[Asterisk-Users] Is this echo problem down to IP Phone hardware?

[Kris Boutilier]

This known as is 'acoustic echo' or 'room reverb' and involves mathematics that is quite a bit different from that used when cancelling regular 'reflected electrical signal' echos, as the signal is being acousically distorted as it echos around the room. On many handsfree handsets it doesn't manifest itself until you move into a physically large room, which increases the reflection delay and overwhelms the internal mechanisms. 
 
It would need to be handled internally by the handset or you would need to insert a hardware echo canceller capable of dealing with this type of echo, assuming your signal is exposed on a T1 somewhere. If it's IP all the way for you then you're really just down to the handset vendors as far as I know - Asterisk doesn't currently offer any form of echo cancellation on the VoIP side.
 
Hope that helps.
 
Kris Boutilier
Information Systems Coordinator
Sunshine Coast Regional District

-----Original Message-----
From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces at lists.digium.com]On Behalf Of Angus Comber
Sent: Friday, August 05, 2005 10:46 AM
To: asterisk-users at lists.digium.com
Subject: [Asterisk-Users] Is this echo problem down to IP Phone hardware?


Hello
 
I have a Grandstream GXP2000 with latest firmware.  When I use it holding the handpiece I don't hear any echo - neither does other end.  However, if I use it handsfree, the other end notices echo when they speak - ie their voice is echoy.  I hear their voice being a bit echoy.
 
Is this purely down to the IP Phone?  Is there anything I can do about it?  I considered buying a more expensive phone - eg a Snom to see what they were like for echo.  Is there something I can do with the Asterisk?  codec to use?  Anything?
 
Angus