The symbian application is not working with my mobile operator internet. I saw its a port restricted NAT they are using. The STUN resolve the IP address 119.35.38.8 and put the on SIP header. I tried to ping or trace route the IP with No luck. It cant be found. I tried using STUN separate client with different STUN server. The result is same IP. But why the hell it cant be found with tracert? The I connected my PC with the internet from mobile with PC suite and tried X-Lite. X-Lite does not work either. Request time out. The last thing I tried is Fring. Fortunately or Unfortunately it works just fine. But seemed like Fring does use their own proxy server to route the SIP packet??? Anything special going on behind???? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20081202/b524ccfb/attachment.html>