Alcatel-Lucent 7950 Quality Of Service Manual page 260

Service Egress QoS Policy Forwarding Class Commands
parent
Syntax parent {root | arbiter-name} [level level] [weight weight-within-level]
no parent
Context config>qos>sap-egress>policer
Description
This command is used to create a child to parent mapping between each instance of the policer and either the
root arbiter or a specific tiered arbiter on the object where the policy is applied. Defining a parent
association for the policer causes the policer to compete for the parent policer's available bandwidth with
other child policers mapped to the policer control hierarchy.
Policer control hierarchies may be created on SAPs context. To create a policer control hierarchy on an
ingress or egress SAP context, a policer-control-policy must be applied to the SAP. Once applied, the
system will create a parent policer that is bandwidth limited by the policy's max-rate value under the root
arbiter. The root arbiter in the policy also provides the information used to determine the various priority
level discard-unfair and discard-all thresholds. Besides the root arbiter, the policy may also contain user
defined tiered arbiters that provide arbitrary bandwidth control for subsets of child policers that are either
directly or indirectly parented by the arbiter.
When the QoS policy containing the policer with a parent mapping to an arbiter name exists on the SAP, the
system will scan the available arbiters on the SAP. If an arbiter exists with the appropriate name, the policer
to arbiter association is created. If the specified arbiter does not exist either because a policer-control-policy
is not currently applied to the SAP or the arbiter name does not exist within the applied policy, the policer is
placed in an orphan state. Orphan policers operate as if they are not parented and are not subject to any
bandwidth constraints other than their own PIR. When a policer enters the orphan state, it is flagged as
operationally degraded due to the fact that it is not operating as intended and a trap is generated. Whenever a
policer-control-policy is added to the SAP or the existing policy is modified, the SAP's policer's parenting
configurations must be reevaluated. If an orphan policer becomes parented, the degraded flag should be
cleared and a resulting trap should be generated.
Executing the parent command will fail if:
•
•
A policer with a parent command applied cannot be configured with stat-mode no-stats in either the QoS
policy or as an override on an instance of the policer
Once a policer is successfully parented to an arbiter, the parent commands level and weight parameters are
used to determine at what priority level and at which weight in the priority level that the child policer
competes with other children (policers or other arbiters) for bandwidth.
The no form of this command is used to remove the parent association from all instances of the policer.
Parameters {root | arbiter-name} — When the parent command is executed, either the keyword root or an arbiter-
name must be specified.
root — The root keyword specifies that the policer is intended to become a child to the root arbiter where
an instance of the policer is created. If the root arbiter does not exist, the policer will be placed in the
orphan state.
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The policer's stat-mode in the QoS policy is set to no-stats
A stat-mode no-stats override exists on an instance of the policer on a SAP or context
7950 XRS Quality of Service Guide