Priority Marking; Traffic Policing - 3Com 4210 9-Port Configuration Manual

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Priority Marking

The priority marking function is to reassign priority for the traffic matching an ACL referenced for traffic
classification.
If 802.1p priority marking is configured, the traffic will be mapped to the local precedence
corresponding to the re-marked 802.1p priority and assigned to the output queue corresponding to
the local precedence.
If local precedence marking is configured, the traffic will be assigned to the output queue
corresponding to the re-marked local precedence.
If DSCP marking is configured, the traffic will be marked with new DSCP precedence.

Traffic Policing

The network will be made more congested by plenty of continuous burst packets if the traffic of each
user is not limited. The traffic of each user must be limited in order to make better use of the limited
network resources and provide better service for more users. For example, a traffic flow can be limited
to get only its committed resources during a time period to avoid network congestion caused by
excessive bursts.
Traffic policing is a kind of traffic control policy used to limit the traffic and the resource occupied by
supervising the traffic. The regulation policy is implemented according to the evaluation result on the
premise of knowing whether the traffic exceeds the specification when traffic policing is performed.
Normally, token bucket is used for traffic evaluation.
Token bucket
The token bucket can be considered as a container with a certain capacity to hold tokens. The system
puts tokens into the bucket at the set rate. When the token bucket is full, the extra tokens will overflow
and the number of tokens in the bucket stops increasing.
DSCP Local precedence
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