[Asterisk-Users] IAX G729 Codec

[Steven Critchfield]

On Thu, 2003-07-10 at 08:24, Simon Woodhead wrote:
> Hi Steven,
> 
> >BTW, my problems where on our private T1 line that sees round trips in
> >the 4ms range. Our semi educated guess was that we had a problem with
> >the jitter buffer causing echo cancel to go nutty when our ping times
> >would occasionally jump to 20ms. When I turned off the jitter buffer,
> >the call quality became so clear that people don't believe we are VoIP.
> 
> Would you mind elaborating on what you mean by going 'nutty'?
> 
> Long distance * to * G.729 over IAX works perfectly but we're also using
> G.729 over H.323 to our telco's Pace Vega Stream. The ping is only 10-12ms,
> occasionally jumping to 20ms. Latency is non-existent and the quality is
> excellent but periodically, mid-way through a call it goes wrong with the
> other party sounding literally like they are underwater. This only happens
> on incoming calls though strangely.

Our problem was that we all of a sudden would get dropped audio, and I
had one user complain of extreme lag occasionally. I didn't have anyone
else experience the lag, but the dropped audio would come and go. It
sometimes would drop out for a second or so. Sound quality when there
was still just perfect.

For your link to the Pace Vega Stream, what codec are you using? I would
assume it would be more of a problem in codec shifting bits or
something, but then again this is a wild guess.  
-- 
Steven Critchfield  <critch at basesys.com>