Configuring egress queue characteristics – Dell POWEREDGE M1000E User Manual

Page 856

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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide

OL-13270-03

Chapter 36 Configuring QoS

Configuring Standard QoS

Beginning in privileged EXEC mode, follow these steps to configure the priority queue. This procedure
is optional.

To return to the default setting, use the no mls qos srr-queue input priority-queue queue-id global
configuration command. To disable priority queueing, set the bandwidth weight to 0, for example, mls
qos srr-queue input priority-queue
queue-id bandwidth 0.

This example shows how to assign the ingress bandwidths to the queues. Queue 1 is the priority queue
with 10 percent of the bandwidth allocated to it. The bandwidth ratios allocated to queues 1 and 2 is
4/(4+4). SRR services queue 1 (the priority queue) first for its configured 10 percent bandwidth. Then
SRR equally shares the remaining 90 percent of the bandwidth between queues 1 and 2 by allocating 45
percent to each queue:

Switch(config)# mls qos srr-queue input priority-queue 1 bandwidth 10

Switch(config)# mls qos srr-queue input bandwidth 4 4

Configuring Egress Queue Characteristics

Depending on the complexity of your network and your QoS solution, you might need to perform all of
the tasks in the next sections. You will need to make decisions about these characteristics:

Which packets are mapped by DSCP or CoS value to each queue and threshold ID?

What drop percentage thresholds apply to the queue-set (four egress queues per port), and how much
reserved and maximum memory is needed for the traffic type?

How much of the fixed buffer space is allocated to the queue-set?

Does the bandwidth of the port need to be rate limited?

How often should the egress queues be serviced and which technique (shaped, shared, or both)
should be used?

Command

Purpose

Step 1

configure terminal

Enter global configuration mode.

Step 2

mls qos srr-queue input
priority-queue
queue-id bandwidth
weight

Assign a queue as the priority queue and guarantee bandwidth on the stack
or internal ring if the ring is congested.

By default, the priority queue is queue 2, and 10 percent of the bandwidth
is allocated to it.

For queue-id, the range is 1 to 2.

For bandwidth weight, assign the bandwidth percentage of the stack
or internal ring. The range is 0 to 40. The amount of bandwidth that
can be guaranteed is restricted because a large value affects the entire
ring and can degrade the switch or stack performance.

Step 3

end

Return to privileged EXEC mode.

Step 4

show mls qos interface queueing

or

show mls qos input-queue

Verify your entries.

Step 5

copy running-config startup-config

(Optional) Save your entries in the configuration file.

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