SIMPLE H. Schulzrinne Internet-Draft Columbia U. Expires: June 23, 2006 December 20, 2005 CIPID: Contact Information in Presence Information Data Format draft-ietf-simple-cipid-07 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 June 23, 2006. Copyright Notice Copyright (C) The Internet Society (2005). Abstract The Presence Information Data Format (PIDF) defines a basic XML format for presenting presence information for a presentity. The Contact Information for Presence Information Data Format (CIPID) is an extension that adds elements to PIDF that provide additional contact information about a presentity and its contacts, including references to address book entries and icons. Schulzrinne Expires June 23, 2006 [Page 1] Internet-Draft CIPID December 2005 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Conventions . . . . . . . . . . . . . . . . . 3 3. CIPID Elements . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1 Card Element . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Display-Name Element . . . . . . . . . . . . . . . . . . . 4 3.3 Homepage Element . . . . . . . . . . . . . . . . . . . . . 4 3.4 Icon Element . . . . . . . . . . . . . . . . . . . . . . . 4 3.5 Map Element . . . . . . . . . . . . . . . . . . . . . . . 4 3.6 Sound Element . . . . . . . . . . . . . . . . . . . . . . 5 4. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5. The XML Schema Definition . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 6.1 URN Sub-Namespace Registration for 'urn:ietf:params:xml:ns:pidf:cipid' . . . . . . . . . . . 7 6.2 Schema Registration for Schema urn:ietf:params:xml:ns:pidf:cipid' . . . . . . . . . . . . 8 7. Internationalization Considerations . . . . . . . . . . . . . 8 8. Security Considerations . . . . . . . . . . . . . . . . . . . 9 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9.1 Normative References . . . . . . . . . . . . . . . . . . . 9 9.2 Informative References . . . . . . . . . . . . . . . . . . 10 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 11 A. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 11 Intellectual Property and Copyright Statements . . . . . . . . 12 Schulzrinne Expires June 23, 2006 [Page 2] Internet-Draft CIPID December 2005 1. Introduction In its function of facilitating communication, the usefulness of presence information can be enhanced by providing basic information about a presentity or contact. This specification describes a basic set of information elements that allow a watcher to retrieve additional information about a presentity or contact. This specification defines extensions to the PIDF [7] (Presence Information Data Format) XML (Extensible Markup Language) [8] document format. We describe elements for providing a "business card", references to the homepage, map, representative sound, display name and an icon. This additional presence information can be used in PIDF [7] documents, together with RPID [9] (Rich Presence Information Data format), future-status [10] and other PIDF extensions. All elements extend the or, less commonly, element in the presence data model [11]. The element is only extended with CIPID elements if the information describes a service referring to another person that is marked by an RPID element with a value other than 'self'. All elements described in this document are optional. RPID and CIPID both provide "rich" presence that goes beyond the basic 'open' and 'closed' status information in PIDF. The presence information described in these two documents can be supplied independently, although in practice, both will often appear in the same PIDF document. CIPID elements describe the more static aspects of somebody's presence information, while RPID focuses on elements that will likely change throughout the day. Thus, CIPID information can often be statically configured by the user through the graphical user interface of a presence client, while this is less likely to be sufficient for RPID. The namespace URI for these elements defined by this specification is a URN [2], using the namespace identifier 'ietf' defined by [4] and extended by [6]: urn:ietf:params:xml:ns:pidf:cipid 2. Terminology and Conventions The key words MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this document are to be interpreted Schulzrinne Expires June 23, 2006 [Page 3] Internet-Draft CIPID December 2005 as described in BCP 14, RFC 2119 [1]. 