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the total. If the traffic of a certain session exceeds the limit, traffic policing can drop the
packets or reset the IP precedence of the packets. See
Figure 8
.
Figure 8
Schematic diagram for traffic policing
Token
bucket
Packets dropped
Packet
classification
Packets to be sent
through this interface
Packets sent
Tokens are put into the
bucket at the set rate
Queue
Traffic policing is widely used in policing traffic entering the networks of internet service
providers (ISPs). It can classify the policed traffic and perform pre-defined policing
actions based on different evaluation results. These actions include:
Forwarding the packets whose evaluation result is ―conforming.‖
Dropping the packets whose evaluation result is ―excess.‖
Modifying the IP precedence of the packets whose evaluation result is
―conforming‖ and forwarding them.
Modifying the IP precedence of the packets whose evaluation result is
―conforming‖ and delivering them into the next-level traffic policing.
Entering the next-level policing (you can set multiple traffic policing levels with each
level focusing on specific objects).
Line rate
The line rate of a physical interface specifies the maximum rate for forwarding packets
(including critical packets).
Line rate also uses token buckets for traffic control. With line rate configured on an
interface, all packets to be sent through the interface are first handled by the token
bucket of line rate. If there are enough tokens in the token bucket, packets can be
