[asterisk-users] FXO Cards - T38

[Steve Underwood]

T.38 is not a codec. A codec has one input and one output. T.38 is an 
interactive protocol. This, however, has nothing to do with what I said. 
If you use G.729 in the same asterisk as my spandsp library, you are 
breaking my licence conditions.

Steve


Rob Hillis wrote:
> T.38 is a codec in exactly the same way that GSM or G.729 is a codec, 
> so yes it /can/ be used at the same time as any other codec - just 
> that only /one/ codec will be used at a time.  What often happens is 
> that the call will initially be established with a codec such as G.729 
> or G.711a, but once fax tones are detected the call will change codecs 
> to T.38.
>
> According to the release notes for 1.6.0-b4...
>
>  - 11873, Added core API changes to handle T.38 origination and termination
>    (The version of app_fax in Asterisk-addons now supports this.)
>   
>
> This should be all that is necessary to run a T.38 gateway.
>
>
> Steve Underwood wrote:
>> Rob Hillis wrote:
>>   
>>> Not unless you're running CallWeaver or Asterisk 1.6.0-beta4.  Asterisk 
>>> has had passthrough support for T.38 for a while (somewhere in 1.4 it 
>>> became available IIRC) but is currently completely incapable of 
>>> terminating or encoding a fax call to T.38.
>>>   
>>>     
>> I thought * was still not capable for T.38 gateway operation. Doesn't 
>> beta 4 just added T.38 termination? And, I believe it misses out some 
>> key elements of doing that properly. Note that T.38 termination is an 
>> addon, so it can't be used with, say, G.729.
>>   
>>> The only real option available at the moment is to keep one PSTN line on 
>>> an ATA with an FXO port and T.38 support available and direct calls from 
>>> the fax machines through to it.  However, I should point out that while 
>>> I believe this should be possible, I haven't actually tried it myself.
>>>
>>>   
>>>     
>> Steve
>>