Turn off inbound fax detection?

I just replaced an older installation based on FreePBX 2.9 and asterisk 1.4 to FreePBX 2.10 and asterisk 1.8.15. Both systems have a Sangoma A101d (1 x T1) card and run dahdi. I copied over the hylafax and iaxmodem configurations that were working fine on the old box to do inbound fax to email.

When I send a fax from another system running iaxmodem/hylafax, all is well. If I try to send a fax from a fax machine, I get:

Redirecting DAHDI/8-1 to fax extension

I’m not using any of the asterisk fax stuff and haven’t defined a fax extension, so this fails with the “ss-noservice” prompt and hangs up.

In chan_dahdi.conf I have “faxdetect=incoming”. If I make this “no”, sending a fax from the remote iaxmodem/hylafax server starts failing, with negotiation issues. Does making it “no” involve some kind of echo cancellation that is killing my fax negotiation?

Some guidance would be appreciated.


Remove the fax module from freepbx

Thanks for responding! I did do that, before I posted. Same result.

Add the following to the PEER details for each trunk:


You can also add it to the Asterisk SIP Settings module, at the bottom, in the custom section.

Hi, thanks for responding!

This gets me back to the original problem, however. The trunk in question is the Dahdi trunk, and if I put “faxdetect=no” in chan_dahdi.conf (I don’t see a way to do this in the GUI for the Dahdi trunk), then inbound faxes all fail with negotiation errors.

I suspect, based on a recent thread in the asterisk-users list, that “faxdetect=incoming” signals some special audio handling to assist with faxing, presumably in the asterisk core.

Basically I need to keep “faxdetect=incoming” in the Dahdi config but tell FreePBX never to redirect to a “fax extension”, and just follow the normal flow I have defined for DIDs.

I’ll play with the dialplan code to see if I can find a workaround and post that here.