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A Uniform Resource Name Namespace for the GSM Association (GSMA) and the International Mobile station Equipment Identity (IMEI)
draft-montemurro-gsma-imei-urn-15

The information below is for an old version of the document.
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This is an older version of an Internet-Draft that was ultimately published as RFC 7254.
Authors Michael Montemurro , Andrew Allen , David McDonald , Paul Gosden
Last updated 2013-07-05
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draft-montemurro-gsma-imei-urn-15
Network Working Group                                 M. Montemurro, Ed.
Internet-Draft                                                  A. Allen
Intended status: Informational                                Blackberry
Expires: January 6, 2014                                     D. McDonald
                                                                  Eircom
                                                               P. Gosden
                                                         GSM Association
                                                            July 5, 2013

A Uniform Resource Name Namespace for the GSM Association (GSMA) and the
         International Mobile station Equipment Identity (IMEI)
                   draft-montemurro-gsma-imei-urn-15

Abstract

   This specification defines a Uniform Resource Name namespace for the
   GSMA (GSM Association)and a sub-namespace for the IMEI (International
   Mobile station Equipment Identity), and an associated parameter for
   the IMEISV (International Mobile station Equipment Identity and
   Software Version number).  The IMEI is 15 decimal digits long and the
   IMEISV is 16 decimal digits long and both are encoded using Binary
   Encoded Decimal (BCD).  The IMEI and IMEISV were introduced as part
   of the specification for Global System for Mobile communications(GSM)
   and are also now incorporated by the 3rd Generation Partnership
   Project (3GPP) as part of the 3GPP specification for GSM, the
   Universal Mobile Telecommunications System (UMTS) and 3GPP LTE (Long
   Term Evolution).  The IMEI and IMEISV are used to uniquely identify
   Mobile Equipment within these systems and are managed by the GSMA.

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/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   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 January 6, 2014.

Copyright Notice

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   Copyright (c) 2013 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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   This document may contain material from IETF Documents or IETF
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   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
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   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.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4

   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4

   3.  Namespace Registration Template  . . . . . . . . . . . . . . .  5
     3.1.  GSMA . . . . . . . . . . . . . . . . . . . . . . . . . . .  5

   4.  Specification  . . . . . . . . . . . . . . . . . . . . . . . .  9
     4.1.  IMEI Format  . . . . . . . . . . . . . . . . . . . . . . .  9
       4.1.1.  Type Allocation Code (TAC) . . . . . . . . . . . . . .  9
       4.1.2.  Serial Number (SNR)  . . . . . . . . . . . . . . . . .  9
       4.1.3.  Spare  . . . . . . . . . . . . . . . . . . . . . . . .  9
       4.1.4.  Binary Encoding  . . . . . . . . . . . . . . . . . . . 10
     4.2.  IMEISV Format  . . . . . . . . . . . . . . . . . . . . . . 10
       4.2.1.  Type Allocation Code (TAC) . . . . . . . . . . . . . . 10
       4.2.2.  Serial Number (SNR)  . . . . . . . . . . . . . . . . . 10
       4.2.3.  Software Version Number (SVN)  . . . . . . . . . . . . 10
       4.2.4.  Binary Encoding  . . . . . . . . . . . . . . . . . . . 10

   5.  Community considerations . . . . . . . . . . . . . . . . . . . 11

   6.  Namespace considerations . . . . . . . . . . . . . . . . . . . 12

   7.  IANA considerations  . . . . . . . . . . . . . . . . . . . . . 12

   8.  Security considerations  . . . . . . . . . . . . . . . . . . . 12

   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13

   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     10.1. Normative references . . . . . . . . . . . . . . . . . . . 13
     10.2. Informative references . . . . . . . . . . . . . . . . . . 14

   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14

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1.  Introduction

   This specification defines a Uniform Resource Name namespace for the
   GSMA (GSM Association) and a sub-namespace for the IMEI
   (International Mobile station Equipment Identity), and associated
   parameter for the Software Version number from the IMEISV
   (International Mobile station Equipment Identity and Software Version
   number) as per the namespace registration requirement found in [1].
   The namespace gsma is a namespace for identities used in GSM, UMTS
   and LTE networks.  The IMEI and the IMEISV are managed by the GSMA,
   so this namespace would be managed by the GSMA.  Whilst this
   specification currently specifies only the IMEI sub-namespace under
   the GSMA URN namespace additional sub-namespaces under the GSMA
   namespace may be specified in the future by the GSMA through the
   publication of future Informational RFCs.

   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 within the TAC.
   The Spare digit is used as a check 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 and SNR
   same as for the IMEI but also a 2 decimal digit Software Version
   Number (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 TS 23.003 [2] that defines the IMEI and
   IMEISV.

