[asterisk-users] Fwd: Re: Asterisk T.38 Pass-Through doesn't work

[Larry Moore]

On 31/07/2013 8:08 PM, Joshua Colp wrote:
> Zoltán Fekete wrote:
>> Thank You Larry!
>>
>> I have discussed with my provider. They are not able to insert the
>> T38MaxBitRate value into the sip answer. :(
>> https://gist.github.com/anonymous/6120148 (line 559)
>>
>> That means we are not able to passtrough T38 Faxes with any asterisk
>> version at all?
>> What do you mean? Am I able to modify and compile the source? Is it
>> compicated? (I'm not a developer)
>
> Based on the SDP in your gist the remote implementation has given no
> attributes with the T.38 stream which makes it pretty broken
> (T38FaxRateManagement is mandatory) and fun. The two hard parts really
> would be 1. Modifying Asterisk in a sane fashion to cope and 2.
> Determining the exact settings to make the implementation happy.
> Defaults as defined in the spec are fine and good, but my experience has
> taught me to throw those out the window when it comes to actual
> implementations.
>

It would seem that having a configurable option would be an idea for 
this scenario.

My testing with Asterisk 1.8 and T.38, I obserevd that setting 
FAXOPT(minrate) or FAXOPT(maxrate)had no effect, I concluded that when 
Astrerisk is receiving it uses hard coded values - is this a sane thing 
to do?!

If Asterisk T.38 reception could be configured to use the values defined 
in FAXOPT(minrate) or FAXOPT(maxrate)this would be a good starting point 
for situations like this one.

Cheers,

Larry.