XCON O. Levin Internet-Draft Microsoft Corporation Expires: April 20, 2006 October 17, 2005 Extensions to the Session Initiation Protocol (SIP) Event Package for Conference State draft-levin-xcon-conference-package-ext-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 April 20, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract This document introduces global elements into the SIP Conference Event Package XML schema to make the conference objects and sub- objects easily accessible by schemas external to the event package, such as the XCON conference control protocols. This document also defines the way to introduce XCON extensions into the SIP Conference Event Package in a backwards compatible manner. This document also defines a set of extensions to the SIP Conference Event Package XML schema being used in the XCON conferencing architecture. Levin Expires April 20, 2006 [Page 1] Internet-Draft Conference Package Extensions October 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Global Objects . . . . . . . . . . . . . . . . . . . . . . . . 3 4. Conference Event Package Schema Extensibility . . . . . . . . 4 5. XCON Extensions to Conference Event Package Schema . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7.1. URN Sub-Namespace Registration for urn:ietf:params:xml:ns:xcon-conference-info . . . . . . . 9 7.2. XML Schema Registration . . . . . . . . . . . . . . . . . 9 7.3. URN Sub-Namespace Registration for urn:ietf:params:xml:ns:conference-info-separator . . . . . 9 7.4. XML Schema Registration . . . . . . . . . . . . . . . . . 10 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9.1. Normative References . . . . . . . . . . . . . . . . . . . 10 9.2. Informative References . . . . . . . . . . . . . . . . . . 11 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . . . 13 Levin Expires April 20, 2006 [Page 2] Internet-Draft Conference Package Extensions October 2005 1. Introduction The SIP Conference State Event Package [8] defines a means for describing a conference object with its sub-objects, such as users, endpoints, sidebars, etc. with optional detailed information for each. This document introduces global elements into the SIP Conference State Event Package XML schema to make the conference objects and the sub-objects easily accessible by schemas external to the event package, such as of the XCON conference control protocols. This allows for uniform definition of the conference elements and sub-elements without replicating them for each XCON sub-system. This document also defines the way to introduce XCON extensions into the SIP Conference Event Package in a backwards compatible manner. The defined technique is compatible with the SIP Conference State Event Package [8] XML definitions and allows for automatic standard XML parsing of the extensions. This document is also being used as a repository for the XCON extensions to the SIP Conference Event Package XML schema. 2. Terminology In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in RFC 2119 [1] and indicate requirement levels for compliant implementations. 3. Global Objects The SIP Conference State Event Package [8] defines a conference object which contains the information about many conference components, such as users, endpoints, sidebars, etc. Using the SIP Events Mechanism RFC 3265 [6], the conference information is always distributed as a single document (full or partial) containing the Conference Object. In order to manipulate the conference information or state, it is desirable to be able to access a sub-object of a conference directly - without the need for processing the whole document. In order to achieve this granularity, this document introduces global elements into the SIP Conference State Event Package XML schema for each major object. This allows for uniform definition of the conference elements and sub-elements without replicating them for each XCON sub-system. This document extends the XML definition of the urn:ietf:params:xml:ns:conference-info namespace as follows: Levin Expires April 20, 2006 [Page 3] Internet-Draft Conference Package Extensions October 2005 4. Conference Event Package Schema Extensibility The conference event package allows a user to subscribe to the information relating to a conference. This document doesn't affect any of the assumptions, procedures, and considerations present in the SIP Conference State Event Package [8]. These include the package name, XML namespace, default filtering policy, subscription duration, the data format name, and the data format. The SIP Conference State Event Package [8] XML definition mandates that any package extension elements belong a name space different from the original schema. The SIP Conference State Event Package schema does allow for extensions from multiple namespaces being simultaneously included. It is envisioned that the extensions will be introduced gradually (i.e. through multiple extension versions) and potentially from different sources. In order to automatically process the extended XML document, it must comply with a standard and therefore deterministic XML schema, which means that a parser recognizing document element contents has to be able to decide, without look ahead, which content model token to match with the current input token, while processing the document from left to right. By simply introducing a new element or elements into the allowed Levin Expires April 20, 2006 [Page 4] Internet-Draft Conference Package Extensions October 2005 places of the SIP Conference State Package schema, each extended sequence seizes to be extensible due to the known "non-deterministic" (i.e., ambiguous) content model. In order to mitigate the problem, this document introduces a concept of a "separator" being defined in a separate name space. The namespace URI for the separator is a URN [2], using the namespace identifier 'ietf' defined by [4] and extended by RFC 3688 [10]. This URN is: urn:ietf:params:xml:ns:conference-info-separator This document introduces the XML definition of the urn:ietf:params:xml:ns:conference-info-separator namespace as follows: For example, if XCON decides to add a free text element to the , the extended schema needs to include the element defined just after the XCON extension(s). The example below illustrates the technique: An XML document example compliant with the extended schema is shown below: Levin Expires April 20, 2006 [Page 6] Internet-Draft Conference Package Extensions October 2005 Agenda: This month's goals http://sharepoint/salesgroup/ web-page THIS CONFERENCE MAY BE RECORDED! 33 By using the technique above, a receiver of the XML document can deterministically parse multiple blocks of unknown extensions and skip them as long as the known extensions appear in the known order. In the example above but without the , the schema would have been ambiguous, since the newly added element can be parsed as either matching the or as part of the . 5. XCON Extensions to Conference Event Package Schema The SIP Conference State Event Package [8] XML definition mandates that any package extension elements need to be defined in a name Levin Expires April 20, 2006 [Page 7] Internet-Draft Conference Package Extensions October 2005 space different from the original schema. This document registers a new namespace URI where all XCON extensions to the SIP Conference Event Package MUST be defined. The namespace URI for XCON extensions is a URN [2], using the namespace identifier 'ietf' defined by [4] and extended by RFC 3688 [10]. This URN is: urn:ietf:params:xml:ns:xcon-conference-info The XCON extensions are defined in the schema below: EDITOR's NOTE: The schema below is just an example of how the XCON extensions need to be schematized. The real extensions TBD based on the requirements. 6. Security Considerations Subscriptions to conference state information can reveal very sensitive information. Moreover, manipulation of this information through conference control protocols requires a strong means for authentication, conference information protection, and applying comprehensive authorization rules by a focus. Users of this specification MUST comply with the security considerations discussed in the SIP Event Package for Conference State [8] and the conference control protocol specifications, such as CCCP [11]. 7. IANA Considerations This document registers two new XML namespaces and two new XML schemas. Levin Expires April 20, 2006 [Page 8] Internet-Draft Conference Package Extensions October 2005 7.1. URN Sub-Namespace Registration for urn:ietf:params:xml:ns:xcon-conference-info This section registers a new XML namespace, as per the guidelines in RFC 3688 [10]. URI: The URI for this namespace is urn:ietf:params:xml:ns:xcon-conference-info Registrant Contact: IETF XCON Working Group , as designated by the IESG XML: BEGIN Centralized Conference Information Namespace

