Alcatel-Lucent 7950 Quality Of Service Manual page 566

Advanced Policy QoS Commands
enqueue-on-pir-zero
Syntax [no] enqueue-on-pir-zero
Context config>qos>adv-config-policy>child-control>offered-measurement
Description
This command is used to enable queuing of new packets when HQoS determines that a queue should stop
forwarding (operational PIR set to zero). The default behavior is to allow the queue to continue to use the
previously determined operational PIR and set the queue's MBS (Maximum Burst Size) to zero. This
prevents new packets from being admitted to the queue until the PIR zero case terminates. The new behavior
when enqueue-on-pir-zero is enabled is to set the operational PIR to zero and leave the queue's MBS set to
the normal value.
This command is ignored for FP1 based forwarding planes as this feature is not supported on Q1 traffic
management devices. This command overrides the limit-pir-zero-drain command for FP2 and above
forwarding planes that are based on the Q2 or greater traffic management devices.
The no form of this command reverts to default behavior.
granularity
Syntax [no] granularity {percent percent-of-admin-pir | rate rate-in-kilobits-per-second}
Context config>qos>adv-config-policy>child-control>offered-measurement
Description
This command is used to create a stepped like behavior where the operational PIR will round up to the
nearest increment of the specified granularity before being applied to the child. The only exception is when
the distributed bandwidth is less than 1% above a lower step value in which case the lower step value is
used.
This stepped behavior may be useful when the bandwidth used by an active child is well known. While the
above-offered-cap function automatically adds a specified amount to the operational PIR of a child, the
granularity function only increments the operational PIR to the next step value. While not expected to be
used in conjunction, the above-offered-cap and granularity commands may be used simultaneously in which
case the above-offered-cap increase will be applied first followed by the granularity rounding to the next
step value.
If the granularity command is used with a percent based value, the rounding up function of the configured
PIR value on the policer or queue is based on the child's administrative PIR. In this case, care should be
taken that the child is either configured with an explicit PIR rate (other than max) or the child's
administrative PIR is defined using the percent-rate command with the local parameter enabled if an explicit
value is not desired. When a maximum PIR is in use on the child, the system attempts to interpret the
maximum child forwarding rate. This rate could be very large if the child is associated with multiple ingress
or egress ports.
If the child's administrative PIR is modified while a percent based granularity is in effect, the system
automatically uses the new relative rounding value the next time the child's operational PIR is determined.
When this command is not specified or removed, the system makes no attempt to round up the child's
determined operational PIR.
The no form of this command is used to remove the operational PIR rounding behavior from all child
Page 566 7950 XRS Quality of Service Guide