Timed Presence Extensions to the Presence Information Data Format (PIDF) to Indicate Status Information for Past and Future Time Intervals
RFC 4481
Document | Type | RFC - Proposed Standard (July 2006; No errata) | |
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Author | Henning Schulzrinne | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4481 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Ted Hardie | ||
Send notices to | (None) |
Network Working Group H. Schulzrinne Request for Comments: 4481 Columbia U. Category: Standards Track July 2006 Timed Presence Extensions to the Presence Information Data Format (PIDF) to Indicate Status Information for Past and Future Time Intervals Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (2006). Abstract The Presence Information Data Format (PIDF) defines a basic XML format for presenting presence information for a presentity. This document extends PIDF, adding a timed status extension (<timed-status> element) that allows a presentity to declare its status for a time interval fully in the future or the past. Table of Contents 1. Introduction ....................................................2 2. Terminology and Conventions .....................................2 3. Timed-Status Element ............................................3 4. Example .........................................................4 5. The XML Schema Definition .......................................5 6. IANA Considerations .............................................6 6.1. URN Sub-Namespace Registration for 'urn:ietf:params:xml:ns:pidf:timed-status' .................6 6.2. Schema Registration for Schema 'urn:ietf:params:xml:ns:pidf:timed-status' .................7 7. Security Considerations .........................................7 8. References ......................................................7 8.1. Normative References .......................................7 8.2. Informative References .....................................7 Contributor's Address ..............................................8 Acknowledgements ...................................................8 Schulzrinne Standards Track [Page 1] RFC 4481 Timed Presence July 2006 1. Introduction Traditionally, presence information, e.g., represented as Presence Information Data Format [3] (PIDF) and augmented by Rich Presence Information Data format [9] (RPID), describes the current state of the presentity. However, a watcher can better plan communications if it knows about the presentity's future plans. For example, if a watcher knows that the presentity is about to travel, it might place a phone call earlier. In this document, we use terms defined in RFC 2778 [7]. In particular, a "presentity", abbreviating presence entity, provides presence information to a presence service. It is typically a uniquely-identified person. RPID already allows a presentity to indicate the period when a particular aspect of its presence is valid. However, the <status> element in the PIDF <tuple> does not have this facility, so that it is not possible to indicate that a presentity will be OPEN or CLOSED in the future, for example. It is also occasionally useful to represent past information since it may be the only known presence information; it may give watchers an indication of the current status. For example, indicating that the presentity was at an off-site meeting that ended an hour ago indicates that the presentity is likely in transit at the current time. It is unfortunately not possible to simply add time range attributes to the PIDF <status> element, as PIDF parsers without this capability would ignore these attributes and thus not be able to distinguish current from future presence status information. This document defines the <timed-status> element that describes the status of a presentity that is either no longer valid or covers some future time period. 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 as described in BCP 14, RFC 2119 [1]. Schulzrinne Standards Track [Page 2] RFC 4481 Timed Presence July 2006 3. Timed-Status Element The <timed-status> element is a child of the <tuple> element and MUST NOT appear as a child of a PIDF <status> element or another <timed-status> element. More than one such element MAY appear within a PIDF <tuple> element. Sources of <timed-status> information should avoid elements that overlap in time, but since overlapping appointments are common inShow full document text