[Freeswitch-users] KVM vs. XEN virtualization

Thu Apr 9 15:21:46 MSD 2015

thanks, the PESQ tool appears to be open-source and free for
non-commercial use, so I started a series of tests. I'll post an
update.
http://www.itu.int/rec/T-REC-P.862-200511-I!Amd2/en

On Thu, Apr 9, 2015 at 12:36 PM, Jayanth Acharya <jayachar88 at gmail.com> wrote:
> See if this helps -
> http://www.voip-info.org/wiki/view/Call+Quality+Metrics
> http://www.tamos.com/htmlhelp/voip-analysis/mosandr_factor.htm
>
>
> On Thu, Apr 9, 2015 at 3:18 PM, Stanislav Sinyagin <ssinyagin at gmail.com>
> wrote:
>>
>> I made additional tests, and... I'm not sure any more. So, I removed
>> the statement about bad precision. This needs a lab environment with
>> predictable network and known CPU load on the host machine.
>>
>> Does anyone know any tools that would automatically detect sound
>> distortions in WAV files and also find the shifts because of slipping
>> clock or lost frames?  Up to now, the only tool I could find is
>> visually comparing the waves in Audacity.
>>
>>
>>
>> On Sun, Apr 5, 2015 at 2:37 AM, Stanislav Sinyagin <ssinyagin at gmail.com>
>> wrote:
>> > here we go:
>> >
>> > https://txlab.wordpress.com/2015/04/05/testing-rtp-clock-precision-on-a-virtual-machine/
>> >
>> >
>> >
>> > On Sat, Apr 4, 2015 at 4:26 PM, Stanislav Sinyagin <ssinyagin at gmail.com>
>> > wrote:
>> >> On Sat, Apr 4, 2015 at 1:03 PM, Regis M
>> >> <regis.freeswitch.org at tornad.net> wrote:
>> >>> How do you check wavs together in audacity ?
>> >>
>> >> you just open two WAV files, align their starting position, and
>> >> visually check the waves. If there's a problem, you would see that
>> >> after few seconds, the waves are not aligned any more.
>> >>
>> >>> 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
>> >>
>> >> Here
>> >> https://github.com/openpreserve/scape-xcorrsound/issues/17
>> >> this is a link to a tool which compares two sound files at the wave
>> >> level. You can also see the sound samples in the ticket.
>> >> The problem is, that currently this tool does not detect such slipping
>> >> frames.
>> >>
>> >> I will also write a detailed article with examples, during the weekend.
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>>
>> >>>
>> >>> 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
>> >>>>>>
>> >>>>>>
>> >>>>>>
>> >>>>>> _________________________________________________________________________
>> >>>>>> 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
>> >>>>>>
>> >>>>>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> >>>>>> 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
>> >>>>>
>> >>>>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> >>>>> 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
>> >>>>
>> >>>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> >>>> 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
>> >>>
>> >>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> >>> 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
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> 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
> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
> http://www.freeswitch.org