Differentiated Services Field Codepoints (DSCP)

Last Updated

2024-11-15

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

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HTML
Plain text

Registries included below

• Differentiated Services Field Codepoints (DSCP)
  • DSCP Pool 1 Codepoints
  • DSCP Pool 3 Codepoints
• ECN Field (Bits 6-7)

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]
NQB (TEMPORARY - registered 2024-11-15, expires 2025-11-15)	101101	45	[draft-ietf-tsvwg-nqb-27]

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

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