[Asterisk-Users] echo problem + choppy sound

[Rich Adamson]

Based only on what I see below (from previous posts), it sounds like you 
have two separate issues going on: 1) echo, and, 2) choppy sound. Those 
should be analyzed as two problems (not one).

You will find plenty of posts in the archives relative to both. In 
general terms, the choppy audio most often is caused by shared IRQ's 
when using a x100p or TDM400 card, and sometimes from a misconfigured 
ethernet nic on the asterisk machine. For the nic card, ensure you are 
running full duplex on the nic "and" whatever the nic is plugged in to.
Both need to be the same (half duplex will work in a low usage 
environment, but full duplex is preferred.)

For the IRQ issue (and we are all assuming you are using a TDM04b card 
since you really didn't say), do a 'cat /proc/interrupts' and make sure 
your TDM card is on its own IRQ. If it is shared with other devices, it 
is likely the cause for choppy audio. You'll see the TDM driver wctdm on 
that list. If it is shared, then move the TDM card from one pci slot to 
another to get it on its own IRQ.

The echo problem is going to be almost aways related to "too high" of 
gains in zapata.conf.  Your rxgain=10 and txgain=10 are way too high as 
others have already noted. Try reducing those to 0 and restart asterisk.
Then increase the values (if needed) by increments of 2 until you find a 
balance between low volume and echo.  I'd suggest doing that "after" 
resolving the IRQ/choppy audio issues.


> I have done this but I still get choppy sound and echo on some calls
> 
> thanks
> 
> */Giovanni Miano <giomiano at gmail.com>/* wrote:
> 
>     Of course,
>     Echo is 2 types: electric and ambiental.
> 
>     If u gain rx o tx more than you need, its return in recive and gen echo
> 
>     Try to decrase value, try to set 0 or .. in samecase -1 -2...
> 
>     2006/3/13, sdgesa gaeharth <pollux1234567890 at yahoo.com
>     <mailto:pollux1234567890 at yahoo.com>>:
> 
>         Can you explain why?
> 
> 
>         */Giovanni Miano <giomiano at gmail.com
>         <mailto:giomiano at gmail.com>>/* wrote:
> 
>             rxgain=10.0
>             txgain=10.0
> 
>              ????
> 
>             Maybe this is a problem
> 
> 
>             2006/3/13, sdgesa gaeharth < pollux1234567890 at yahoo.com
>             <mailto:pollux1234567890 at yahoo.com> >:
> 
>                 I still hear a slight echo of my voice when I talk with
>                 somone out the PSTN.  The voice on the other end sounds
>                 very choppy and a little distorted. When I talk to other
>                 people within our office, the sound is perfect.Can some
>                 help?
> 
>                 We are all using:
> 
>                 Polycom 501 <--> asterisk <--> PSTN
> 
>                 zapata.conf:
>                 [channels]
>                 group = 1
>                 language=en
>                 context=incoming
>                 signalling=fxs_ks
>                 switchtype=national
>                 usecallerid=yes
>                 hidecallerid=no
>                 callwaiting=yes
>                 musiconhold=default
>                 usecallingpres=yes
>                 callwaitingcallerid=yes
>                 threewaycalling=yes
>                 transfer=yes
>                 canpark=yes
>                 cancallforward=yes
>                 callreturn=yes
>                 echocancel=yes
>                 echotraining=yes
>                 echocancelwhenbridged=yes
>                 rxgain=10.0
>                 txgain=10.0
>                 channel => 1-4
>