Patent ID: 8661077

Claim:
A method for providing a failover measure in a communications network that includes a plurality of notifier servers, the method comprising: receiving, at a first notifier server from a watcher entity client, a first subscription request for SIP event information associated with one or more watched entity clients; receiving, at a watcher information (WINFO) entity, session initiation protocol (SIP) event subscription information that includes an identifier indicating that the first notifier server serves the watcher entity client; storing the SIP event subscription information in the WINFO entity; detecting the unavailability of the first notifier server; and sending an instruction message to the watcher entity client, based on the identifier in the stored SIP event subscription information, to direct the watcher entity client to terminate a subscription for the SIP event information serviced by the first notifier server and to generate a second subscription request for the SIP event information, wherein the second subscription request for the SIP event information is sent to a failover server.