I have the below gateways.xml file. FS 1.6.19. <include> <gateway name="VoIP-1"> <param name="outbound-proxy" value="xx.xx.xx.xx" /> <param name="register-proxy" value="xx.xx.xx.xx" /> <param name="proxy" value="xx.xx.xx.xx" /> <param name="register-transport" value="tcp" /> <param name="username" value="1222" /> <param name="password" value="***" /> <param name="extension-in-contact" value="true" /> <param name="auth-username" value="***" /> <param name="retry-seconds" value="30" /> <param name="expire-seconds" value="3600" /> </gateway> </include> But the REGISTER and the INVITE's are being sent out using UDP!. The strange part is the SIP headers both in the Request URI and the contact header contain "transport=tcp". send 750 bytes to udp/[xx.xx.xx.xx]:5060 at 23:30:20.632901: ------------------------------------------------------------------------ REGISTER sip:xx.xx.xx.xx;transport=tcp SIP/2.0 Via: SIP/2.0/UDP xx.xx.xx.xx;rport;branch=z9hG4bKj7QXQX0X8tD3j Max-Forwards: 70 From: <sip:1222@xx.xx.xx.xx>;tag=6Be8aaD192rcK To: <sip:1222@1xx.xx.xx.xx> Call-ID: a8905624-0576-421f-ba71-fb50c700e876 CSeq: 9232391 REGISTER Contact: <sip:1222@xx.xx.xx.xx:5060;transport=tcp;gw=VoIP-1> If I remove the Register-Proxy and Outbound-Proxy and just use Proxy everything works fine on TCP. Also, if I set the transport param in the SIP profile to TCP things work fine. But I have multiple gateways in the same profile, so setting the SIP profile is less desirable. Am I missing something or is this a bug ? Any help really appreciated! Thanks, Shaks