I have a Tandberg video conference bridge and gateway connected to a 3750 switch. The audio is marked EF and the video CS3. I configured AutoQos on the switch and trust DSCP on the ports. When we reach a large video conference of 25 or more attendies, we begin to have problems. The Tandberg starts to ratchet some of the video streams down, some to below 180kps, and the conference quality begins to suffer.
The only change to the default AutoQOS config I've made is changing the "mls qos trust dscp" on the uplinks, adding a QOS policy on the Tandberg ports to mark the video with CS3 and trust the audio DSCP (Tandberg had a bug that didn't mark the video packets) and adding
to the uplinks.
Will the default AutoQOS queue/buffer/SRR share and shape commands be adequate for 25 to 30 simultaneous video streams? We allow about 500k per stream.
I read through the 3750 QOS guide, but am a bit confused with the explanations of the queuing and SRR workings. I know that CS3 is mapped to COS-3, but don't know which queue it goes in and whether or not it gets shaped/disgarded when too much video is present.
Once I am sure that the 3750 QOS is working OK, and not causing problems with our large conference calls, then I'll expand my troubleshooting to the rest of the network.
I've attached a text file with the 3750 config, and 'show mls qos int statistics' that show the packets are being marked.