I have the following setup:
[fax] -> [FXS Gateway] -> Asterisk (Sip) -> PSTN
FXS Gateway = Grandstream GXW 4004
Asterisk = 1.4.4 (AsteriskNOW beta5)
For some reason, when I call the fax machine (whether it is from a SIP phone or from the PSTN) I get the first beep of the handshake and then silence. It is almost like asterisk detected there is a fax and decided to do something else with it.
Does anyone know why this is happening and how to stop Asterisk from doing this. I have tried this on a few other Asterisk platforms:
1.2.18 - works fine
1.2.18 (different server) - no audio after first beep. This used to be 1.2.12 (I think) which worked, then I upgraded to 1.2.18 and it started breaking.
Any help appreciated!