Octet (computing)
This article needs additional citations for verification. (September 2008) |
octet | |
---|---|
Unit system | units derived from bit |
Unit of | digital information, data size |
Symbol | o |
In primary units of information | 1 o = 8 bits |
The octet is a
might be ambiguous, as the byte has historically been used for storage units of a variety of sizes.The term octad(e) for eight bits is no longer common.[1][2]
Definition
The international standard
Octets can be represented using number systems of varying bases such as the
The term octet (symbol: o
In
A variable-length sequence of octets, as in
Octad
Historically, in Western Europe, the term octad (or octade) was used to specifically denote eight bits,[2][1] a usage no longer common. Early examples of usage exist in British,[2] Dutch and German sources of the 1960s and 1970s, and throughout the documentation of Philips mainframe computers.[1] Similar terms are triad for a grouping of three bits and decade for ten bits.
Unit multiples
Unit multiples of the octet may be formed with
SI prefixes | |||
---|---|---|---|
1 kilooctet (ko) | = 103 octets | = 1000 octets | |
1 megaoctet (Mo) | = 106 octets | = 1000 ko | = 1000000 octets |
1 gigaoctet (Go) | = 109 octets | = 1000 Mo | = 1000000000 octets |
1 teraoctet (To) | = 1012 octets | = 1000 Go | = 1000000000000 octets |
1 petaoctet (Po) | = 1015 octets | = 1000 To | = 1000000000000000 octets |
1 exaoctet (Eo) | = 1018 octets | = 1000 Po | = 1000000000000000000 octets |
1 zettaoctet (Zo) | = 1021 octets | = 1000 Eo | = 1000000000000000000000 octets |
1 yottaoctet (Yo) | = 1024 octets | = 1000 Zo | = 1000000000000000000000000 octets |
Binary prefixes | |||
---|---|---|---|
1 kibioctet (Kio, also written Ko, as distinct from ko) | = 210 octets | = 1024 octets | |
1 mebioctet (Mio) | = 220 octets | = 1024 Kio | = 1048576 octets |
1 gibioctet (Gio) | = 230 octets | = 1024 Mio | = 1073741824 octets |
1 tebioctet (Tio) | = 240 octets | = 1024 Gio | = 1099511627776 octets |
1 pebioctet (Pio) | = 250 octets | = 1024 Tio | = 1125899906842624 octets |
1 exbioctet (Eio) | = 260 octets | = 1024 Pio | = 1152921504606846976 octets |
1 zebioctet (Zio) | = 270 octets | = 1024 Eio | = 1180591620717411303424 octets |
1 yobioctet (Yio) | = 280 octets | = 1024 Zio | = 1208925819614629174706176 octets |
Use in Internet Protocol addresses
The octet is used in representations of Internet Protocol computer network addresses.[4] An
An IPv6 address consists of sixteen octets, displayed in hexadecimal representation (two hexits per octet), using a colon character (:) after each pair of octets (16 bits are also known as hextet) for readability, such as 2001:0db8:0000:0000:0123:4567:89ab:cdef.[5]
See also
Notes
- Intel convention.
References
- ^ a b c "Philips - Philips Data Systems' product range - April 1971" (PDF). Philips. 1971. Archived from the original (PDF) on 2016-03-04. Retrieved 2016-10-03.
- ^ ISBN 1483122107. 978-1483122106.
- Cie. Bullin France in 1965-66, I insisted that "byte" be deprecated in favor of "octet". […]
- ^ Kozierok, Charles M. (2005-09-20) [2001]. "The TCP/IP Guide - Binary Information and Representation: Bits, Bytes, Nibbles, Octets and Characters - Byte versus Octet". 3.0. Archived from the original on 2017-04-03. Retrieved 2017-04-03.
- .
External links
- The dictionary definition of octet at Wiktionary