H3C SR6600 Configuration Manual

Also see for SR6600 SPE-FWM: Configuration guide Configuration guide Command reference Command reference Command reference

Contents

5-2Complicated evaluationYou can set two token buckets (referred to as the C bucket and E bucket respectively) in order toevaluate more complicated conditions and implement more flexible regulation policies. For example,traffic policing uses four parameters:z CIR: Rate at which tokens are put into the C bucket, that is, the average packet transmission orforwarding rate allowed by the C bucket.z CBS: Size of the C bucket, that is, transient burst of traffic that the C bucket can forward.z Peak information rate (PIR): Rate at which tokens are put into the E bucket, that is, the averagepacket transmission or forwarding rate allowed by the E bucket.z Excess burst size (EBS): Size of the E bucket, that is, transient burst of traffic that the E bucket canforward.Figure 5-1 A two-bucket systemFigure 5-1 shows a two-bucket system, where the size of C bucket is CBS and that of the E bucket isEBS.In each evaluation, packets are measured against the buckets:z If the C bucket has enough tokens, packets are colored green.z If the C bucket does not have enough tokens but the E bucket has enough tokens, packets arecolored yellow.z If neither the C bucket nor the E bucket has sufficient tokens, packets are colored red.Traffic PolicingThe typical application of traffic policing is to supervise the specification of certain traffic entering anetwork and limit it within a reasonable range, or to "discipline" the extra traffic. In this way, the networkresources and the interests of the carrier are protected. For example, you can limit bandwidthconsumption of HTTP packets to less than 50% of the total. If the traffic of a certain session exceeds thelimit, traffic policing can drop the packets or reset the IP precedence of the packets.