[asterisk-users] Transfer to fax

[Kevin P. Fleming]

On 02/24/2012 05:00 PM, Mike Diehl wrote:
> On Friday 24 February 2012 3:17:04 pm Mike Diehl wrote:
>> On Friday 24 February 2012 2:39:48 pm Kevin P. Fleming wrote:
>>> On 02/24/2012 03:32 PM, Mike Diehl wrote:
>>>> Hi all,
>>>>
>>>> I've got a user that has one phone number an wants to be able to us it
>>>> for both voice and fax.
>>>>
>>>> When a fax call comes in, he wants to do some incantation on the keypad
>>>> and have the call go to the fax machine.
>>>>
>>>> As I see it, he has 3 options.
>>>>
>>>> 1.  (blind?) Transfer it to the fax extension.
>>>>
>>>> 2.  Use features.conf to create a key sequence, say *2, to
>>>> dial/transfer to a fax extension.
>>>>
>>>> 3.  Use fax detect (SIP) to do it automatically.  However I'm also
>>>> using FFA, so I suspect these are mutually exclusive.
>>>
>>> They are not. Enabling faxdetect should do exactly what you want; it
>>> will redirect the call to the 'fax' extension in the current context,
>>> and you can then Dial() your FAX machine (or send the call to
>>> ReceiveFAX).
>>
>> Thank you.  Then, that's what I'll do.
>
> On second though, I think my suggestion that FFA and fax detect were mutually
> exclusive stemmed from the idea that a call that was being
> originated/answered/handled by FFA would have it's call disconnected and
> redirected by fax detect.
>
> If this is the case, it changes my dial plan logic, and I'm not sure I fully
> understand what changes I'll need to make.
>
> For all I know, it might even simplify things by isolating all fax handling in
> one block.

Well, first you should not have faxdetect enabled on outbound channels. 
That takes care of the 'originating' part.

If you have an inbound channel that you *know* you are sending to 
ReceiveFAX, then you can just disable faxdetect on that channel before 
doing so (this is why we made 'faxdetect' configurable from the 
dialplan). Alternatively, you can just let calls that you *know* are 
going to go to ReceiveFAX (dedicated FAX DIDs, for example) just 'idle' 
in the dialplan listening to silence until faxdetect kicks in and sends 
them to ReceiveFAX.

Note that the usage of FFA is not relevant here; whether you are using 
Fax for Asterisk, the free version of it, or res_fax_spandsp, the 
behavior and scenarios would be the same.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
Jabber: kfleming at digium.com | SIP: kpfleming at digium.com | Skype: kpfleming
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at www.digium.com & www.asterisk.org