asterisk users - Dec 2006 - Xen, Asterisk & ISDN: Timing Problems

Hi,

is anybody running asterisk on a xen domU and can give an opinion on the 
following:

I have delegated a FritzCard and a HFC card to my domU and installed an 
asterisk setup that was running on the same isdn hardware but on a 
dedicated machine flawlessly.

I experienced what I believed to be timing problems: sometimes calls on 
the Fritzcard did not seem to "reach" asterisk, when calls were being 
made, sometimes they were horribly distorted. I quickly abandoned the 
project at the time for lack of time. I would now make another trial.

Can anybody tell me if the problems I was having were more likely to 
result from the fact that the isdn hardware was dedicated to the domU 
(i.e. maybe that produces some sort of bottleneck!?) or from too little 
ram allocated to my domU? (I believe I had 128 MB or so)

Thanks,
Arik

I would vote RAM. I've been using a FXO card in xen for a good year now 
with no issues at all. In fact, my zttest timings are the same between 
xen and native. 

Arik Raffael Funke wrote:
> Hi,
>
> is anybody running asterisk on a xen domU and can give an opinion on 
> the following:
>
> I have delegated a FritzCard and a HFC card to my domU and installed 
> an asterisk setup that was running on the same isdn hardware but on a 
> dedicated machine flawlessly.
>
> I experienced what I believed to be timing problems: sometimes calls 
> on the Fritzcard did not seem to "reach" asterisk, when calls
were
> being made, sometimes they were horribly distorted. I quickly 
> abandoned the project at the time for lack of time. I would now make 
> another trial.
>
> Can anybody tell me if the problems I was having were more likely to 
> result from the fact that the isdn hardware was dedicated to the domU 
> (i.e. maybe that produces some sort of bottleneck!?) or from too 
> little ram allocated to my domU? (I believe I had 128 MB or so)
>
> Thanks,
> Arik
>
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
>
> asterisk-users mailing list
> To UNSUBSCRIBE or update options visit:
>   http://lists.digium.com/mailman/listinfo/asterisk-users
>
>
-- 
Jason
The place where you made your stand never mattered,
only that you were there... and still on your feet

Arik Raffael Funke wrote:
> Hi,
>
> is anybody running asterisk on a xen domU and can give an opinion on
> the following:
>
> I have delegated a FritzCard and a HFC card to my domU and installed
> an asterisk setup that was running on the same isdn hardware but on a
> dedicated machine flawlessly.
>
> I experienced what I believed to be timing problems: sometimes calls
> on the Fritzcard did not seem to "reach" asterisk, when calls
were
> being made, sometimes they were horribly distorted. I quickly
> abandoned the project at the time for lack of time. I would now make
> another trial.
>
> Can anybody tell me if the problems I was having were more likely to
> result from the fact that the isdn hardware was dedicated to the domU
> (i.e. maybe that produces some sort of bottleneck!?) or from too
> little ram allocated to my domU? (I believe I had 128 MB or so)
>
> Thanks,
> Arik
>
You are doing something that in my opinion requires advanced expertise
and experimentation. Start out by using a host with at least 2 CPU cores
and at least 1 gb RAM. Give your domU half the RAM and don't run any
other domU's. If it doesn't work that way, you need to look at xen
config options and the way your kernel is built. If you can get it to
work, then you can try it with less resources and other domU's running.

That has been fixed in the current Xen, and as far as I can tell works 
without problems. (At least for some NICs I had dedicated to another domU.)

Regards,
Arik


Howard Lowndes wrote:
> I have to run Asterisk on the dom0 host as earlier versions of Xen had 
> problems handing PCI control over to a domU kernel.  Does anyone know if 
> this has been fixed yet?
> 
> 
> Arik Raffael Funke wrote:
>> Thanks. What kernels do you use for dom0 and the domU's?
Custom-built
>> or out of the box?
>>
>> - Arik
>>
>>
>> jason wrote:
>>> I would vote RAM. I've been using a FXO card in xen for a good
year
>>> now with no issues at all. In fact, my zttest timings are the same 
>>> between xen and native.
>>> Arik Raffael Funke wrote:
>>>> Hi,
>>>>
>>>> is anybody running asterisk on a xen domU and can give an
opinion on
>>>> the following:
>>>>
>>>> I have delegated a FritzCard and a HFC card to my domU and
installed
>>>> an asterisk setup that was running on the same isdn hardware
but on
>>>> a dedicated machine flawlessly.
>>>>
>>>> I experienced what I believed to be timing problems: sometimes
calls
>>>> on the Fritzcard did not seem to "reach" asterisk,
when calls were
>>>> being made, sometimes they were horribly distorted. I quickly 
>>>> abandoned the project at the time for lack of time. I would now
make
>>>> another trial.
>>>>
>>>> Can anybody tell me if the problems I was having were more
likely to
>>>> result from the fact that the isdn hardware was dedicated to
the
>>>> domU (i.e. maybe that produces some sort of bottleneck!?) or
from
>>>> too little ram allocated to my domU? (I believe I had 128 MB or
so)
>>>>
>>>> Thanks,
>>>> Arik
>>>>
>>>> _______________________________________________
>>>> --Bandwidth and Colocation provided by Easynews.com --
>>>>
>>>> asterisk-users mailing list
>>>> To UNSUBSCRIBE or update options visit:
>>>>   http://lists.digium.com/mailman/listinfo/asterisk-users
>>>>
>>>>
>>>
>>
>> _______________________________________________
>> --Bandwidth and Colocation provided by Easynews.com --
>>
>> asterisk-users mailing list
>> To UNSUBSCRIBE or update options visit:
>>   http://lists.digium.com/mailman/listinfo/asterisk-users
>>
>