[Freeswitch-users] KVM vs. XEN virtualization
Stanislav Sinyagin
ssinyagin at gmail.com
Tue Apr 7 01:59:49 MSD 2015
Errol,
I guess most of the calls on your servers are bridged, and for bridged
calls FreeSWITCH does not refer to the system timer, and sends out the RTP
packets as soon as they are ready. The timer is important if the server
originates the media stream, such as playing back audio files, and also in
conferences. Also the stream errors that I found were almost unnoticeable
for a human listener: 3-4 frames lost within a 30 second sample are not too
much of a big deal.
So, KVM still looks fine for many applications, and I'm trying to find out
the source of the problem that I encountered. I will do more tests.
@James, cpuinfo shows... different things! Thanks for pointing to that.
VM in ams1: QEMU Virtual CPU version 1.0
VM in ams3, where I found the original problem: Intel(R) Xeon(R) CPU
E5-2630L v2 @ 2.40GHz
VM in lon1: Intel(R) Xeon(R) CPU E5-2630L v2 @ 2.40GHz
On Mon, Apr 6, 2015 at 7:22 PM, Errol Samuels <ewsamuels at gmail.com> wrote:
> Hi Stanislav,
>
> Just to let you know I have a customer using all 3 virtualization
> technologies mentioned (KVM, Xen and VMWare) and they all seem to be
> happy. However for the larger setups with 2500+ users my preference is KVM
> without a doubt. I have for example an install with 4 FusionPBX /
> Freeswitch VMs with Kamailio in Front for residential phone service all
> sharing same Postgres DB and serving 5000 users, 4000 DIDs running for more
> than a year with no voice quality issues. We using Proxmox for this setup
> and it works great.
>
> Test 3
> ======
> This one is using Proxmox and -t20 with some strange results!?
>
> *VM: * KVM with 4 Cores / 8GB Ram and *Virtio Drivers* for Network and HD)
> *OS:* Ubuntu 12.04.5 LTS / Linux 3.13.0-40-generic x86_64
>
> root at voip-admin:~# date && cyclictest -t20 -p 80 -d 0 -n -i 125 -l 240000
> && date
> Mon Apr 6 13:03:00 EDT 2015
> # /dev/cpu_dma_latency set to 0us
> policy: fifo: loadavg: 1.16 0.61 0.32 1/227 9038
>
> T: 0 ( 9000) P:80 I:125 C: 240000 Min: 2 Act: 29 Avg: 2957 Max:
> 3835266
> T: 1 ( 9001) P:80 I:125 C: 240000 Min: 2 Act: 9 Avg: 3018 Max:
> 3888022
> T: 2 ( 9002) P:80 I:125 C: 240000 Min: 2 Act: 28 Avg: 2978 Max:
> 3835499
> T: 3 ( 9003) P:80 I:125 C: 240000 Min: 2 Act: 31 Avg: 2975 Max:
> 3857444
> T: 4 ( 9004) P:80 I:125 C: 240000 Min: 2 Act: 29 Avg: 3029 Max:
> 3859799
> T: 5 ( 9005) P:80 I:125 C: 240000 Min: 2 Act: 22 Avg: 2985 Max:
> 3838433
> T: 6 ( 9006) P:80 I:125 C: 240000 Min: 2 Act: 14 Avg: 3044 Max:
> 3872244
> T: 7 ( 9007) P:80 I:125 C: 240000 Min: 4 Act: 10 Avg: 3007 Max:
> 3867133
> T: 8 ( 9008) P:80 I:125 C: 240000 Min: 3 Act: 20 Avg: 3071 Max:
> 3905688
> T: 9 ( 9009) P:80 I:125 C: 240000 Min: 4 Act: 13 Avg: 3022 Max:
> 3856911
> T:10 ( 9010) P:80 I:125 C: 240000 Min: 2 Act: 9 Avg: 3016 Max:
> 3885199
> T:11 ( 9011) P:80 I:125 C: 240000 Min: 3 Act: 32 Avg: 3011 Max:
> 3862044
