Hi, I made this project to use my house´s phone on the office with 3cx: PSTN - Gateway Linksys SPA 3102 - Ethernet - 3CX server - ADSL Modem - Internet - ADSL Modem - Router - IP Phone. I did some tests with 3cx phone to see how it´s working, and it worked in these situations: - 3cx server with 3CX phone conecting local IP - worked. - 3cx server with 3CX phone conecting external IP - worked. But when I did a test using de 3CX phone at the Office´s LAN, I got this error: Attempting to connect xx.xxx.xxx.xx using network intervace ***.***.***.*** phone got as local port 4469 integration with 3cx call assistant is off rtp engine ok sip engine ok sound mic device ok  sound ring device ok  sound play device ok  phone is sending STUN request Phone connection failed, server not responding At the 3cx Phone the configuration was this: I am out of the office - external IP xx.xxx.xxx.xx of PBX. At 3CX phone system in the Server Activity screen doesn´t apear anything. I made de firewall test and it passed. What´s the problem? Help please.