[asterisk-users] T38 fax detection using g729

[Larry Moore]

On 13/04/2011 10:14 PM, Niccolò Belli wrote:
> Hi, I continue the discussion from
> https://issues.asterisk.org/view.php?id=19103
>
> If T.38 reinvite detection should still work, why it doesn't?
> If I use faxdetect = t38 it does never detect the fax, even using alaw.
>

That is because the remote endpoint, eutelia, will need to detect the 
Fax Tones and send the T.38 ReINVITE to you, they may not have T.38 enabled.

It would appear in your case your Asterisk installation will need to 
detect the Fax Tones so as to make the decision the incoming call is a 
fax and then switch to the fax extension. For Asterisk to detect the Fax 
Tones you will need to set faxdetect to either yes or cng, you will also 
require using alaw or ulaw codec.

As a suggestion you could configure your incoming calls from eutelia to 
go directly to the fax receive function whilst having the g729 codec 
enabled, I expect you will then see T.38 re-invite come from Asterisk.

What is in your configuration for 159?

Larry.