> T:12 ( 9012) P:80 I:125 C: 240000 Min: 3 Act: 16 Avg: 3012 Max:
> 3888333
> T:13 ( 9013) P:80 I:125 C: 240000 Min: 2 Act: 23 Avg: 2949 Max:
> 3844433
> T:14 ( 9014) P:80 I:125 C: 240000 Min: 2 Act: 25 Avg: 3009 Max:
> 3878488
> T:15 ( 9015) P:80 I:125 C: 240000 Min: 3 Act: 12 Avg: 3019 Max:
> 3870499
> T:16 ( 9016) P:80 I:125 C: 240000 Min: 3 Act: 24 Avg: 2972 Max:
> 3856044
> T:17 ( 9017) P:80 I:125 C: 240000 Min: 3 Act: 34 Avg: 3023 Max:
> 3872944
> T:18 ( 9018) P:80 I:125 C: 240000 Min: 2 Act: 25 Avg: 2988 Max:
> 3869488
> T:19 ( 9019) P:80 I:125 C: 240000 Min: 2 Act: 10 Avg: 2949 Max:
> 3847277
> Mon Apr 6 13:03:30 EDT 2015
>
> This is interesting if not alarming..lol
>
>
> I re-ran the test on DO again below but with -t20 this time now the
> latency seems to be ~9ms.
>
> Test 4
> =====
> *VM: *Digital Ocean KVM at AMS3 / 2 Cores / 2GB Ram / 40GB SSD
> *OS:* Debian Wheezy 7.8 64 bit / Linux 3.2.0-4-amd64 x86_64
>
> root at demo:~# date && cyclictest -t20 -p 80 -d 0 -n -i 125 -l 240000 &&
> date
> Mon Apr 6 16:57:30 UTC 2015
> # /dev/cpu_dma_latency set to 0us
> policy: fifo: loadavg: 1.31 0.59 0.34 1/122 31201
>
> T: 0 (31181) P:80 I:125 C: 240000 Min: 4 Act: 20 Avg: 34 Max:
> 8447
> T: 1 (31182) P:80 I:125 C: 240000 Min: 2 Act: 13 Avg: 29 Max:
> 5022
> T: 2 (31183) P:80 I:125 C: 240000 Min: 2 Act: 6 Avg: 27 Max:
> 4998
> T: 3 (31184) P:80 I:125 C: 240000 Min: 2 Act: 8 Avg: 27 Max:
> 6140
> T: 4 (31185) P:80 I:125 C: 240000 Min: 3 Act: 19 Avg: 31 Max:
> 7474
> T: 5 (31186) P:80 I:125 C: 240000 Min: 3 Act: 8 Avg: 32 Max:
> 7454
> T: 6 (31187) P:80 I:125 C: 240000 Min: 4 Act: 10 Avg: 32 Max:
> 7507
> T: 7 (31188) P:80 I:125 C: 240000 Min: 4 Act: 11 Avg: 32 Max:
> 9008
> T: 8 (31189) P:80 I:125 C: 240000 Min: 2 Act: 18 Avg: 28 Max:
> 5737
> T: 9 (31190) P:80 I:125 C: 240000 Min: 2 Act: 12 Avg: 28 Max:
> 7462
> T:10 (31191) P:80 I:125 C: 240000 Min: 2 Act: 8 Avg: 29 Max:
> 7432
> T:11 (31192) P:80 I:125 C: 240000 Min: 4 Act: 25 Avg: 27 Max:
> 7404
> T:12 (31193) P:80 I:125 C: 240000 Min: 3 Act: 18 Avg: 30 Max:
> 8496
> T:13 (31194) P:80 I:125 C: 240000 Min: 4 Act: 18 Avg: 32 Max:
> 5962
> T:14 (31195) P:80 I:125 C: 240000 Min: 2 Act: 8 Avg: 30 Max:
> 8573
> T:15 (31196) P:80 I:125 C: 240000 Min: 4 Act: 17 Avg: 32 Max:
> 5963
> T:16 (31197) P:80 I:125 C: 240000 Min: 3 Act: 15 Avg: 31 Max:
> 7477
> T:17 (31198) P:80 I:125 C: 240000 Min: 4 Act: 16 Avg: 31 Max:
> 9010
> T:18 (31199) P:80 I:125 C: 240000 Min: 3 Act: 18 Avg: 35 Max:
> 7447
> T:19 (31200) P:80 I:125 C: 240000 Min: 2 Act: 15 Avg: 34 Max:
> 7471
> Mon Apr 6 16:58:00 UTC 2015
>
> BR
>
> Errol
>
>
>
>
> On Mon, Apr 6, 2015 at 5:13 PM, Stanislav Sinyagin <ssinyagin at gmail.com>
> wrote:
>
>> A customer is setting up a new telephony switch, and I'm helping them to
>> organize the testing. I noticed the slipping frames in received audio, and
>> then at first I though it's the failure at the receiving side, but then
>> figured out it's my host at DO that is generating unaligned RTP flow.
