Line Rate; Configuring Traffic Policing; Configuration Procedure - 3Com 4500G Family Configuration Manual

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 firstly handled by the token bucket at line rate. If there are enough
tokens in the token bucket, packets can be forwarded; otherwise, packets are put into QoS queues for
congestion management. In this way, the traffic passing the physical interface is controlled.
Figure 4-2 Line rate implementation
In the token bucket approach to traffic control, bursty traffic can be transmitted so long as enough
tokens are available in the token bucket; if tokens are inadequate, packets cannot be transmitted until
the required number of tokens are generated in the token bucket. Thus, traffic rate is restricted to the
rate for generating tokens, thus limiting traffic rate and allowing bursty traffic.
Line rate can only limit the total traffic rate on a physical port, while traffic policing can limit the rate of a
flow on a port. To limit the rate of all the packets on a port, using line rate is easier.

Configuring Traffic Policing

Configuration Procedure

Follow these steps to configure traffic policing:
To do...
Enter system view
Create a class and enter
class view
Configure the match
criteria
Exit class view
Create a behavior and
enter behavior view
Use the command...
system-view
traffic classifier tcl-name [ operator
{ and | or } ]
if-match match-criteria
quit
traffic behavior behavior-name
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Remarks
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