Method and system for realizing cross network segment signaling interworking of videoconference system

The invention discloses a method and a system for realizing cross network segment signaling interworking of a videoconference system, and is used for realizing RAS signaling interworking between a terminal and a gatekeeper in different network segments, wherein the method comprises the steps that: the terminal is registered to an RAS agent, the RAS agent establishes the mapping relation between a serial number in the RAS signaling message and the source IP address as well as port of the terminal after receiving the RAS signaling message initiated by the terminal, and forwards the RAS signaling message to a gatekeeper; and the RAS agent sends the RAS response message to the corresponding terminal according to the established mapping relation after receiving the RAS response message replied by the gatekeeper. The technical scheme of the invention can realize the RAS signaling communication between a plurality of terminals in different network segments and the gatekeepers in extranets.