--+--+-----+-----+--+--+ 1 2 3 4 5 6 7 8 Octets Figure1.1: IMEI Format 4.3. IMEISV Format 4.3.1. Type Allocation Code (TAC) The TAC is the same as the TAC in the IMEIin(see Section4.2.1.4.2.1). 4.3.2. Serial Number (SNR) The SNR is the same as the SNR in the IMEIin(see Section4.2.2.4.2.2). 4.3.3. Software Version Number (SVN) The Software Version Number is allocated by the mobile device manufacturer to identify the software version of the mobile device. 4.3.4. Binary Encoding When included in a cellular signalingmessagemessage, the IMEISV format is 16 decimal digits encoded in 8 octets using BCD as defined in 3GPP TS 24.008 [6]. Figure 2 is an abstract representation of aBCD encodedBCD-encoded IMEISV stored in memory (the actual storage format in memory is implementation specific). In Figure22, the most significant digit of the TAC is coded in the most significant bits of octet 1. The most significant digit of the SNR is coded in the most significant bits of octet 5. The most significant digit of the SVN is coded in the most significant bits of octet 8. When included in an identity element in a cellular signalingmessagemessage, the most significant digit of the TAC is included in digit 1 of the identity element in Figure 10.5.4 of 3GPP TS 24.008 [6]. 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Decimal Digits +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ | | | | | T | S | S | | A | N | V | | C | R | N | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+ 1 2 3 4 5 6 7 8 Octets Figure2.2: IMEISV Format 5. CommunityconsiderationsConsiderations GSM,UMTSUMTS, and LTE mobile devices will be interoperating with Internet devices for a variety of voice and data services. To do this, they need to make use of Internet protocols that will operate end to end between devices in GSM/UMTS/LTE networks and those in the generalinternet.Internet. Some of these protocols require the use ofURN'sURNs as identifiers. Within the GSM/UMTS/LTE networks, mobile devices are identified by their IMEI or IMEISV. Internet users will need to be able to receive and include the GSMA URN in various Internet protocol elements to facilitate communication between pureinternet basedInternet-based devices and GSM/UMTS/LTE mobile devices.ThusThus, the existence and syntax of these namespacesneedsneed to be available to the generalinternet communityInternet community, and the namespace needs to be reserved with IANA in order to guarantee uniqueness and prevent potential namespace conflicts both within theinternetInternet and within GSM/UMTS/LTE networks. Conversely, Internet implementations will not generally possess IMEI identifiers. The identifiers generated by such implementations will typically be URNs within namespaces other than'gsma','gsma' and may, depending on context, even be non-URN URIs. Implementations are advised to be ready to process URIs other than 'gsma' namespaced URNs, so as to aid in interoperability. 6. NamespaceconsiderationsConsiderations A URN was considered the most appropriate URI to represent the IMEI andIMEISVIMEISV, as these identifiers may be used and transported similarly to the Universally Unique Identifier(UUID)(UUID), which is defined as a URN in RFC 4122 [12]. Since specifications for protocols that are used to transport device identifiers often require the device identifier to be globally unique and in the URNformatformat, it is necessary that the URN formats are defined to represent the IMEI and IMEISV. 7. IANAconsiderationsConsiderations In accordance with BCP 66 (RFC 3406) [1], IANAis asked to registerhas registered the Formal URN Namespace 'gsma' in theRegistry of URN Namespaces,"Uniform Resource Names (URN) Namespaces" registry, using the registration template presented in Section 3 of this document. 8. Security andprivacy considerationsPrivacy Considerations IMEIs (but with the Spare value set to the value of the CheckDigit)digit) are displayable on most mobile devices and in many cases are printed on the case within the battery compartment. Anyone with brief physical access to the mobile device can therefore easily obtain the IMEI.ThereforeTherefore, IMEIs MUST NOT be used as security capabilities (identifiers whose mere possession grants access).UnfortuantelyUnfortunately, there are currently examples of some applicationswhichthat are using the IMEI forauthorisation. Alsoauthorization. Also, some service provider's customer service departments have been known to use knowledge of the IMEI as "proof" that the caller is the legitimate owner of the mobile device. Both of these are inappropriate uses of the IMEI.WhilstWhile the specific software version of the mobile device only identifies thelower layerlower-layer software that has undergone and passed certificationtestingtesting, and not the operating system or application software, the software version could identify software that is vulnerable to attacks or is known to contain security holes.TherforeTherefore, the IMEISV MUST only be delivered to trusted entities within carrier networks and not provided to theinternetInternet at large, as it could help a malicious device identify that the mobile device is running software that is known to be vulnerable to certain attacks. This