Port Priority to Transmit Queue Mapping (S-, K-Series)

S- and K-Series module ports support up to 16 transmit queues per port depending upon the port type. Use the show cos port-type txq command in any command mode to determine the port types and number of transmit queues supported on your module. Packets entering a port are either set for an 802.1p priority value or take on the default priority value for this port. The behavior of a packet as it exits the port is dependent upon the priority value assigned to the packet and the transmit queue it exits the port on.

802.1p priority values can be mapped directly to transmit queues on a per port basis. Regardless of the 802.1p priority mapped to a queue, the queue itself has a priority from low to high where queue 0 has the lowest priority and the highest queue value has the highest priority. For example, in a strict queuing configuration, the highest queue number would empty first before moving on to the next highest queue number. See Preferential Queue Treatment for Packet Forwarding for a detailed discussion of preferential queue treatment.

Use the set port priority-queue command to map 802.1p priorities to transmit queues on a per port basis.

The following example sets priority 5 packets to transmit queue 1 on port ge.1.1

System(rw)->set port priority-queue ge.1.1 5 1
System(rw)->show port priority-queue ge.1.1
Port          P0 P1 P2 P3 P4 P5 P6 P7
------------  -- -- -- -- -- -- -- --
ge.1.1        1  0  0  1  2  1  3  3
System(rw)->