Accton Technology VS4512DC manual Selecting the Queue Mode, 151

Class of Service Configuration

Web – Click Priority, Traffic Classes. Mark an interface and click Select to display the current mapping of CoS values to output queues. Assign priorities to the traffic classes (i.e., output queues) for the selected interface, then click Apply.

CLI – The following example shows how to change the CoS assignments to a one-to-one mapping.

Console(config)#interface ethernet 1/1								4-84
Console(config)#queue cos-map 0 0								4-150
Console(config)#queue cos-map 1							1
Console(config)#queue cos-map 2							2
Console(config)#exit
Console#show queue	cos-map ethernet 1/1							4-151
Information of Eth	1/1
Traffic Class : 0	1	2	3	4	5	6	7
Priority Queue: 0	1	2	1	2	2	3	3

*Mapping specific values for CoS priorities is implemented as an interface configuration command, but any changes will apply to the all interfaces on the switch.

Selecting the Queue Mode

You can set the switch to service the queues based on a strict rule that requires all traffic in a higher priority queue to be processed before lower priority queues are serviced, or use Weighted Round-Robin (WRR) queuing that specifies a relative weight of each queue. WRR uses a predefined relative weight for each queue that determines the percentage of service time the switch services each queue before moving on to the next queue. This prevents the head-of-line blocking that can occur with strict priority queuing.

Command Attributes

•WRR – Weighted Round-Robin shares bandwidth at the egress ports by using scheduling weights 1, 4, 16, and 64 for queues 0 through 3 respectively. (This is the default selection.)

•Strict – Services the egress queues in sequential order, transmitting all traffic in the higher priority queues before servicing lower priority queues.

Web – Click Priority, Queue Mode. Select Strict or Wrr, then click Apply.

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