Using E.164 numbers with the Session Initiation Protocol (SIP)
RFC 3824
Document | Type | RFC - Informational (June 2004; No errata) | |
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Authors | Jon Peterson , Hong Liu , Ben Campbell , James Yu | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3824 (Informational) | |
Action Holders |
(None)
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||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Allison Mankin | ||
Send notices to | (None) |
Network Working Group J. Peterson Request for Comments: 3824 H. Liu Category: Informational J. Yu NeuStar B. Campbell dynamicsoft June 2004 Using E.164 numbers with the Session Initiation Protocol (SIP) Status of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004). Abstract There are a number of contexts in which telephone numbers are employed by Session Initiation Protocol (SIP) applications, many of which can be addressed by ENUM. Although SIP was one of the primary applications for which ENUM was created, there is nevertheless a need to define procedures for integrating ENUM with SIP implementations. This document illustrates how the two protocols might work in concert, and clarifies the authoring and processing of ENUM records for SIP applications. It also provides guidelines for instances in which ENUM, for whatever reason, cannot be used to resolve a telephone number. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Handling Telephone Numbers in SIP . . . . . . . . . . . . . . 3 4. Design Principles . . . . . . . . . . . . . . . . . . . . . . 5 5. Authoring NAPTR Records for SIP . . . . . . . . . . . . . . . 6 5.1. The Service Field . . . . . . . . . . . . . . . . . . . 6 5.2. Creating the Regular Expression: Matching . . . . . . . 6 5.3. Creating the Regular Expression: The URI . . . . . . . . 7 5.4. Setting Order and Preference amongst Records . . . . . . 8 5.5. Example of a Well-Formed ENUM NAPTR Record Set for SIP. 8 6. Processing ENUM Records . . . . . . . . . . . . . . . . . . . 8 6.1. Contending with Multiple SIP records . . . . . . . . . . 8 Peterson, et al. Informational [Page 1] RFC 3824 SIPPING E.164 June 2004 6.2. Processing the Selected NAPTR Record . . . . . . . . . . 9 7. Compatibility with RFC 3761. . . . . . . . . . . . . . . . . . 10 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 9.2. Informative References . . . . . . . . . . . . . . . . . 12 A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 15 Full Copyright Statement . . . . . . . . . . . . . . . . . . . 16 1. Introduction ENUM (E.164 Number Mapping, RFC 3761 [1]) is a system that uses DNS (Domain Name Service, RFC 1034 [4]) in order to translate certain telephone numbers, like '+12025332600', into URIs (Uniform Resource Identifiers, RFC 2396 [9]), like 'sip:user@sipcarrier.com'. ENUM exists primarily to facilitate the interconnection of systems that rely on telephone numbers with those that use URIs to route transactions. E.164 [10] is the ITU-T standard international numbering plan, under which all globally-reachable telephone numbers are organized. SIP (Session Initiation Protocol, RFC 3261 [2]) is a text-based application protocol that allows two endpoints in the Internet to discover one another in order to exchange context information about a session they would like to share. Common applications for SIP include Internet telephony, instant messaging, video, Internet gaming, and other forms of real-time communications. SIP is a multi-service protocol capable of initiating sessions involving different forms of real-time communications simultaneously. The most widespread application for SIP today is Voice-over-IP (VoIP). As such, there are a number of cases in which SIP applications are forced to contend with telephone numbers. Unfortunately, telephone numbers cannot be routing in accordance with the traditional DNS resolution procedures standardized for SIP (see [14]), which rely on SIP URIs. ENUM provides a method for translating E.164 numbers into URIs, including potentially SIP URIs. This document therefore provides an account of how SIP can handle telephone numbers by making use of ENUM. Guidelines are proposed for the authoring of the DNS records used by ENUM, and for client-sideShow full document text