concern isasimilarconcernto concerns regarding the use of the User-Agent header inSIP (Sessionthe Session InitiationProtocol)Protocol (SIP) as specified in RFC 3261 [13].ThereforeTherefore, the IMEISV (that is, the IMEI URN with a 'svn' parameter) MUST NOT be delivered to devices that are not trusted. IMEIs are almost alwaysaspersonally identifiableinformationinformation, and so these URNs MUST be treated as personally identifiable information in all cases. In order to prevent violating a user'sprivacyprivacy, the IMEI URN MUST NOT be included in messages intended to convey any level of anonymity. Since the IMEI is permanently assigned to the mobile device and is not modified when the ownership of the mobile devicechanges,changes (even upon a complete software reload of the device), the IMEI URN MUST NOT be used as a user identifier or user address by an application. Using the IMEI to identify a user or as a user address could result in communications destined for a previous owner of a device being received by the new device owner or could allow the new device owner to access information or services owned by the previous device owner. Additionally, since the IMEI identifies the mobile device, it potentially could be used to identify and track users for the purposes ofsurvelliencesurveillance and call data mining if sent in the clear. Since the IMEI is personally identifiableinformationinformation, uses of the IMEI URN with IETF protocols require a specification and IETFexpert reviewExpert Review [14] in order to ensure thattheprivacy concerns are appropriately addressed. Protocols carrying the IMEI URN SHOULD at a minimum use channels that are strongly hop-by-hopencrypted channelsencrypted, andthatit is RECOMMENDED that end-to-end encryptionis usedbe used. Additional security considerations are specified in 3GPP TS 22.016 [9].SpecificallySpecifically, the IMEI is to be incorporated in a modulewhichthat is contained within the terminal. The IMEI SHALL NOT be changed after the terminal's production process. It SHALL resist tampering,i.e.i.e., manipulation and change, by any means(e.g.(e.g., physical,electricalelectrical, and software). 9. Acknowledgements This document draws heavily on the 3GPP work on Numbering,AddressingAddressing, and Identification in 3GPP TS 23.003 [2] and also on the style and structure used in RFC 4122 [12]. The authors would like to thank Cullen Jennings, Lisa Dusseault, Dale Worley, Ivo Sedlacek, Atle Monrad, James Yu, Mary Barnes, Tim Bray, S. Moonesamy, Alexey Melnikov, Martin Duerst, John Klensin, Paul Kyzivat, Christer Holmberg, Barry Leiba, and Stephen Farrell for their help and comments. 10. References 10.1. NormativereferencesReferences [1] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, "Uniform Resource Names (URN) Namespace Definition Mechanisms", BCP 66, RFC 3406, October 2002. [2] 3GPP,"TS 23.003: Numbering,"Numbering, addressing andidentification (Release 8)",identification", 3GPP23.003, September 2012, <ftp://ftp.3gpp.org/Specs/archive/23_series/23.003/>.TS 23.003 (Release 8), March 2014, <ftp://ftp.3gpp.org/Specs/ archive/23_series/23.003/>. [3]GSMAGSM Association, "IMEI Allocation and Approval Guidelines", PRDTS 06TS.06 (DG06)versionVersion 6.0, July 2011,<http://www.gsma.com/ newsroom/wp-content/uploads/2012/06/<http://www.gsma.com/newsroom/wp-content/uploads/2012/06/ ts0660tacallocationprocessapproved.pdf>. [4] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [5] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008. [6] 3GPP,"TS 24.008: Mobile"Mobile radio interface Layer 3 specification; Core network protocols; Stage3 (Release 8)",3", 3GPP24.008,TS 24.008 (Release 8), June 2013,<ftp://ftp.3gpp.org/Specs/archive/24_series/24.008/>.<ftp://ftp.3gpp.org/Specs/archive/24_series/ 24.008/>. [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, November 2003. [8] Moats, R., "URN Syntax", RFC 2141, May 1997. [9] 3GPP,"TS 22.016: International"International Mobile station Equipment Identities(IMEI) (Release 8)",(IMEI)", 3GPP22.016,TS 22.016 (Release 8), December 2009, <ftp://ftp.3gpp.org/Specs/archive/22_series/22.016/>. 10.2. InformativereferencesReferences [10] Allen, A., Ed., "Using the International Mobile station EquipmentIdentity(IMEI) URNIdentity (IMEI) Uniform Resource Name (URN) as an InstanceID, work in progress", Internet Draft draft-allen-dispatch-imei-urn-as-instanceid-13, FebruaryID", RFC 7255, May 2014. [11] Jennings, C., Mahy, R., and F. Audet, "Managing Client- Initiated Connections in the Session Initiation Protocol (SIP)", RFC 5626, October 2009. [12] Leach, P., Mealling, M., and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005. [13] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. [14] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. Authors' Addresses Michael Montemurro (editor) Blackberry 4701 TahoeDrDr. Mississauga, Ontario L4W 0B4 CanadaEmail:EMail: mmontemurro@blackberry.com Andrew Allen Blackberry 1200 Sawgrass Corporate Parkway Sunrise, Florida 33323 USAEmail:EMail: aallen@blackberry.com David McDonald EircomEmail:EMail: David.McDonald@meteor.ie Paul Gosden GSM Association 1st Floor, Mid City Place, 71 HighHolborn,Holborn London EnglandEmail:EMail: pgosden@gsma.com