Dell N3200-ON EMC Networking N-Series Switches User Guide version 6.6.3 - Page 1583

In the first line of the configuration below, the first integer after the minthresh keyword configures green-colored Congestion Enabled TCP packets in CoS queues 0 and 1 that exceed the WRED threshold (13% or ~38 Kbytes) to mark packets as Congestion Experienced. The first integer after the maxthresh parameter configures the upper threshold for green-colored TCP packets to the same value as the min-thresh threshold. This causes the switch to mark all ECN-capable queued packets as Congestion Experienced when the threshold is reached or exceeded. TCP packets without ECN capability bits set are dropped according to the normal WRED processing when the threshold is exceeded. Packets on other CoS queues are handled in the standard manner, i.e., tail-dropped when insufficient buffer is available. Yellow and red packet configuration (second and third threshold parameters) is kept at the defaults, as no metering to reclassify packets from green to yellow or red is present. The last threshold parameter configures non-TCP packets in CoS queues 0 and 1 to be processed with the WRED defaults. The ecn keyword enables ECN marking of ECN-capable packets on CoS queues 0 and 1. The weighting constant is set to 0 in the second line of the configuration, as described in the DCTCP paper cited above. Finally, CoS queues 0 and 1 are configured for WRED in the last line of the configuration. console(config)#random-detect queue-parms 0 1 min-thresh 13 30 20 100 max-thresh 13 90 80 100 drop-prob-scale 100 10 10 10 ecn console(config)#random-detect exponential-weighting-constant 0 console(config)#cos-queue random-detect 0 1 Class-of-Service 1583