This is a static archive of our old Q&A Site. Please post any new questions and answers at ask.wireshark.org.

VOIP QoS in monitoring??

0

Hello WireShark.org I have a small experiment on voice over ip, I 've done it by asterisk. I have a question about monitoring packets of VoIP when the Qos 802.11e is activated. How can I detect the quality of service is running?? the DSCP(0x00) is not changed when I activet it or don't.

Thanks very much

asked 19 Jul '13, 19:05

hamad's gravatar image

hamad
6113
accept rate: 0%

edited 19 Jul '13, 19:08


2 Answers:

0

The QoS mechanisms of 802.11e are totally different from the DiffServ mechanism (DSCP flags).

As you did not say how you configured your systems, I ask you to read the following overview of 802.11e and then rethink what you did and what you expected to see.

http://www.networkworld.com/news/tech/2003/0623techupdate.html

BTW: I'm not sure if asterisk is able to have an influence on 802.11e. Can you please add some information how you configured asterisk?

Regards
Kurt

answered 22 Jul '13, 15:19

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
24.8k1039237
accept rate: 15%

0

To confirm, this is wireless VoIP? When you "activated" 802.11e, I assume this was at your wireless access point? Did you configure the access point to also map the 802.11e classes with DSCP code points and mark the IP headers accordingly?

Really to the heart of your question, if the DSCP markings are all best-effort, ask yourself "In this network design, what device is responsible for marking the IP header with DSCP values that map to these 802.11e classes that I've defined?". If Wireshark is showing you best-effort packets, either that device is not marking the packets correctly, the traffic is being misclassified or marked closer to the source, or the DSCP markings are getting stripped closer to the destination (this would depend on where you're tapping into the network).

answered 22 Jul '13, 19:10

Quadratic's gravatar image

Quadratic
1.9k6928
accept rate: 13%

edited 22 Jul '13, 19:12