Cisco Nexus 1000V Quality of Service Configuration Guide, Release 4.2(1)SV1(5.1)
DSCP and Precedence Values
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Table of Contents

DSCP and Precedence Values

Commonly Used DSCP Values

IP Precedence Values

DSCP and Precedence Values

This appendix provides the DSCP and precedence values used in QoS class maps and policy maps.

Commonly Used DSCP Values

Unless noted as a restriction, you can mark both incoming and outgoing packets.

Table 7-1 lists the commonly used DSCP values that are described in RFC 2475.

 

Table 7-1 Commonly Used DSCP Values

DSCP Value
Decimal Value
Meaning
Drop Probability
Equivalent IP Precedence Value

101 110

46

High Priority

Expedited Forwarding (EF)

N/A

101 - Critical

000 000

0

Best Effort

N/A

000 - Routine

001 010

10

AF11

Low

001 - Priority

001 100

12

AF12

Medium

001 - Priority

001 110

14

AF13

High

001 - Priority

010 010

18

AF21

Low

010 - Immediate

010 100

20

AF22

Medium

010 - Immediate

010 110

22

AF23

High

010 - Immediate

011 010

26

AF31

Low

011 - Flash

011 100

28

AF32

Medium

011 - Flash

011 110

30

AF33

High

011 - Flash

100 010

34

AF41

Low

100 - Flash Override

100 100

36

AF42

Medium

100 - Flash Override

100 110

38

AF43

High

100 - Flash Override

001 000

8

CS1

 

1

010 000

16

CS2

 

2

011 000

24

CS3

 

3

100 000

32

CS4

 

4

101 000

40

CS5

 

5

110 000

48

CS6

 

6

111 000

56

CS7

 

7

000 000

0

Default

 

 

101 110

46

EF

 

 

IP Precedence Values

Table 7-2 lists the RFC 791 precedence values from least to most important.

 

Table 7-2 Precedence Values

Value
Description

000 (0)

Routine or Best Effort

001 (1)

Priority

010 (2)

Immediate

011 (3)

Flash (mainly used for voice signaling or for video)

100 (4)

Flash Override

101 (5)

Critical (mainly used for voice RTP)

110 (6)

Internet

111 (7)

Network