[asterisk-users] TE121 - Idle system load at ~0.3 - Bad DAHDI 2.2.0.2 behaviour ?!

[Shaun Ruffell]

On 11/11/2009 02:08 PM, Ex Vito wrote:
>   We've been experiencing some tough time regarding a new Asterisk installation
>   connected to the PSTN via an ISDN PRI with a Digium TE121 with the optional
>   VPMADT032 echo cancellation module.

It appears there may be a regression in dahdi-linux 2.2.0 with regards 
to the wcte12xp driver and the VPMADT032 module (as discussed 
https://issues.asterisk.org/view.php?id=15724).  Would you be willing to 
try at least revision 7584 of 
http://svn.asterisk.org/svn/dahdi/linux/branches/2.2 and report your 
results on that issue?

>
>   Extra information / question:
>
>   A quick peek at https://issues.asterisk.org/view.php?id=15498&nbn=18
>   also lead me to test loading the wcte12xp driver with "vpmsupport=0".
>
>   The system load behaviour is exactly the same.

The idle load you're seeing can be a little misleading, but essentially, 
once you load the drivers for both the wctdm24xxp and wcte12xp, there is 
a fixed cost associated with continuously moving the TDM data to/from 
the card.  The load imposed by the drivers would only go up after this 
point if a) software echocan is enabled, or b) you're conferencing many 
calls in the kernel.  Otherwise....it's fixed.

-- 
Shaun Ruffell
Digium, Inc. | Linux Kernel Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: www.digium.com & www.asterisk.org