3. CIPID Elements Unless otherwise noted below, each element may only appear at most once. 3.1 Card Element The element includes a URI pointing to a business card, e.g., in LDIF [13] or vCard [12] format. 3.2 Display-Name Element The element includes the name identifying the tuple or person that the presentity suggests should be shown by the watcher user interface. It is left to the watcher user interface design to choose whether to heed this suggestion or use some other suitable string. The CIPID information MAY contain multiple display names, but only if they are labeled with different 'xml:lang' attributes. This allows a Korean-speaking presentity to convey its display name in different Latin and Hangul, for example. 3.3 Homepage Element The element provides a URI pointing to general information about the tuple or person, typically a web home page. 3.4 Icon Element The element provides a URI pointing to an image (icon) representing the tuple or person. The watcher can use this information to represent the tuple or person in a graphical user interface. Presentities SHOULD provide images of sizes and aspect ratios that are appropriate for rendering as an icon. Support for JPEG, PNG and GIF formats is REQUIRED. 3.5 Map Element The element provides a URI pointing to a map related to the tuple or person. The watcher can use this information to represent the tuple or person in a graphical user interface. The map may be either an image, an HTML client-side image map or a geographical information system (GIS) document, e.g., encoded as GML. Support for images formatted as PNG and GIF is REQUIRED. Schulzrinne Expires June 23, 2006 [Page 4] Internet-Draft CIPID December 2005 3.6 Sound Element The element provides a URI pointing to a sound related to the tuple or person. The watcher MAY use the sound object, such as a MIDI or MP3 file, referenced by the URL to inform the watcher that the presentity has assumed the status OPEN. Implementors are advised to create user interfaces that provide the watcher with the opportunity to choose whether to play such sounds. Support for sounds coded as MPEG-2 Layer 3 (MP3) is RECOMMENDED. The sound object might also be used to indicate how to pronounce the presentity's name. 4. Example An example using CIPID only is shown below: open im:alice@example.net 2005-11-21T16:14:29Z http://example.com/~alice/card.vcd Alice Lewis http://example.com/~alice http://example.com/~alice/me.png http://example.com/~alice/gml-map.xml http://example.com/~alice/hello.wav 2005-11-21T09:00:00+05:00 An example combining RPID and CIPID is shown below: Schulzrinne Expires June 23, 2006 [Page 5] Internet-Draft CIPID December 2005 open im:someone@mobile.example.net 2005-05-30T22:00:29Z closed http://example.com/~assistant/card.vcd http://example.com/~assistant im:assistant@example.com 2005-05-30T22:00:29Z http://example.com/~someone/card.vcd http://example.com/~someone http://example.com/~someone/icon.gif http://example.com/~someone/gml-map.xml http://example.com/~someone/whoosh.wav 2005-05-30T22:02:44+05:00 5. The XML Schema Definition The schema is shown below. Schulzrinne Expires June 23, 2006 [Page 6] Internet-Draft CIPID December 2005 Describes CIPID tuple extensions for PIDF. Figure 1: CIPID schema 6. IANA Considerations This document calls for IANA to register a new XML namespace URN and schema per [6]. 6.1 URN Sub-Namespace Registration for 'urn:ietf:params:xml:ns:pidf:cipid' URI: urn:ietf:params:xml:ns:pidf:cipid Description: This is the XML namespace for XML elements defined by RFCXXXX to describe contact information presence information extensions for the status element in the PIDF presence document format in the application/pidf+xml content type. Registrant Contact: IETF, SIMPLE working group, simple@ietf.org; Henning Schulzrinne, hgs@cs.columbia.edu XML: Schulzrinne Expires June 23, 2006 [Page 7] Internet-Draft CIPID December 2005 BEGIN CIPID -- Contact Information in Presence Information Data Format

Namespace for contact information presence extension (status)

urn:ietf:params:xml:ns:pidf:cipid

See RFCXXXX.

