[Freeswitch-users] KVM vs. XEN virtualization

[Regis M]

How do you check wavs together in audacity ?
Can you send me 2 samples wav (send... and recorded) so I could see the
20ms diff that you exposed...

Is there a way to automate the result checking, so it could help to monitor
itsp quality


2015-04-04 12:53 GMT+02:00 Stanislav Sinyagin <ssinyagin at gmail.com>:

> Important is to send the media through two independent carriers - then you
> can be sure that your clock is compared against a high quality one.
> On Apr 4, 2015 12:46 PM, "Regis M" <regis.freeswitch.org at tornad.net>
> wrote:
>
>> Hi,
>>
>> It's a very interresting test and conclusion.
>>
>> I will try to build a similar environnement on my freeswitch to check
>> some system :)
>>
>> thanks
>>
>>
>>
>> 2015-04-04 2:16 GMT+02:00 Stanislav Sinyagin <ssinyagin at gmail.com>:
>>
>>> hi,
>>>
>>> Here are some test results which might be interesting:
>>>
>>> I've set up a test FreeSWITCH server at digitalocean (they use KVM),
>>> and originated test calls to some ITSP accounts. Each call played a
>>> test sound file (voice samples from ITU:
>>> http://www.itu.int/net/itu-t/sigdb/genaudio/AudioForm-g.aspx?val=1000050
>>> ), and on the receiving end another FreeSWITCH server was recording
>>> the received session. The receiving server was on a XEN VM. Both
>>> servers talked G711 to their corresponding ITSP accounts.
>>>
>>> Then I compared the source audio and received audio in Audacity editor.
>>>
>>> The tests showed that the received voice wave shifts 20ms from the
>>> original sound every few seconds, randomly back and forward. This
>>> skewing was always present, regardless of ITSP and time of day.
>>>
>>> Then I moved the sending server to a XEN VM, and the waves appeared
>>> almost perfectly synchronized (there was a 5ms skew in one test, and I
>>> guess it's related to transcoding buffer, as the sound was obviously
>>> transcoded).
>>>
>>> The effect was always visible with a 30-second sample, and I also made
>>> additional tests with 2-minute samples.
>>>
>>> It would also be interesting to test this from a VmWare VM. If someone
>>> wants to run such a test, feel free to contact me directly.
>>>
>>>
>>> cheers,
>>> stan
>>>
>>> _________________________________________________________________________
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>>
>>
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting at freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users at lists.freeswitch.org
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>> http://www.freeswitch.org
>>
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> Official FreeSWITCH Sites
> http://www.freeswitch.org
> http://confluence.freeswitch.org
> http://www.cluecon.com
>
> FreeSWITCH-users mailing list
> FreeSWITCH-users at lists.freeswitch.org
> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
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