[Asterisk-Dev] potential problem with IAX.

[Steven Critchfield]

While running some tests on our new software, we have found what we
think may be a bug in the way IAX handles silence.  

We have a machine with a T400P and a PRI located at our colo facility.
We have a P-t-P T1 to our office. In our office we have a machine with a
T100P connected to a channel bank. We are currently running our AGI apps
on the machine in our office. Our intent later on is to have multiple
machines in our colo that run this agi app via IAX. 

Our problem as we have observed it, is that when we make a call from our
PSTN connection to the machine in our office to run our application, our
application will go into record mode for a period greater than 2
minutes. When we press a DTMF key to exit the record function, the first
prompt or 2 are not played. We have run Monitor on the channel during
this action, and can tell that the machine running the AGI app played
the prompts, and when we ran the monitor app on the colo machine we can
tell that it didn't record the prompts. 

We are guessing at this moment, that while recording in AGI, there is no
audio being written out to the channel. When we play a prompt, the other
side spends some time dealing with the new audio that it hasn't received
in a while.

So far, for testing, we put a ast_write in the section of the
record_handle function that deals with voice frames. The audio output
was not acceptable, but the prompts didn't get lost. I was wondering if
this is the appropriate track to fix this problem, or is it just a side
effect that the write seems to have fixed the problem. If it is the
correct way to fix the problem, I could research a better sounding fix
for the agi problem.
-- 
Steven Critchfield <critch at basesys.com>