4-3Figure 4-2 Schematic diagram for GTSTokenbucketPackets droppedPacketclassificationPackets to be sentthrough this interfacePackets sentTokens are put into thebucket at the set rateQueueTraffic policing is widely used in policing traffic entering the networks of internet service providers (ISPs).It can classify the policed traffic and perform pre-defined policing actions based on different evaluationresults. These actions include:z Forwarding the packets whose evaluation result is “conforming”.z Dropping the packets whose evaluation result is “excess”.Traffic ShapingTraffic shaping provides measures to adjust the rate of outbound traffic actively. A typical traffic shapingapplication is to limit the local traffic output rate according to the downstream traffic policing parameters.The difference between traffic policing and GTS is that packets to be dropped in traffic policing arecached in a buffer or queue in GTS, as shown in Figure 4-3. When there are enough tokens in the tokenbucket, these cached packets are sent at an even rate. Traffic shaping may result in an additional delaywhile traffic policing does not.