   The GSM Association (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
   mobile phones and wireless services work globally and are easily
   accessible.  Further details about the GSMA role in allocating the
   IMEI and the IMEISV and the IMEI and IMEISV allocation guidelines can
   be found in GSMA PRD TS.06 [3].

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

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   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [4].

3.  Namespace Registration Template

3.1.  GSMA

   Namespace ID:  "gsma" requested

   Registration Information:

   Registration version number:  1

   Registration date:  2013-07-02

   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 ASCII characters and has a
      hierarchical structure expressed using the augmented Backus-Naur
      Form (ABNF) defined in [8] as follows:

       gsma-urn = "urn:gsma:" gsma-specifier
                  *(":" gsma-specifier-defined-substring)
                  *(";" gsma-specifier-param)

       gsma-specifier  = "imei" / gsma-specifier-defined-string
       gsma-specifier-defined-string  = gsma-approved-nonempty-string
       gsma-specifier-defined-substring  = imeival / gsma-approved-nonempty-string
       gsma-specifier-defined-param-name  = gsma-approved-nonempty-string
       gsma-specifier-defined-param-val = gsma-approved-nonempty-string
       gsma-specifier-param =
                       "svn=" software-version-string /
                       "vers=" gsma-format-version-string /
                       gsma-specifier-defined-param-name
                       ["=" gsma-specifier-defined-param-val]
       software-version-string = 2DIGIT
       gsma-format-version-string = DIGIT
       gsma-approved-nonempty-string = 1*unreserved

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       unreserved  = ALPHA / DIGIT / "-" / "." / "_"

      A sub-namespace for the IMEI is defined under the GSMA namespace.
      Other sub-namespaces may be defined in the future to include other
      identifiers in the GSM, UMTS or LTE networks or future networks
      deployed by members of the GSMA.

      An IMEI is an identifier under the GSMA namespace that uniquely
      identifies the mobile devices used in the GSM, UMTS 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 [5]) as a URN, it is necessary to
      convert the received binary (Binary Coded Decimal (BCD)encoded)
      bit sequence to a decimal digit string representation.  Each field
      has its value printed as a decimal digit string with the most
      significant digit first.

      The following augmented Backus-Naur Form (ABNF) includes the set
      of core rules in RFC 5234 [8], and are not repeated here.

      A URN with the "imei" gsma-specifier contains exactly one gsma-
      specifier-defined-substring, and its formal definition is provided
      by the following ABNF [8]:

      imeival =  tac "-" snr "-" spare
      tac      = 8DIGIT
      snr      = 6DIGIT
      spare    = DIGIT
      For example:
         urn:gsma:imei:90420156-025763-0;vers=0

      The optional "vers" parameter is included for extensibility of the
      namespace, for example if the IMEI format is extended in the
      future (such as with additional digits or using hex digits).  A
      value of "vers" 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 format specified here requires the publication
      of a future Informational RFC.

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      draft-allen-dispatch-imei-urn-as-instanceid-10 [9] defines how the
      GSMA IMEI URN can be used as an instance ID as specified in RFC
      5626 [10].  Any future value of the "vers" parameter other than
      equal to 0 or the definition of additional parameters that are
      intended to be used as part of an instance ID will require an
      update to draft-allen-dispatch-imei-urn-as-instanceid-10 [9].

      The IMEISV is an identifier that uniquely identifies mobile
      devices and their associated software versions used in the GSM,
      UMTS and LTE networks.  The representation of the IMEISV is
      defined in 3GPP TS 23.003 [2].

      To represent the IMEISV 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 the IMEISV and
      the spare digit in the IMEI gsma-specifier-defined-substring is
      set to zero.
      For example:
         urn:gsma:imei:90420156-025763-0;svn=42

      The <gsma-specifier>, <gsma-specifier-defined-string>, <gsma-
      specifier-defined-substring>, <gsma-specifier-defined-param-name>
      and <gsma-specifier-defined-param-val> can comprise any ASCII
      characters compliant with the above ABNF.  The exclusion of the
      colon from the list of other characters means that the colon can
      only occur as a delimiter between string values.  The exclusion of
      the semicolon from the list of other characters means that the
      semicolon can only occur as a delimiter for parameter values.  The
      exclusion of the "=" character from the list of other characters
      means that the "=" character can only occur as an operator for
      parameter values.

      The GSMA will take responsibility for the gsma-specifier "imei"
      and manage the URNs in its sub-namespace.

      Additional gsma-specifiers may be added in the future through
      Informational RFCs.

