[asterisk-users] Asterisk 1.6 vs 1.4?

Tzafrir Cohen tzafrir.cohen at xorcom.com
Thu Jun 5 04:57:12 CDT 2008


On Thu, Jun 05, 2008 at 03:40:14AM +1000, Rob Hillis wrote:
> 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.

Unless there are some really strange OSLEC patches floating around, of
which I'm not aware, this should not be the case.

OSLEC uses exactly the same EC interface to Asterisk as the built-in
one and HPEC do. Any chance you didn't actually fully unload zaptel?

-- 
               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com  iax:guest at local.xorcom.com/tzafrir



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