SIPPING Working Group G. Camarillo Internet-Draft Ericsson Expires: May 22, 2004 A. Niemi H. Khartabil M. Isomaki Nokia November 22, 2003 Session Initiation Protocol (SIP) Exploder Invocation draft-camarillo-sipping-exploders-solution-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 May 22, 2004. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This document defined the SIP EXPLODE method, which is used to instruct user agents to send a request to a set of destinations. Camarillo, et al. Expires May 22, 2004 [Page 1] Internet-Draft SIP Exploder Invocation November 2003 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. The EXPLODE Method . . . . . . . . . . . . . . . . . . . . . . . 3 4. The Template Disposition-Type . . . . . . . . . . . . . . . . . 3 5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Normative References . . . . . . . . . . . . . . . . . . . . . . 5 Informational References . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Intellectual Property and Copyright Statements . . . . . . . . . 8 Camarillo, et al. Expires May 22, 2004 [Page 2] Internet-Draft SIP Exploder Invocation November 2003 1. Introduction The need for exploders in SIP is described in [6]. Mechanisms to invoke exploders in SIP need to meet the requirements listed there. The SIP REFER method [4] allows a user agent to request another user agent to send a request to a third party. Still, we need to define a new method due to the following two reasons: 1. REFER allows only a single destination (i.e., a single Refer-To URI.) 2. REFER's implicit subscriptions are problematic in certain scenarios. We introduce a new method called EXPLODE that carries a set of destinations in a URI list. The Request-URI of an EXPLODE method carries a URI in a list parameter that points to the URI list. The URI may be carried in the EXPLODE request itself or may be fetched from somewhere (e.g., using XCAP.) EXPLODE methods do not establish any type of subscription. If a user agent sending a EXPLODE request is interested in some aspect of the explosion, it can send a SUBSCRIBE request to the URI received in the response to the EXPLODE. 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. The EXPLODE Method EXPLODE is a SIP method as defined by RFC 3261 [2]. The EXPLODE method indicates that the recipient (identified by the Request-URI) should contact a set of third parties using the contact information provided in the URI list that the list parameter of the Request-URI points to. The protocol for emitting and responding to an EXPLODE request is identical to that for a BYE request in RFC 3261 [2]. 4. The Template Disposition-Type When using REFER, the new request to be sent is described using URI Camarillo, et al. Expires May 22, 2004 [Page 3] Internet-Draft SIP Exploder Invocation November 2003 parameters. For example, the following Refer-To header field contains the values of the Accept-Contact and Call-ID header fields of the new request. Refer-To: Exploders typically generate several similar requests towards different destinations. So, although it is possible to add the same URI parameters to all the URIs in the definition of the URI list, it is not an efficient way to encode that information. We define a new disposition-type: template. Bodies of this disposition-type (typically sipfrag bodies as defined in RFC 3420 [3]) provide the exploder with a template for the messages to be sent. The following example shows a body whose disposition-type is template. It indicates that the requests to be sent should be MESSAGEs carrying the text "Hello world." Content-Disposition: template Content-type: message/sipfrag Content-Length: xxx MESSAGE sip:whoever.invalid SIP/2.0 Content-Type: text/plain Content-Length: 12 Hello World. If any of the URIs in a Explode-To header field has a URI parameter indicating a different value for a header field than the one indicated in the template, the exploder MUST use the value in the URI parameter. Note that in order to include the method in a sipfrag body, it is necessary to include the Request-URI as well (the whole Request-line needs to be included as specified in RFC 3420 [3]. If the Explode-To header field only contains one URI, this URI SHOULD be placed in the Request-URI of the template body. Otherwise, it is RECOMMENDED that the Request-URI in the template body is an invalid URI. 5. Example We need to add the whole call flow. Camarillo, et al. Expires May 22, 2004 [Page 4] Internet-Draft SIP Exploder Invocation November 2003 EXPLODE sip:exploder@example.com;list=cid:cn35t8jf02@example.com SIP/2.0 Via: SIP/2.0/TCP client.example.com:5060;branch=z9hG4bK74bf9 Max-Forwards: 70 From: Alice ;tag=9fxced76sl To: Exploder Call-ID: 3848276298220188511@client.example.com CSeq: 1 EXPLODE Contact: Conten-Type: multipart/mixed;boundary="boundary1" Content-Length: xxx --boundary1 Content-Disposition: template Content-type: message/sipfrag Content-Length: xxx MESSAGE sip:whoever.invalid SIP/2.0 Content-Type: text/plain Content-Length: 12 Hello World. --boundary1 Content-Type: application/resource-lists+xml Content-Length: xxx Content-ID: --boundary1-- Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] 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. Camarillo, et al. Expires May 22, 2004 [Page 5] Internet-Draft SIP Exploder Invocation November 2003 [3] Sparks, R., "Internet Media Type message/sipfrag", RFC 3420, November 2002. Informational References [4] Sparks, R., "The Session Initiation Protocol (SIP) Refer Method", RFC 3515, April 2003. [5] Roach, A., Rosenberg, J. and B. Campbell, "A Session Initiation Protocol (SIP) Event Notification Extension for Resource Lists", draft-ietf-simple-event-list-04 (work in progress), June 2003. [6] Camarillo, G., "Requirements for Session Initiation Protocol (SIP) Exploder Invocation", draft-camarillo-sipping-exploders-00 (work in progress), September 2003. Authors' Addresses Gonzalo Camarillo Ericsson Hirsalantie 11 Jorvas 02420 Finland EMail: Gonzalo.Camarillo@ericsson.com Aki Niemi Nokia P.O. Box 321 NOKIA GROUP, FIN 00045 Finland EMail: Aki.Niemi@nokia.com Hisham Khartabil Nokia P.O. Box 321 NOKIA GROUP, FIN 00045 Finland EMail: Hisham.Khartabil@nokia.com Camarillo, et al. Expires May 22, 2004 [Page 6] Internet-Draft SIP Exploder Invocation November 2003 Markus Isomaki Nokia Itamerenkatu 11-13 Helsinki 00180 Finland EMail: Markus.Isomaki@nokia.com Camarillo, et al. Expires May 22, 2004 [Page 7] Internet-Draft SIP Exploder Invocation November 2003 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. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. 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This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION Camarillo, et al. Expires May 22, 2004 [Page 8] Internet-Draft SIP Exploder Invocation November 2003 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Camarillo, et al. Expires May 22, 2004 [Page 9]