Hi to all I'm using ser software sip proxy server, with micronet ipphone as UA, I want to send calls behind NAT router ,knowing that my UA is behind the NAT ,But the proxy server is in same host with the NAT DEVICE(same ip address), all the UA using uotbound proxy & did n't support STUN. can you help me. waiting for your reply salma VOIP Administrator University of Khartoum Sudan