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

[Tobias Wolf]

Kevin P. Fleming schrieb:
> 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.
> 
Alright, understood.

>> 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?
> 
Have done that, no messages appear while receiving a fax. I know that i have 
seen such messages before the upgrade. I have another asterisk server which is 
bristuffed, and there i can see this message with 'dmesg'.

I am absolutly positive that DAHDI was not built with NO_ECHOCAN_DISABLE, since 
i have only downloaded the package and done a 'make; make install' without 
touching anything of the source code.

By the way, i am using DAHDI-linux 2.1.0.3.

Regards

-- 

   Tobias Wolf