SIPPING Working Group G. Camarillo Internet-Draft Ericsson Expires: August 6, 2004 February 6, 2004 Ad-Hoc URI List Management in the Session Initiation Protocol (SIP) draft-camarillo-sipping-adhoc-management-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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 August 6, 2004. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document defines two mechanisms to manage ad-hoc URI lists in SIP. In the first mechanism, the user agent sends an updated version of the entire list to the server. In the second mechanism, the server provides the user agent with a URI (e.g., http) that can be used to manipulate the list using an out-of-band mechanim (e.g., XCAP). We define the Associated-List-Manipulation header field that carries a URI that allows manipulating an ad-hoc list. Camarillo Expires August 6, 2004 [Page 1] Internet-Draft Ad-Hoc URI List Management February 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. List Substitution . . . . . . . . . . . . . . . . . . . . . . 3 4. Out-of-Band Management . . . . . . . . . . . . . . . . . . . . 3 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 5.1 List Substitution . . . . . . . . . . . . . . . . . . . . . . 6 5.2 Out-of-Band Management . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7 Normative References . . . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . 9 Camarillo Expires August 6, 2004 [Page 2] Internet-Draft Ad-Hoc URI List Management February 2004 1. Introduction SIP messages can carry URI lists using the "list" SIP and SIPS URI parameter defined in [3]. An application server receiving a SIP request with a URI list creates a so called ad-hoc URI list, which is valid for the duration of the service provided by the server. Once an ad-hoc URI list is created at the server, the user agent may need to manipulate it (e.g., add URIs to the list and remove URIs from the list). Section 3 and Section 4 describe two methods to perform ad-hoc URI list management. 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 [1] and indicate requirement levels for compliant implementations. 3. List Substitution A user agent MAY provide an application server with an updated version of the ad-hoc list by sending a request with a "list" parameter [3] in its Request-URI. The "list" parameter MUST contain a pointer to the updated list. (The method of this request depends on the service being delivered.) On reception of such a request, the application server MUST substitute the previous ad-hoc list with the list referenced by the "list" parameter. 4. Out-of-Band Management Section 3 describes how to send a complete URI list to an application server that substitutes the previous one. Following this approach, a user agent that wants to modify a single URI in a long URI list needs to resend the whole list. Still, there are URI list management mechanisms, such as the XCAP usage defined in [2], that allow user agents to manipulate URI lists more efficiently. We define a new SIP header field called Associated-List-Manipulation that allows a server to provide a URI to the client to manipulate the ad-hoc list using an out-of-band mechanism. The XCAP Usage for Resource Lists MUST be supported. Other mechanisms MAY be supported. The ABNF of the Associated-List-Manipulation header field is: Camarillo Expires August 6, 2004 [Page 3] Internet-Draft Ad-Hoc URI List Management February 2004 List-Manipulation = "Associated-List-Manipulation" HCOLON absoluteURI 5. Examples This section shows how to use the mechanisms described in Section 3 and Section 4 to manipulate the list of participants in an ad-hoc conference. This example illustrates the use of both mechanisms. It does not mandate how ad-hoc conference services have to be implemented. When the ad-hoc conferencing server in this example receives an initial INVITE with a URI list, it sends out an INVITE to each URI in the list and creates an ad-hoc conference with all of them. If, at a later point, a URI is added to the list, the conference server INVITEs the new user. If a URI is removed from the list, the conference server BYEs the user. Carol creates an ad-hoc conference on the server by sending the INVITE request shown in Figure 1. The list parameter in the Request-URI points to a MIME body that carries the list of participants. INVITE sip:ad-hoc@example.com;list=cid:cn35t8jf02@example.com SIP/2.0 Via: SIP/2.0/TCP client.chicago.example.com ;branch=z9hG4bKhjhs8ass83 Max-Forwards: 70 To: "Ad-Hoc Conferences" From: Carol ;tag=32331 Call-ID: