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DSCP & QoS Reference

DSCP names, decimal, binary and typical use for every marking.

NameDSCPBinaryPrecTypical use
CS0 / Default (DE)00000000Best-effort
CS180010001Scavenger / low priority
AF11100010101Low-drop, class 1
AF12120011001Medium-drop, class 1
AF13140011101High-drop, class 1
CS2160100002Network management (OAM)
AF21180100102Low-drop, class 2
AF22200101002Medium-drop, class 2
AF23220101102High-drop, class 2
CS3240110003Call signaling
AF31260110103Low-drop, class 3
AF32280111003Medium-drop, class 3
AF33300111103High-drop, class 3
CS4321000004Real-time interactive / video
AF41341000104Low-drop, class 4
AF42361001004Medium-drop, class 4
AF43381001104High-drop, class 4
CS5401010005Broadcast video
EF461011105Voice / real-time (low latency, low jitter)
CS6481100006Network control (routing protocols)
CS7561110007Reserved / network control

DSCP is the upper 6 bits of the IPv4 ToS / IPv6 Traffic Class byte. EF (46) is the standard marking for voice; the AF classes carry drop-precedence within a queue; CS values map 1:1 to legacy IP precedence.

About this tool

Free DSCP and QoS values reference. A searchable table of every standard DSCP marking — CS0 to CS7, the AF classes and EF — with the decimal value, 6-bit binary, IP precedence and the traffic type each is typically used for. The lookup engineers reach for when designing or troubleshooting QoS. Everything runs entirely in your browser — nothing you type is sent to a server.

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