[Asterisk-Users] Polycom hand/head set echo and Zapata config

[Kevin Smith]

Hey everyone,

I have been trying to figure this out and I am just getting no where 
with it. The office is using Polycom IP 601 phones. Everything sounds 
great in terms of quality on both heads. However, users of the phone are 
having trouble with their headsets and handsets. Some users are hearing 
their voices back come back on the phone. If they adjust their volume 
lower, then it goes away, but then they can hardly hear the customer.

I have tried using the noise suppression and cancellation features on 
the sip.conf for the phone but that hasn't worked either. Has anyone had 
this before and have you found a way to adjust the phone to cancel the 
echo? Or am I wrong and it isn't the phone but the zapata.conf for 
asterisk or the TDM card? Is there a way to boost the volume of the 
caller without adjusting the phones? For example the rxgain and txgain 
in the zapata.conf file.

Any suggestions would be greatly helpful.

Thanks,
Kevin