[asterisk-users] T38modem in loopback mode does not work on asterisk 1.4.20.1

[David Backeberg]

On Wed, Apr 15, 2009 at 3:29 AM, Florian Hackenberger
<f.hackenberger at chello.at> wrote:
> Thanks for the explanation! Sounds all good. There is one remaining
> question however. As you mentioned T.30, is app_fax capable of
> terminating T.38?

Yes although I'm speaking about 1.6. I can't say for certain what is
required on 1.4. You need to set up SIP to listen for T.38

in sip.conf:
[general]
t38pt_udptl = yes

in your dialplan
ReceiveFax() and SendFax()
will automatically detect whether it's possible to do fax as T.38, or
it will instead do audio fax over your voip codec of choice. Ideally
G.711. Your VoIP gateway should certainly be capable of acting as a
T.38 gateway, at least mine does.