Dell C1048P Port Extender Networking Command-Line Reference Guide for the C900 - Page 1794

Version 9.3.0.0 Description Introduced on the Z9000 platform. Usage Information You can add or remove ECN marking configuration on a list of queues on all backplane ports. All of the configured attributes apply to all the backplane ports and are for each queue. You can configure all the data queues. You can configure queues 0 to 7. By default, ECN marking is disabled on all queues. When you enable WRED with ECN and the number of packets in the queue is below the minimum threshold, packets are transmitted per the usual WRED treatment. When you enable WRED with ECN and the number of packets in the queue is between the minimum threshold and the maximum threshold, one of the following three scenarios can occur: • If the transmission endpoints are ECN-capable and traffic is congested, and the WRED algorithm determines that the packet should be dropped based on the drop probability, the packet is transmitted and marked so the routers know the system is congested and can slow transmission rates. • If neither endpoint is ECN-capable, the packet may be dropped based on the WRED drop probability. This behavior is the identical treatment that a packet receives when WRED is enabled without ECN configured on the router. • If the network is experiencing congestion, the packet is transmitted. No further marking is required. When you enable WRED with ECN and the number of packets in the queue is above the maximum threshold, packets are dropped based on the drop probability. This behavior is the identical treatment a packet receives when WRED is enabled without ECN configured on the router. Example Dell(conf)#service-class wred ecn 0, 3-5, 7 backplane show qos dot1p-queue-mapping Displays the dot1p priority to queue mapping on the switch. C9000 Series Syntax Defaults show qos dot1p-queue-mapping • dot1p Priority: 0 1 2 3 4 5 6 7 • Queue: 0 0 0 1 2 3 3 3 Command Modes EXEC Privilege Command History This guide is platform-specific. For command information about other platforms, refer to 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