INTERNET-DRAFT Edward Lewis February 19, 2007 NeuStar, Inc. Expires August 19, 2007 E.212 Parameters for the "tel" URI draft-lewis-enum-teluri-e212-00.txt By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Abstract Parameters are defined in the "tel" Uniform Resource Identifier (URI) to carry ITU E.212-related information. 1 Introduction Three parameters are defined for the tel URI [RFC3966] to permit storage of E.212 [ITUE212] data. E.212 data has three components, the Mobile Country Code (MCC), the Mobile Network Code (MNC), and the Mobile Subscriber Identification Number (MSIN). Collectively, these form the Internation Mobile Subscriber Identity. To store an IMSI, and therefore all three components, just one parameter would be needed if not for concern over exposing the MSIN in a public database like DNS. There is a need to publically view the MCC and MNC numbers though, so individual parameters are defined for those values. The parameter for the entire IMSI will be "imsi", the parameter for the MCC will be "mcc" and the parameter for the MNC will be "mnc." In the parlance of RFC 4694 [RFC4694], these parameters are suitable for placement in static content. 2 Terminology The key words "MUST," "SHOULD," and "MAY" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 3 Formal Syntax The following syntax specification uses the Augmented Backus-Naur Form (ABNF) as described in RFC 4234 [RFC4234] and defines the three parameters, imsi, mcc, and mnc by extending the "parameter" production rule of the "tel" URI defined in [RFC3966]. parameter = / imsi / mcc / mnc imsi = ";imsi=" imsi-digits mcc = ";mcc=" 3(DIGIT) mnc = ";mnc=" (2(DIGIT) / 3(DIGIT)) imsi-digits = (upto) 15(DIGIT) ; ed.note, fix this 4 Normative Rules If the imsi parameter is in use, all three values are expected to be present. Rules for the use of the parameter's value are contained in the ITU document defining the IMSI. The other two parameters, mcc and mnc are used in tandem to identify the network serving the telephone number. 5 Examples For a telephone number +1-571-555-1000, served on a network whose MCC is 330, MNC is 110 and MSIN is 123456789, the two "tel" URI's that might appear with these parameters are: tel:+15715551000;imsi=330110123456789 tel:+15715551000;mcc=330;mnc=110 6 Security Considerations The one concern raised in this document is the potential concern over the privacy required for the MSIN that appears in the IMSI. If the IMSC parameter is used, the operator must understand the exposure that may be had by the data. The full IMSI ought to be restricted to situations in which the exposure of the MSIN is acceptable. To alleviate this concern, the MCC and MNC parameters are defined, these are expected to be what appears in a pubic or otherwise widely (or externally) distributed environment. 7 IANA Considerations This document requires no IANA actions. 8 Internationalization Considerations There are no internationalization considerations in these parameters. All data are numeric. 9 References 9.1 Normative [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966, December 2004. [RFC4234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 4234, October 2005. [ITUE212] ITU-T Recommendation E.212, "The International Identification Plan for Mobile Terminals and Mobile Users, " May 2004. 9.2 Informative (ed.note - do I need this, i.e., should it be mentioned in IANA consid.?) [TELREG] Jennings, C. and V. Gurbani, "The Internet Assigned Numbers Authority (IANA) tel Uniform Resource Identifier (URI) Parameter Registry", Work in Progress, May 2006. 10 Author's Address Edward Lewis NeuStar 46000 Center Oak Plaza Sterling, VA 20166, US Phone: +1-571-434-5468 EMail: ed.lewis@neustar.biz Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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