Hello all. I am triying to use FS (git) with an external gateway. This is the schema: FS (has public IP over virtual interface eth0:1 - xxx.xxx.xxx.xxx) -> INTERNET -> Router TP-LINK (with ports forwarded to GW) -> HT503 (192.168.0.160). HT503 has two sip accounts. One for an internal extension (FXS) and one for PSTN (FXO). I can make calls from an internet softphone to FXS and the phone attached rings, but when I pecked up I can't hear audio in both directions. The same happens when I call FXO to make a PSNT call. The PSTN calls is ok but no audio in both directions. BUT, if I picked up the internal phone attached to FXS and make a call to an internal extension o calls to 5000 I hear the IVR and audio flows in both directions. Because a rule in HT503 on FXO port, when receive a call from PSTN this forwarding to 1015 extension. This works and I hear the audio in both directions. FS in running on a Centos 6 VPS. Are there a way to debug this? Some lights? Thank you Normando