LevelOne GTL-2691 - Manual (Page 1176)

C HAPTER 41 | Quality of Service Commands
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◆ Policing is based on a token bucket, where bucket depth (i.e., the
maximum burst before the bucket overflows) is by specified the
committed-burst field, and the average rate tokens are added to the
bucket is by specified by the committed-rate option. Note that the
token bucket functions similar to that described in RFC 2697 and RFC
2698.
◆ The behavior of the meter is specified in terms of one token bucket (C),
the rate at which the tokens are incremented (CIR – Committed
Information Rate), and the maximum size of the token bucket (BC –
Committed Burst Size).
The token bucket C is initially full, that is, the token count Tc(0) = BC.
Thereafter, the token count Tc is updated CIR times per second as
follows:
■
If Tc is less than BC, Tc is incremented by one, else
■
Tc is not incremented.
When a packet of size B bytes arrives at time t, the following happens:
■
If Tc(t)-B ≥ 0, the packet is green and Tc is decremented by B down
to the minimum value of 0, else
■
else the packet is red and Tc is not decremented.
E XAMPLE
This example creates a policy called “rd-policy,” uses the class command to
specify the previously defined “rd-class,” uses the set command to classify
the service that incoming packets will receive, and then uses the police
flow command to limit the average bandwidth to 100,000 Kbps, the burst
rate to 4000 bytes, and configure the response to drop any violating
packets.
Console(config)#policy-map rd-policy
Console(config-pmap)#class rd-class
Console(config-pmap-c)#set ip dscp 3
Console(config-pmap-c)#police flow 100000 4000 violate-action drop
Console(config-pmap-c)#
police srtcm-color This command defines an enforcer for classified traffic based on a single
rate three color meter (srTCM). Use the no form to remove a policer.
S YNTAX
[no] police {srtcm-color-blind | srtcm-color-aware}
committed-rate committed-burst excess-burst
exceed-action {drop | new-dscp}
violate action {drop | new-dscp}
srtcm-color-blind - Single rate three color meter in color-blind
mode.
srtcm-color-aware - Single rate three color meter in color-aware
mode.