Alcatel-Lucent 7950 Quality Of Service Manual page 286

Service Queue QoS Policy Commands
percent-rate
Syntax percent-rate pir-percent [cir cir-percent] [port-limit|local-limit]
percent-rate pir-percent police [port-limit|local-limit]
no percent-rate
Context config>qos>sap-egress>queue
config>qos>sap-ingress>queue
Description
The percent-rate command within the SAP ingress and egress QOS policy enables supports for a queue's
PIR and CIR rate to be configured as a percentage of the egress port's line rate or of its parent scheduler's
rate. When the rates are expressed as a port-limit, the actual rates used per instance of the queue will vary
based on the port speed. For example, when the same QOS policy is used on a 1-Gigabit and a 10-Gigabit
Ethernet port, the queue's rates will be 10 times greater on the 10 Gigabit port due to the difference in port
speeds. This enables the same QOS policy to be used on SAPs on different ports without needing to use SAP
based queue overrides to modify a queue's rate to get the same relative performance from the queue.
If the port's speed changes after the queue is created, the queue's PIR and CIR rates will be recalculated
based on the defined percentage value.
When the rates are expressed as a local-limit, the actual rates used per instance of the queue are relative to
the queue's parent scheduler rate. This enables the same QOS policy to be used on SAPs with different
parent scheduler rates without needing to use SAP based queue overrides to modify a queue's rate to get the
same relative performance from the queue. If the parent scheduler rate changes after the queue is created, the
queue's PIR and CIR rates will be recalculated based on the defined percentage value.
The rate and percent-rate commands override one another. If the current rate for a queue is defined using the
percent-rate command and the rate command is executed, the percent-rate values are deleted. In a similar
fashion, the percent-rate command causes any rate command values to be deleted. A queue's rate may
dynamically be changed back and forth from a percentage to an explicit rate at anytime.
Queue rate overrides can only be specified in the form as configured in the QoS policy (a SAP override can
only be specified as a percent-rate if the associated QoS policy was also defined as percent-rate). Likewise,
a SAP override can only be specified as a rate (kbps) if the associated QoS policy was also defined as a rate.
Queue-overrides are relative to the limit type specified in the QOS policy.
The no form of this command returns the queue to its default shaping rate and cir rate. When no percent-rate
is defined within a SAP ingress or egress queue-override, the queue reverts to the defined shaping and CIR
rates within the SAP ingress and egress QOS policy associated with the queue.
Parameters
pir-percent — The pir-percent parameter is used to express the queue's PIR as apercentage dependant on
the use of the port-limit or local-limit.
Values
cir cir-percent — The cir keyword is optional and when defined the required cir-percent CIR parameter
expresses the queue's CIR as a percentage dependant on the use of the port-limit or local-limit.
Values
port-limit — The port-limit keyword specifies that the configure PIR and CIR percentages are relative to
the rate of the port (including the ingress-rate/egress-rate setting) to which this queue connects.
local-limit — The local-limit keyword specifies that the configure PIR and CIR percentages are relative to
the rate of the queue's parent scheduler rate or agg-rate rate at egress.
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Percentage ranging from 0.01 to 100.00. The default is 100.00.
Percentage ranging from 0.00 to 100.00. The default is 100.00
7950 XRS Quality of Service Guide