[asterisk-dev] fallback to audio faxing when T.38 INVITE fail with 488/606 Not acceptable

[Olle E. Johansson]

13 jan 2010 kl. 12.51 skrev Kevin P. Fleming:

> Kristijan Vrban wrote:
>> Hello, i use 1.4 asterisk (1.4.28 and svn) to make T.38 passthrough
>> between a Siemens hiQ9200 (british telecom) and an asterisk 1.6.2 with
>> app_fax/spandsp as T.38 termination endpoint.
>> this is working. But in the case that the hiQ9200 reply our T.38
>> INVITE with a  606 Not Acceptable, the 1.4 asterisk just hangup up,
>> and does not ACK this reply to fallback to audio faxing.
> 
> 6xx response codes are fatal responses; the call must be terminated when
> one is received. The proper response for a endpoint that wishes to
> refuse a T.38 re-INVITE is a 488.

I don't really agree. fatal responses to an in-dialog request is fatal for the transaction, not for the dialog.

However, the original message was a bit unclear if it was a re-invite or an invite.

/O