Class of Service Configuration
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NXA-ENET24 - Software Management Guide
Mapping CoS Values to Egress Queues - 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.
Mapping CoS Values to Egress Queues - CLI
The following example shows how to map CoS values 1 and 2 to CoS priority queue 0, value 0 and 3 to CoS
priority queue 1, values 4 and 5 to CoS priority queue 2, and values 6 and 7 to CoS priority queue 3.
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
•Priority: CoS value. (Range: 0-7, where 7 is the highest priority)
• Traffic Class: Output queue buffer.
• Range: 0-3, where 3 is the highest CoS priority queue
• CLI shows Queue ID.
FIG. 156 Web - Traffic Classes
FIG. 157 CLI - Traffic Classes
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.
Command Attributes
• WRR: Weighted Round-Robin shares bandwidth at the egress ports by using scheduling weights 1, 4, 16,
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.