Configuring The Dscp-To-Cos Map - Cisco Catalyst 2950 Software Configuration Manual

Configuring QoS
Table 24-3 Default CoS-to-DSCP Map
CoS value
DSCP value
If these values are not appropriate for your network, you need to modify them.
Beginning in privileged EXEC mode, follow these steps to modify the CoS-to-DSCP map:
Command
Step 1
configure terminal
Step 2 mls qos map cos-dscp dscp1...dscp8
Step 3 end
Step 4 show mls qos maps cos-dscp
Step 5
copy running-config startup-config
To return to the default map, use the no mls qos map cos-dscp global configuration command.
This example shows how to modify and display the CoS-to-DSCP map:
Switch# configure terminal
Switch(config)#mls qos map cos-dscp 8 8 8 8 24 32 56 56
Switch(config)# end
Switch# show mls qos maps cos-dscp
Cos-dscp map:

Configuring the DSCP-to-CoS Map

You use the DSCP-to-CoS map to map DSCP values in incoming packets to a CoS value, which is used
to select one of the four egress queues.
The Catalyst 2950 switches support these DSCP values: 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and
56.
Table 24-4
Table 24-4 Default DSCP-to-CoS Map
DSCP values 0
CoS values
If these values are not appropriate for your network, you need to modify them.
Catalyst 2950 Desktop Switch Software Configuration Guide
24-22
0 1
0 8
Purpose
Enter global configuration mode.
Modify the CoS-to-DSCP map.
For dscp1...dscp8, enter 8 DSCP values that correspond to CoS values 0
to 7. Separate each DSCP value with a space.
The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48,
and 56.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
cos: 0 1 2 3 4
--------------------------------
dscp: 8 8 8 8 24 32 56 56
shows the default DSCP-to-CoS map.
8, 10
0 1
2 3 4
16 24 32
5 6 7
16, 18 24, 26 32, 34
2 3 4
Chapter 24
5 6 7
40 48 56
40, 46 48
5 6
Configuring QoS
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