Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring QoS
Configuring Standard QoS
Beginning in privileged EXEC mode, follow these steps to allocate bandwidth between the ingress
queues. This procedure is optional.
To return to the default setting, use the no mls qos srr-queue input bandwidth global configuration
command.
This example shows how to assign the ingress bandwidth to the queues. Priority queueing is disabled,
and the shared bandwidth ratio allocated to queue 1 is 25/(25+75) and to queue 2 is 75/(25+75):
Switch(config)# mls qos srr-queue input priority-queue 2 bandwidth 0
Switch(config)#
mls qos srr-queue input bandwidth 25 75
Configuring the Ingress Priority Queue
You should use the priority queue only for traffic that needs to be expedited (for example, voice traffic,
which needs minimum delay and jitter).
The priority queue is guaranteed part of the bandwidth to reduce the delay and jitter under heavy network
traffic on an oversubscribed ring (when there is more traffic than the backplane can carry, and the queues
are full and dropping frames).
SRR services the priority queue for its configured weight as specified by the bandwidth keyword in the
mls qos srr-queue input priority-queue queue-id bandwidth weight global configuration command.
Then, SRR shares the remaining bandwidth with both ingress queues and services them as specified by
the weights configured with the
mls qos srr-queue input bandwidth weight1 weight2 global
configuration command.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 mls qos srr-queue input bandwidth
weight1 weight2
Assign shared round robin weights to the ingress queues.
The default setting for weight1 and weight2 is 4 (1/2 of the bandwidth is
equally shared between the two queues).
For weight1 and weight2 , the range is 1 to 100. Separate each value with
a space.
SRR services the priority queue for its configured weight as specified by
the
bandwidth keyword in the mls qos srr-queue input priority-queue
queue-id bandwidth weight global configuration command. Then, SRR
shares the remaining bandwidth with both ingress queues and services
them as specified by the weights configured with the
mls qos srr-queue
input bandwidth weight1 weight2 global configuration command. For
more information, see the “Configuring the Ingress Priority Queue”
section on page 1-82 .
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.