END 6.2 Schema Registration for Schema urn:ietf:params:xml:ns:pidf:cipid' URI: please assign Registrant Contact: IESG XML: See Figure 1 7. Internationalization Considerations CIPID delivers only URLs, except for the element. The resolution of the URLs can negotiate appropriate language and character sets within the URL-designated protocol. For the display name and to handle Internationalized Resource Identifiers (IRIs) [14], since CIPID is represented in XML, it provides native support for encoding information using the Unicode character set and its more compact representations including UTF-8. Conformant XML processors recognize both UTF-8 and UTF-16. Though XML includes provisions to identify and use other character encodings through use of an "encoding" attribute in an declaration, use of UTF-8 is RECOMMENDED in environments where parser encoding support incompatibility exists. The XML 'xml:lang' attribute can be used to identify the language and script for the element. The specification allows multiple occurrences of this element so that the presentity can convey display names in multiple scripts and languages. If no 'xml: Schulzrinne Expires June 23, 2006 [Page 8] Internet-Draft CIPID December 2005 lang' attribute is provided, the default value is "i-default" [3]. 8. Security Considerations The security issues are similar to those for RPID [9]. Watchers need to restrict which content types of content pointed to by , , , , and elements they render. Also, when a watcher accesses these URIs, the presentity may deduce that the watcher is currently using the presence application. Thus, a presence application concerned about leaking this information may want to cache these objects for later use. (A presentity could easily customize the URLs for each watcher, so that it can tell who is referencing the objects.) This caching behavior may cause the information to become stale, out-of-sync with the current data until the cache is refreshed. Fortunately, the elements in CIPID are expected to retain the same content for periods measured in days, so that privacy-conscious applications may well decide to perform caching over durations that reveal little current activity information. Presentities need to keep in mind that clients may cache the content referenced by URIs for long periods as they use their presence system to construct presence documents using this extension. If the referenced content needs to change frequently, the presentity could, for example, update the presence document with a new URI to encourage clients to notice. Icons and other URIs in this document could be used as a covert channel to convey messages to the watcher, outside the content monitoring that might be in place for instant messages or other communications channels. Thus, entities that worry about such channels may want to prohibit the usage of URLs pointing to resources outside their domain, for example. Implementors must take care to adhere to the mechanisms for verifying the identity in the referenced server's certificate against the URI. For instance, if the URI scheme is https, the requirements of RFC 2818 [5], section 3.1, must be met. In particular, the domain represented in the URI must match the subjectAltName in the certificate presented by the referenced server. If this identity check fails, the referenced content SHOULD NOT be retrieved and MUST NOT be used. 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. Schulzrinne Expires June 23, 2006 [Page 9] Internet-Draft CIPID December 2005 [2] Moats, R., "URN Syntax", RFC 2141, May 1997. [3] Alvestrand, H., "IETF Policy on Character Sets and Languages", BCP 18, RFC 2277, January 1998. [4] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, August 1999. [5] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. [6] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, January 2004. [7] Sugano, H., Fujimoto, S., Klyne, G., Bateman, A., Carr, W., and J. Peterson, "Presence Information Data Format (PIDF)", RFC 3863, August 2004. [8] Yergeau, F., Paoli, J., Sperberg-McQueen, C., Bray, T., and E. Maler, "Extensible Markup Language (XML) 1.0 (Third Edition)", W3C REC REC-xml-20040204, February 2004. 9.2 Informative References [9] Schulzrinne, H., "RPID: Rich Presence Extensions to the Presence Information Data Format (PIDF)", draft-ietf-simple-rpid-09 (work in progress), September 2005. [10] Schulzrinne, H., "Timed Presence Extensions to the Presence Information Data Format (PIDF) to Indicate Status Information for Past and Future Time Intervals", draft-ietf-simple-future-04 (work in progress), June 2005. [11] Rosenberg, J., "A Data Model for Presence", draft-ietf-simple-presence-data-model-06 (work in progress), October 2005. [12] Dawson, F. and T. Howes, "vCard MIME Directory Profile", RFC 2426, September 1998. [13] Good, G., "The LDAP Data Interchange Format (LDIF) - Technical Specification", RFC 2849, June 2000. [14] Duerst, M. and M. Suignard, "Internationalized Resource Identifiers (IRIs)", RFC 3987, January 2005. Schulzrinne Expires June 23, 2006 [Page 10] Internet-Draft CIPID December 2005 Author's Address Henning Schulzrinne Columbia University Department of Computer Science 450 Computer Science Building New York, NY 10027 US Phone: +1 212 939 7004 Email: hgs+simple@cs.columbia.edu URI: http://www.cs.columbia.edu Appendix A. Acknowledgments This document is based on discussions within the IETF SIMPLE working group. Spencer Dawkins, Vijay Gurbani, Avshalom Houri, Hisham Khartabil, Paul Kyzivat, Eva Leppanen, Mikko Lonnfors, Aki Niemi, Jon Peterson, Jonathan Rosenberg and Robert Sparks provided helpful comments. Schulzrinne Expires June 23, 2006 [Page 11] Internet-Draft CIPID December 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. Schulzrinne Expires June 23, 2006 [Page 12]