Disclosed are methods, systems, and computer program products for notifying a Session Initiation Protocol (SIP) entity of a fast switchover event. According to one method a first SIP entity having an active host and a standby host is provided. At the active host a SUBSCRIBE message is received from a...http://www.google.com.tw/patents/US8051189?utm_source=gb-gplus-share專利 US8051189 - Methods, systems, and computer program products for session initiation protocol (SIP) fast switchover
