asterisk users - Feb 2008 - Zaptel timer on Intel Dual Core servers

Friends,

I'm having severe problems with zaptel timers on Intel Dual Core  
systems with SMP code enabled. Ztdummy, zaptel connected to Digium TDM  
or PRI cards - all ends up with large timer probems - zttest going  
down to 50% accuracy on some systems, even to -1 on ztdummy systems  
and voice quality is no more.  A restart is the only way to get back  
to a working system.

We're only running a few meetme's with a total of 10 participants, so  
the load is not excessive. Only SIP calls, nothing else (it's me,  
right :-) ) ? If I hit the system with SIPP targeting an extension  
only doing playback, which doesn't even use zttimer, the timer slides  
away.

I've played around with the irqbalance daemon, but don't see any big  
differences with or without it.

My question is if anyone else have seen this and if anyone has a  
possible solution?

Thanks in advance for your help!

/Olle

> My question is if anyone else have seen this and if anyone has a
> possible solution?
Nearly all of the boxes we've built over the last few months have been
either Core2 Duo or Core2 Quad based and we haven't seen any timer issues.
In most cases these are purely IP boxes (no PRI or TDM cards) with ztdummy.
We've had plenty of meetme conferences over that time and I've not
noticed any problems.

I'll run zttest on a couple of them over the weekend and see what results we
get, but certainly, there haven't been any complaints about quality during
conferences.

Regards,

Chris
-- 
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Johansson Olle E <oej at edvina.net> writes:
> Friends,
>
> I'm having severe problems with zaptel timers on Intel Dual Core  
> systems with SMP code enabled. Ztdummy, zaptel connected to Digium TDM  
> or PRI cards - all ends up with large timer probems - zttest going  
> down to 50% accuracy on some systems, even to -1 on ztdummy systems  
> and voice quality is no more.  A restart is the only way to get back  
> to a working system.
It's a bit difficult to guess what is wrong. You may want to look at
which kernel version you use, and the options used.

Perhaps trying maxcpus=1 on the SMP kernel would be interesting.


/Benny

On Sat, Feb 02, 2008 at 09:46:42AM +0100, Johansson Olle E
wrote:
> Friends,
> 
> I'm having severe problems with zaptel timers on Intel Dual Core  
> systems with SMP code enabled. Ztdummy, zaptel connected to Digium TDM  
> or PRI cards - all ends up with large timer probems - zttest going  
> down to 50% accuracy on some systems, even to -1 on ztdummy systems  
> and voice quality is no more.  A restart is the only way to get back  
> to a working system.
A restart of asterisk? Not touhcing the kernel modules? 

What CPU is it, exactly? /proc/cpuinfo would help.

What version of Zaptel? Asterisk? Kernel? distribution?

What happens if you don't run those meetme-s?
> 
> We're only running a few meetme's with a total of 10 participants,
so
> the load is not excessive. Only SIP calls, nothing else (it's me,  
> right :-) ) ? If I hit the system with SIPP targeting an extension  
> only doing playback, which doesn't even use zttimer, the timer slides  
> away.
When exactly does a playback to a SIP channel use timing from zaptel? I
know that bad zaptel timer is known to mess sound playback anywhere. I
just don't fuly understand why.

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