Advanced Configuration and Management Guide

USING THE CLI

To change the minimum guaranteed bandwidth percentages of the queues, enter commands such as the following. Note that this example uses the default queue names.

HP9300(config)# qos

profile qosp3 75 qosp2 10 qosp1 10 qosp0 5

 

Profile qosp3

:

PREMIUM

bandwidth requested

75%

calculated

75%

Profile qosp2

:

HIGH

bandwidth requested

10%

calculated

13%

Profile

qosp1

:

NORMAL

bandwidth

requested

10%

calculated

8%

Profile

qosp0

:

BEST-EFFORT bandwidth

requested

5%

calculated

4%

HP9300(config)# write memory

Notice that the CLI displays the percentages you request and the percentages the device can provide based on your request. The values are not always the same, as explained below.

Syntax: [no] qos profile <queue> <percentage> <queue> <percentage> <queue> <percentage> <queue> <percentage>

Each <queue> parameter specifies the name of a queue. You can specify the queues in any order on the command line, but you must specify each queue.

The <percentage> parameter specifies a number for the percentage of the device’s outbound bandwidth that are allocating to the queue.

NOTE: The percentages you enter must equal 100. Also, the percentage for the premium queue (the highest priority queue) must be at least 50.

If you enter percentages that are less than the minimum percentages supported for a queue, the CLI recalculates the percentages to fall within the supported minimums. Here is an example. In this example, the values entered for all but the best-effort queue (the lowest priority queue) are much lower than the minimum values supported for those queues.

HP9300(config)# qos

qosp3 1

qosp2 1 qosp1

2 qosp0 96

 

 

 

Warning - qosp3 bandwidth should be at least 50%

 

 

 

bandwidth scheduling mechanism: weighted priority

 

 

 

Profile qosp3

: PREMIUM

bandwidth

requested

1%

calculated

50%

Profile qosp2

: HIGH

bandwidth

requested

1%

calculated

25%

Profile qosp1

: NORMAL

bandwidth

requested

2%

calculated

13%

Profile qosp0

: BEST-EFFORT bandwidth

requested

96%

calculated

12%

This example shows the warning message that is displayed if you enter a value that is less than 50% for the premium queue. This example also shows the recalculations performed by the CLI. The CLI must normalize the values because the weighted fair queuing algorithm and queue hardware require specific minimum bandwidth allocations. You cannot configure the hardware to exceed the weighted fair queuing limitations.

The CLI normalizes the percentages you enter by increasing the percentages as needed for queues that have less than the minimum percentage, converting the percentages to weights (which the weighted fair queuing algorithm uses), and applying the following equations to calculate the percentages:

qosp3 = w3 / (w3 + 1)

qosp2 = (1 – qosp3) * w2 / (w2 + 1)

qosp1 = (1 – qosp3 – qosp2) * w1 / (w1 + 1)

qosp0 = 1 – qosp3 – qosp2 – qosp1

The value “w” stands for “weight”. Thus, these calculations determine the weights that the weighted fair queuing algorithm will use for each queue.

For results that do not differ widely from the percentages you enter, enter successively lower percentages for each queue, beginning with the premium queue. If you enter a higher percentage for a particular queue than you enter for a higher queue, the normalized results can vary widely from the percentages you enter.

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