Cisco 4500M

29-47
Software Configuration Guide—Release 12.2(25)EW
OL-6696-01
Chapter 29 Configuring QoS
Configuring QoS
To modify the CoS-to-DSCP map, perform this task:
To return to the default map, use the no qos dscp policed global configuration command.
This example shows how to map DSCP 50 to 57 to a marked-down DSCP value of 0:
Switch# configure terminal
Switch(config)# qos map dscp policed 50 51 52 53 54 55 56 57 to dscp 0
Switch(config)# end
Switch# show qos maps dscp policed
Policed-dscp map:
d1 : d2 0 1 2 3 4 5 6 7 8 9
---------------------------------------
0 : 00 01 02 03 04 05 06 07 08 09
1 : 10 11 12 13 14 15 16 17 18 19
2 : 20 21 22 23 24 25 26 27 28 29
3 : 30 31 32 33 34 35 36 37 38 39
4 : 40 41 42 43 44 45 46 47 48 49
5 : 00 00 00 00 00 00 00 00 58 59
6 : 60 61 62 63
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.
Table 29-5 shows the default DSCP-to-CoS map.
If the values above are not appropriate for your network, you need to modify them.
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(config)# qos map dscp policed
dscp-list to dscp mark-down-dscp
Modifies the policed-DSCP map.
• For dscp-list, enter up to 8 DSCP values separated by
spaces. Then enter the to keyword.
• For mark-down-dscp, enter the corresponding policed
(marked down) DSCP value.
Step 3
Switch(config)# end
Returns to privileged EXEC mode.
Step 4
Switch# show qos maps dscp policed
Verifies your entries.
Step 5
Switch# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Table 29-5 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 01234 5 6 7