Differentiated Services Codepoint (DSCP) mapping

A codepoint must have an 802.1p priority assignment (0 - 7) before you can configure a policy for prioritizing packets. If a codepoint you want to use shows No-override in the Priority column of the DSCP map (show qos dscp-map), then you must assign a 0 - 7 priority before proceeding (qos dscp-map priority command).

The DSCP Policy Table associates an 802.1p priority with a specific ToS byte codepoint in an IPv4 packet. This enables you to set a LAN policy that operates independently of 802.1Q VLAN-tagging.

A partial display of the default DSCP Policy Table is show in the table below.

You can use the following command to list the current DSCP Policy table.

Syntax:


show qos dscp-map

Displays the DSCP Policy Table.

Partial display from the default DSCP Policy Table

DSCP CodePoint

DSCP Value

802.1p tag

DSCP Policy name

000000

0

0

cs0

000001

1

0

 

000010

2

0

 

000011

3

0

 

000100

4

0

 

000101

5

0

 

000110

6

0

 

000111

7

0

 

001000

8

1

cs1

001001

9

1

 

001010

10

1

af11

001011

11

1

 

001100

12

1

af12

001101

13

1

 

001110

14

1

af13

001111

15

1

 

010000

16

2

cs2

010001

17

2

 

010010

18

2

af21

010011

19

2