1-3QoS Supported By Switch 4500 SeriesThe Switch 4500 series support the QoS features listed in Table 1-1:Table 1-1 QoS features supported by Switch 4500 seriesQoS Feature Description Refer to …TrafficclassificationClassify incoming traffic basedon ACLs. The Switch 4500series support the followingtypes of ACLs:z Basic ACLsz Advanced ACLsz Layer-2 ACLsz User-defined ACLsz For information about ACLs, refer to theACL Operation and ACL Commandmanuals.z For information about traffic classification,refer to Traffic Classification.The Switch 4500 series supportperforming the following QoSactions for packets matching thespecified ACL:z Priority markingz Traffic policingz VLAN Mappingz Traffic mirroringz For information about priority marking,refer to Priority Marking.z For information about traffic policing, referto Traffic Policing.z For information about VLAN Mapping,refer to VLAN Mapping.z For information about traffic mirroring,refer to Traffic mirroring.QoS actionYou can configure the followingQoS actions as required on theSwitch 4500 series:z Priority trust modez Protocol packet priorityz Line ratez For information about priority trust mode,refer to Priority Trust Mode.z For information about specifying priorityfor protocol packets, refer to ProtocolPriority.z For information about line rate, refertoLine Rate.Congestionavoidance WRED For information about congestion avoidanceand WRED, refer to Congestion Avoidance.CongestionmanagementThe Switch 4500 series supportSP, WFQ, and WRR queuescheduling algorithms andsupport the following five queuescheduling modes:z SPz WFQz WRRz SP+WFQz SP+WRRFor information about SP, WFQ, and WRR,refer to Queue Scheduling.Introduction to QoS FunctionsTraffic ClassificationTraffic here refers to service traffic; that is, all the packets passing the switch.Traffic classification means identifying packets that conform to certain characteristics according tocertain rules. It is the foundation for providing differentiated services.In traffic classification, the priority bit in the type of service (ToS) field in IP packet header can be used toidentify packets of different priorities. The network administrator can also define traffic classificationpolicies to identify packets by the combination of source address, destination address, MAC address, IP
