System and method for reestablishing, with a client device, a signaling session associated with a call in progress

A system for re-establishing a signaling session with a client device, comprising:

• a processor;
• and
• a memory,
• wherein the memory stores a signaling session table for storing IP addresses associated with signaling sessions for calls in progress involving client devices;
• wherein the memory stores computer executable instructions that when executed by the processor implement a session border controller (SBC) for communicating with the client device and being separate from the client device;
• the SBC including a module operable to detect, by comparing an IP address of a media packet from a media session involving the client device with an IP address stored for a signaling session associated with the media session in the signaling session table, a change in the IP address of the client device, wherein detecting a change in the IP address of the client device includes monitoring IP addresses comprising:
• 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;
• and
• wherein the signaling session is terminated, and, in response to detecting the change in the IP address, the module is operable to send 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, to receive a registration message from the client device to re-register the signaling session, and, in response to the registration message, to re-establish the signaling session.

A non-transitory computer readable medium having stored thereon having stored thereon instructions, that when executed by a processor implement steps 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.