The PIR value 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 governed by the queue’s ability to absorb bursts and is user-configurable using its maximum burst size (MBS) value.
The PIR value is provisioned on ingress and egress service queues within service ingress QoS policies and service egress QoS policies, respectively.
The PIR values for network queues are defined within network queue policies and are specific for each forwarding class. The PIR value for each queue for the forwarding class is defined as a percentage of the network interface bandwidth.
When defining the PIR for a queue, the value specified is the administrative PIR for the queue. The 7705 SAR maps a user-configured value to a hardware supported rate that it uses to determine the operational PIR for the queue. The user has control over how the administrative PIR is converted to an operational CIR if a slight adjustment is required. The interpretation of the administrative PIR is discussed in Adaptation Rule.