<div dir="ltr"><div><div><div>Stanislav,<br><br></div>If you have a spare box around you could install Proxmox on it since that uses KVM and works great too.<br><br></div>regards,<br><br></div>Errol<br> <br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Apr 6, 2015 at 9:40 AM, Stanislav Sinyagin <span dir="ltr"><<a href="mailto:ssinyagin@gmail.com" target="_blank">ssinyagin@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I'm using the smallest $5 machines at DO in Amsterdam and London, and<br>
Xen is on my colocated physical machine in Zurich.<br>
<br>
I'm still collecting the statistics. It's all started when I had my<br>
call generator at DO, and I noticed regular slipping frames on the<br>
receiving side. The calls were definitely going through TDM links,<br>
because I know the receiving side.<br>
<br>
I'm still testing it. Sometimes I get slipping frames from the Xen<br>
calls, but never such regular slips as I got with DO. Sometimes on a<br>
DO host, the calls run quite fine, but those were on a weekend in the<br>
middle of the night. I'll continue testing during the week.<br>
<br>
What would be good, is to have a KVM machine where the physical host<br>
is controlled, so that we can see its overall CPU load during the<br>
tests.<br>
<div class="HOEnZb"><div class="h5"><br>
<br>
<br>
On Mon, Apr 6, 2015 at 10:15 AM, Errol Samuels <<a href="mailto:ewsamuels@gmail.com">ewsamuels@gmail.com</a>> wrote:<br>
> Good job and Thanks for sharing!<br>
><br>
>> KVM at <a href="http://digitalocean.com" target="_blank">digitalocean.com</a>, Debian 7 64bit, FreeSWITCH 1.4.15: bad precision<br>
><br>
><br>
> As someone who has been using KVM for a few years and has just migrated<br>
> about 20 VMs across to Digital Ocean about 6 weeks ago I admit I am a little<br>
> concerned about this finding.<br>
><br>
> Just out of curiosity can you tell me the specs of the VM that you tested<br>
> with and which DO Datacenter? I am using NYC3 so perhaps and I will do some<br>
> tests as soon as I have some time.<br>
><br>
> With regards to Xen was this at Linode or inhouse?<br>
><br>
> Thanks<br>
><br>
> Errol<br>
><br>
><br>
><br>
> On Sun, Apr 5, 2015 at 1:37 AM, Stanislav Sinyagin <<a href="mailto:ssinyagin@gmail.com">ssinyagin@gmail.com</a>><br>
> wrote:<br>
>><br>
>> here we go:<br>
>><br>
>> <a href="https://txlab.wordpress.com/2015/04/05/testing-rtp-clock-precision-on-a-virtual-machine/" target="_blank">https://txlab.wordpress.com/2015/04/05/testing-rtp-clock-precision-on-a-virtual-machine/</a><br>
>><br>
>><br>
>><br>
>> On Sat, Apr 4, 2015 at 4:26 PM, Stanislav Sinyagin <<a href="mailto:ssinyagin@gmail.com">ssinyagin@gmail.com</a>><br>
>> wrote:<br>
>> > On Sat, Apr 4, 2015 at 1:03 PM, Regis M<br>
>> > <<a href="mailto:regis.freeswitch.org@tornad.net">regis.freeswitch.org@tornad.net</a>> wrote:<br>
>> >> How do you check wavs together in audacity ?<br>
>> ><br>
>> > you just open two WAV files, align their starting position, and<br>
>> > visually check the waves. If there's a problem, you would see that<br>
>> > after few seconds, the waves are not aligned any more.<br>
>> ><br>
>> >> Can you send me 2 samples wav (send... and recorded) so I could see the<br>
>> >> 20ms<br>
>> >> diff that you exposed...<br>
>> >><br>
>> >> Is there a way to automate the result checking, so it could help to<br>
>> >> monitor<br>
>> >> itsp quality<br>
>> ><br>
>> > Here<br>
>> > <a href="https://github.com/openpreserve/scape-xcorrsound/issues/17" target="_blank">https://github.com/openpreserve/scape-xcorrsound/issues/17</a><br>
>> > this is a link to a tool which compares two sound files at the wave<br>
>> > level. You can also see the sound samples in the ticket.<br>
>> > The problem is, that currently this tool does not detect such slipping<br>
>> > frames.<br>
>> ><br>
>> > I will also write a detailed article with examples, during the weekend.<br>
>> ><br>
>> ><br>
>> ><br>
>> ><br>
>> ><br>
>> >><br>
>> >><br>
>> >> 2015-04-04 12:53 GMT+02:00 Stanislav Sinyagin <<a href="mailto:ssinyagin@gmail.com">ssinyagin@gmail.com</a>>:<br>
>> >>><br>
>> >>> Important is to send the media through two independent carriers - then<br>
>> >>> you<br>
