Patent ID: 8130766

Claim:
A system for implementing multimedia calls across a private network boundary, comprising a public network and at least one private network, characterized in that the system comprises: at least one media gateway for connecting with multimedia terminals of various protocols; at least one boundary gateway for connecting the private network and the public network, and performing the translation of a private network address and a public network address, wherein each boundary gateway is provided with a unique subnetwork ID to correspond to the private network connected therewith; and the boundary gateway is used for receiving the signaling message from a media gateway connected therewith, establishing a signaling tunnel from the boundary gateway to the call controller according to its own subnetwork ID, and sending the signaling message to the call controller through the signaling tunnel; a call controller for establishing calls and controlling service logics, in which is recorded the correspondence relationship information of all said boundary gateways and the subnetwork IDs; wherein the call controller processes the call concerning a private network according to the subnetwork ID information, and wherein the media gateway initiates the call and sends the call number to the call controller the call controller, after receiving the call number, analyzes the call number, and determines the boundary gateway connected with the media gateway and the called side boundary gateway, the call controller sends a command request to establish a media channel to the calling side boundary gateway and the called side boundary gateway respectively according to the subnetwork IDs of the calling side boundary gateway and the called side boundary gateway, the call controller receives the information of the media ports allocated and returned by the calling side boundary gateway and the called side boundary gateway respectively, and notifies the information of the media ports to the opposite side boundary gateways respectively, the calling side boundary gateway, after receiving the notification of the media port information of the called side boundary gateway, establishes a media channel from the boundary gateway to the called side boundary gateway, the media gateway having initiated the call transmits the media traffic through the established media channel, and after the media gateway finishes transmitting the media traffic in the media channel, removes the media channel automatically.