1 Presence-specific dictionary for Sigcomp draft-garcia-simple-presence-dictionary-02.txt 68 th IETF Prague, Check Republic SIPPING WG 21/22-March-2007 Miguel Garcia

2 Introduction and scope SigComp (RFC 3320) provides a framework for compressing text-based protocols The SIP and SDP static dictionary for Sigcomp (RFC 3485) creates a static dictionary of SIP and SDP strings for boosting compression. However, RFC 3485 does not operate on XML documents. There is significant interest, specially in the wireless community, to minimize the byte consumption of the presence service. Idea: add a presence-specific static dictionary to the SigComp Framework Can coexist with the SIP/SDP dictionary Endpoints can announce both dictionaries during SigComp initialization Studies and early implementations reveal that, once applied all the defined optimizations, an additional 10% savings can be achieved with the presence- specific dictionary.

3 Input documents The draft considers strings from the following documents: RFC 3858: Watcher information RFC 3863: PIDF RFC 4419: Location object RFC 4661: Filters RFC 4662: Resource Lists RFC 4479: A Data Model for Presence RFC 4480: RPID RFC 4481: Timed Presence Extensions to the PIDF RFC 4482: CIPID Prescaps Partial PIDF XML Patch Operations OMA extensions to PIDF

4 Next steps Eye globes to examine the draft or a fraction of the draft Any missing presence document? Are the priorities correct? NOTE: Priorities help building a more efficient dictionary by placing most commonly used strings at the bottom. The document is otherwise thought to be complete.