Subinterface queuing and scheduling (7250 IXR-X4)

To enable queuing and scheduling on subinterfaces, you must change the traffic management mode for the system from the default value of eight priorities to two priorities. In two-priority mode, queuing and scheduling on subinterfaces operates similarly to the interface queue behavior, with some exceptions:

• Similar to interface queues, subinterface queue definitions are specified under the qos queues context.
• To enable subinterface queuing and scheduling, you must assign a buffer allocation profile to the subinterface; however, given the scale of the systems, not all subinterfaces can be enabled for subinterface queuing.
• Buffer allocation profiles operate similarly on subinterfaces as on interfaces.
• With queue scheduler policies, the default operation differs in that all queues in the subinterface policy are attached to WRR scheduler 1, rather than strict priority scheduler 0 as in the interface policy. In addition, configuration of priority levels and committed rates is supported for the subinterface input queues, and on scheduler 1, configuration of peak rates is supported for the subinterface input queues and output interfaces.
• Queue management profiles are similar for interface and subinterface queues in that they define WRED curves or alternatively enable ECN. However, if ECN is enabled for a given subinterface queue, the ECN counters are not collected per subinterface queue. Instead aggregate ECN counters are collected per interface.
• For VOQ statistics on subinterfaces, the default setting for qos interfaces interface voq-statistics is false, while for interfaces the default setting is true.