1-2traffic, and setting priority of the packets. To meet those requirements, the network should be providedwith better service capability.Major Traffic Control TechniquesFigure 1-1 End-to-end QoS modelTraffic classification, traffic policing, traffic shaping, congestion management, and congestionavoidance are the foundations for a network to provide differentiated services. Mainly they implementthe following functions.z Traffic classification identifies traffic based on certain matching rules. It is a prerequisite fordifferentiated services and is usually applied in the inbound direction of a port.z Traffic policing confines traffic to a specific specification and is usually applied in the inbounddirection of a port. You can configure restriction or penalty measures against the exceeding trafficto protect carrier benefits and network resources.z Traffic shaping adapts output traffic rate usually to the input capability of the receiving device toavoid packet drop and port congestion. Traffic shaping is usually applied in the outbound directionof a port.z Congestion management handles resource competition during network congestion. Generally, itputs packets into queues first, and then schedules the packets with a certain algorithm. Congestionmanagement is usually applied in the outbound direction of a port.z Congestion avoidance monitors the use of network resources and drops packets actively whencongestion reaches certain degree. It relieves network load by adjusting traffic. Congestionavoidance is usually applied in the outbound direction of a port.Traffic classification is the basis of all the above-mentioned traffic management technologies. Itidentifies packets using certain rules and makes differentiated services possible. Traffic policing, trafficshaping, congestion management, and congestion avoidance are methods for implementing networktraffic control and network resource management. They are occurrences of differentiated services.
