[asterisk-users] Asterisk 1.6 vs 1.4?

[Rob Hillis]

Tzafrir Cohen wrote:
> On Thu, Jun 05, 2008 at 03:00:01AM +1000, Rob Hillis wrote:
>   
>> Why on earth are you running two layers of echo cancellation - hardware 
>> and software?  To be honest, I think this is asking for trouble - I've 
>> seen two occasions where having Oslec and hardware echo cancellation has 
>> caused significant problems with audio quality - the usual symptoms are 
>> gaps in the conversation as the hardware cancellation eliminates the 
>> majority of the echo and the software cancellation subsequently 
>> eliminates parts of the conversation.
>>     
> If you use a hardware EC (or technically: a span-specific echo
> cancellation method) the generic Zaptel echo canceller (software-based,
> OSLEC in this case) will not be used.

That's not always been my experience with OSLEC.  HPEC and the generic 
Zaptel echo canceller seem to work this way, but as I've said, I've had 
two cases where I've had to remove OSLEC to stop it degrading voice 
quality where there is a hardware echo canceller in play.