1-8Table 1-5 802.1p priority-to-local precedence mapping table802.1p priority Local precedence0 21 02 13 34 45 56 67 7Protocol PriorityProtocol packets generated by a switch carry their own priority. You can set a new IPprecedence or DSCP precedence for the specific type of protocol packets to implementQoS.Priority MarkingThe priority marking function is to reassign priority for the traffic matching an ACLreferenced for traffic classification.z If 802.1p priority marking is configured, the traffic will be mapped to the localprecedence corresponding to the re-marked 802.1p priority and assigned to the outputqueue corresponding to the local precedence.z If local precedence marking is configured, the traffic will be assigned to the outputqueue corresponding to the re-marked local precedence.z If IP precedence or DSCP marking is configured, the traffic will be marked with new IPprecedence or DSCP precedence.Traffic PolicingThe network will be made more congested by plenty of continuous burst packets if thetraffic of each user is not limited. The traffic of each user must be limited in order to makebetter use of the limited network resources and provide better service for more users. Forexample, traffic can be limited to get only its committed resources during a time period toavoid network congestion caused by excessive bursts.Traffic policing is a kind of traffic control policy used to limit the traffic and the resourceoccupied by supervising the traffic. The regulation policy is implemented according to theevaluation result on the premise of knowing whether the traffic exceeds the specificationwhen traffic policing is performed. Normally, token bucket is used for traffic evaluation.
