[Asterisk-Users] asterisk using tdm400p has echo

[Jared Armstrong]

I had to turn on the aggressive echo cancellation in the zaptel drivers
for mine. Which is much better, but we still get occasional pops.

The funny part is only the asterisk side of the connection hears the
echo. 

Jared Armstrong

-----Original Message-----
From: Rich Adamson [mailto:radamson at routers.com] 
Sent: Thursday, October 27, 2005 8:22 AM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [Asterisk-Users] asterisk using tdm400p has echo


> > > Hi list, i'm having a problem with asterisk+pstn termination, i
just
> > > bought a TDM400p and connect my phone line(bellsouth) now when im
> > > using the pstn through asterisk there's an echo, i don't know if
this
> > > is already have been resolved. If it does please point me to the
> > > instruction how to resolve this.
> >
> > Try reading README.fxotune and using fxotune to see if it improves
it.  
> 
> If you do an fxotune and all of the coefficients are 0, does this mean
that fxotune is not 
making
> any changes?
> 
> I've got 6 lines that are coming from a channel bank into two TDM
cards and have significant
> echo, even with Asterisk HEAD and KB1.  I just ran fxotune, and all 6
lines came back with all
> 0's in fxotune.conf...

Based on what Matt has mentioned previously, fxotune only sets the
impedence
to proper values today. He has not implemented the code to set the
coefficients
as yet, therefore the expected values are zero's.