Cisco Systems 4500 Configuring DSCP Maps

37-53
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 37 Configuring Quality of Service Configuring QoS on Supervisor Engines II-Plus, II+10GE, IV, V, V-10GE, 4924, 4948, and 4948-10GE
Configuring a High Priority Transmit Queue
To configure transmit queue 3 at a higher priority, perform this task:
This example shows how to configure transmit queue 3 to high priority:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet 1/1
Switch(config-if-tx-queue)# tx-queue 3
Switch(config-if-tx-queue)# priority high
Switch(config-if)# end
Switch#
Configuring DSCP Maps
The following sections describes how to configure the DSCP maps. It contains this configuration
information:
• Configuring the CoS-to-DSCP Map, page 37-53
• Configuring the Policed-DSCP Map, page 37-54
• Configuring the DSCP-to-CoS Map, page 37-55
All the maps are globally defined and are applied to all ports.
Configuring the CoS-to-DSCP Map
You use the CoS-to-DSCP map to map CoS values in incoming packets to a DSCP value that QoS uses
internally to represent the priority of the traffic.
Table 37-3 shows the default CoS-to-DSCP map.
If these values are not appropriate for your network, you need to modify them.
Command Purpose
Step 1 Switch(config)# interface {fastethernet |
gigabitethernet} slot/interface Selects the interface to configure.
Step 2 Switch(config-if)# tx-queue 3 Selects transmit queue 3 to configure.
Step 3 Switch(config-if)# [no] priority high Sets the transmit queue to high priority.
Use the no keyword to clear the transmit queue priority.
Step 4 Switch(config-if)# end Exits configuration mode.
Step 5 Switch# show qos interface Verifies the configuration.
Table 37-3 Default CoS-to-DSCP Map
CoS value 012 345 6 7
DSCP value 0 8 16 24 32 40 48 56