Thanks guys for the infos. Actually, after posting, I figured that running the STUN server and Freeswitch on the same server is not the magical solution I though it was, since a symmetric NAT firewall will also prevent reusing a UDP port if the remote port is different (which it would, one to send datagrams to the STUN server, and another port to send datagrams to Freeswitch). I've searched for a Windows GUI STUN client so the user could first run this to check what type of firewall he has, but didn't find any. Vovida's http://sourceforge.net/projects/stun/ STUN client is command-line, and the http://sofia-sip.sourceforge.net/ Sofia project doesn't offer binaries, much less Windows binaries. Maybe there are STUN servers out there that display results on a web page? I'll read up on the alternatives to make SIP work even with symmetrical NAT firewalls. Thank you. -- View this message in context: http://freeswitch-users.2379917.n2.nabble.com/Freeswitch-as-STUN-server-tp57... Sent from the freeswitch-users mailing list archive at Nabble.com.