Differentiated Services Field Codepoints (DSCP)
Differentiated Services Field Codepoints (DSCP)
2023-07-21
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 , a pool of
16 codepoints (Pool 2) to be reserved for experimental or Local Use
(EXP/LU) as defined in , 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 . The pools are defined in the
following table (where 'x' refers to either '0' or '1').
Differentiated Services Field Codepoints (DSCP)
RFC3260, Section 4
See for considerations when assigning
a new codepoint from the DSCP registry.
1
xxxxx0
Standards Action
2
xxxx11
Experimental or Local Use
Reserved for experimental or Local Use
3
xxxx01
Standards Action
DSCP Pool 1 Codepoints
RFC3260, Section 4
Standards Action
CS0
000000
0
CS1
001000
8
CS2
010000
16
CS3
011000
24
CS4
100000
32
CS5
101000
40
CS6
110000
48
CS7
111000
56
AF11
001010
10
AF12
001100
12
AF13
001110
14
AF21
010010
18
AF22
010100
20
AF23
010110
22
AF31
011010
26
AF32
011100
28
AF33
011110
30
AF41
100010
34
AF42
100100
36
AF43
100110
38
EF
101110
46
VOICE-ADMIT
101100
44
DSCP Pool 3 Codepoints
RFC3260, Section 4
Standards Action
LE
000001
1
ECN Field (Bits 6-7)
RFC Required
The registrations are identical for IPv4 and IPv6.
00
Not-ECT (Not ECN-Capable Transport)
01
ECT(1) (ECN-Capable Transport(1))
10
ECT(0) (ECN-Capable Transport(0))
11
CE (Congestion Experienced)
ECT(1) is for experimental use only RFC8311, Section 4.2