Ingress Child Policer Stat-Mode - Alcatel-Lucent 7950 Quality Of Service Manual

Ingress Child Policer Stat-Mode

Ingress Child Policer Stat-Mode
A policer has multiple types of input traffic and multiple possible output states for each input
traffic type. These variations differ between ingress and egress.
For ingress policing, each offered packet has a priority and a profile state. The priority is used by
the policer to choose either the high or low priority PIR threshold-be. Every offered packet is
either priority high or priority low. The offered profile state defines how a packet will interact with
the policers CIR bucket state. The combinations of priority and initial profile are as follows:
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•
•
•
•
•
NOTE: When de1out is enabled, DEI = 0 is considered as undefined profile and DEI = 1 is
considered the same as profile out
The possible output results for the ingress policer are:
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•
In order to conserve counter resources, the system supports a policer stat-mode command that is
used to identify what counters are actually needed for the policer. Not every policer will have a
CIR defined, so the output green/yellow states will not exist. Also, not every policer will have both
high and low priority or explicit in-profile or out-of-profile offered traffic types. Essentially, the
stat-mode command allows the counter resources to be allocated based on the accounting needs of
the individual policers.
Setting the stat-mode does not modify the packet handling behavior of the policer. For example, if
the configured stat-mode does not support in-profile and out-of-profile output accounting, the
policer is not blocked from having a configured CIR rate. The CIR rate will be enforced, but the
amount of in-profile and out-of-profile traffic output from the policer will not be counted
separately (or maybe not at all based on the configured stat-mode).
A policer is created with minimal counters sufficient to provide total offered and total discarded
(the total forwarded is computed as the sum of the offered and discarded counters). The stat-mode
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Offered priority low, undefined profile
Offered priority low, explicit profile in
Offered priority low, explicit profile out
Offered priority high, undefined profile
Offered priority high, explicit profile in
Offered priority high, explicit profile out
Output green (in-profile)
Output yellow (out-of-profile)
Output red (discard)
7950 XRS Quality of Service Guide