Numbers

10Base-2

A specification from the Institute of Electrical and Electronics Engineers for local-area

network (LAN) cable and related equipment. 10Base-2 LANs transmit data at 10

megabits per second over thin Ethernet coaxial cabling spanning distances of up to

185 meters.

10Base-5

A local-area network (LAN) cable specification from the Institute of Electrical and

Electronics Engineers. 10Base-5 LANs transmit data at 10 megabits per second over

thick Ethernet coaxial cabling spanning distances of up to 500 meters.

10Base-F

A local-area network (LAN) physical-media specification from the Institute of

Electrical and Electronics Engineers. 10Base-F LANs transmit data at 10 megabits per

second over fiber-optic cable.

10Base-FL

A version of the 10Base-F specification supporting fiber-optic links (asynchronous

connections linked by Ethernet repeaters). See 10Base-F.

10Base-T

A broadly used standard for Ethernet local-area network (LAN) wiring and related

equipment. As specified by the Institute of Electrical and Electronics Engineers,

10Base-T LANs transmit data at 10 megabits per second over unshielded twisted-pair

(UTP) wires (similar to the wiring commonly used for indoor phone lines). See

Ethernet and UTP.

10Base-x series

A series of Institute of Electrical and Electronics Engineers (IEEE) specifications for

Ethernet local-area network (LAN) cabling and related equipment, supporting speeds

of up to 10 megabits per second (Mbps). Several common standards in this series

are defined in separate entries (see 10Base-2, 10Base-5, 10Base-F, 10Base-FL

and 10Base-T). The "10Base" prefix stands for "10 Mbps baseband" (see

baseband); similar IEEE specifications for faster LANs use "100Base" and

"1000Base" prefixes (see 100Base-x series and 1000Base-x series). The letter or

numeral at the end of each specification name denotes the type of cable — "F" for

fiber, "T" for twisted-pair, and numerals for various types of coaxial cable. See

Ethernet.

100Base-F

A physical-media specification from the Institute for Electrical and Electronics

Engineers, supporting Fast Ethernet local-area networks operating at 100 megabits

per second over fiber-optic cable. See Fast Ethernet and fiber-optic.

100Base-FX

A version of the 100Base-F fiber-optic cable standard supporting half- and full-duplex

operation. See 100Base-F.

100Base-T

A widely used standard for Fast Ethernet local-area network (LAN) wiring and related

equipment. As specified by the Institute of Electrical and Electronics Engineers,

100Base-T LANs transmit data at 100 megabits per second over unshielded twistedpair

(UTP) copper cable. See Fast Ethernet and UTP.

100Base-TX

A version of the 100Base-T specification supporting both full-duplex and half-duplex

transmission over two pairs of unshielded twisted-pair wires. See 100Base-T.

100Base-x series

A series of Institute of Electrical and Electronics Engineers (IEEE) specifications for

Fast Ethernet local-area network (LAN) cabling and related equipment (see Fast

Ethernet). Several common standards in this series are defined in separate entries

(see 100Base-F, 100Base-FX, 100Base-T and 100Base-TX). These specifications

are similar to those of the IEEE's 10Base-x series, but are designed for higher-speed

transmission — up to 100 megabits per second (Mbps), rather than 10 Mbps (see

10Base-x series).

100VG-AnyLAN

An Institute for Electrical and Electronics Engineers (IEEE) standard for Ethernet and

token ring local-area networks (LANs) transmitting at 100 megabit per second.

(Originally dubbed "100Base-VG" as an IEEE Ethernet specification, it was renamed

after token ring compatibility was added). In the 1990s, 100VG-AnyLAN was

promoted heavily by Hewlett-Packard, among other vendors, as a technically

superior LAN alternative to 100Base-T with Fast Ethernet, but it ultimately failed to

win out in the marketplace. See 100Base-T and Fast Ethernet.

1000Base-LX

An physical network specification for long-wavelength laser transmission over fiberoptic

cable, defined by the Institute for Electrical and Electronics Engineers.

1000Base-LX supports Ethernet transmission at 1,000 megabits per second over

links up to 10 kilometers long, depending on the type of cable used. See Gigabit

Ethernet.

