DELL N3000 User Manual

Configuring Data Center Bridging Features

To understand the first level of scheduling, consider Table 29-1. Assume that 

we have eight ingress ports, each one receiving line rate traffic with one dot1p 

priority each. The table shows the mapping of dot1p priorities to the cos-

queues, the min-bandwidth settings, and scheduler modes.

In this scenario, the input to the TCGs is as follows:

• All of the pri0 traffic reaches the TCG0. This is because there is no other 

priority contending for the same TCG. The minimum bandwidth setting 

on the CoS queue does not have any effect.

• TCG1 would receive 10% each of pri1 and pri3 and 80% of pri2. Even 

though strict mode is enabled for pri2, the minimum bandwidth of pri1 

and pri3 is first honored before applying strict mode on pri2.

• TCG2 receives 25% each of pri4 and pri5 traffic and the other 50% can be 

of pri6 or pri7. This is based on the minimum bandwidth ratio, which is 

15:15:30, converted to 1:1:2. 

0

0

10

WRR

0

100% of pri0

1

1

10

WRR

1

10% each of

2

2

10

Strict

1

pri1, pri3 and 

3

3

10

WRR

1

80% of pri2

4

4

15

WRR

2

25% each

5

5

15

WRR

2

of pri4, pri5

6

6

30

WRR

2

and 50% of 

7

6

 –

 –

 –

pri6/pri7