Cisco Systems WSC4500X16SFP Configuring the DSCP-to-CoS Map

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Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter27 Configuring Quality of Service
Configuring QoS
Note In the above policed-DSCP map, the marked-down DSCP values are shown in the body of the matrix.
The d1 column specifies the most-significant digit of the original DSCP; the d2 row specifies the
least-significant digit of the original DSCP. The intersection of the d1 and d2 values provides the
marked-down value. For example, an original DSCP value of 53 corresponds to a marked-down DSCP
value of 0.
Configuring the DSCP-to-CoS Map
You use the DSCP-to-CoS map to generate a CoS value.
Table27-5 shows the default DSCP-to-CoS map.
If the values above are not appropriate for your network, you need to modify them.
To modify the DSCP-to-CoS map, perform this task:
To return to the default map, use the no qos dscp to cos global configuration command.
This example shows how to map DSCP values 0, 8, 16, 24, 32, 40, 48, and 50 to CoS value 0 and to
display the map:
Switch# configure terminal
Switch(config)# qos map dscp 0 8 16 24 32 40 48 50 to cos 0
Switch(config)# end
Switch# show qos maps dscp cos
Table27-5 Default DSCP-to-CoS Map
DSCP value 0–7 8–15 16–23 24–31 32–39 40–47 48–55 56–63
CoS value 0123456 7
Command Purpose
Step1 Switch# configure terminal Enters global configuration mode.
Step2 Switch(config)# qos map dscp
dscp-list
to cos
cos
Modifies the DSCP-to-CoS map.
•For dscp-list, enter up to 8 DSCP values separated by spaces.
Then enter the to keyword.
•For cos, enter only one CoS value to which the DSCP values
correspond.
The DSCP range is 0 to 63; the CoS range is 0 to 7.
Step3 Switch(config)# end Returns to privileged EXEC mode.
Step4 Switch# show qos maps dscp to cos Verifies your entries.
Step5 Switch# copy running-config
startup-config
(Optional) Saves your entries in the configuration file.