2 policers – CANOGA PERKINS 9145ELB NID Software Version 4.01 User Manual

Page 137

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Bandwidth Profiles

9145ELB NID Software User’s Manual

Policers

127

Figure 11-1 Bandwidth Profiling Algorithm

When a packet is received of size B bytes in length, the algorithm checks to see if there are at
least B tokens currently in the C bucket. If so, the C bucket is decremented by B and the packet
is forwarded on with a compliance level of Green. If there are less than B tokens in the C bucket,
the E bucket is checked to see if it has sufficient tokens. If the E bucket has at least B tokens,
then the packet is forwarded on with a compliance level of Yellow. If both the C and E buckets
have insufficient tokens, the packet is said to have a compliance level of Red, and is discarded.

11.2 Policers

Policers limit the ingress traffic on User Ports, according to an associated bandwidth profile.
There are a maximum of 128 policers per User Port.

A policer is created and destroyed by the system and has the following attributes:

a unique numerical policer ID

a textual name

a policing bandwidth profile record attached to the policer. Several policers may share the

same bandwidth profile.

the attached traffic flow type. A policer may be attached to:

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