[asterisk-users] How to detect if a call is fax or not

[Gordon Henderson]

On Sun, 23 Mar 2008, Pete Kay wrote:

> Hi
> I got my hylafax running to receive and send fax.  Since I only have one
> number, I want to know if there is anyway to detect if a call signal is fax
> then redirect it to fax-to-email, otherwise route the call to my analog
> phone?   Is it something that can be done?

If coming in on a Zap channel, then:

In /etc/zapata.conf in the relevant channel definition you need:

   faxdetect=incoming

Then in the dialplan you need to answer the incoming call (as you've no 
other way of telling if it's a FAX calling), and listen in for a second or 
2 (with a Wait(2) instruction), then if it's an incoming FAX, asterisk 
will jump to the fax extension, then you can Dial the hylafax extension, 
etc.

Or if it's not a fax, at this point the caller is now paying for the call, 
because you've answered it, so be nice to them - play a message, ring the 
phones, etc.

Personally, for a simple installation like this, I'd install spandsp, 
rxfax & txfax and not use hylafax, but if hylafax is something you're used 
to then go that route...

Gordon