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diff --git a/doc/rfc/rfc5509.txt b/doc/rfc/rfc5509.txt new file mode 100644 index 0000000..8a30e6a --- /dev/null +++ b/doc/rfc/rfc5509.txt @@ -0,0 +1,337 @@ + + + +Network Working Group S. Loreto +Request for Comments: 5509 Ericsson +Category: Standards Track April 2009 + + + Internet Assigned Numbers Authority (IANA) Registration + of Instant Messaging and Presence DNS SRV RRs + for the Session Initiation Protocol (SIP) + +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) 2009 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 + Provisions Relating to IETF Documents in effect on the date of + publication of this document (http://trustee.ietf.org/license-info). + Please review these documents carefully, as they describe your rights + and restrictions with respect to this document. + +Abstract + + This document registers with IANA two new DNS SRV protocol labels for + resolving Instant Messaging and Presence services with SIP. + + + + + + + + + + + + + + + + + + + +Loreto Standards Track [Page 1] + +RFC 5509 IANA SRV Label for SIP April 2009 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 3. DNS SRV Usage of SIP with 'im' and 'pres' URIs . . . . . . . . 3 + 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 + 5.1. Instant Messaging SRV Protocol Label Registration . . . . . 5 + 5.2. Presence SRV Protocol Label Registration . . . . . . . . . 5 + 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 5 + 7. Normative References . . . . . . . . . . . . . . . . . . . . . 6 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 6 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Loreto Standards Track [Page 2] + +RFC 5509 IANA SRV Label for SIP April 2009 + + +1. Introduction + + The Service Record (SRV) [RFC2782] identifies the host(s) that will + support particular services. The DNS is queried for SRV RR in the + general form: + + _Service._Proto.Name + + Service: the symbolic name of the desired service + + Proto: the protocol of the desired service + + Name: the domain name for which this record is valid + + "Address Resolution for Instant Messaging and Presence" [RFC3861] + provides guidance for locating the services associated with URIs that + employ the following two URI schemes [RFC3986]: 'im' for INSTANT + INBOXes [RFC3860] and 'pres' for PRESENTITIES [RFC3859]. + + In order to ensure that the association between "_im" and "_pres" and + their respective underlying services are deterministic, the IANA has + created two independent registries: the Instant Messaging SRV + Protocol Label registry and the Presence SRV Protocol Label registry. + + This document defines and registers the "_sip" protocol label in both + registries so that computer programs can resolve 'im:' and 'pres:' + URIs down to SIP addresses. + + Moreover, this document explains how the use of SIP for Presence and + Instant Messaging uses SRV. + + +2. Terminology + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in RFC 2119 [RFC2119]. + + +3. DNS SRV Usage of SIP with 'im' and 'pres' URIs + + Although there are standard procedures for resolving 'im' and 'pres' + URIs (Section 3 of [RFC3861]), the labels for SIP are not registered. + + Section 5 of [RFC3428] states that if a user agent (UA) is presented + with an IM URI (e.g., "im:fred@example.com") as the address for an + instant message, it SHOULD resolve it to a SIP URI, and place the + resulting URI in the Request-URI of the MESSAGE request before + + + +Loreto Standards Track [Page 3] + +RFC 5509 IANA SRV Label for SIP April 2009 + + + sending. + + Following the procedures defined in [RFC3861], in order to resolve + the IM URI, the UA performs a SRV lookup for: + + _im._sip.example.com + + Assuming that the example.com domain offers a SIP service for instant + messaging at simple.example.com, this will result in a resolution of + _im._sip.example.com. to simple.example.com. Thus, the instant + messaging URI im:fred@example.com would resolve to a SIP URI of + sip:fred@simple.example.com. + + SIP supports both pager [RFC3428] and session [RFC4975] IM mode. + However, a DNS SRV lookup does not specify which SIP IM mode a domain + offer. If the user agent client (UAC) supports both session mode and + pager mode, it is then suggested to try session mode first; if that + mode is rejected, the UAC has to be ready to fall back to pager mode. + + Section 5 of [RFC3856] states that procedures defined in [RFC3861] + are also used to resolve the protocol-independent PRES URI for a + presentity (e.g., "pres:fred@example.com") into a SIP URI. + + Following the procedures defined in [RFC3861], in order to resolve + the PRES URI, the UA performs a SRV lookup for: + + _pres._sip.example.com + + Assuming that the example.com domain offers a SIP presence service at + simple.example.com, this will result in a resolution of + _pres._sip.example.com. to simple.example.com. Thus, the protocol- + independent PRES URI pres:fred@example.com would resolve to a SIP URI + of sip:fred@simple.example.com. + + +4. Security Considerations + + This document merely serves for the registration of DNS SRV labels in + the appropriate IANA registry. The document does not specify a + protocol; therefore, there are no security issues associated with it. + + +5. IANA Considerations + + This specification registers a new SRV protocol label in both the + Instant Messaging SRV Protocol Label registry and the Presence SRV + Protocol Label registry. + + + + +Loreto Standards Track [Page 4] + +RFC 5509 IANA SRV Label for SIP April 2009 + + +5.1. Instant Messaging SRV Protocol Label Registration + + "Address Resolution for Instant Messaging and Presence" [RFC3861] + defines an Instant Messaging SRV Protocol Label registry for + protocols that can provide services that conform to the "_im" SRV + Service label. Because SIP is one such protocol, IANA registers the + "_sip" protocol label in the "Instant Messaging SRV Protocol Label + Registry", as follows: + + Protocol label: _sip + + Specification: RFC 5509 + + Description: Instant messaging protocol label for the use of SIP for + Presence and Instant Messaging protocol as defined by + [RFC3428]. + + Registrant Contact: Salvatore Loreto <salvatore.loreto@ericsson.com> + +5.2. Presence SRV Protocol Label Registration + + "Address Resolution for Instant Messaging and Presence" [RFC3861] + defines a Presence SRV Protocol Label registry for protocols that can + provide services that conform to the "_pres" SRV Service label. + Because the use of SIP for Presence and Instant Messaging is one such + protocol, the IANA registers the "_sip" protocol label in the + "Presence SRV Protocol Label Registry", as follows: + + Protocol label: _sip + + Specification: RFC 5509 + + Description: Presence protocol label for the use of SIP for Presence + and Instant Messaging protocol as defined by [RFC3856]. + + Registrant Contact: Salvatore Loreto <salvatore.loreto@ericsson.com> + + +6. Acknowledgments + + The need for this registration was discussed with Jon Peterson and + Peter Saint-Andre. + + Miguel Garcia reviewed this document on behalf of the Real-time + Applications and Infrastructure (RAI) Area Review Team (ART). + + + + + + +Loreto Standards Track [Page 5] + +RFC 5509 IANA SRV Label for SIP April 2009 + + +7. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for + specifying the location of services (DNS SRV)", RFC 2782, + February 2000. + + [RFC3428] Campbell, B., Rosenberg, J., Schulzrinne, H., Huitema, C., + and D. Gurle, "Session Initiation Protocol (SIP) Extension + for Instant Messaging", RFC 3428, December 2002. + + [RFC3856] Rosenberg, J., "A Presence Event Package for the Session + Initiation Protocol (SIP)", RFC 3856, August 2004. + + [RFC3859] Peterson, J., "Common Profile for Presence (CPP)", + RFC 3859, August 2004. + + [RFC3860] Peterson, J., "Common Profile for Instant Messaging + (CPIM)", RFC 3860, August 2004. + + [RFC3861] Peterson, J., "Address Resolution for Instant Messaging + and Presence", RFC 3861, August 2004. + + [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform + Resource Identifier (URI): Generic Syntax", STD 66, + RFC 3986, January 2005. + + [RFC4975] Campbell, B., Mahy, R., and C. Jennings, "The Message + Session Relay Protocol (MSRP)", RFC 4975, September 2007. + + +Author's Address + + Salvatore Loreto + Ericsson + Hirsalantie 11 + Jorvas 02420 + Finland + + Email: Salvatore.Loreto@ericsson.com + + + + + + + + + +Loreto Standards Track [Page 6] + + |