Hello To solve the issue of opening UDP ports dynamically on the firewall that protects a remote SIP client located elsewhere on the Net, the most used solution is to have the client use STUN to open UDP ports, learn its public IP address, and then re-use those UDP ports to register with the IP PBX and let SIP/RTP packets in through the firewall. While not actively handing calls, STUN-capable SIP clients send keep-alive datagrams regularly to keep the UDP ports open on their firewall. Unfortunately, symmetric NAT firewalls don't allow re-using UDP ports to work with another host. So I was wondering if Freeswitch could run as STUN server or if someone knew of a good open-source STUN server that I could install on the same host as the Freeswitch server? http://img545.imageshack.us/img545/3580/ippbxstun.png Would this solve the issue? If not, I guess the alternatives are trying UPnP, NAT-PMP, or IAX, and if all else fails, running OpenVPN and configure both end-points to pass all SIP/RTP packets through this TCP tunnel. Thank you for any feedback. -- 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.