Version Description9.3.0.0 Introduced on the Z9000 platform.Usage Information You can add or remove ECN marking configuration on a list of queues on all backplaneports. All of the configured attributes apply to all the backplane ports and are for eachqueue. You can configure all the data queues. You can configure queues 0 to 7. Bydefault, ECN marking is disabled on all queues. When you enable WRED with ECN andthe number of packets in the queue is below the minimum threshold, packets aretransmitted per the usual WRED treatment. When you enable WRED with ECN and thenumber of packets in the queue is between the minimum threshold and the maximumthreshold, one of the following three scenarios can occur:• If the transmission endpoints are ECN-capable and traffic is congested, and theWRED algorithm determines that the packet should be dropped based on thedrop probability, the packet is transmitted and marked so the routers know thesystem is congested and can slow transmission rates.• If neither endpoint is ECN-capable, the packet may be dropped based on theWRED drop probability. This behavior is the identical treatment that a packetreceives when WRED is enabled without ECN configured on the router.• If the network is experiencing congestion, the packet is transmitted. No furthermarking is required. When you enable WRED with ECN and the number of packetsin the queue is above the maximum threshold, packets are dropped based on thedrop probability. This behavior is the identical treatment a packet receives whenWRED is enabled without ECN configured on the router.Example Dell(conf)#service-class wred ecn 0, 3-5, 7 backplaneshow qos dot1p-queue-mappingDisplays the dot1p priority to queue mapping on the switch.C9000 SeriesSyntax show qos dot1p-queue-mappingDefaults • dot1p Priority: 0 1 2 3 4 5 6 7• Queue: 0 0 0 1 2 3 3 3Command Modes EXEC PrivilegeCommand History This guide is platform-specific. For command information about other platforms, referto the relevant Dell Networking OS Command Line Reference Guide.The following is a list of the Dell Networking OS version history for this command.Quality of Service (QoS) 1794
