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

[Iskren Hadzhinedev]

Ah, a big miss on my behalf, I apologize. So what should I be looking at ?
The packet stream looks consistent, but then again I’ve no idea how to figure out what’s going on 
in order to debug this...

Thanks,
-- 
*Iskren Hadzhinedev*



See here:  http://sokratisg.net/2012/04/01/udp-tcp-checksum-errors-from-tcpdump-nic-hardware-offloading/[1]






On Fri, Oct 17, 2014 at 9:49 AM, Iskren Hadzhinedev <iskren.hadzhinedev at ikiji.com[2]> 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*
 


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.



consulting at freeswitch.org[3]
http://www.freeswitchsolutions.com[4]
http://www.freeswitch.org[5]
http://confluence.freeswitch.org[6]
http://www.cluecon.com[7]
[8]
FreeSWITCH-users at lists.freeswitch.org[9]
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users[10]
http://lists.freeswitch.org/mailman/options/freeswitch-users[11]
http://www.freeswitch.org[5]





-- Guillermo Ruiz Camauer





--------
[1] http://sokratisg.net/2012/04/01/udp-tcp-checksum-errors-from-tcpdump-nic-hardware-offloading/
[2] mailto:iskren.hadzhinedev at ikiji.com
[3] mailto:consulting at freeswitch.org
[4] http://www.freeswitchsolutions.com
[5] http://www.freeswitch.org
[6] http://confluence.freeswitch.org
[7] http://www.cluecon.com
[8] 
[9] mailto:FreeSWITCH-users at lists.freeswitch.org
[10] http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
[11] http://lists.freeswitch.org/mailman/options/freeswitch-users
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