[Asterisk-Users] TDM-400P Sound Quality issues

[Rich Adamson]

> I spent a bunch of time troubleshooting the SIP end of things, thinking that's where the 
problem was, until I realized that every other SIP
> connection I make (from remote) yields a high quality call.  ie.  I can dial another SIP 
client and maintain high quality audio.  Additionally, I can
> dial an extension that not only SIP connects to my server, but from there goes out an IAX2 
connection to another remote Asterisk server, from
> there to another SIP client, and the audio quality is excellent.
>  
> Therefore, I don't think the audio issue I'm experiencing is on the SIP end.
>  
> Are there some wierd SIP -> ZAP timing / conversion / other issues that could be causing this?
>  
> thoughts?

Pure guess... you're probably bumping into some of the same issues
that many of us TDM users are hitting. Seems like either an interrupt
handling (latency) or pci bus issue. You'll find hundreds of postings
relative to this over the last six months or so. Not everyone has
problems with the TDM, but some have found that swapping motherboards
does clear up the issue. 

Processor speed and ram have nothing to do with it, nor does single vs
dual processors, etc. 

Several people have opened trouble tickets with digium, but seems all
have gone into a black hole (thus far).