Deploying Qos In A Network - HP MSR4080 Configuration Manual

Traffic classification.
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• Traffic policing.
Traffic shaping.
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Rate limit.
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• Congestion management.
Congestion avoidance.
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The following section briefly introduces these QoS techniques.
All QoS techniques in this document are based on the DiffServ model.

Deploying QoS in a network

Figure 2 Position of the QoS techniques in a network
As shown in
congestion avoidance mainly implement the following functions:
Traffic classification—Uses match criteria to assign packets with the same characteristics to a traffic
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class. Based on traffic classes, you can provide differentiated services.
Traffic policing—Polices flows and imposes penalties to prevent aggressive use of network resources.
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You can apply traffic policing to both incoming and outgoing traffic of a port.
Traffic shaping—Adapts the output rate of traffic to the network resources available on the
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downstream device to eliminate packet drops. Traffic shaping usually applies to the outgoing traffic
of a port.
Congestion management—Provides a resource scheduling policy to determine the packet
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forwarding sequence when congestion occurs. Congestion management usually applies to the
outgoing traffic of a port.
• Congestion avoidance—Monitors the network resource usage. It is usually applied to the outgoing
traffic of a port. When congestion worsens, congestion avoidance reduces the queue length by
dropping packets.
Figure 2, traffic classification, traffic shaping, traffic policing, congestion management, and
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