d432fa84b4c76e66710 CSeq: 1 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY Allow-Events: dialog Accept: application/sdp, message/sipfrag, application/resource-lists+xml Conten-Type: multipart/mixed;boundary="boundary1" Content-Length: 731 --boundary1 Content-Type: application/sdp Content-Length: 160 v=0 o=carol 2890844526 2890842807 IN IP4 chicago.example.com Camarillo Expires August 6, 2004 [Page 4] Internet-Draft Ad-Hoc URI List Management February 2004 s=Example Subject c=IN IP4 192.0.0.1 t=0 0 m=audio 20000 RTP/AVP 0 m=video 20002 RTP/AVP 31 --boundary1 Content-Type: application/resource-lists+xml Content-Length: 367 Content-ID: --boundary1-- Figure 1: INVITE request SIP/2.0 200 OK Via: SIP/2.0/TCP client.chicago.example.com ;branch=z9hG4bKhjhs8ass83;received=192.0.2.4 To: "Ad-Hoc Conferences" ;tag=733413 From: Carol ;tag=32331 Call-ID: d432fa84b4c76e66710 CSeq: 1 INVITE Contact: ;isfocus Associated-List-Manipulation: http://xcap.example.com/lists/yourlist Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY Allow-Events: dialog, conference Accept: application/sdp, application/conference-info+xml, application/resource-lists+xml, message/sipfrag Supported: replaces, join Content-Type: application/sdp Content-Length: 312 v=0 o=focus431 2890844526 2890842807 IN IP4 ms5.conf.example.com s=Example Subject i=Example Conference Hosted by Example.com u=http://conf.example.com/3402934234 Camarillo Expires August 6, 2004 [Page 5] Internet-Draft Ad-Hoc URI List Management February 2004 e=3402934234@conf-help.example.com p=+1-888-555-1212 c=IN IP4 ms5.conf.example.com t=0 0 m=audio 49170 RTP/AVP 0 m=video 51372 RTP/AVP 31 Figure 2: 200 (OK) response The conference server responds with the 200 (OK) in Figure 1, which carries the URI for the conference in its Contact header field and a URI for manipulating the URI list in its Associated-List-Manipulation header field. 5.1 List Substitution Carol wants to remove Bill and Joe from the conference. She sends the re-INVITE in Figure 3 to the conference server with an updated URI list in a "list" parameter. INVITE sip:34@example.com;isfocus;list=cid:cn35t8j@example.com SIP/2.0 Via: SIP/2.0/TCP client.chicago.example.com ;branch=z9hG4bKhjhs8ass83 Max-Forwards: 70 To: "Ad-Hoc Conferences" From: Carol ;tag=32331 Call-ID: d432fa84b4c76e66710 CSeq: 2 INVITE Contact: Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY Allow-Events: dialog Accept: application/sdp, message/sipfrag, application/resource-lists+xml Conten-Type: multipart/mixed;boundary="boundary1" Content-Length: xxx --boundary1 Content-Type: application/sdp Content-Length: 160 v=0 o=carol 2890844526 2890842807 IN IP4 chicago.example.com s=Example Subject c=IN IP4 192.0.0.1 t=0 0 m=audio 20000 RTP/AVP 0 Camarillo Expires August 6, 2004 [Page 6] Internet-Draft Ad-Hoc URI List Management February 2004 m=video 20002 RTP/AVP 31 --boundary1 Content-Type: application/resource-lists+xml Content-Length: xxx Content-ID: --boundary1-- Figure 3: Re-INVITE 5.2 Out-of-Band Management Now, Carol wants to add Alice to the conference. This time, she uses the http URI received in the Associated-List-Manipulation header field. She uses XCAP to add Alice's URI, so no SIP traffic is exchanged between her and the server. 6. Security Considerations TBD. 7. IANA Considerations This document registers the Associated-List-Manipulation SIP header field, which is described in Section 4. This header field is to be added to the header field registry under http://www.iana.org/ assignments/sip-parameters. Header Name: Associated-List-Manipulation Compact Form: (none) 8. Acknowledgments Adam Roach, Jonathan Rosenberg, and Orit Levin provided useful comments on this document. Normative References Camarillo Expires August 6, 2004 [Page 7] Internet-Draft Ad-Hoc URI List Management February 2004 [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Rosenberg, J., "An Extensible Markup Language (XML) Configuration Access Protocol (XCAP) Usage for Presence Lists", draft-ietf-simple-xcap-list-usage-01 (work in progress), October 2003. [3] Camarillo, G., "Providing a Session Initiation Protocol (SIP) Application Server with a List of URIs", draft-camarillo-sipping-uri-list-00 (work in progress), November 2003. Author's Address Gonzalo Camarillo Ericsson Hirsalantie 11 Jorvas 02420 Finland EMail: Gonzalo.Camarillo@ericsson.com Camarillo Expires August 6, 2004 [Page 8] Internet-Draft Ad-Hoc URI List Management February 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. 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