[asterisk-users] Questions on hardware or software-based echo cancellation

[Kevin P. Fleming]

On 01/12/2012 06:39 AM, Olivier wrote:
> Hi,
>
> I'm having some questions related to echo cancellation configuration
> on a Digium board enabled systems (B410P, TE420, TE420B, ....) for
> cases when a hardware ech canceller is present or not.
>
> I read in TEXXX manual that when setting echocancel=yes in
> chan_dahdi.conf on a VPMOCT64-equiped system, 128ms hardware echo
> cancellation was enabled.
>
> 1. I'm correct thinking that it is then impossible to switch from
> hardware to software echo can without removing the VPMOCT64 module
> itself ?
> 2. Does the same also apply to HA8 and its VPMOCT032 module ?

With DAHDI 2.6 (and possibly 2.5), it is possible to override the 
configuration and apply a software echo canceller to a channel even if 
it has a hardware one. With prior versions, yes, the echo cancellation 
module would have to be physically removed (or disabled using a 
parameter to the kernel module).

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
Jabber: kfleming at digium.com | SIP: kpfleming at digium.com | Skype: kpfleming
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
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