[Asterisk-Users] Ugly echo cancel, with Bristuff/Zaphfc

[Tzafrir Cohen]

On Sun, Jan 15, 2006 at 04:56:57AM +0100, Pisac wrote:
> I'm using bristuffed Asterisk with ISDN/ZAPHFC
> I have VERY ugly (outgoing) sound through ISDN/HFC if echocancel=yes in
> zapata.conf, but without echocancel I have bad (incoming) echo
> Through PSTN/FXO sound is ok with or without echocancel.
> 
> I tried other echo cancellers (in zconfig.h) two times:
> 
> ECHO_CAN_KB1 (this was default)
> ECHO_CAN_MARK2
> ECHO_CAN_MG2
> 
> after any change I compiled (make clean all && make install) all drivers
> which are bristuffed, without recompiling Asterisk (should I?), but...
> 
> ... I always have EXACTLY same (ugly) sound and same (appearing of) echo
> cancelling.
> 
> Seems to me that echo canceller do not changing no matter what I choose
> in zconfig.h. This must be some bristuff echo cancel "patch" to zaptel
> source? 

The bristuff change to zaptel (the kernel level), other than adding
kernel modules is very limited. Echo cancelation in itself is done in
the kernel space in Zaptel.

> Before I bristuffed Asterisk, I was playing with zconfig.h and I
> remember that difference between echo canceller were very obvious.
> 
> Anybody have some knowledge about bristuffed echo cancelling?

Bristuff does change chan_zap. Something you could try to verify what I
have just written is to try working with a bristuffed Zaptel and
non-bristuffed Asterisk. This should work.

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