H3C Technologies H3C SR8800 - Manual (Page 30)

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performed according to the characteristics and demands of applications to minimize the effects of
congestion.
Major traffic management technologies
Figure 5 Positions of the QoS techniques in a network
As shown in Figure 5 , traffic classification, traffic shaping, traffic policing, congestion management, and
congestion avoidance mainly implement the following functions:
• Traffic classification uses certain match criteria to assign packets with the same characteristics to a
class. Based on classes, you can provide differentiated services.
• Traffic policing polices flows entering or leaving a device. You can apply traffic policing to both
incoming and outgoing traffic of a port. When a flow exceeds the pre-set threshold, some restriction
or punishment measures can be taken to prevent overconsumption of network resources.
• Traffic shaping proactively adapts the output rate of traffic to the network resources available on the
downstream device to eliminate packet drop. Traffic shaping is usually applied to the outgoing
traffic of a port.
• Congestion management provides a resource scheduling policy to arrange the forwarding
sequence of packets when congestion occurs. Congestion management is usually applied to the
outgoing traffic of a port.
• Congestion avoidance monitors the usage status of network resources and is usually applied to the
outgoing traffic of a port. As congestion becomes worse, it actively reduces the queue length by
dropping packets.