Dell(conf-wred)#wred thresh-2Dell(conf-wred)#threshold min 300 max 400 max-drop-rate 803 Associate a service class for each WRED profile, and assign the WRED profile to specific queues onbackplane ports.CONFIGURATION modeDell(conf)#service-class wred green queue5 thresh-1 queue7 thresh-2 backplaneDell(conf)#service-class wred yellow queue1 thresh-2 queue3 thresh-1 backplaneDell(conf)#service-class wred weight queue0 11 queue6 4 queue7 9 backplane4 Create a global buffer pool that serves as a shared buffer accessed by multiple queues when theminimum guaranteed buffers for a queue are consumed. The switch supports four global service-poolsin the egress direction.modeDell(conf)#service-pool wred green pool0 thresh-1 pool1 thresh-2Dell(conf)#service-pool wred yellow pool0 thresh-3 pool1 thresh-4Dell(conf)#service-pool wred weight pool0 11 pool1 45 Enable ECN marking on specific queues on backplane ports with a service class.CONFIGURATION modeDell(conf)#service-class wred ecn 0, 3-5, 7 backplanePre-Calculating Available QoS CAMSpacePre-calculating available QoS CAM space allows you to measure the number of CAM entries a policy-mapconsumes.This feature allows you to avoid applying a policy-map on an interface that requires more CAM entries thanare available and receive a CAM full error message (shown in the following example). The partial policy-mapconfiguration might cause unintentional system behavior.%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3Cam(PolicyQos) for class 2 (Te 12/20) entries on portpipe 1 for linecard 12%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3 Cam(PolicyQos) for class 5(Te 12/22) entries on portpipe 1 for linecard 12Use the test cam-usage command to verify that there are enough available CAM entries before applying apolicy-map to an interface so that you avoid exceeding the QoS CAM space and partial configurations. Thiscommand measures the size of the specified policy-map and compares it to the available CAM space in apartition for a specified port-pipe.Test the policy-map size against the CAM space for a specific port-pipe or all port-pipes using thesecommands:Quality of Service (QoS) 936
