Alcatel-Lucent 7950 Quality Of Service Manual page 200

Service Ingress QoS Policy Commands
rate
Syntax rate {max | kilobits-per-second} [cir {max | kilobits-per-second}]
no rate
Context config>qos>sap-ingress>policer
Description
This command is used to configure the policer's metering and optional profiling rates. The metering rate is
used by the system to configure the policer's PIR leaky bucket's decrement rate while the profiling rate
configures the policer's CIR leaky bucket's decrement rate. The decrement function empties the bucket
while packets applied to the bucket attempt to fill it based on the each packets size. If the bucket fills faster
than how much is decremented per packet, the bucket's depth eventually reaches it's exceed (CIR) or violate
(PIR) threshold. The cbs, mbs, and high-prio-only commands are used to configure the policer's PIR and
CIR thresholds.
If a packet arrives at the policer while the bucket's depth is less than the threshold associated with the
packet, the packet is considered to be conforming to the bucket's rate. If the bucket depth is equal to or
greater than the threshold, the packet is considered to be in the exception state. For the CIR bucket, the
exception state is exceeding the CIR rate while the PIR bucket's exception state is violating the PIR bucket
rate. If the packet is violating the PIR, the packet is marked red and will be discarded. If the packet is not
red, it may be green or yellow based on the conforming or exceeding state from the CIR bucket.
When a packet is red neither the PIR or CIR bucket depths are incremented by the packets size. When the
packet is yellow the PIR bucket is incremented by the packet size, but the CIR bucket is not. When the
packet is green, both the PIR and CIR buckets are incremented by the packet size. This ensures that
conforming packets impact the bucket depth while exceeding or violating packets do not.
The policer's adaptation-rule command settings are used by the system to convert the specified rates into
hardware timers and decrement values for the policer's buckets.
By default, the policer's metering rate is max and the profiling rate is 0 Kbps (all packets out-of-profile).
The rate settings defined for the policer in the QoS policy may be overridden on an sla-profile or SAP
where the policy is applied.
The no form of this command is used to restore the default metering and profiling rate to a policer.
Parameters {max | kilobits-per-second} — Specifying the keyword max or an explicit kilobits-per-second parameter
directly following the rate command is required and identifies the policer's metering rate for the PIR
leaky bucket. When the policer is first created, the metering rate defaults to max. The kilobits-per-
second value must be expressed as an integer and defines the rate in kilobits-per-second. The integer
value is multiplied by 1,000 to derive the actual rate in bits-per-second. When max is specified, the
maximum policer rate used will be equal to the maximum capacity of the card on which the policer is
configured. If the policer rate is set to a value larger than the maximum rate possible for the card, then
the PIR used is equivalent to max.
Values
cir {max | kilobits-per-second} — The optional cir keyword is used to override the default CIR rate of the
policer. Specifying the keyword max or an explicit kilobits-per-second parameter directly following the
cir keyword is required and identifies the policer's profiling rate for the CIR leaky bucket. When the
policer is first created, the profiling rate defaults to 0 Kbps. The kilobits-per-second value must be
expressed as an integer and defines the rate in kilobits-per-second. The integer value is multiplied by
1,000 to derive the actual rate in bits-per-second. When max is specified, the maximum policer rate
Page 200
max or 1—2000000000
7950 XRS Quality of Service Guide