agree... if anything... with really low bandwidth you'd likely want to slow down/de-prioritize streaming...
also... expediting critical stuff and clamping bulk will get you infinately better results than just upping video... ( a middle teir traffic generally speaking )
I tried to use the webex remarking similar to the OP, but am getting hung up on the firewall complaining about the "--dport" argument.
I connmark on forward of a new connection, then remark traffic when we see that connmark as packets are forwarded within the connection so they land in the Cake DiffServ4 video tin.
Here is the code
# Identify outbound TCP & UDP traffic from any device with destination port 9000 and mark the connection with the value 30
iptables -t mangle -A FORWARD -o eth0 -p all --dport 9000 -j CONNMARK -set-mark 30
# Identify outbound packets on connections with a connmark of "30" and tag the packets with DSCP 30 (AF33)
iptables -t mangle -A FORWARD -o eth0 -m connmark --mark 30 -j DSCP --set-dscp 30