QoS between vlans on same switch

[mack ragan_1]

We have a DWDM fiber wide are network. A Cisco router connects our network to this WAN. We are trying to optimize video conferencing between sites on the WAN. We have a 5406 as the perimeter router that is connected to the Cisco router at our site. Assume that a QoS policy is implemented and working using DSCP 34 (100010) up to and including the Cisco rtr. Also assume that the IP of the vid conf device at the remote site is 1.2.3.4.

On the 5406, port e10 is connected to the Cisco rtr, and is tagged into vlan10. Port e15 is connected to our vid conf device, and is untagged into vlan15. We have changed the dscp map so that codepoint 100010 maps to priority 7. We then assign a port-based qos policy to port e15 using "qos dscp 100010". This should ensure that the prioritization is enforced outbound for all packets coming from port e15, right?

We have done nothing to prioritize traffic on the vlan level for either vlan, and nothing to prioritize traffic on port e10. So, the big question is: when a packet comes into our site from the vid conf device at the other site, with dscp 34 and priority 7 set, will our 5406 honor the bit and priority all the way to port e15? Or, does it get lost when it moves from vlan10 to vlan15? I'm thinking that on the 5406 I need the command "qos device-priority 1.2.3.4 dscp 100010". Note: we have not looked at a packet capture yet.