[Freeswitch-users] VoipTalk NAT

Hi, This is my first post so my apologies if I get the protocol wrong or if I'm posting to the wrong place. Has anyone any experience of setting up Freeswitch to accept incoming calls via VoipTalk (http://www.voiptalk.org) through a firewall/router. I have tried every possible combination of domain/realm and proxy settings but can't get it working. Everything works fine when the freeswitch machine is connected directly to the modem and a software voip-phone runs ok on the same machine through the router so the firewall is letting the traffic through. Any help greatly appreciated. Many thanks Andy