>>
>> So, now I'm trying to figure out what would be the best virtualized
>> environment to run FreeSWITCH :)
>>
>>
>>
>>
>>
>> On Mon, Apr 6, 2015 at 6:05 PM, Brian West <brian at freeswitch.org> wrote:
>>
>>> I've never had issues running under KVM on Proxmox, Looking back at this
>>> thread was there a specific issue that you're trying to solve that put you
>>> on to this path of testing?
>>>
>>> On Mon, Apr 6, 2015 at 10:51 AM, Stanislav Sinyagin <ssinyagin at gmail.com
>>> > wrote:
>>>
>>>> yes, and we're trying to find the one that works with minimal impact
>>>> on quality :)
>>>>
>>>> I'm thinking to move my test server (the one on receiving side) from
>>>> Xen VM to a physical ARM machine at https://www.scaleway.com/ in
>>>> France. It would record audio and raw UDP packets and provide them for
>>>> downloading to everyone.
>>>>
>>>> Do we know about any timing issues on ARM platform?
>>>>
>>>> if someone sponsors some additional DID numbers, that will be
>>>> appreciated.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, Apr 6, 2015 at 5:30 PM, Anthony Minessale
>>>> <anthony.minessale at gmail.com> wrote:
>>>> > Depending on the host and guest OS the timing will be a product of
>>>> several
>>>> > thing.
>>>> > If some of the features FS tries to detect are emulated, it can be a
>>>> > problem.
>>>> >
>>>> > The primary thing FS looks for is a kernel with timerfd support.
>>>> > This should be the most accurate. If the guest OS supports timerfd
>>>> but its
>>>> > using emulated hardware, it might not work as well as it should.
>>>> >
>>>> > So on something like openvz, you might have support for timerfd in
>>>> your
>>>> > debian 7/8 instance but the host kernel has no support at all.
>>>> > So in theory kvm would be preferred since it actually boots the guest
>>>> kernel
>>>> > and you have a chance for it to hit the real timer hardware.
>>>> >
>>>> > If no timerfd is present, it reverts to the single thread ms precision
>>>> > thread with conditional broadcast for timing.
>>>> > You can also manually configure a combo of one timerfd timer and
>>>> shared
>>>> > broadcast.
>>>> >
>>>> > This param in switch.conf.xml helps to tune a few behavior you might
>>>> want to
>>>> > compare results on.
>>>> >
>>>> > enable-softtimer-timerfd
>>>> >
>>>> > true|fd-per-timer --- Use one fd for each timer instance (default)
>>>> >
>>>> > false --- Don't use timerfd at all
>>>> >
>>>> > broadcast --- Use one timerfd and share it with conditional
>>>> > broadcasts
>>>> >
>>>> > This is one reason we do not support virtualization as its too
>>>> variable to
>>>> > provide definitive policies to make things work every time.
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > On Mon, Apr 6, 2015 at 10:17 AM, Stanislav Sinyagin <
>>>> ssinyagin at gmail.com>
>>>> > wrote:
>>>> >>
>>>> >> I didn't yet have time to learn this utility - how do we interpret
>>>> the
>>>> >> results?
