Cisco 4500M User Manual

29-43
Software Configuration Guide—Release 12.2(25)EW
OL-6696-01
Chapter 29 Configuring QoS
Configuring QoS
Configuring Transmit Queues
The following sections describes how to configure the transmit queues:
• Mapping DSCP Values to Specific Transmit Queues, page 29-43
• Allocating Bandwidth Among Transmit Queues, page 29-44
• Configuring Traffic Shaping of Transmit Queues, page 29-44
• Configuring a High Priority Transmit Queue, page 29-45
Depending on the complexity of your network and your QoS solution, you might need to perform all of
the procedures in the next sections, but first you will need to make decisions about these characteristics:
• Which packets are assigned (by DSCP value) to each queue?
• What is the size of a transmit queue relative to other queues for a given port?
• How much of the available bandwidth is allotted to each queue?
• What is the maximum rate and burst of traffic that can be transmitted out of each transmit queue?
Mapping DSCP Values to Specific Transmit Queues
To map the DSCP values to a transmit queue, perform this task:
This example shows how to map DSCP values to transit queue 2.
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# qos map dscp 50
to tx-queue 2
Switch(config)# end
Switch#
This example shows how to verify the configuration.
Switch# show qos maps dscp tx-queue
DSCP-TxQueue Mapping Table (dscp = d1d2)
d1 :d2 0 1 2 3 4 5 6 7 8 9
-------------------------------------
0 : 02 02 02 01 01 01 01 01 01 01
1 : 01 01 01 01 01 01 02 02 02 02
2 : 02 02 02 02 02 02 02 02 02 02
3 : 02 02 03 03 03 03 03 03 03 03
4 : 03 03 03 03 03 03 03 03 04 04
5 : 04 04 04 04 04 04 04 04 04 04
6 : 04 04 04 04
Switch#
Command Purpose
Step 1
Switch(config)# [no] qos map dscp dscp-values to
tx-queue queue-id
Maps the DSCP values to the transit queue. dscp-list can
contain up 8 DSCP values. The queue-id can range from
1 to 4.
Use the no qos map dscp to tx-queue command to clear
the DSCP values from the transit queue.
Step 2
Switch(config)# end
Exits configuration mode.
Step 3
Switch# show qos maps dscp tx-queues
Verifies the configuration.

Cisco 4500M Specifications

General

Brand	Cisco
Model	4500M
Category	Network Router
Language	English