This chapter contains sections titled:

• Overview of the Presence Service

• The Presence Life Cycle

• Presence Information Data Format

• The Presence Data Model for SIP

• Mapping the SIP Presence Data Model to the PIDF

• Rich Presence Information Data Format

• CIPID

• Timed Presence Extension to the PIDF

• Presence Capabilities

• Presence Publication

• Presence Subscription and Notification

• Watcher Information

• URI-list Services and Resource Lists

• XML Configuration Access Protocol

• Presence Optimizations