>>>> >>
>>>> >> On Apr 6, 2015 4:39 PM, "Errol Samuels" <ewsamuels at gmail.com> wrote:
>>>> >>>
>>>> >>> Ok Sergey,
>>>> >>>
>>>> >>> Here it goes:
>>>> >>>
>>>> >>> Test 1
>>>> >>> ====
>>>> >>> VM: Digital Ocean KVM at AMS3 / 2 Cores / 2GB Ram / 40GB SSD
>>>> >>> OS: Debian Wheezy 7.8 64 bit / Linux 3.2.0-4-amd64 x86_64
>>>> >>>
>>>> >>> policy: fifo: loadavg: 6.22 1.53 0.58 1/164 31050 : 195
>>>> Max:
>>>> >>> 42869
>>>> >>> T:12 (31021) P:80 I:125 C: 238830 Min: 2 Act: 18 Avg: 196
>>>> Max:
>>>> >>> 42846
>>>> >>> T: 0 (31009) P:80 I:125 C: 239000 Min: 2 Act: 12 Avg: 190
>>>> Max:
>>>> >>> 42845
>>>> >>> T: 1 (31010) P:80 I:125 C: 239002 Min: 2 Act: 18 Avg: 196
>>>> Max:
>>>> >>> 42866
>>>> >>> T: 2 (31011) P:80 I:125 C: 239004 Min: 3 Act: 10 Avg: 191
>>>> Max:
>>>> >>> 42890
>>>> >>> T: 3 (31012) P:80 I:125 C: 239004 Min: 3 Act: 8 Avg: 197
>>>> Max:
>>>> >>> 42876
>>>> >>> T: 4 (31013) P:80 I:125 C: 239005 Min: 2 Act: 27 Avg: 194
>>>> Max:
>>>> >>> 42846
>>>> >>> T: 5 (31014) P:80 I:125 C: 239008 Min: 2 Act: 26 Avg: 196
>>>> Max:
>>>> >>> 42872
>>>> >>> T: 6 (31015) P:80 I:125 C: 239013 Min: 2 Act: 12 Avg: 196
>>>> Max:
>>>> >>> 42843
>>>> >>> T: 7 (31016) P:80 I:125 C: 239013 Min: 2 Act: 19 Avg: 194
>>>> Max:
>>>> >>> 42848
>>>> >>> T: 8 (31017) P:80 I:125 C: 239013 Min: 2 Act: 14 Avg: 190
>>>> Max:
>>>> >>> 42856
>>>> >>> T: 9 (31018) P:80 I:125 C: 239014 Min: 2 Act: 14 Avg: 197
>>>> Max:
>>>> >>> 42865
>>>> >>> T:10 (31019) P:80 I:125 C: 239016 Min: 2 Act: 9 Avg: 197
>>>> Max:
>>>> >>> 42868
>>>> >>>
>>>> >>>
>>>> >>> Test 2
>>>> >>> ====
>>>> >>> VM: Linode (Xen) London / 8 Cores (E5-2670 0 @ 2.60GHz) / 4GB Ram
>>>> >>> OS: Ubuntu 12.04.4 LTS / Linux 3.18.5-x86_64-linode52 x86_64
>>>> >>>
>>>> >>> policy: fifo: loadavg: 6.50 1.56 0.55 15/246 30752 97
>>>> Max:
>>>> >>> 1030
>>>> >>> T:16 (30726) P:80 I:125 C: 239853 Min: 5 Act: 77 Avg: 97
>>>> Max:
>>>> >>> 1066
>>>> >>> T: 0 (30710) P:80 I:125 C: 239946 Min: 5 Act: 63 Avg: 98
>>>> Max:
>>>> >>> 1245
>>>> >>> T: 1 (30711) P:80 I:125 C: 239946 Min: 5 Act: 67 Avg: 98
>>>> Max:
>>>> >>> 1091
>>>> >>> T: 2 (30712) P:80 I:125 C: 239945 Min: 5 Act: 119 Avg: 97
>>>> Max:
>>>> >>> 1351
>>>> >>> T: 3 (30713) P:80 I:125 C: 239945 Min: 5 Act: 99 Avg: 98
>>>> Max:
>>>> >>> 932
>>>> >>> T: 4 (30714) P:80 I:125 C: 239945 Min: 5 Act: 35 Avg: 98
>>>> Max:
>>>> >>> 1413
>>>> >>> T: 5 (30715) P:80 I:125 C: 239945 Min: 5 Act: 35 Avg: 98
>>>> Max:
>>>> >>> 1407
>>>> >>> T: 6 (30716) P:80 I:125 C: 239944 Min: 5 Act: 110 Avg: 97
>>>> Max:
>>>> >>> 1173
>>>> >>> T: 7 (30717) P:80 I:125 C: 239947 Min: 5 Act: 85 Avg: 99
