The PIR defines the maximum rate at which packets are allowed to exit the queue. It does not specify the maximum rate at which packets may enter the queue; this is determined by the ability of the queue to absorb bursts. The actual transmission rate of an egress queue depends on more than just its PIR. Each queue is competing for transmission bandwidth with other queues. Each queue PIR, CIR, and the relative priority and weight of the scheduler serving the queue, all combine to affect a queue's ability to transmit packets.
When defining the PIR for a queue, the value specified is the administrative PIR for the queue.The user has some control over how the administrative PIR is converted to an operational PIR if the hardware does not support the exact CIR and PIR values specified. See Adaptation rule for queues for information about the interpretation of the administrative PIR.
The PIR for a queue is provisioned in the appropriate queue policy associated with the service object (that is, a network, hybrid, or access port, or and access SAP, as applicable).