Patton electronic 2160 user manual QoS Vlan Tag Priority Table

Model 2160 Series User Manual 4 • Web configuration

VLAN Tag Priority Table. Select a packet with an assigned priority to correspond with each queue.

Figure 33. QoS - VLAN Tag Priority Table

Configuration Example. As an example, you can set the Model 2160 to 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 to provide each queue before moving on to the next queue. This prevents the head-of-line blocking that can occur with strict priority queuing.

Table 10. WRR Scheduling Configuration Example Values

Queue	0	1	2	3
Type 1	WRR	WRR	WRR	WRR
Weight	1	2	4	8

For this example, set up the WRR (Type 1) to share bandwidth by using scheduling weights 1, 2, 4 and 8 for queues 0 through 3 respectively.

Priority	0	1	2	3	4	5	6	7
Queue	1	0	0	1	2	2	3	3

According to the two tables above, the QoS values map to the Egress Queues as follows:

		Queue		0	1	2	3
		Weight		2	15	7	8
Priority	0		1	2	3	4	5	6	7
Queue	0		0	2	2	3	3	1	1

This example displays that:

•Packets with priority 0 and priority 1 go to Queue 0.

•Packets with priority 2 and priority 3 go to Queue 2.

•Packets with priority 4 and priority 5 go to Queue 3.

•Packets with priority 6 and priority 7 go to Queue 1.

•When, data flow traffic is jammed:

-Queue 1 Packets will go first because weight is equal to 15 (the biggest value).

-Queue 3 Packets will go next because the weight is the second largest value.

-Queue 2 Packets are the next after Queue 3 Packets.

-Queue 0 Packets are the last one to send.

Advanced Configuration Options 55