The OCTET is a unit of digital information in computing and telecommunications that consists of eight bits . The term is often used when the term byte 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 Definition
* 1.1 Octad
* 2 Unit multiples * 3 Use in internet protocol addresses * 4 References * 5 External links
A variable-length sequence of octets, as in Abstract Syntax Notation One (ASN.1), is referred to as an octet string.
The international standard IEC 60027-2, chapter 3.8.2, states that a byte is an octet of bits. However, the unit byte has historically been platform -dependent and has represented various storage sizes in the history of computing. Due to the influence of several major computer architectures and product lines, the byte became overwhelmingly associated with eight bits. This meaning of byte is codified in such standards as ISO/IEC 80000-13 . While byte and octet are often used synonymously, those working with certain legacy systems are careful to avoid ambiguity.
Octets can be represented using number systems of varying bases such as the hexadecimal , decimal , or octal number systems . The binary value of all eight bits set (or activated) is 7002255000000000000♠111111112, equal to the hexadecimal value 7002255000000000000♠FF16, the decimal value 7002255000000000000♠25510, and the octal value 7002255000000000000♠3778. One octet can be used to represent decimal values ranging from 0 to 255.
The term octet (symbol: o) is often used when the use of byte might
be ambiguous. It is frequently used in the
Request for Comments (RFC)
publications of the
Internet Engineering Task Force
Historically, in Western Europe, the term octad (or octade) was used
to specifically denote 8 bits; however, this usage is no longer
common. Early examples of usage exist in British, Dutch and German
sources of the 1960s and 1970s, and throughout the documentation of
Unit multiples of the octet may be formed with SI prefixes and binary prefixes (power of 2 prefixes) as standardized by the International Electrotechnical Commission during 1998.
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
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 to represent
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