Configuring Data Center Bridging Features 999Enhanced Transmission SelectionNetworks classify and prioritize traffic to provide different servicecharacteristics to end user traffic flows. Administrators may wish to guaranteeor limit bandwidth for certain traffic, ensure lossless behavior for other traffic,and control the queue discipline/drop characteristics for best-effort traffic.Additionally, it is desirable for a switch to support sharing bandwidth amongbursty sources while still enabling prioritization of time-sensitive ormanagement traffic that requires minimum latency.Enhanced transmission selection (ETS) provides uniform management forsharing bandwidth between congestion managed and traditional classes on asingle bridged network. Using priority-based processing and weightallocations, Traffic Class Groups (TCGs) carrying different types of trafficsuch as LAN, SAN, and management traffic can be configured to provideminimum bandwidth guarantees, unused bandwidth sharing, and lossless orbest-effort transmit characteristics. Dell Networking N4000 switches supportstrict priority and Weighted Deficit Round Robin (WDRR) scheduling withup to two lossless traffic classes. WDRR schedules traffic based on averagebandwidth consumed vs. frame counts.ETS OperationThe normal (default) operation of Dell Networking switches, whenuncongested, is that packets are scheduled for output in the order in whichthey are received, that is, using FIFO scheduling. The class of service (CoS)mechanism enables the administrator to schedule packets for output ahead ofother packets when the switch is congested, choose which type of packets todrop when the switch is congested, and assign a minimum bandwidthguarantee to ensure scheduling fairness. These mechanisms operate at theCoS queue level; that is, the minimum bandwidth guarantees are madeacross all configured CoS queues.show lldp tlv-selectinterface {all |interface}Display the interface TLV configuration for all interfacesor for the specified interface.show lldp dcbx interface{all status |interface[detail]}Display the interface TLV configuration for all interfacesor for the specified interface.Command Purpose
