Operation Manual – QoSH3C S5500-EI Series Ethernet SwitchesChapter 2 Traffic Classification,TP, and LR Configuration2-1Chapter 2 Traffic Classification, TP, and LRConfigurationWhen configuring traffic classification, TP, and LR, go to these section for informationyou are interested in:z Traffic Classification Overviewz TP and LR Overviewz Traffic Evaluation and Token Bucketz LR Configurationz Displaying and Maintaining LR2.1 Traffic Classification Overview2.1.1 Traffic ClassificationTraffic classification is to identify packets conforming to certain characters according tocertain rules. It is the basis and prerequisite for proving differentiated services.A traffic classification rule can use the precedence bits in the type of service (ToS) fieldof the IP packet header to identify traffic with different precedence characteristics. Atraffic classification rule can also classify traffic according to the traffic classificationpolicy set by the network administrator, such as the combination of source addresses,destination addresses, MAC addresses, IP protocol or the port numbers of theapplications. Traffic classification is generally based on the information in the packetheader and rarely based on the content of the packet. The classification result isunlimited in range. They can be a small range specified by a quintuplet (source address,source port number, protocol number, destination address, and destination portnumber), or all the packets to a certain network segment.Generally, the precedence of bits in the ToS field of the packet header is set whenpackets are classified on the network border. Thus, IP precedence can be used directlyas the classification criterion inside the network. Queue techniques can also processpackets differently according to IP precedence. The downstream network can eitheraccept the classification results of the upstream network or re-classify the packetsaccording to its own criterion.The purpose of traffic classification is to provide differentiated services, so trafficclassification is significant only when it is associated with a certain traffic control orresource assignment action. The specific traffic control action to be adopted dependson the phase and the current load status. For example, when the packets enter thenetwork, TP is performed on the packets according to CIR; before the packets flow outof the node, TS is performed on the packets; when congestion occurs, queue
