[Freeswitch-users] In-call artifacts with PCMA/PCMU

Guillermo Ruiz Camauer grcamauer at gmail.com
Fri Oct 17 17:43:13 MSD 2014


See here:
http://sokratisg.net/2012/04/01/udp-tcp-checksum-errors-from-tcpdump-nic-hardware-offloading/



On Fri, Oct 17, 2014 at 9:49 AM, Iskren Hadzhinedev <
iskren.hadzhinedev at ikiji.com> wrote:

>  Hello,
>
> Apologies for the late reply.
>
> I don’t think there’s any transcoding, as the endpoint negotiation is set
> to “generous” and examining the SDPs shows that both endpoints negotiate on
> PCMA/PCMU. I got a pcap of the RTP streams with tcpdump and I see that from
> the 126500 packets, 62964 are marked with “bad udp cksum”. All packets with
> bad udp checksum are originating from the FreeSWITCH box. Is this
> information helpful at all and what else can I do to figure out the reason
> behind these issues? Thank you!
>
>
>
> Kind regards,
>
> --
>
> Iskren Hadzhinedev
>
>
>
>
> On Tuesday 14 October 2014 10:03:32 Michael Jerris wrote:
>
> is there even any transcoding involved in your scenario?  Are the
> artifacts present in the inbound stream as well.  I would get a tcpdump and
> analyze the inbound and outbound streams to see a bit more detail of what
> is going on.
>
>
> Mike
>
>
> On Oct 14, 2014, at 5:12 AM, Iskren Hadzhinedev <
> iskren.hadzhinedev at ikiji.com> wrote:
>
>
> Hi everyone,
>
>
>
> Some of the calls using PCMA/PCMU have artifacts (distorted sound,
> “robotic” voice, stutter) on what looks like a random basis. The other
> codecs I have tried don’t have issues (tried GSM, iLBC,G722, G729, SILK).
> Apart from FreeSWITCH, the only other thing running on the machine is a
> static webpage served by nginx and the load is almost always at 0. Any help
> or advise on how to chase down this issue is highly appreciated!
>
>
>
> System specs:
>
> Machine: Xen VM
>
> RAM: 1GB
>
> CPU: Dualcore 2.4 Ghz 64bit
>
> OS: CentOS 6.5
>
> FreeSWITCH Version: 1.5.13b+git~20140621T003222Z~47891d5caa~64bit
>
>
>
> Max # simultaneous calls: 12
>
> Calls per second: at most 3
>
>
>
> Endpoints used for testing:
>
> Hardware phones: Yealink T42G, Yealink T48G, Gigaset DE900, Cisco 7975
> (with SIP firmware)
>
> Softphones: CounterPath Bria for Android, CsipSimple (android), Linphone,
> Jitsi
>
> Mobile provider and a landline via gateway.
>
>
>
>
> _________________________________________________________________________
> 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
>



-- 
Guillermo Ruiz Camauer
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.freeswitch.org/pipermail/freeswitch-users/attachments/20141017/31ac12c7/attachment-0001.html 


Join us at ClueCon 2016 Aug 8-12, 2016
More information about the FreeSWITCH-users mailing list