Presence Information Data Format (PIDF) Extension for Partial Presence
RFC 5262

Network Working Group                                        M. Lonnfors
Request for Comments: 5262                                         Nokia
Category: Standards Track                                    E. Leppanen
                                                              Individual
                                                            H. Khartabil
                                                      Ericsson Australia
                                                           J. Urpalainen
                                                                   Nokia
                                                          September 2008

 Presence Information Data Format (PIDF) Extension for Partial Presence

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.

Abstract

   The Presence Information Document Format (PIDF) specifies the
   baseline XML-based format for describing presence information.  One
   of the characteristics of the PIDF is that the document always needs
   to carry all presence information available for the presentity.  In
   some environments where low bandwidth and high latency links can
   exist, it is often beneficial to limit the amount of transported
   information over the network.  This document introduces a new MIME
   type that enables transporting of either only the changed parts or
   the full PIDF-based presence information.

Lonnfors, et al.            Standards Track                     [Page 1]
RFC 5262                      Partial PIDF                September 2008

Table of Contents

   1. Introduction ....................................................2
   2. Conventions .....................................................3
   3. Structure of PIDF Diff Documents ................................3
      3.1. 'version' Attribute ........................................4
      3.2. 'entity' Attribute .........................................4
   4. Usage of 'application/pidf-diff+xml' ............................4
   5. IANA Considerations .............................................5
      5.1. URN Sub-Namespace Registration for
           'urn:ietf:params:xml:ns:pidf-diff' .........................5
      5.2. application/pidf-diff+xml MIME Type ........................6
      5.3. XML Schema Registration ....................................7
   6. Examples ........................................................8
   7. XML Schema .....................................................11
   8. Interoperability Considerations ................................12
   9. Security Considerations ........................................13
   10. Internationalization Considerations ...........................13
   11. Error Handling ................................................13
   12. Acknowledgments ...............................................13
   13. References ....................................................13
      13.1. Normative references .....................................13
      13.2. Informative references ...................................14

1.  Introduction

   The Presence Information Document Format (PIDF) [RFC3863] specifies
   the baseline XML-based format for describing presence information.
   One of the characteristics of the PIDF is that the document always
   needs to carry all presence information available for the presentity.
   In some environments where low bandwidth and high latency links can
   exist, it is often beneficial to limit the amount of transported
   information over the network.

   This document introduces a new MIME-Type 'application/pidf-diff+xml',
   which enables transporting of either only the changed parts or the
   full PIDF based presence information.  The root element of the
   document distinguishes whether the partial or full PIDF document
   content was transported.

      Note: With this new MIME-Type, applications can easily negotiate
      the support of partial updates of presence by using the Accept
      header.  If PIDF had initially been designed for partial updates,
      a new separate MIME-Type would have been unnecessary.

Lonnfors, et al.            Standards Track                     [Page 2]
RFC 5262                      Partial PIDF                September 2008

2.  Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",