Advanced QoS Policies
Quality of Service Guide 681
If the granularity command is used with a percent based value, the sensitivity is a function of the
configured PIR value on the policer or queue. 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.
Except for the overall cap on the offered input into the virtual scheduler, the child’s administrative PIR
has no effect on the calculated sensitivity if an explicit rate is specified.
If the child’s administrative PIR is modified while a percent based granularity is in effect, the system
automatically uses the new relative sensitivity value the next time the child’s offered rate is
determined.
The no form of this command is used to restore the default offered rate sensitivity behavior to all child
policers and queues associated with the policy.
Parameters percent-of-admin-pir — When the percent qualifier is used, this parameter specifies the
percentage of the child’s administrative PIR that should be used as the threshold sensitivity
to offered rate change. If a value of 0 or 0.00 is used, the system will interpret this equivalent
to no granularity.
Default None, the sensitivity percentage value must be specified when the
percent qualifier is used.
Values 1.00 to 100.00
rate-in-kilobits-per-second — When the rate qualifier is used, this parameter specifies an explicit
number of kilobits-per-second (1000 bits-per-second) that should be as the child’s offered
rate change sensitivity value. If a rate sensitivity of 0 is specified, the system interprets this
equivalent to no granularity.
Default None, the sensitivity rate value must be specified when the rate
qualifier is used.
Values 0 to 100,000,000
max-decrement
Syntax [no] max-decrement {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 limit how fast a child queue or policer can ‘give up’ bandwidth that it has
been allotted from the virtual scheduler in a single iteration. If the child’s new offered rate has
decreased by more than the maximum decrement limit, the system ignores the new offered rate and
instead uses the old offered rate less the maximum decrement limit.
To Next Page
Loading...
