IMS Presence Subscription and Notification Flow

The flow below covers IMS presence subscription and notification (SUBSCRIBE/NOTIFY). To follow presence signaling in a real capture, VisualEther renders the SIP event-package exchange from a Wireshark PCAP as a sequence diagram.

IP Multimedia Subsystem (IMS) provides a framework and building blocks for building advanced telecom services. One such service is network wide publication and subscription of presence information. Users can subscribe to presence information for their contacts. If the contact accepts their request, the subscriber will be registered for presence notification. Whenever the friend publishes presence information, the IMS presence framework will notify the subscribed users.