Differentiated Services Field Codepoints (DSCP) 2025-09-19 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'). 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 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 RFC3260, Section 4 Standards Action LE 000001 1 NQB 101101 45 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