Mapping CoS Values to Egress Queues
This switch processes Class of Service (CoS) priority tagged traffic by using four
priority queues for each port, with service schedules based on Weighted Round
Robin (WRR). Up to 8 separate traffic priorities are defined in IEEE 802.1p. The
default priority levels are assigned according to recommendations in the IEEE
802.1p standard as shown in the following table.
Queue
0
1
2
3
0
1
2
Priority
3
4
5
6
7
The priority levels recommended in the IEEE 802.1p standard for various net-
work applications are shown in the following table. However, you can map the
priority levels to the switch’s output queues in any way that benefits application
traffic for your own network.
Priority Level
Traffic Type
1
Background
2
(Spare)
0 (default)
Best Effort
3
Excellent Effort
4
Controlled Load
5
Video, less than 100 milliseconds latency and jitter
6
Voice, less than 10 milliseconds latency and jitter
7
Network Control
> Priority – CoS value. (Range: 0 to 7, where 7 is the highest priority)
> Traffic Class – Output queue buffer. (Range: 0 - 3, where 3 is the highest CoS
priority queue)
75