Namespace for Centralized Conference Information

urn:ietf:params:xml:ns:xcon-conference-info

See RFCXXXX.

END 7.2. XML Schema Registration This specification registers a schema, as per the guidelines in RFC 3688 [10]. URI: please assign Registrant Contact: IETF XCON Working Group , as designated by the IESG XML: The XML can be found as the sole content of Section 5 7.3. URN Sub-Namespace Registration for urn:ietf:params:xml:ns:conference-info-separator This section registers a new XML namespace, as per the guidelines in RFC 3688 [10]. Levin Expires April 20, 2006 [Page 9] Internet-Draft Conference Package Extensions October 2005 URI: The URI for this namespace is urn:ietf:params:xml:ns:conference-info-separator Registrant Contact: IETF XCON Working Group , as designated by the IESG XML: BEGIN Separator for Conference Information Namespace

Namespace for Separator for Conference Information

urn:ietf:params:xml:ns:conference-info-separator

See RFCXXXX.

END 7.4. XML Schema Registration This specification registers a schema, as per the guidelines in RFC 3688 [10]. URI: please assign Registrant Contact: IETF XCON Working Group , as designated by the IESG XML: The XML can be found as the sole content of Section 4 8. Acknowledgements 9. References 9.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Moats, R., "URN Syntax", RFC 2141, May 1997. Levin Expires April 20, 2006 [Page 10] Internet-Draft Conference Package Extensions October 2005 [3] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998. [4] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, August 1999. [5] 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. [6] Roach, A., "Session Initiation Protocol (SIP)-Specific Event Notification", RFC 3265, June 2002. [7] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, November 2003. [8] Rosenberg, J., "A Session Initiation Protocol (SIP) Event Package for Conference State", draft-ietf-sipping-conference-package-12 (work in progress), July 2005. [9] Barnes, M., "A Framework and Data Model for Centralized Conferencing", draft-ietf-xcon-framework-01 (work in progress), July 2005. 9.2. Informative References [10] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [11] Levin, O. and G. Kimchi, "Centralized Conference Data Model", draft-levin-xcon-cccp-02 (work in progress), February 2005. Levin Expires April 20, 2006 [Page 11] Internet-Draft Conference Package Extensions October 2005 Author's Address Orit Levin Microsoft Corporation One Microsoft Way Redmond, WA 98052 US Email: oritl@microsoft.com Levin Expires April 20, 2006 [Page 12] Internet-Draft Conference Package Extensions October 2005 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. 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. 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 (2005). 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 20, 2006 [Page 13]