Alcatel-Lucent 7450 Quality Of Service Manual page 328

Service SAP QoS Policy Command Reference
Description This command enables the forwarding of traffic exceeding the PIR for a SAP egress or a network
egress queue group (configured in the egress queue group template) policer. This traffic is forwarded
as exceed-profile instead of being dropped.
Default
no enable-exceed-pir
high-prio-only
Syntax high-prio-only percent-of-mbs
no high-prio-only
Context config>qos>sap-egress>policer
Description This command is used to configure the percentage of the policer's PIR leaky bucket's MBS (maximum
burst size) that is reserved for high priority traffic. While the mbs value defines the policer's high
priority violate threshold, the percentage value defined is applied to the mbs value to derive the
bucket's low priority violate threshold. See the mbs command details for information on which types
of traffic is associated with each violate threshold.
Default 10
Parameters percent-of-mbs — The percent-of-mbs parameter is required when specifying high-prio-only and
mbs
Syntax mbs {size [bytes | kilobytes] | default}
no mbs
Context config>qos>sap-egress>policer
Description This command is used to configure the policer's PIR leaky bucket's high priority violate threshold. The
high-prio-only command is applied to the MBS value to derive the bucket's low priority violate
threshold. For egress, trusted in-profile packets and untrusted high priority packets use the policer's
high priority violate threshold while trusted out-of-profile and untrusted low priority packets use the
policer's low priority violate threshold. At egress, in-profile packets use the policer's high priority
violate threshold and out-of-profile packets use the policer's low priority violate threshold.
The PIR bucket's violate threshold represent the maximum burst tolerance allowed by the policer. If
the policer's offered rate is equal to or less than the policer's defined rate, the PIR bucket depth hovers
around the 0 depth with spikes up to the maximum packet size in the offered load. If the offered rate
increases beyond the metering rate, the amount of data allowed above the rate is capped by the
threshold. The low priority violate threshold provides a smaller burst size for the lower priority traffic
associated with the policer. Since all lower priority traffic is discarded at the lower burst tolerance size,
the remaining burst tolerance defined by high-prio-only is available for the higher priority traffic.
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is expressed as a percentage.
Values 0 to 100
Default 10
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