[Freeswitch-users] Audio quality issues

[Steve Underwood]

Hi Grant,

Two possibilities spring to mind:

- If your audio is coming from a disk, can that disk keep up?
- How good is your ethernet switch?

Notice in the second point I said how good, not how expensive. Many 
switches choke on a large number of small media packets, including some 
expensive big name products.

Regards,
Steve

On 10/22/2013 06:01 PM, Grant Bagdasarian wrote:
>
> The network shouldn’t be an issue, since we have at least 1Gbps lines. 
> The tests stay within the network.
>
> I forgot to mention the calls are being distributed across two 
> machines by a Kamailio instance.
>
> So for a total of 800 concurrent calls generated by Sipp, each machine 
> has 400 active calls.
>
> CPU load reaches about 70% per machine.
>
> At this point both FS machines are virtualized, since the performance 
> gain wasn’t that much compared to physical.
>
> The VM host shows it is using ~3/4 of its CPU resources.
>
> Htop shows that the normal priority threads(green) and the kernel 
> threads(red) are about the same length.
>
> Also, FS is running on Ubuntu Server 12.04 x64.
>
> *From:*freeswitch-users-bounces at lists.freeswitch.org 
> [mailto:freeswitch-users-bounces at lists.freeswitch.org] *On Behalf Of 
> *Stanislav Sinyagin
> *Sent:* Tuesday, October 22, 2013 11:11 AM
> *To:* FreeSWITCH Users Help
> *Subject:* Re: [Freeswitch-users] Audio quality issues
>
> 800 calls at 64kbps is 51Mbps.
> Could there be a network issue, like a 100Mbps line between the endpoints?
>
> How heavy is your CPU load? "htop" command would be helpful in this.
>
> ------------------------------------------------------------------------
>
> *From:*Grant Bagdasarian <GB at cm.nl <mailto:GB at cm.nl>>
> *To:* "FreeSWITCH Users Help (freeswitch-users at lists.freeswitch.org 
> <mailto:freeswitch-users at lists.freeswitch.org>)" 
> <freeswitch-users at lists.freeswitch.org 
> <mailto:freeswitch-users at lists.freeswitch.org>>
> *Sent:* Tuesday, October 22, 2013 10:14 AM
> *Subject:* [Freeswitch-users] Audio quality issues
>
> Hello,
>
> I was wondering what the maximum concurrent calls for FS before audio 
> quality becomes an issue? I assume the specs of the machine would also 
> affect this.
>
> We are currently running FS on a Six Core (12 Threads) Intel E5-2430 
> CPU and get about 800 concurrent calls at 10-20 CPS. The audio quality 
> at these rates is still fair, but we do notice some quality issue’s.
>
> Going above these numbers screws up the audio quality: choppy sound, 
> audio drops etc. We aren’t doing any heavy media processing, just 
> simply playing a file (G711-Alaw) which lasts about 2 minutes during 
> the load test.
>
> These numbers are for one way audio, where Sipp doesn’t echo the RTP 
> back. These numbers get lower once Sipp echo’s the RTP.
>
> I’ve tried FS on a physical box and also on a virtual box (ESXi 5.1), 
> but the performance gain on physical vs virtual isn’t that much.
>
> I disabled all the modules we don’t need, like CDR’s, conferencing, etc.
>
> Are there any parameters(config files)/modules that can affect the 
> quality of the audio stream?
>
> Regards,
>
> Grant
>
>