Internet Assigned Numbers Authority

Differentiated Services Field Codepoints (DSCP)

Last Updated
2023-07-21
Note
The Differentiated Services (Diffserv) architecture specifies use 
of the DS field in the IPv4 and IPv6 packet headers to carry one
of 64 distict differentiated services field codepoint (DSCP) values. 
The codepoint space is divided into three pools for the purpose of 
codepoint assignment and management: a pool of 32 codepoints (Pool 1)
to be assigned by Standards Action as defined in [RFC8126], a pool of 
16 codepoints (Pool 2) to be reserved for experimental or Local Use 
(EXP/LU) as defined in [RFC8126], and a pool of 16 codepoints (Pool 3) 
which are initially available for experimental or local use, but 
which should be preferentially utilized for standardized assignments 
if Pool 1 is ever exhausted. Pool 3 codepoints are now utilized for 
standardized assignments and are no longer available for experimental
or local use, as specified by [RFC8436]. The pools are defined in the 
following table (where 'x' refers to either '0' or '1').
  
Available Formats

XML

HTML

Plain text

Registries included below

Differentiated Services Field Codepoints (DSCP)

Reference
[RFC2474][RFC3260, Section 4]
Note
See [RFC9435] for considerations when assigning
a new codepoint from the DSCP registry.
    
Available Formats

CSV
Pool Codepoint Space Registration Procedure Note
1 xxxxx0 Standards Action
2 xxxx11 Experimental or Local Use Reserved for experimental or Local Use
3 xxxx01 Standards Action

DSCP Pool 1 Codepoints

Registration Procedure(s)
Standards Action
Reference
[RFC2474][RFC3260, Section 4]
Available Formats

CSV
Name Value (Binary) Value (Decimal) Reference
CS0 000000 0 [RFC2474]
CS1 001000 8 [RFC2474]
CS2 010000 16 [RFC2474]
CS3 011000 24 [RFC2474]
CS4 100000 32 [RFC2474]
CS5 101000 40 [RFC2474]
CS6 110000 48 [RFC2474]
CS7 111000 56 [RFC2474]
AF11 001010 10 [RFC2597]
AF12 001100 12 [RFC2597]
AF13 001110 14 [RFC2597]
AF21 010010 18 [RFC2597]
AF22 010100 20 [RFC2597]
AF23 010110 22 [RFC2597]
AF31 011010 26 [RFC2597]
AF32 011100 28 [RFC2597]
AF33 011110 30 [RFC2597]
AF41 100010 34 [RFC2597]
AF42 100100 36 [RFC2597]
AF43 100110 38 [RFC2597]
EF 101110 46 [RFC3246]
VOICE-ADMIT 101100 44 [RFC5865]

DSCP Pool 3 Codepoints

Registration Procedure(s)
Standards Action
Reference
[RFC2474][RFC3260, Section 4][RFC8436]
Available Formats

CSV
Name Value (Binary) Value (Decimal) Reference
LE 000001 1 [RFC8622]

ECN Field (Bits 6-7)

Registration Procedure(s)
RFC Required
Reference
[RFC3168]
Note
The registrations are identical for IPv4 and IPv6.
    
Available Formats

CSV
Binary Keyword Reference
00 Not-ECT (Not ECN-Capable Transport) [RFC3168]
01 ECT(1) (ECN-Capable Transport(1))[1] [RFC8311][RFC Errata 5399][RFC9331]
10 ECT(0) (ECN-Capable Transport(0)) [RFC3168]
11 CE (Congestion Experienced) [RFC3168]

Footnote

[1]
ECT(1) is for experimental use only [RFC8311, Section 4.2]