I have something strange. I have removed my old external IP already from the firewall. So it can't be used anymore... Internally 3CX works great with my phones. I'm trying to use on my Android phone a connection to the 3CX server for my company. I’m trying this from both my G3 connection and my wifi. 3CX softphone makes the connection, and set it to available. Within the 3CX Admin console, I can see that the phone connects correctly. When I dial a number, the connection is made, but no voice. When I check the logging, it still uses the old IP of my PABX System. 11-okt-2015 13:59:17.213 [MS105000] C:1.1: No RTP packets were received:remoteAddr=10.117.11.70:42000,extAddr=0.0.0.0:0,localAddr=XXX.YYY.ZZZ.125:9000 I have configured the / Settings / Networking / STUN Server. I had the correct new IP’s filled in. But I’m also testing with STUN configured. 11-okt-2015 13:56:35.089 [CM506002]: Resolved SIP external IPort (XXX.YYY.ZZZ.126:5060) on Transport 192.168.178.116:5060 11-okt-2015 13:56:34.918 [CM506001]: STUN request to resolve SIP external IPort mapping is sent to STUN server 126.96.36.199:3478 over Transport 192.168.178.116:5060 Firewall checker give all greens, and passes with success.. So no errors on there. I’m a little lost now, where 3CX keeps getting the old IP from?