[asterisk-users] res_fax T.38 Gateway with SpanDSP - Force ReINVITE?

[Larry Moore]

On 23/10/2014 10:07 PM, Larry Moore wrote:
>
>
> On 22/10/2014 11:23 AM, Tim Nelson wrote:
>> Greetings-
>>
>> Working with the T.38 gateway functionality that is sparsely documented
>> [1], I'm attempting to get the following functional:
>>
>
> What type of endpoint are you using which is originating the call and is
> it T.38 capable?
>
> Larry.
>

Have you had a look at 
https://wiki.asterisk.org/wiki/display/AST/SIP+Direct+Media+Reinvite+Glare+Avoidance

As an exercise you could disable T.38 on 'Asterisk calling system', if 
you have an ATA which is originating the call to 'Asterisk calling 
system' disable T.38 on that device too and disable in your sip.conf 
using t38pt_udptl=no.

If you are using SendFax() on 'Asterisk calling system' ensure T.38 is 
not able to be used.

If using an ATA connecting to 'Asterisk calling system' ensure you have 
set in your peer's configuration canreinvite=no or directmedia=no, 
depending on the version of Asterisk you are running on this system.

On Asterisk system in '(box in question)' set directmedia=no for the 
peer which is connecting to 'SIP Provider' and also to 'Asterisk calling 
system', you may want to set setvar=FAXOPT(gateway)=yes in your peer 
config to 'SIP Provider' otherwise it will need to be set in your dialplan.

Set your verbose & debug to at least 3 on '(box in question)', possibly 
a little higher and send a fax - you may now see the Fax Gateway detect 
CED. Not sure if this is suppressed in

You may want enable udptl debugging on '(box in question)'.

Larry.