>> >>> can be sure that your clock is compared against a high quality one.<br>
>> >>><br>
>> >>> On Apr 4, 2015 12:46 PM, "Regis M" <<a href="mailto:regis.freeswitch.org@tornad.net">regis.freeswitch.org@tornad.net</a>><br>
>> >>> wrote:<br>
>> >>>><br>
>> >>>> Hi,<br>
>> >>>><br>
>> >>>> It's a very interresting test and conclusion.<br>
>> >>>><br>
>> >>>> I will try to build a similar environnement on my freeswitch to check<br>
>> >>>> some system :)<br>
>> >>>><br>
>> >>>> thanks<br>
>> >>>><br>
>> >>>><br>
>> >>>><br>
>> >>>> 2015-04-04 2:16 GMT+02:00 Stanislav Sinyagin <<a href="mailto:ssinyagin@gmail.com">ssinyagin@gmail.com</a>>:<br>
>> >>>>><br>
>> >>>>> hi,<br>
>> >>>>><br>
>> >>>>> Here are some test results which might be interesting:<br>
>> >>>>><br>
>> >>>>> I've set up a test FreeSWITCH server at digitalocean (they use KVM),<br>
>> >>>>> and originated test calls to some ITSP accounts. Each call played a<br>
>> >>>>> test sound file (voice samples from ITU:<br>
>> >>>>><br>
>> >>>>> <a href="http://www.itu.int/net/itu-t/sigdb/genaudio/AudioForm-g.aspx?val=1000050" target="_blank">http://www.itu.int/net/itu-t/sigdb/genaudio/AudioForm-g.aspx?val=1000050</a><br>
>> >>>>> ), and on the receiving end another FreeSWITCH server was recording<br>
>> >>>>> the received session. The receiving server was on a XEN VM. Both<br>
>> >>>>> servers talked G711 to their corresponding ITSP accounts.<br>
>> >>>>><br>
>> >>>>> Then I compared the source audio and received audio in Audacity<br>
>> >>>>> editor.<br>
>> >>>>><br>
>> >>>>> The tests showed that the received voice wave shifts 20ms from the<br>
>> >>>>> original sound every few seconds, randomly back and forward. This<br>
>> >>>>> skewing was always present, regardless of ITSP and time of day.<br>
>> >>>>><br>
>> >>>>> Then I moved the sending server to a XEN VM, and the waves appeared<br>
>> >>>>> almost perfectly synchronized (there was a 5ms skew in one test, and<br>
>> >>>>> I<br>
>> >>>>> guess it's related to transcoding buffer, as the sound was obviously<br>
>> >>>>> transcoded).<br>
>> >>>>><br>
>> >>>>> The effect was always visible with a 30-second sample, and I also<br>
>> >>>>> made<br>
>> >>>>> additional tests with 2-minute samples.<br>
>> >>>>><br>
>> >>>>> It would also be interesting to test this from a VmWare VM. If<br>
>> >>>>> someone<br>
>> >>>>> wants to run such a test, feel free to contact me directly.<br>
>> >>>>><br>
>> >>>>><br>
>> >>>>> cheers,<br>
>> >>>>> stan<br>
>> >>>>><br>
>> >>>>><br>
>> >>>>><br>
>> >>>>> _________________________________________________________________________<br>
>> >>>>> Professional FreeSWITCH Consulting Services:<br>
>> >>>>> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
>> >>>>> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
>> >>>>><br>
>> >>>>> Official FreeSWITCH Sites<br>
>> >>>>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >>>>> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
>> >>>>> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
>> >>>>><br>
>> >>>>> FreeSWITCH-users mailing list<br>
>> >>>>> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
>> >>>>> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
>> >>>>><br>
>> >>>>> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
>> >>>>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >>>><br>
>> >>>><br>
>> >>>><br>
>> >>>><br>
>> >>>> _________________________________________________________________________<br>
>> >>>> Professional FreeSWITCH Consulting Services:<br>
>> >>>> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
>> >>>> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
>> >>>><br>
>> >>>> Official FreeSWITCH Sites<br>
>> >>>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >>>> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
>> >>>> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
>> >>>><br>
>> >>>> FreeSWITCH-users mailing list<br>
>> >>>> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
>> >>>> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
>> >>>><br>
>> >>>> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
>> >>>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >>><br>
