Audio problem on call

guys I have a problem with asterisk/freepbx I can make and receive calls, but it remains silent on both sides, how do I solve it? I have freepx16 installed on Debian 12 and another on Ubuntu with the same symptoms! Thanks in advance

I had the same problem.

The usual causes are incorrect NAT settings, incorrect firewall settings, or dynamic NAT/firewall rules on routers timing out.

Having a selective lack of routing to a media server, as in the other reply, is relatively rare, and, in you look at the whole thread, you will see that a lot more information than you have provided is generally needed to find the specific cause.

In my case, the nat settings were correct but it was a codec issue! I am using linphone and I need to select PCMA if I want to be heard, while my brother who connects to my network via vpn needs to use speex 16000hz codec.

We found out fiddling with the settings