Class Fair Hierarchical Policing (CFHP)
Quality of Service Guide 855
CFHP Policer Control Policy
Provisioning CFHP entails creating policer control policies (policer-control-policy), applying
a policer control policy to the ingress or egress context of a SAP or to the ingress or egress
context of a subscriber profile (sub-profile) much the same way scheduler policies
(scheduler-policy) are applied.
Applying a policer control policy to a SAP creates an instance of the policy that is used to
control the bandwidth associated with the child policers on the SAP. In a similar fashion, an
instance of the policy is created when a subscriber profile associated with the policy is applied
to a subscriber context. The subscriber policy instance is used to control the bandwidth of the
child policers created by the SLA profile instances within the subscriber context.
Policer control policies can only be applied to SAPs created on Ethernet ports. When the
policy instance is created, any policers created on the SAP that have an appropriate parent
command defined are considered child policers.
Policer Control Policy Root Arbiter
Similar to a scheduler context within a scheduler-policy, the policer-control-policy contains
objects called an arbiter that control the amount of bandwidth that may be distributed to a set
of child policers. Each policer control policy always contains a root arbiter that represents the
parent policer. The max-rate defined for the arbiter specifies the decrement rate for the parent
policer that governs the overall aggregate rate of every child policer associated with the
policy instance. The root arbiter also contains the parent policers MBS configuration
parameters that the system uses to individually configure the priority thresholds for each
policer instance.
Child policers may parent directly to the root arbiter or to one of the tier 1 or tier 2 explicitly
created arbiters.
Each arbiter provides bandwidth to its children using eight strict levels. Children parented at
level 8 are first to receive bandwidth. The arbiter continues to distribute bandwidth until
either all of its children's bandwidth requirements are met or until the bandwidth its allowed
to distribute is exhausted. The root arbiter is special in that its strict priority levels directly
represent the priority thresholds within the parent policer.
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