SIP O. Levin Internet-Draft Microsoft Corporation Expires: April 17, 2005 October 17, 2004 Using of Feature Tags with REFER method in SIP draft-ietf-sip-refer-with-feature-param-00 Status of this Memo This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668. 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 April 17, 2005. Copyright Notice Copyright (C) The Internet Society (2004). Abstract This document extends the REFER method, defined in RFC-3515, to be used with feature parameters defined in RFC-3840. Levin Expires April 17, 2005 [Page 1] Internet-Draft REFER with Feature Param October 2004 Table of Contents 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Definition . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1 isfocus Feature Tag Usage . . . . . . . . . . . . . . . . 6 4.2 Voice and Video Feature Tags Usage . . . . . . . . . . . . 6 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 8. Normative References . . . . . . . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . 10 Levin Expires April 17, 2005 [Page 2] Internet-Draft REFER with Feature Param October 2004 1. 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 [1]. To simplify discussions of the REFER method and its extensions, three new terms are being used throughout the document: o REFER-Issuer: the UA issuing the REFER request o REFER-Recipient: the UA receiving the REFER request o REFER-Target: the UA designated in the Refer-To URI Levin Expires April 17, 2005 [Page 3] Internet-Draft REFER with Feature Param October 2004 2. Introduction This document extends REFER method defined in RFC-3515 [3] to be used with feature parameters defined in RFC-3840 [4] . Levin Expires April 17, 2005 [Page 4] Internet-Draft REFER with Feature Param October 2004 3. Definition The Refer-To BNF from RFC-3515: Refer-To = ("Refer-To" / "r") HCOLON ( name-addr / addr-spec ) * (SEMI generic-param) is extended to: Refer-To = ("Refer-To" / "r") HCOLON ( name-addr / addr-spec ) * (SEMI refer-param) refer-param = generic-param / feature-param where feature-param is defined in Section 9 of RFC-3840 [4]. Levin Expires April 17, 2005 [Page 5] Internet-Draft REFER with Feature Param October 2004 4. Examples 4.1 isfocus Feature Tag Usage The syntax below shows how the "isfocus" feature tag can be used by REFER-Issuer to tell the REFER-Recipient that the REFER-Target is a conference focus and, consequently, sending an INVITE will bring the REFER-Recipient into the conference: Refer-To: sip:conf44@example.com;isfocus 4.2 Voice and Video Feature Tags Usage The syntax below shows how a REFER-Issuer can tell the REFER-Recipient that the REFER-Target supports audio and video and, consequently, that a video and audio session can be established by sending an INVITE to the REFER-Target: Refer-To: sip:videophone@example.com;audio;video Levin Expires April 17, 2005 [Page 6] Internet-Draft REFER with Feature Param October 2004 5. IANA Considerations None. Levin Expires April 17, 2005 [Page 7] Internet-Draft REFER with Feature Param October 2004 6. Security Considerations This extension doesn't introduce new security threads beyond those identified and addressed in the core SIP specifications. Levin Expires April 17, 2005 [Page 8] Internet-Draft REFER with Feature Param October 2004 7. Acknowledgements The author would like to thank Jonathan Rosenberg and Alan Johnston for providing helpful guidance to this work. 8 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. [3] Sparks, R., "The Session Initiation Protocol (SIP) Refer Method", RFC 3515, April 2003. [4] Rosenberg, J., Schulzrinne, H. and P. Kyzivat, "Indicating User Agent Capabilities in the Session Initiation Protocol (SIP)", RFC 3840, August 2004. Author's Address Orit Levin Microsoft Corporation One Microsoft Way Redmond, WA 98052 USA Phone: +1-425-722-2225 EMail: oritl@microsoft.com Levin Expires April 17, 2005 [Page 9] Internet-Draft REFER with Feature Param October 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights 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; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Levin Expires April 17, 2005 [Page 10]