Queue scheduler policies for subinterfaces

Similar to interface operation, each output queue on a subinterface is mapped to either scheduler 0 or scheduler 1, as defined by the scheduler policies, with the following restrictions:

• Scheduler 0 — must have a priority setting of strict, providing strict priority scheduling behavior
• Scheduler 1 — must have no priority configuration defined, providing WRR scheduling behavior

However, when the traffic-managment-mode is set to two-priorities, by default all queues in the subinterface policy are attached to scheduler 1, which is served WRR with equal weights, providing round-robin scheduling. This differs from the operation when the traffic-managment-mode is set to eight-priorities, in which all interface queues are served by strict priority scheduler 0 by default.

Scheduler 0 on subinterfaces

Scheduler 0 operation on subinterfaces is as follows:

• Scheduler 0 supports five priority levels.
• Individual queues are mapped to a priority level based on the value of the scheduler input priority-level parameter. This configuration is supported only for scheduler 0 inputs.
• If multiple queues are mapped to the same priority level, they are served in round-robin fashion.
• Scheduler 0 also supports the configuration of a committed rate, but not a peak rate, for the input queues. You must configure a meaningful committed rate value to prevent packet loss.
• The PIR value for strict priority queues in scheduler policies is set to the same value as CIR, but this PIR value is neither enforced nor configurable for subinterfaces.
• When strict priority is enabled (priority strict), any configured weight is ignored.

Scheduler 1 on subinterfaces

The bandwidth for scheduler 1 inputs is distributed based on the assigned queue weights, committed rate, and peak rate.

Scheduler output parameters

In the subinterface scheduler policy, a scheduler output container exists for every scheduler defining an output type and peak-rate percentage. By default, output-type is set to interface and peak-rate-percent is set to 100.

Default subinterface queue scheduler policy

A default scheduler policy named default is attached to every subinterface that has queuing enabled, as shown in the following output.

--{ candidate shared default }--[  ]--
# info qos scheduler-policies scheduler-policy default
    scheduler 1 {
        input 0 {
          input-type queue
            queue-name queue-0
            weight 1
        }
        input 1 {
            input-type queue
            queue-name queue-1
            weight 1
        }
           input 2 {
              input-type queue
            queue-name queue-2
              weight 1
        }
        input 3 {
            input-type queue
            queue-name queue-3
            weight 1
        }
        input 4 {
              input-type queue
            queue-name queue-4
              weight 1
        }
        input 5 {
            input-type queue
            queue-name queue-5
            weight 1
        }
        input 6 {
              input-type queue
            queue-name queue-6
              weight 1
        }
        input 7 {
            input-type queue
            queue-name queue-7
            weight 1
        }
        output {
                output-type interface
                peak-rate-pecent 100
        }
    }