I have a video streaming multicast server witch performs rather poorly in a LAN environment. I used IGMP snooping for multicast and that part works just fine. However some of the clients are experiencing unacceptable latency and jitter (the video app freezes).
I tried to apply some layer 2 QoS as follows:
1. on the acces port to which the server is connected I used an input service policy which sets CoS to 6 and DSCP to 48;
2. on the trunk ports between the switches - mls qos trust cos;
Then, I started a live capture of traffic from one on the clients which showed that all packets/frames came with default CoS and DSCP of 0 - therefore no QoS in place.
I use Catalyst 4500, 3550 and 2950 series switches in my network.