Patent ID: 7920549

Claim:
A method for supporting transmission of packetized voice calls, the method comprising: receiving a signaling message for establishing a voice call from a first endpoint associated with a first domain to a second endpoint associated with a second domain, wherein the first endpoint queries a first server to determine information relating to a firewall and network address translator that the first endpoint is behind, and to log into a second server configured to establish a media path between the first endpoint and the second endpoint, wherein a first proxy server serving the first endpoint communicates with a third server to convert a directory number corresponding to the second endpoint to a network address, the first proxy server communicating with a second proxy server serving the second endpoint to establish the voice call, wherein the first server, the second server and the third server are maintained by service provider; authenticating the first endpoint to permit exchange of a media stream over the media path; and relaying the media stream, if the first endpoint is successfully authenticated.