   Relevant ancillary documentation:
      See IMEI Allocation and Approval Guidelines [3] and 3GPP TS 23.003
      [2].

   Identifier uniqueness considerations:
      Identifiers in the "gsma" namespace are defined and assigned in
      the requested namespace by the GSMA after ensuring that the URNs
      to be assigned are unique.  Uniqueness is achieved by checking
      against the registry of previously assigned names.

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      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 Mobile Equipment.
      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
      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" and GSMA is the long standing acronym
      for the trade association that represents the mobile phone
      operators 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 IMEISVs are stored in the Mobile
      Equipment so they remain persistent.  The SVN 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:
      GSMA will manage the <gsma-specifier> (including "imei"), <gsma-
      defined-string>, <gsma-specifier-defined-substring>, <gsma-
      specifier-param>, <gsma-specifier-defined-param-name> and <gsma-
      specifier-defined-param-val> identifier resources to maintain
      uniqueness.

      The process for IMEI and IMEISV assignment is documented in GSMA
      TS 06[3]

   Process for identifier resolution:
      Since the GSMA namespace 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 gsma-specifier-params values in the same
      sequential order, with the exception that the gsma-specifier-param
      "vers=0" is to be ignored for the purposes of comparison.  All of
      these comparisons are to be case-insensitive.

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      Any identifier in GSMA namespaces can be compared using the normal
      mechanisms for percent-encoded UTF-8 strings.

   Conformance with URN Syntax:
      The string representation of the GSMA URN and of the IMEI sub-
      namespace is fully compatible with the URN syntax.

   Validation 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:  GSMA URN is global in scope.

4.  Specification

4.1.  IMEI Format

4.1.1.  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.

4.1.2.  Serial Number (SNR)

   The SNR is a 6 decimal digit value.  The SNR is an individual serial
   number that uniquely identifies each Mobile Equipment within the TAC.

4.1.3.  Spare

   The Spare is a single decimal digit.  When the IMEI is stored on the
   Mobile Equipment and network equipment it contains a value that is
   used as a Check Digit and is intended to avoid manual reporting
   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
   Mobile Equipment, (including when in the IMEI URN format).  Annex B
   of 3GPP TS 23.003 [2] defines a mechanism for computing the actual
   check digit in order to validate the TAC and SNR.

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4.1.4.  Binary Encoding

   When included in a cellular signaling message the IMEI format is 15
   decimal digits encoded in 8 octets using BCD as defined in 3GPP TS
   24.008 [5].  Figure 1 is an abstract representation of a BCD encoded
   IMEI stored in memory (the actual storage format in memory is
   implementation specific).  In Figire 1 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
   signaling message 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
   [5].

       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
                    Figure 1.  IMEI Format

4.2.  IMEISV Format

4.2.1.  Type Allocation Code (TAC)

   The TAC is the same as the TAC in the IMEI in Section 4.1.1.

4.2.2.  Serial Number (SNR)

   The SNR is the same as the SNR in the IMEI in Section 4.1.2.

4.2.3.  Software Version Number (SVN)

   The Software Version Number is allocated by the mobile device
   manufacturer to identify the software version of the mobile device.

4.2.4.  Binary Encoding

   When included in a cellular signaling message the IMEISV format is 16
   decimal digits encoded in 8 octets using BCD as defined in 3GPP TS
   24.008 [5].  Figure 2 is an abstract representation of a BCD encoded
   IMEISV stored in memory (the actual storage format in memory is

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   implementation specific).  In Figire 2 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 signaling message 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 [5].

       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
                     Figure 2.  IMEISV Format

5.  Community considerations

   GSM, UMTS 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 general
   internet.  Some of these protocols require the use of URN's 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 pure internet based
   devices and GSM/UMTS/LTE mobile devices.  Thus the existence and
   syntax of these namespaces needs to be available to the general
   internet community and the namespace needs to be reserved with IANA
   in order to guarantee uniqueness and prevent potential namespace
   conflicts both within the internet 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," 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.

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6.  Namespace considerations

   A URN was considered the most appropriate URI to represent the IMEI
   and IMEISV as these identifiers may be used and transported similarly
   to the Universally Unique Identifier (UUID)which is defined as a URN
   in [11].  Since specifications for protocols that are used to
   transport device identifiers often require the device identifier to
   be globally unique and in the URN format it is necessary that the URN
   formats are defined to represent the IMEI and IMEISV.

7.  IANA considerations

   In accordance with BCP 66 [1], IANA is asked to register the Formal
   URN Namespace 'GSMA' in the Registry of URN Namespaces, using the
   registration template presented in Section 3 of this document.

