ENUM WG R. Mahy Internet-Draft Plantronics Expires: December 24, 2006 June 22, 2006 A Telephone Number Mapping (ENUM) Service Registration for Instant Messaging (IM) Services draft-ietf-enum-im-service-01.txt Status of this Memo 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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 24, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document registers a Telephone Number Mapping (ENUM) service for Instant Messaging (IM). Specifically, this document focuses on provisioning 'im:' URIs in ENUM. 1. Introduction ENUM (E.164 Number Mapping, RFC 3761 [1]) is a system that uses DNS (Domain Name Service, RFC 1034 [2]) to translate telephone numbers, Mahy Expires December 24, 2006 [Page 1] Internet-Draft IM Enumservice June 2006 such as '+12025332600', into URIs (Uniform Resource Identifiers, RFC 2396 [3]), such as 'im:user@example.com'. ENUM exists primarily to facilitate the interconnection of systems that rely on telephone numbers with those that use URIs to identify resources. Instant Messaging (IM) is a service defined in RFC 2778 [5] that allows users to send and receive typically short, often textual messages in near real-time. The IETF has defined a generic URI used to identify an IM service for a particular resource: the 'im:' URI scheme (defined in RFC 3861 [4]). RFC 3861 [4] also defines rules for discovering service running specific protocols, such as SIP (the Session Initiation Protocol, RFC 3261 [7]) and XMPP (the eXtensible Messaging and Presence Protocol, RFC 3921 [8]) from a specific 'im:' URI. RFC 3953 [9] already defines an enumservice for presence services which returns 'pres:' URIs (also defined in RFC 3861 [4]). This document registers an enumservice for advertising IM information associated with an E.164 number. 2. ENUM Service Registration - im As defined in RFC 3761 [1], the following is a template covering information needed for the registration of the enumservice specified in this document: Enumservice Name: "im" Enumservice Type: "im" Enumservice Subtypes: N/A URI scheme(s): "im:" Functional Specification: This Enumservice indicates that the resource identified is an 'im:' URI. The 'im:' URI scheme does not identify any particular protocol that will be used to handle instant messaging receipt or delivery, rather the mechanism in RFC 3861 [4] is used to discover whether an IM protocol supported by the party querying ENUM is also supported by the target resource. Security considerations: See section 3. Intended usage: COMMON Mahy Expires December 24, 2006 [Page 2] Internet-Draft IM Enumservice June 2006 Author: Rohan Mahy (rohan@ekabal.com) 3. Security Considerations The Domain Name System (DNS) does not make policy decisions about which records it provides to a DNS resolver. All DNS records must be assumed to be available to all inquirers at all times. The information provided within an ENUM record set must therefore be considered open to the public -- which is a cause for some privacy considerations. Revealing an IM URI by itself is unlikely to introduce many privacy concerns, although, depending on the structure of the URI, it might reveal the full name or employer of the target. The use of anonymous URIs mitigates this risk. More serious security concerns are associated with potential attacks against an underlying Instant Messaging system (for example, message forgery and tampering). For this reason, IM protocols have a number of security requirements (detailed in RFC 2779 [6]) that call for authentication, integrity and confidentiality properties, and similar measures to prevent such attacks. Any instant messaging protocol used in conjunction with the 'im:' URI scheme is required to meet these requirements. Unlike a traditional telephone number, the resource identified by an im URI may require that callers provide cryptographic credentials for authentication and authorization before instant messages are exchanged. In concert with instant messaging protocols, ENUM can actually provide far greater protection from unwanted callers than does the existing PSTN, despite the public availability of ENUM records. 4. IANA Considerations This document requests registration of the "im" Enumservice according to the definitions in this document and RFC 3761 [1]. 5. References 5.1 Normative References [1] Faltstrom, P. and M. Mealling, "The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application (ENUM)", RFC 3761, April 2004. [2] Mockapetris, P., "Domain names - concepts and facilities", Mahy Expires December 24, 2006 [Page 3] Internet-Draft IM Enumservice June 2006 STD 13, RFC 1034, November 1987. [3] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. [4] Peterson, J., "Address Resolution for Instant Messaging and Presence", RFC 3861, August 2004. 5.2 Informational References [5] Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence and Instant Messaging", RFC 2778, February 2000. [6] Day, M., Aggarwal, S., Mohr, G., and J. Vincent, "Instant Messaging / Presence Protocol Requirements", RFC 2779, February 2000. [7] 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. [8] Saint-Andre, P., Ed., "Extensible Messaging and Presence Protocol (XMPP): Instant Messaging and Presence", RFC 3921, October 2004. [9] Peterson, J., "Telephone Number Mapping (ENUM) Service Registration for Presence Services", RFC 3953, January 2005. Author's Address Rohan Mahy Plantronics Email: rohan@ekabal.com Mahy Expires December 24, 2006 [Page 4] Internet-Draft IM Enumservice June 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Mahy Expires December 24, 2006 [Page 5]