Address Resolution for Instant Messaging and Presence
RFC 3861
Document | Type |
RFC - Proposed Standard
(August 2004; No errata)
Was draft-ietf-impp-srv (impp WG)
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Author | Jon Peterson | ||
Last updated | 2015-10-14 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 3861 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Ted Hardie | ||
Send notices to | (None) |
Network Working Group J. Peterson Request for Comments: 3861 NeuStar Category: Standards Track August 2004 Address Resolution for Instant Messaging and Presence Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2004). Abstract Presence and instant messaging are defined in RFC 2778. The Common Profiles for Presence and Instant Messaging define two Universal Resource Identifier (URI) schemes: 'im' for INSTANT INBOXes and 'pres' for PRESENTITIES. This document provides guidance for locating the resources associated with URIs that employ these schemes. Table of Contents 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Address Resolution. . . . . . . . . . . . . . . . . . . . . . . 3 4. Domain Name Lookup. . . . . . . . . . . . . . . . . . . . . . . 4 5. Processing SRV RRs. . . . . . . . . . . . . . . . . . . . . . . 4 6. Processing Multiple Addresses . . . . . . . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 9. Contributors. . . . . . . . . . . . . . . . . . . . . . . . . . 6 10. Normative References. . . . . . . . . . . . . . . . . . . . . . 6 11. Author's Address. . . . . . . . . . . . . . . . . . . . . . . . 7 12. Full Copyright Statement. . . . . . . . . . . . . . . . . . . . 8 Peterson Standards Track [Page 1] RFC 3861 IM&P SRV August 2004 1. Introduction Presence and instant messaging are defined in RFC 2778 [5]. The Common Profiles for Presence (CPP) [2] and Instant Messaging (CPIM) [1] define two Universal Resource Identifier (URI) schemes: 'im' for INSTANT INBOXes and 'pres' for PRESENTITIES. This document provides rules for locating the resources associated with URIs that employ these schemes via the Domain Name Service (DNS) [4]. These rules could no doubt be applied to the resolution of other URI schemes that are unrelated to instant messaging and presence. CPIM and CPP both specify operations that have 'source' and 'destination' attributes. While only the semantics, not the syntax, of these attributes are defined by CPIM and CPP, many instant messaging and presence protocols today support the use of URIs to reflect the source and destination of their operations. The 'im' and 'pres' URI schemes allow such protocols to express the identities of the principals associated with a protocol exchange. When these operations pass through a CPIM or CPP gateway, these URIs could be relayed without modification, which has a number of desirable properties for the purposes of interoperability. These URI schemes are also useful in cases where no CPIM/CPP gatewaying will occur. If a particular principal's endpoint supports multiple instant messaging applications, for example, then a domain that identifies that host might use the sort of DNS records described in this document to provide greater compatibility with clients that support only one instant messaging protocol. A client would look up the corresponding record to the supported protocol, and learn how to contact the endpoint for that protocol. The principal in this instance would use an IM URI as their canonical address. In some architectures, these URIs might also be used to locate a CPIM or CPP gateway that serves a particular domain. If a particular IM service provider wishes to operate CPIM/CPP gateways in its own domain that map standard Internet protocols to an internal proprietary protocol, that gateway could be identified by an IM URI. In that case, the DNS records used to dereference the IM URI would serve a purpose similar to that of Mail Exchange (MX) records. The system described in this document relies on the use of DNS service (SRV) [7] records and address (A) records. Peterson Standards Track [Page 2] RFC 3861 IM&P SRV August 2004 2. Terminology In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in BCP 14, RFC 2119 [3] and indicate requirement levels forShow full document text