1000Base-SX

A physical network standard for short-wavelength laser transmission over fiber-optic

cable, defined by the Institute for Electrical and Electronics Engineers. 1000Base-SX

supports Ethernet transmission at 1,000 megabits per second over links up to 500

meters long, depending on the type of fiber-optic cable used. See Gigabit Ethernet.

1000Base-T

An Institute for Electrical and Electronics Engineers standard for copper cabling and

related equipment used in Gigabit Ethernet networks. 1000Base-T supports

transmission at 1,000 megabits per second over unshielded twisted pair (UTP) cable.

See UTP and Gigabit Ethernet.

1000Base-x

A series of Gigabit Ethernet network cable and equipment specifications from

Institute for Electrical and Electronics Engineers (IEEE). For definitions of some of the

better-known standards in this series, see 1000Base-LX, 1000Base-SX and

1000Base-T. These standards are similar to those of the IEEE's 10Base-x and

100Base-x series, but support data transmission at higher speeds — up to 1,000

megabits per second. See 10Base-x series, 100Base-x series and Gigabit

Ethernet.

1394

A high speed serial bus specification from the Institute of Electrical and Electronics

Engineers. See FireWire.

23B+D

An abbreviation for the Integrated Services Digital Network (ISDN) Primary Rate

Interface (PRI), composed of 23 bearer (B) channels and one data (D) channel. See

ISDN and PRI.

24x7 (24 hours a day, seven days a week)

Continuous, round-the clock availability of a system or service.

2B+D

An abbreviation for the ISDN Basic Rate Interface (BRI), composed of two bearer (B)

channels and one data (D) channel. See ISDN and BRI.

2PC (two-phase commit)

A method for coordinating a single transaction across two or more database

management systems (DBMSs) or other resource managers. 2PC guarantees the

logical integrity of data by ensuring that transaction updates are either finalized in all

participating databases or fully backed out of all of them (that is, the update occurs

"everywhere or nowhere"). 2PC is a required component of distributed databases,

and is implemented in transaction management software that may be part of a

DBMS, online transaction processing (OLTP) monitor or front-end application tool.

See DBMS and OLTP.

3270

An interactive communications terminal used to communicate with an IBM

mainframe or compatible system.

3380

An IBM direct-access storage device family introduced in 1980.

3390

An IBM family of storage products introduced in 1989.

3480

A half-inch tape cartridge format introduced by IBM in 1984.

3990

An IBM storage controller family introduced in 1987, supporting a wide range of

devices, including 3380, 3390 and Random Access Method of Accounting and Control

(RAMAC) systems. See 3380, 3390 and RAMAC.

3-D visualization

The use of interactive graphics to represent and manipulate high-volume,

multidimensional data as graphical objects with a wide range of characteristics

(including x/y/z axes, size, color, shape or movement).

3-D Web

Web site technology that provides a virtual, three-dimensional "space" for visitors to

explore (for example, through the use of Virtual Reality Modeling Language; see

VRML).

3G (third generation)

The term used to refer to the next generation of wireless communications

technology, the "first generation" having been analog cellular, and the "second

generation" being today's digital cellular networks. An initiative of the International

Telecommunication Union and regional standards bodies, 3G aims to provide

universal, high-speed (up to four megabits per second), high-bandwidth wireless

services supporting a variety of advanced applications. See UMTS, IMT-2000 and

EDGE.

3GPP (3rd Generation Partnership Project)

A collaboration agreement, established in 1998 among several telecommunications

standards bodies, to produce a series of technical specifications and standards for

third-generation (3G) wireless communications. See 3G.

3GL (third-generation language)

A high-level programming language — such as FORTRAN, COBOL, BASIC or C — that

compiles to machine language.

3PL (third-party logistics)

A type of service provider that offers advanced logistics services, such as

transportation management, inventory maintenance and logistical modeling.

3rd Generation Partnership Project (see 3GPP)

4GL (fourth-generation language)

A high-level language suitable for end-user or programmer data access and capable

of reasonably complex data manipulation. A common example is Microsoft's Visual

Basic. 4GLs includes two categories of software development tools: application

generators for production applications, and information generators for decision

support applications. 4GLs are relatively nonprocedural and easier to use than thirdgeneration

languages (3GLs), but are less powerful and more wasteful of computer

resources. See 3GL.

802.1d

An Institute of Electrical and Electronics Engineers specification for local-area

network spanning trees. See spanning tree.

