SIPPING Working Group N. Bishai Internet-Draft S. Loreto Intended status: Standards Track Ericsson Expires: January 5, 2009 A. Haruna Nokia Jul 4, 2008 Updates to Referred-By in the Session Initiation Protocol (SIP). draft-loreto-sipping-3892bis-00 Status of this Memo 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 becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 January 5, 2009. Abstract SIP has a mechanism for conveying the asserted identity of the originator of a request by means of the P-Asserted-Identity header field. When exploding a SIP MESSAGE request to a pre-defined group URI and when exploding a SIP INVITE request to an ad-hoc group or to a pre-defined group URI, the Referred-By header field in the resulting exploded requests is set to the P-Asserted-Identity header field or to the From header field. The Referred-By header is only included if the P-Asserted-Identity header field or From header field needs to carry another value, e.g. the URI of a pre-defined group, or a conference focus URI. Since the P-Asserted-Identity header field Bishai, et al. Expires January 5, 2009 [Page 1] Internet-Draft Updates to Referred-By SIP header Jul 2008 may carry up to two values, the Referred-By definition needs to be extended to allow up to two values as well. Table of Contents 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Inclusion of up to two URIs in a Referred-By header . . . . . . 3 4. Behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. Referrer Behaviour . . . . . . . . . . . . . . . . . . . . 4 5. Referrer Behaviour . . . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. Security considerations . . . . . . . . . . . . . . . . . . . . 4 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 8.1. Normative References . . . . . . . . . . . . . . . . . . . 5 8.2. Informational References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 5 Intellectual Property and Copyright Statements . . . . . . . . . . 7 Bishai, et al. Expires January 5, 2009 [Page 2] Internet-Draft Updates to Referred-By SIP header Jul 2008 1. 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 [RFC2119] and indicate requirement levels for compliant implementations. 2. Introduction SIP has a mechanism for conveying the asserted identity of the originator of a request by means of the P-Asserted-Identity header field. When exploding a SIP MESSAGE request to a pre-defined group URI and when exploding a SIP INVITE request to an ad-hoc group using [I-D.ietf-sip-uri-list-conferencing] or to a pre-defined group URI for SIP, the Referred-By header field in the resulting exploded requests is set to P-Asserted-Identity header field or From header field. The Referred-By header is only included if the P-Asserted- Identity header field or From header fields need to carry another value, e.g. the URI of a pre-defined group, or a conference focus URI. Since the P-Asserted-Identity header field may carry up to two values as specified in [RFC3325], the Referred-By definition in [RFC3892] needs to be extended to allow up to two values as well. This document extends [RFC3892] by allowing all values of the P-Asserted-Identity header field to be carried in the Referred-By header field. 3. Inclusion of up to two URIs in a Referred-By header [RFC3892] does not allow more than one URI in the Referred-By header. However, if the contents of the Referred-By header come from a P-Asserted-Identity header field, then all of the URIs present in the P-Asserted-Identity header field should be copied into the Referred-By header field. 4. Behaviour This updates [RFC3892] by allowing a Referred-By header to contain up to two URIs as defined for P-Asserted-Identity header field in [RFC3325]. Bishai, et al. Expires January 5, 2009 [Page 3] Internet-Draft Updates to Referred-By SIP header Jul 2008 4.1. Referrer Behaviour A server generating a SIP Request because of exploder functionality for SIP MESSAGE sent to a pre-defined group URI or for SIP INVITE sent to an ad-hoc group as defined in [I-D.ietf-sip-uri-list-conferencing] or to a pre-defined group URI, MAY include up to two URIs in a Referred-By header field in a request to report the identity of the user on behalf of which the server is acting and whose identity the server is in a position to assert. A server SHOULD do so only in cases where it can expect to be trusted by the first proxy. If Privacy was requested then there will only be one URI in the Referred-By header containing an anonymous URI. 5. Referrer Behaviour The BNF in [RFC3892] is augmented from this: Referred-By = ("Referred-By" / "b") HCOLON referrer-uri *( SEMI (referredby-id-param / generic-param) ) referrer-uri = ( name-addr / addr-spec ) to this: Referred-By = ("Referred-By" / "b") HCOLON referrer-uri *(COMMA referrer-uri) *( SEMI (referredby-id-param / generic-param) ) referrer-uri = ( name-addr / addr-spec ) A Referred-By header field value MUST consist of exactly one name- addr or addr-spec. There may be one or two Referred-By values. If there is one value, it MUST be a sip, sips, or tel URI.If there are two values, one value MUST be a sip or sips URI and the other MUST be a tel URI. 6. IANA Considerations 7. Security considerations The use of the Referred-By header raises a number of security considerations, which are discussed fully in [RFC3892]. This document raises no additional security considerations. Bishai, et al. Expires January 5, 2009 [Page 4] Internet-Draft Updates to Referred-By SIP header Jul 2008 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3261] 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. [RFC3325] Jennings, C., Peterson, J., and M. Watson, "Private Extensions to the Session Initiation Protocol (SIP) for Asserted Identity within Trusted Networks", RFC 3325, November 2002. [RFC3892] Sparks, R., "The Session Initiation Protocol (SIP) Referred-By Mechanism", RFC 3892, September 2004. 8.2. Informational References [I-D.ietf-sip-uri-list-conferencing] Camarillo, G. and A. Johnston, "Conference Establishment Using Request-Contained Lists in the Session Initiation Protocol (SIP)", draft-ietf-sip-uri-list-conferencing-02 (work in progress), November 2007. Authors' Addresses Nadia Bishai Ericsson 8500 Decarie Blvd. Montreal H4P-2N2 Canada Email: nadia.bishai@ericsson.com Salvatore Loreto Ericsson Hirsalantie 11 Jorvas 02420 Finland Email: salvatore.loreto@ericsson.com Bishai, et al. Expires January 5, 2009 [Page 5] Internet-Draft Updates to Referred-By SIP header Jul 2008 Adamu Haruna Nokia Finland Email: adamu.haruna@nokia.com Bishai, et al. Expires January 5, 2009 [Page 6] Internet-Draft Updates to Referred-By SIP header Jul 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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. 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Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Bishai, et al. Expires January 5, 2009 [Page 7]