On 3/15/06, Bill Stewart <bill.stewart@pobox.com> wrote:
... The basic model is client/server, with servers that can proxy requests to other servers, where the job of a server is to provide presence service so that clients can find each other, and actual media channels are client-to-client. (This does mean that you sometimes need to tunnel through NAT and firewalls.) Because servers can proxy requests to other servers, it's no longer a simple hierarchy model.
there is also TRIP: http://www.voip-info.org/wiki-TRIP an inter-domain routing protocol for VoIP (like BGP for voice). for various political reasons this has never seemed to go anywhere. i posted a patch for gcc 3.x a while back if anyone wants to build the vovida trip daemon on a modern system.