Force Fax Receive Answer on 4 particular zap channels without need for fax detection

Here’s the scenario.
We have 4 fax numbers. Each of these numbers corresponds to a particular zap channel from our T-1.

I know I can set in the incoming route to have asterisk handle the fax by selecting “system” and “zaptel” detection. The problem is that I don’t want to detect if it’s a fax or not, I know it is a fax due to it coming in on that zap channel that is our fax number.

Some fax machines do not send out tones. What I want to do is when a call comes in on a zap channel that is dedicated for faxes I want Trixbox to answer and immediately begin receiving a fax.

Is this possible? I’ve played around some with a custom context using the faxreceive macro but no luck yet.



This is easily accomplished with a combination of the Inbound Zap Channel routing and a Fax destination. If your faxes come in on channel 4 (for example) then you would set the “Zaptel Channel” destination to “4”. Make sure the zapata.conf configuration is from-zaptel.

Next, your destination for the Fax. If you want the fax to go to a real fax machine that is attached to your system then you would choose the corresponding extension as your destination. If you want it to go the the “System” fax (spandsp) then you need to do another step prior to this. In either case you set detection type to none and if you are going to use the “System” fax then set an email address here where the fax should be emailed.

To get it to the “System” (spandsp) fax you need to create a destination that points there. Go to the MIsc Destinations and in the “Feature Codes Short Cuts” choose “Dial System Fax” as the destination and then name it accordingly. Once you have done that, you can go back to the Incoming Route for your Fax Channel and use that as the destination.

That’s it - the call will come in on that channel, it will be assigned the designated email address you supply on the Incoming Routes screen. It won’t bother with Fax detection (because you chose none). It will go straight to the specified destination which is either a real fax or the spandsp “System” fax that you configured in Misc Destinations and if using the “System” it will use the email address specified above for delivery.

Philippe Lindheimer - FreePBX Project Lead
http// - IRC #freepbx

Thanks Philippe, I’ll try that out.