8.  Security considerations

   IMEIs (but with the Spare value set to the value of the Check Digit)
   are displayable on most mobile devices and in many cases is printed
   on the case within the battery compartment.  Anyone with brief
   physical access to the mobile device can therefore easily obtain the
   IMEI.  Therefore the IMEI MUST NOT be used as security capabilities
   (identifiers whose mere possession grants access).  Unfortuantely
   there are currently examples of some applications which are using the
   IMEI for authorisation.  Also some service providers 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.

   Whilst the specific software version of the mobile device only
   identifies the lower layer software that has undergone and passed
   certification testing and not the operating system or application
   software there is still a possibility that the software version could
   identify software that is vulnerable to attacks or is known to
   contain security holes.  Therfore care SHOULD be taken regarding use
   of the IMEISV as it could help a malicious device identify mobile
   device running software that is known to be vulnerable to certain
   attacks.  This is a similar concern to the use of the User-Agent
   header in SIP as specified in RFC 3261 [12].  Therefore the IMEISV
   (that is, the IMEI URN with svn parameter) MUST NOT be delivered to
   devices that are not trusted.  Further, because IMEIs can be loosely
   correlated to a user, they need to be treated as any other personally
   identifiable information.  In particular, the IMEI URN MUST NOT be
   included in messages intended to convey any level of anonymity.

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   Additional security considerations are specified in 3GPP TS 22.016
   [6].  Specifically the IMEI is to be incorporated in a module which
   is contained within the terminal.  The IMEI SHALL NOT be changed
   after the terminal's production process.  It SHALL resist tampering,
   i.e. manipulation and change, by any means (e.g. physical, electrical
   and software).

9.  Acknowledgements

   This document draws heavily on the 3GPP work on Numbering, Addressing
   and Identification in 3GPP TS 23.003 [2] and also on the style and
   structure used in RFC 4122 [11].  The authors would like to thank
   Cullen Jennings, Lisa Dusseault, Dale Worley, Ivo Sedlacek, Atle
   Monrad, James Yu and Mary Barnes for their help and comments.

10.  References

10.1.  Normative references

   [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, addressing and identification
         (Release 8)", 3GPP 23.003, December 2012,
         <ftp://ftp.3gpp.org/Specs/archive/23_series/23.003/>.

   [3]   GSMA Association, "IMEI Allocation and Approval Guidelines",
         PRD TS.06 (DG06) version 6.0, July 2011, <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]   3GPP, "TS 24.008: Mobile radio interface Layer 3 specification;
         Core network protocols; Stage 3 (Release 8)", 3GPP 24.008,
         June 2013,
         <ftp://ftp.3gpp.org/Specs/archive/24_series/24.008/>.

   [6]   3GPP, "TS 22.016: International Mobile station Equipment
         Identities (IMEI)(Release 7)", 3GPP 22.016, December 2009,
         <ftp://ftp.3gpp.org/Specs/archive/22_series/22.016/>.

   [7]   Moats, R., "URN Syntax", RFC 2141, May 1997.

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10.2.  Informative references

   [8]   Crocker, D. and P. Overell, "Augmented BNF for Syntax
         Specifications: ABNF", STD 68, RFC 5234, January 2008.

   [9]   Allen, A., "Using the International Mobile station Equipment
         Identity(IMEI)URN as an Instance ID, work in progress",
         Internet Draft draft-allen-dispatch-imei-urn-as-instanceid-10,
         July 2013.

   [10]  Jennings, C., Mahy, R., and F. Audet, "Managing Client-
         Initiated Connections in the Session Initiation Protocol
         (SIP)", RFC 5626, October 2009.

   [11]  Leach, P., Mealling, M., and R. Salz, "A Universally Unique
         IDentifier (UUID) URN Namespace", RFC 4122, July 2005.

   [12]  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.

Authors' Addresses

   Michael Montemurro (editor)
   Blackberry
   4701 Tahoe Dr
   Mississauga, Ontario  L4W 0B4
   Canada

   Phone: unlisted
   Fax:   unlisted
   Email: mmontemurro@blackberry.com

   Andrew Allen
   Blackberry
   1200 Sawgrass Corporate Parkway
   Sunrise, Florida  33323
   USA

   Phone: unlisted
   Fax:   unlisted
   Email: aallen@blackberry.com

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   David McDonald
   Eircom

   Phone: unlisted
   Fax:   unlisted
   Email: David.McDonald@meteor.ie

   Paul Gosden
   GSM Association
   1st Floor, Mid City Place, 71 High Holborn,
   London
   England

   Phone: unlisted
   Fax:   unlisted
   Email: pgosden@gsma.com

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