Solved: Show QoS Markings on SX20

t.svatek · ‎10-11-2012

Hi

Is there a way to show the current QoS Marking during a call? This would be very helpfull to verify QoS. There is an option on CTS-Devices, but I haven´t found this on SX20, Codian-MCU etc.

thanks

Tino

Martin Koch · ‎10-15-2012

Hi Tino, how are you?

There is no real proper way for media statistics and info afterwards on the TC/TE systems, thats not nice

thats true, ... I would +1 on a feature request.

Do you wonder more about what the system tags or what kind of markings it receives?

Having a switch with a monitor port might also worth checking if you do not trust the markings of the

end devices and some more debugging if its on the way in between. Your switches routers

might also be able to give you more info.

If you just want to check whats going on thats nicely done with tcpdump on the endpoint without

the need of tansfering any files.

First check in the xconf which media ports are used, I guess thats the default:

*c xConfiguration RTP Ports Range Start: 2326

*c xConfiguration RTP Ports Range Stop: 2486

Then login as root execute for example:

tcpdump -c 1000 -s0 -v -nl -i eth0 udp and portrange 2326-2484

This should show you whats going on. It will show you the first 1000 packets and then stop, you can reexecute it afterwards if needed.

You will see something like:

10:30:53.432868 IP (tos 0x0, ttl 50, id 0, offset 0, flags [DF], proto UDP (17), length 376)

vcse.2776 > 192.168.200.10.2478: UDP, length 348

10:30:53.441999 IP (tos 0x88, ttl 64, id 8699, offset 0, flags [none], proto UDP (17), length 1320)

192.168.200.10.2480 > vcse.2776: UDP, length 1292

This shows you the pacekt from the VCS does not arrive with taging.

Here is a nice site which shows what tos hex value (thats shown in tcpdump) is what DSCP value.

http://www.tucny.com/Home/dscp-tos

In this case 0x88 TOS (hex) = 34 DSCP (dec) = af41 DSCP Class

If you need to know more about which media port is used for what, execute in TSH:

xstatus // Media

Hope that helps :-)

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View solution in original post

Marius Nedregaard · ‎10-14-2012

Hi,

You can do an TCPdump directly from root account in the command line interface ..

You would then be able to identify outgoing and incoming QoS markings

//Marius

Sent from Cisco Technical Support iPhone App

t.svatek · ‎10-15-2012

Hi Marius

yes, a tcpdump seems to be the only way to do this at the moment, but it´s not too easy to capture rtp-traffic only with it, as you have to know the IPs, Ports and Protocol or you have to transfer it from the codec to your PC to use Wireshark. Not too handy.

Additionally you cannot do this for past calls, where the users created a ticket afterwards. So no chance to check QoS-Markings for these calls.

On CTS-Endpoints is easy: login via web, show call statistics and voila. Also for call history.