>>>> Max:
>>>> >>> 1144
>>>> >>> T: 8 (30718) P:80 I:125 C: 239948 Min: 4 Act: 69 Avg: 99
>>>> Max:
>>>> >>> 916
>>>> >>> T: 9 (30719) P:80 I:125 C: 239947 Min: 4 Act: 40 Avg: 97
>>>> Max:
>>>> >>> 916
>>>> >>> T:10 (30720) P:80 I:125 C: 239948 Min: 5 Act: 61 Avg: 97
>>>> Max:
>>>> >>> 1024
>>>> >>> T:11 (30721) P:80 I:125 C: 239946 Min: 6 Act: 84 Avg: 98
>>>> Max:
>>>> >>> 2082
>>>> >>> T:12 (30722) P:80 I:125 C: 239947 Min: 4 Act: 40 Avg: 98
>>>> Max:
>>>> >>> 2142
>>>> >>> T:13 (30723) P:80 I:125 C: 239946 Min: 5 Act: 49 Avg: 98
>>>> Max:
>>>> >>> 1986
>>>> >>> T:14 (30724) P:80 I:125 C: 239946 Min: 4 Act: 113 Avg: 99
>>>> Max:
>>>> >>> 2061
>>>> >>>
>>>> >>> This is with system defaults.
>>>> >>>
>>>> >>> regards,
>>>> >>>
>>>> >>> Errol
>>>> >>>
>>>> >>>
>>>> >>>
>>>> >>>
>>>> >>> On Mon, Apr 6, 2015 at 1:27 PM, Sergey Safarov <s.safarov at gmail.com
>>>> >
>>>> >>> wrote:
>>>> >>>>
>>>> >>>> Errol can you test VM timer with utility
>>>> >>>> https://rt.wiki.kernel.org/index.php/Cyclictest
>>>> >>>>
>>>> >>>> My VM currently have folowing results
>>>> >>>>
>>>> >>>> [root at fs1 ~]# date && /tmp/rt-tests/cyclictest -t42 -p 80 -d 0
>>>> -n -i
>>>> >>>> 125 -l 240000 && date
>>>> >>>> Sun Apr 5 07:01:31 GMT 2015
>>>> >>>> # /dev/cpu_dma_latency set to 0us
>>>> >>>> policy: fifo: loadavg: 2.38 0.93 0.50 1/194 1574
>>>> >>>>
>>>> >>>> T: 0 ( 1531) P:80 I:125 C: 240000 Min: 2 Act: 12 Avg: 16
>>>> Max:
>>>> >>>> 1302
>>>> >>>> T: 1 ( 1532) P:80 I:125 C: 240000 Min: 2 Act: 15 Avg: 14
>>>> Max:
>>>> >>>> 2895
>>>> >>>> T: 2 ( 1533) P:80 I:125 C: 240000 Min: 3 Act: 10 Avg: 12
>>>> Max:
>>>> >>>> 2888
>>>> >>>> T: 3 ( 1534) P:80 I:125 C: 240000 Min: 1 Act: 16 Avg: 13
>>>> Max:
>>>> >>>> 1333
>>>> >>>> T: 4 ( 1535) P:80 I:125 C: 240000 Min: 2 Act: 20 Avg: 14
>>>> Max:
>>>> >>>> 2962
>>>> >>>> T: 5 ( 1536) P:80 I:125 C: 240000 Min: 1 Act: 12 Avg: 14
>>>> Max:
>>>> >>>> 2946
>>>> >>>> T: 6 ( 1537) P:80 I:125 C: 240000 Min: 2 Act: 10 Avg: 13
>>>> Max:
>>>> >>>> 1363
>>>> >>>> T: 7 ( 1538) P:80 I:125 C: 240000 Min: 2 Act: 12 Avg: 13
>>>> Max:
>>>> >>>> 1344
>>>> >>>> T: 8 ( 1539) P:80 I:125 C: 240000 Min: 3 Act: 12 Avg: 16
>>>> Max:
>>>> >>>> 1408
>>>> >>>> T: 9 ( 1540) P:80 I:125 C: 240000 Min: 1 Act: 8 Avg: 13
>>>> Max:
>>>> >>>> 2882
>>>> >>>> T:10 ( 1541) P:80 I:125 C: 239974 Min: 2 Act: 12 Avg: 13
>>>> Max:
>>>> >>>> 2908
>>>> >>>>
>>>> >>>>
>>>> >>>> On Mon, Apr 6, 2015 at 11:15 AM, Errol Samuels <
>>>> ewsamuels at gmail.com>
>>>> >>>> wrote:
>>>> >>>>>
>>>> >>>>> Good job and Thanks for sharing!
