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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 29 Configuring QoS
Configuring Standard QoS
Configuring Egress Queues on Gigabit-Capable Ethernet Ports
This section describes how to configure the egress queues on Gigabit-capable Ethernet ports. For
information on configuring 10/100 Ethernet ports, see
“Configuring Egress Queues on 10/100 Ethernet
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 (limit) is allotted to each queue?
•
What drop percentage thresholds apply to each queue and which DSCP values map to each
threshold?
•
Is one of the queues the expedite (high-priority) egress queue?
•
How much of the available bandwidth is allotted to each queue?
These sections contain this configuration information:
•
Mapping CoS Values to Select Egress Queues, page 29-57
•
Configuring the Egress Queue Size Ratios, page 29-58
•
Configuring Tail-Drop Threshold Percentages, page 29-59
•
Configuring WRED Drop Thresholds Percentages, page 29-61
•
Configuring the Egress Expedite Queue, page 29-62
•
Allocating Bandwidth among Egress Queues, page 29-63
Mapping CoS Values to Select Egress Queues
Beginning in privileged EXEC mode, follow these steps to map CoS ingress values to select one of the
egress queues:
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
mls qos
Enable QoS on the switch.
Step 3
interface interface-id
Enter interface configuration mode, and specify the egress
Gigabit-capable Ethernet interface.