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Deploying QoS in a network
Figure 2 Position of the QoS techniques in a network
As shown in
, traffic classification and traffic policing mainly implement the following
functions:
•
Traffic classification
—Uses match criteria to assign packets with the same characteristics to
a traffic class. Based on traffic classes, you can provide differentiated services.
•
Traffic policing
—Polices flows and imposes penalties to prevent aggressive use of network
resources. You can apply traffic policing to both incoming and outgoing traffic of a port.
QoS processing flow in a device
briefly describes how the QoS module processes traffic.
1.
Traffic classifier identifies and classifies traffic for subsequent QoS actions.
2.
The QoS module takes various QoS actions on classified traffic as configured, depending on
the traffic processing phase and network status. For example, you can configure the QoS
module to perform traffic policing for incoming traffic.
Figure 3 QoS processing flow
WAN
Traffic classification
Traffic policing
Traffic policing
Traffic policing
Traffic direction
Traffic policing
Traffic policing
Priority marking
Classify
packets
Classification
Packets received
on the interface
Tokens
Drop
Other
actions
Token bucket
CAR
Mark
Tokens
Classify
packets
Classification
Packets sent
out of the
interface
Drop
Other
actions
Send
Token bucket
Traffic policing
CAR