20-51
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 20 Configuring QoS
Configuring QoS
To return to the default bandwidth setting, use the no wrr-queue bandwidth interface configuration
command.
This example shows how to configure the weight ratio of the WRR scheduler running on the egress
queues. In this example, four queues are used (no expedite queue), and the ratio of the bandwidth
allocated for each queue is 1/(1+2+3+4), 2/(1+2+3+4), 3/(1+2+3+4), and 4/(1+2+3+4), which is 1/10,
1/5, 3/10, and 2/5 for queues 1, 2, 3, and 4.
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# wrr-queue bandwidth 1 2 3 4
Configuring Egress Queues on 10/100 Ethernet Ports
This section describes how to configure the egress queues on 10/100 Ethernet ports. For information on
configuring Gigabit-capable Ethernet ports, see the
“Configuring Egress Queues on Gigabit-Capable
Ethernet Ports” section on page 20-44
.
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 assigned (by CoS value) to each queue?
•
How much of the available buffer space is allotted to each queue?
•
Is one of the queues the expedite (high-priority) egress queue?
•
How much of the available bandwidth is allotted to each queue?
Step 4
wrr-queue bandwidth weight1 weight2
weight3 weight4
Assign WRR weights to the egress queues.
By default, all the weights are set to 25 (1/4 of the bandwidth is allocated
to each queue).
For weight1 weight2 weight3 weight4, enter the ratio, which determines
the ratio of the frequency in which the WRR scheduler drops packets.
Separate each value with a space. The range is 0 to 65536.
All four queues participate in the WRR unless the expedite queue
(queue 4) is enabled, in which case weight4 is ignored (not used in the
ratio calculation). The expedite queue is a strict-priority queue, and it
is serviced until empty before the other queues are serviced.
A weight of 0 means no bandwidth is allocated for that queue, and the
available bandwidth is shared among the remaining queues.
Step 5
end
Return to privileged EXEC mode.
Step 6
show mls qos interface queueing
Verify your entries.
Step 7
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose