Hi, i would like to configure a FS system so that only if both peers have a public IP address they can speak each other. The condition is that the client are mobile and can connect from whatever network, so apply-nat-acl does not work because some mobile carrier use fancy internal IP address such as 1.1.1.1 . All clients connect with SIP/TLS and there is no SIP ALG that mangle the SDP, so we can be sure that what FS see is exactly what the SIP client has sent. Given that, i would like FS to always do proxy_media unless BOTH two leg of the call have a public IP address. I know that's not extremely efficient and that in theory two SIP clients with one behind NAT and one with public IP can speak each other, but even in such conditions there may be unpredictable issues. How the NAT handling of FS could be modified to do that and let bypass_media only when both SIP client have a public IP address? Fabio