>>>> >>>>>
>>>> >>>>>> KVM at digitalocean.com, Debian 7 64bit, FreeSWITCH 1.4.15: bad
>>>> >>>>>> precision
>>>> >>>>>
>>>> >>>>>
>>>> >>>>> As someone who has been using KVM for a few years and has just
>>>> migrated
>>>> >>>>> about 20 VMs across to Digital Ocean about 6 weeks ago I admit I
>>>> am a little
>>>> >>>>> concerned about this finding.
>>>> >>>>>
>>>> >>>>> Just out of curiosity can you tell me the specs of the VM that you
>>>> >>>>> tested with and which DO Datacenter? I am using NYC3 so perhaps
>>>> and I will
>>>> >>>>> do some tests as soon as I have some time.
>>>> >>>>>
>>>> >>>>> With regards to Xen was this at Linode or inhouse?
>>>> >>>>>
>>>> >>>>> Thanks
>>>> >>>>>
>>>> >>>>> Errol
>>>> >>>>>
>>>> >>>>>
>>>> >>>>>
>>>> >>>>> On Sun, Apr 5, 2015 at 1:37 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
>>>> >>>>
>>>> >>>>
>>>> >>>>
>>>> >>>>
>>>> >>>>
>>>> _________________________________________________________________________
>>>> >>>> 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
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > --
>>>> > Anthony Minessale II ♬ @anthmfs ♬ @FreeSWITCH ♬
>>>> >
>>>> > ☞ http://freeswitch.org/ ☞ http://cluecon.com/ ☞
>>>> > http://twitter.com/FreeSWITCH
>>>> > ☞ irc.freenode.net #freeswitch ☞ http://freeswitch.org/g+
>>>> >
>>>> > ClueCon Weekly Development Call
>>>> > ☎ sip:888 at conference.freeswitch.org ☎ +19193869900
>>>> >
>>>> > https://www.youtube.com/watch?v=9XXgW34t40s
>>>> >
>>>> >
>>>> _________________________________________________________________________
>>>> > 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
>>>>
>>>
>>>
>>>
>>> --
>>>
>>> *Brian West*
>>> brian at freeswitch.org
>>>
>>>
>>> *Twitter: @FreeSWITCH , @briankwest*
>>> http://www.freeswitchbook.com
>>> http://www.freeswitchcookbook.com
>>>
>>> ClueCon 2015 Call for Speakers
>>> <https://www.cluecon.com/call-for-speakers/> | Register
>>> <https://freeswitch.com/cart.php?gid=1> TODAY! | Reddit: /r/freeswitch
>>> <https://www.reddit.com/r/freeswitch>
>>>
>>> *T:*+19184209001 | *F:*+19184209002 | *M:*+1918424WEST (9378)
>>> *iNUM:*+883 5100 1420 9001 | *ISN:*410*543 | *Skype:*briankwest
>>>
>>> _________________________________________________________________________
>>> 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
>
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