Patent ID: 7764668

Claim:
A first signaling gateway managed by a service provider and connected to communication terminals and second signaling gateways, at least one of the second signaling gateways being managed by a different service provider, comprising: a transmitting/receiving part that receives a signaling message from the communication terminals or the second signaling gateways and transmits the signaling message outside of the first signaling gateway to a destination; and a control part that, based on first information indicating a position of the first signaling gateway on a path through which the signaling message passes to the destination, and second information indicating a status of whether an extended processing has been executed by the second signaling gateways on the path in a session to which the signaling message belongs, the first information and the second information being included in the signaling message, decides, on the basis of the second information, whether to execute the extended processing in the first signaling gateway, and executes the extended processing therein only if the extended processing has not been executed by the second signaling gateways to avoid redundant execution along the path in the session, wherein the extended processing includes communicating with a real-time transport protocol (RTP) proxy server, a presence server, a web server, or a quality of service (QoS) control server coupled to the first signaling gateway via a network, wherein processing required by the session to which the signaling message belongs is a plurality of independent processing including the extended processing, and wherein the first signaling gateway and the second signaling gateways are SIP (Session Initiation Protocol) proxy servers.