[Asterisk-Users] Re: Echo SIP-T100P-PRI

[Ryan Thrash]

On Aug 19, 2004, at 5:33 PM, Rich Adamson wrote:

> Mike Schwartz wrote:
>>>> I'm experience echo on outgoing calls:
>>>>  Snom 200 ----> Asterisk ----> T100P ----> PRI ----> called party
>>>>
>>>> I am getting echo on the Snom 200 phone. The called party does not
>>>> hear the echo.

<snip>

> When that discussion was going on a few weeks ago, the echo issue
> seemed to have been narrowed down to two possibiliites; 1) interrupt
> service latency, or, 2) PCI bus latencies. Processor speed does not
> seem to be a driving factor as noted above.
>
> I've not heard anyone (as yet) come up with the tools or process for
> actually identifying the root-cause. Would be nice for those of us
> that aren't programmers.

Some more echo food for thought. It's most noticeable on very short, 
hard sounds (like "CH"), so as someone mentioned, reverb might be the 
right description. I've spent the better part of several hours 
experimenting with various combinations of adjusting taps from 32 to 
256, echowhenbridged on and off and txgain adjustments. I just flat 
can't get it to go away...

I'm also one of those "luck" ones with a Supermicro box (dual Xeons and 
plenty of RAM). How in the heck would/should I go about figuring out 
what the interrupt service latency or the PCI bus latency is doing. Any 
other thoughts on the front? I'm using GS phones so maybe their echo 
can algorithms are to blame... hmmm...

Here's to hoping,
Ryan Thrash