>> >>><br>
>> >>><br>
>> >>> _________________________________________________________________________<br>
>> >>> Professional FreeSWITCH Consulting Services:<br>
>> >>> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
>> >>> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
>> >>><br>
>> >>> Official FreeSWITCH Sites<br>
>> >>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >>> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
>> >>> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
>> >>><br>
>> >>> FreeSWITCH-users mailing list<br>
>> >>> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
>> >>> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
>> >>><br>
>> >>> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
>> >>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >><br>
>> >><br>
>> >><br>
>> >><br>
>> >> _________________________________________________________________________<br>
>> >> Professional FreeSWITCH Consulting Services:<br>
>> >> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
>> >> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
>> >><br>
>> >> Official FreeSWITCH Sites<br>
>> >> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> >> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
>> >> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
>> >><br>
>> >> FreeSWITCH-users mailing list<br>
>> >> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
>> >> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
>> >><br>
>> >> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
>> >> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>><br>
>> _________________________________________________________________________<br>
>> Professional FreeSWITCH Consulting Services:<br>
>> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
>> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
>><br>
>> Official FreeSWITCH Sites<br>
>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
>> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
>> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
>><br>
>> FreeSWITCH-users mailing list<br>
>> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
>> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
>> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
>> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
><br>
><br>
><br>
> _________________________________________________________________________<br>
> Professional FreeSWITCH Consulting Services:<br>
> <a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
> <a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
><br>
> Official FreeSWITCH Sites<br>
> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
> <a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
> <a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
><br>
> FreeSWITCH-users mailing list<br>
> <a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
> <a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
> UNSUBSCRIBE:<a href="http://lists.freeswitch.org/mailman/options/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/options/freeswitch-users</a><br>
> <a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
<br>
_________________________________________________________________________<br>
Professional FreeSWITCH Consulting Services:<br>
<a href="mailto:consulting@freeswitch.org">consulting@freeswitch.org</a><br>
<a href="http://www.freeswitchsolutions.com" target="_blank">http://www.freeswitchsolutions.com</a><br>
<br>
Official FreeSWITCH Sites<br>
<a href="http://www.freeswitch.org" target="_blank">http://www.freeswitch.org</a><br>
<a href="http://confluence.freeswitch.org" target="_blank">http://confluence.freeswitch.org</a><br>
<a href="http://www.cluecon.com" target="_blank">http://www.cluecon.com</a><br>
<br>
FreeSWITCH-users mailing list<br>
<a href="mailto:FreeSWITCH-users@lists.freeswitch.org">FreeSWITCH-users@lists.freeswitch.org</a><br>
<a href="http://lists.freeswitch.org/mailman/listinfo/freeswitch-users" target="_blank">http://lists.freeswitch.org/mailman/listinfo/freeswitch-users</a><br>
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</div></div></blockquote></div><br></div>