802.1p

An Institute of Electrical and Electronics Engineers specification for priority queues

within local-area networks.

802.1q

A virtual local-area network (VLAN) specification from the Institute of Electrical and

Electronics Engineers. See VLAN.

802.1x

A port-based authentication protocol from the Institute of Electrical and Electronics

Engineers.

802.11

A series of standards issued by the Institute of Electrical and Electronics Engineers

for wireless local-area networks (WLANs). Various specifications cover WLAN

transmission speeds from one megabit per second (Mbps) to 54 Mbps. There are

three main physical-layer standards — see 802.11a, 802.11b and 802.11g.

802.11a

An Institute of Electrical and Electronics Engineers standard for the physical layer of

wireless local-area networks (WLANs) operating in the five-gigahertz radio band. It

has eight radio channels, each with a maximum link rate of 54 megabits per second;

however, maximum user throughput will be about half this, and the throughput is

shared by all users of the same radio channel. Frequency bands allowed for 802.11a

(also called Wi-Fi5) differ in different parts of the world. See Wi-Fi5 and WLAN.

802.11b

A standard for the physical layer of wireless local-area networks (WLANs) operating

at 2.4 gigahertz, from the Institute of Electrical and Electronics Engineers. Also called

Wi-Fi, 802.11b specifies three radio channels, each with a maximum link rate of 11

megabits per second; however, maximum user throughput will be about half this,

and the throughput is shared by all users of the same radio channel. See Wi-Fi and

WLAN.

802.11g

An Institute of Electrical and Electronics Engineers physical-layer standard for

wireless local-area networks operating at 2.4 gigahertz. It provides three available

radio channels, each with a maximum link rate of 54 megabits per second. Support

for complementary-code-keying modulation makes 802.11g backwardly compatible

with 802.11b. The addition of further modulation schemes, such as orthogonal

frequency division multiplexing (see OFDM), achieves higher link rates. See 802.11b

and OFDM.

802.12

A competing standard to the Institute of Electrical and Electronics Engineers' (IEEE's)

more widespread Ethernet (802.3) specification for local-area networks. Introduced

in the 1990s in conjunction with the 100VG-AnyLAN standard, IEEE 802.12 networks

use a "demand priority" access control mechanism, and can transport both Ethernet

and token ring data frames. See 100VG-AnyLAN.

802.15

A Institute of Electrical and Electronics Engineers working group addressing

standardization of wireless personal-area networks (PANs). See PAN.

802.15.4

A draft standard for low-data-rate, low-power-consumption wireless networking in

the 2.4-gigahertz radio band. With data rates of less than 220 kilobits per second

over 75 meters, 802.15.4 (dubbed "ZigBee" by the vendor group that promotes it) is

suitable for many automation and remote-control applications. (See ZigBee and

ZigBee Alliance .)

802.3

A protocol specification for Ethernet local-area networks (LANs) from the Institute of

Electrical and Electronics Engineers (IEEE). 802.3 and the IEEE's 10Base-x series of

cable specifications are the dominant standards used in today's LANs operating at 10

megabits per second (see 10Base-x series). Several extensions to the 802.3

standard support higher data rates (see 802.3u, 802.3z and 802.3ae).

802.3ae

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3

Ethernet network protocol specification. IEEE 802.3ae, also known as 10-Gigabit

Ethernet, supports data rates of 10 gigabits per second. See 802.3.

802.3u

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3

Ethernet network protocol specification. IEEE 802.3u is also known as Fast Ethernet

because it supports higher data rates than 802.3 — 100 megabits per second (Mbps)

instead of 10 Mbps. See 802.3 and Fast Ethernet.

802.3z

An extension of the Institute of Electrical and Electronics Engineers' (IEEE's) 802.3

Ethernet network protocol specification. IEEE 802.3z, also known as Gigabit

Ethernet, supports data transmission rates up to one gigabit per second. See 802.3

and Gigabit Ethernet.

802.5

A token ring network protocol specification from the Institute for Electrical and

Electronics Engineers. See token ring.

802.6

A metropolitan-area network (MAN) specification from the Institute for Electrical and

Electronics Engineers. See MAN.

80x86

A family of Intel microprocessors once used in IBM-compatible PCs and workstations.

It includes the 80286, 80386 and 80486. The first Pentium processors are members

of the same family, but the numerical designations have been dropped. See

Pentium.