Patent ID: 7173928

Claim:
A method of operating a telephony service provider system for providing a media session channel for communication of real time streaming media data from a remote caller client to a callee client served by an address translation firewall, the method comprising: receiving a ping datagram, the ping datagram being originated by the callee client, addressed to the telephony service provider system, and having its source network address and source port number translated by the address translation firewall, the ping datagram further including identification of the callee client; extracting a translated source network address and a translated source port number from the ping datagram to identify an open signaling channel to the callee client from the telephone service provider system that can be reverse translated by the address translation firewall; receiving a session signaling message initiated by a remote caller client, the session signaling message identifying the callee client and identifying a caller network address and a caller port number established by the remote caller client for receipt of media session datagrams; determining a designated network address and designated port number to which the callee client is to send media session datagrams, the designated network address and the designated port number being: the caller network address and the caller port number if the caller network address as identified in the session signaling message matches an extracted source address extracted from the session signaling message; and a relay server network address and a relay server port number if the caller network address as identified in the session signaling message is different than the extracted source address extracted from the session signaling message; and sending a client session signaling message to the callee client on the open signaling channel by utilizing the translated source network address and translated source port number in response to receipt of the session signaling message from the remote caller client, the client session signaling message including identification of the designated network address and designated port number.