4-3
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…
Use the command…
Remarks
Enter system view
system-view
—
Create a class and enter
class view
traffic classifier
tcl-name
[
operator
{
and
|
or
} ]
—
Configure the match
criteria
if-match match-criteria
—
Exit class view
quit
—
Create a behavior and
enter behavior view
traffic behavior behavior-name
—
