Inbound analog faxes not being detected over SIP on asterisk 1.6.2 and FreePBX 2.7

I just installed a new PiAF system (17554 32bit with asterisk 1.6.2 with freepbx upgrade to 2.7) and have not been able to get inbound analog faxing to work over SIP. I have an older PiAF with 1.4 and spandsp working with analog SIP inbound faxes with minimal problems.

The system doesn’t seem to detect the fax tones, but I can’t see any method of debugging whether or not asterisk is even trying to detect the tones. The inbound call “waits” for the amount of time I have specified(10 sec) in the GUI while waiting for the fax tones, but it always goes on to voice.

I have installed a free instance of the Fax for Asterisk from digium. I have set the fax detection to SIP as I believe that can detect analog faxing over SIP, at least it does on my personal home pbx which is based on elastix 2.x which looks to have comparable software versions to this new PiAF system.

So my questions are:

  • am I correct in using ‘sip’ for my fax detection?
  • is there any way to have asterisk log that it is attempting to detect fax tones? Changing the verbose level doesn’t do it.

If I understand the process correctly, the fax tone detection is totally separate from actually receiving faxes and a standard part of 1.6?

thanks for any information,