Patent ID: 8572255

Claim:
A method for re-establishing, with a client device, a signaling session associated with a call in progress, comprising: at a session border controller (SBC) separate from the client device: monitoring, by the SBC, Internet protocol (IP) addresses of media packets received from the client device during a call in progress having an associated signaling session and detecting, by the SBC, a change in the IP address for the client device from the media packets, wherein the signaling session is terminated, wherein monitoring the IP addresses comprises: receiving a first real time transport protocol (RTP) packet; extracting and storing the IP address of the first RTP packet; receiving a second RTP packet from the same media session as the first RTP packet; extracting the IP address from the second RTP packet; and comparing the IP address stored for first packet with the IP address extracted from the second RTP packet; in response to detecting a change in the IP address for the client device from the media packets, sending a notification message from the SBC to the client device, wherein the notification message notifies the client device associated with the changed IP address to re-establish the signaling session; receiving a registration message from the client device to re-establish the signaling session; and re-establishing the signaling session for the call in progress.