Hi, I am trying connect remote extension to my 3CX PBX. My PBX is behind a NAT has IP address 192.168.1.14, phone (remote extension) is also behind a different NAT. I'm using Patton 4638 Gateway with Public IP address as a router to connect to Internet. There are configured NAPT, with full-cone UDP translation. I have enabled STUN on the phone, remote extension is succesfully registered in PBX (behind a Patton router). If I call this extension from my phone (on the same private network as PBX), call is established, but I can't hear anything. In oposite direction (from remote ext. to ext on the same private network as PBX) call cannot be established. Firewall checker does complete successfully. Can anybody help me?