[Asterisk-Users] Fun with Echo

[shadowym]

This ALL pretty much depends on YOUR particular install because the loop
length and signal level to your local exchange will vary from site to site.


Believe me, you can drive yourself insane trying to come up with some
magical formula that JUST works because it usually won't happen that way.
Software echo cancellers are simply not good enough for many situations.  

You can try get away with it and you may be successful sometimes.  IMHO a
good project plan should ALWAYS make sure there is a bit extra in the budget
to add a good hardware echo can if required.  I personally don't want the
headaches anymore and just include hardware echo can all the time.  Most
good ones do other things like clear up the sound quality as well.  It's
just a more professional way to go no matter how you look at it. 

> -----Original Message-----
> From: Steve Davies [mailto:davies147 at gmail.com] 
> Sent: Friday, June 09, 2006 4:16 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [Asterisk-Users] Fun with Echo
> 
> On 6/8/06, Brian Swan <swannie at swannie.net> wrote:
> [snip]
> >
> > I've followed the numerous suggestions in the mailing list archives 
> > which is what has enabled me to get this far.  After trying all the 
> > echo cancelers, and all the settings on each I settled on:
> >
> > - KB1 (with AGGRESSIVE_SUPRESSOR)
> > - echocancel=128
> > - echotraining=600
> > - rxgain=0
> > - txgain=0
> >
> [snip]
> 
> My personal preference, which works best in the most places is:
> 
> - MG2 (with default DEFINEs, no aggressive etc)
> - echocancel=yes
> - echotraining=yes
> - rxgain=0
> - txgain=0
> 
> Although in some cases:
> - rxgain=-0.3
> - txgain=-0.3
> seems to help a tiny bit.
> 
> The MG2 canceller made a HUGE difference to our success rate 
> in removing echo, I do not rate the updates to MG2 that are 
> in trunk, but the released version (1.2.6) is excellent.
> 
>