[asterisk-users] Disabling Echo Cancellation on a per Call basis

[Kevin P. Fleming]

Tobias Wolf wrote:

> Does this only take place if fax detection is enabled in DAHDI or is it 
> something that happens everytime a CED tone is send over the line?

FAX detection is not done in DAHDI, it's done in chan_dahdi (in
Asterisk). CED detection is done in the echo canceler itself, so it is
completely independent of Asterisk (or any application, for that
matter). Correctly responding to CED is something that an echo canceler
must do just to be compliant with various specifications.

> Unfortunatly my Linux Machine seems not to log messages from DAHDI.
> I have looked into /var/log/kern.log
> There are messages from the kernel module like;
> Feb 11 17:38:12 officepbx kernel: wcte1xxp: Setting yellow alarm
> Feb 11 17:38:21 officepbx kernel: wcte1xxp: Clearing yellow alarm
> 
> But no messages about echo can. Maybe i am missing configuration for the kernel 
> module to enable logging ?

It's logged as a LOG_NOTICE message and is always generated, unless
DAHDI was built with NO_ECHOCAN_DISABLE defined, which would be
uncommon. However, /var/log/kern.log on your system might be only from
the boot process. Have you checked 'dmesg' as the system is running?

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