[cisco-voip] Echo on international calls

[John Kougoulos]

On Wed, 26 Jan 2011, polo person wrote:

> Hi,
> 
> We upgraded our Call Manager from v7 to V8.0.2.41900-3  over the Christmas period.  Before xmas all seemed ok, but just
> after xmas, one of our sites (whose extensions will probably all be registered with one sub) reported that they were
> hearing a bad echo on inbound international calls after 2 to 3 seconds after call set up.  They don't make many (if any)
> outbound international calls, and the inbound calls only happen for the first couple of weeks after xmas and have now
> died down. (Yeah.... really helpful!)
> 
> Where would you clever folks start to look on this one?
>

You could increase the echo-cancel coverage on the voice gateways. Maybe 
it had nothing to do with the call manager upgrade, unless something has 
changed on the codecs. eg. I've seen echo cancelling work better with g729 
vs g711.

Regards,
John