L

LA-MAINT

IMP Logical Address Maintenance

LAA

Locally-Administered Address

LAN

See Local Area Network.

LAN ADAPTER

A card which is installed on a workstation and is used to attach the workstation to a local area network (LAN).

LAN ADAPTER PROTOCOL SUPPORT

(LAPS) LAN networking software that provides Application Program Interfaces for NetBIOS and IEEE 802.2.

LAN APPLICATION

A program that shares data and resources among workstations through the transmission of data across a local area network (LAN). LAN applications must adhere to an NDIS-compliant LAN protocol, such as NetBIOS IEEE 802.2, or TCP/IP, to be supported by the LAN Distance product.

LAN DISTANCE ADMINISTRATOR

A user-type designation for the user who performs LAN Distance system management tasks. See User and LAN Distance Security Administrator.

LAN DISTANCE BRIDGE

A bridge established by a LAN Distance Connection Server workstation for the wide area connections to its LAN. The LAN Distance bridge routes and filters LAN traffic for the LAN Distance wide area network.

LAN DISTANCE CONNECTION SERVER

See IBM LAN Distance Connection Server.

LAN DISTANCE CONNECTION SERVER WORKSTATION

The LAN Distance connection agent for a LAN. It is the location of central answering, system management, and security resources for the LAN Distance connection to a LAN.

LAN DISTANCE REMOTE

See IBM LAN Distance Remote.

LAN DISTANCE REMOTE WORKSTATION

A workstation on which the LAN Distance Remote product is installed. It can establish LAN Distance connections to or from a LAN Distance Remote workstation and a LAN Distance Connection Server workstation.

LAN DISTANCE SECURITY ADMINISTRATOR

A user-type designation for the user who manages LAN Distance security, including configuration of the security policy and administration of the User Account database. See User and see also LAN Distance Administrator.

LAN DISTANCE SYSTEM

The set of workstations that a LAN Distance administrator supports. It includes the workstations on which the LAN Distance product is installed and all the workstations that can participate in LAN Distance wide-area connections.

LAN DISTANCE WIDE AREA NETWORK.

The set of workstations that can communicate with each other over their interrelated LAN Distance connections. In the Remote-to-Remote environment, it includes the entire virtual LAN. In the Remote-to-LAN environment, it includes remote workstations, the LAN Distance Connection Server workstation to which they are connected, and the LAN-attached workstations that are allowed to communicate with the remote workstations.

LAN MANAGER

The Microsoft networking environment.

LAN PROTOCOL

The protocol used for information transfer among the workstations attached on a LAN. The LAN protocols supported by the LAN Distance product must be NDIS-compliant (for example, IEEE 802.2, NetBIOS, and TCP/IP).

LAN REQUESTER

A component of the OS/2 program that allows users to access shared network resources made available by an OS/2 LAN Server. Using the client/server model, the LAN Requester component would reside on the client workstation.

LAN RESOURCE

A directory or file resource, printer, or serial device that is physically attached to a LAN and is managed by the LAN's administrative software.

LAN TRANSPORT PROTOCOL

See LAN Protocol

LAN-ATTACHED WORKSTATION.

A workstation physically residing on a local area network (LAN). Contrast to a standalone workstation.

LAN/1E LINK

An Allen-Bradley broadband link with interfaces to RS-232-C links in a local area network.

LAN/3E LINK

An Allen-Bradley broadband link that interfaces to a variety of links in a local area network.

LAN/PCE LINK

An Allen-Bradley broadband link that links personal computers in a local area network.

LAP

Link Access Procedure

LAPB

Link Access Procedure Balanced

LAPD

Link Access Procedure D Channel

LAPM

See Link Access Procedure for Modems.

LAPS

See LAN Adapter Protocol Support.

LARP

Locus Address Resolution Protocol

LAT

See Local Area Transport.

LATA

See Local Access and Transport Area.

LAVC

Local Area VAX Cluster

LAYER

Part of a network architecture that performs services and passes data to another part. Many network architectures are designed with seven layers, with each layer providing isolated functions.

Long Distance

LDP

Loader Debugger Protocol

LEAF-1

Leaf-1 Protocol

LEAF-2

Leaf-2 Protocol

LEASED LINE

A dedicated or private line leased for exclusive use. A telecommunications line on which connections do not have to be established by dialing a telephone number; the line is reserved for use between specific locations and is activated directly. See also Nonswitched Line.

LEAST-SIGNIFICANT BYTE

In a group of bytes, the byte farthest to the right that represents the number of ones. The least-significant byte is often stored in memory as the first byte of the set.

LEC

See Local Exchange Carrier.

LESS

View a file forwards or backwards.

LEVEL 1 CABLE

10BaseT cable known as telephone cable - quad or unshielded 4-conductor twisted pair. It is commonly used in residential telephone installations. The bandwidth is <5khz. Later versions of the spec do not allow telephone cable, although it can be used if there is existing cable.

LEVEL 1 IS

An IS that routes NPDUs directly to systems in their own area. For NPDUs outside the a level 1 area, the NPDU is routed towards a level 2 IS.

LEVEL 2 IS

An IS that routes NPDUs from one area to another within the routing domain.

LEVEL 3 CABLE

Unshielded 8-conductor twisted pair cable commonly used in small office networks which supports a bandwidth to 10Mbps.

LEVEL 5 CABLE

Physically similar to Level 3 Cable, but allows throughputs up to 100Mbps. This permits realtime video services.

LEVEL CONVERTER

An interface card that attaches to the serial interface card. The level converter handles data, control, and clocking signals to enable communication between the serial interface card and other devices such as a modem.

LEX

Generator of lexical analysis programs.

National Semiconductor part prefix that indicates the device is in device family: Linear (Bifet)

IC part number prefix indicating National Semiconductor Corp.

Largest Frame

LGBC

See Lightguide building cable.

National Semiconductor part prefix that indicates the device is in device family: Linear (Hybrid)

IC part number prefix indicating National Semiconductor Corp.

LIGHTGUIDE BUILDING CABLE

type of fiber-optic cable

LIM (LOTUS/INTEL/MICROSOFT) 3.2 AND 4.0

See Expanded Memory Specification.

LINE

The physical medium, such as a telephone wire, used to transmit data.

LINE NOISE

Random signal disturbances that sometimes occur over telephone lines. Noise can disrupt communications and corrupt the transmitted data.

LINE PRINTER DAEMON

A process on Berkeley spooler implementations that provides LPR support.

LINEAR ARRAY

Solid-state video detector consisting of a single row of light-sensitive elements; used in linear array cameras.

LINEAR BURSTS

See Peripheral Component Interconnect bus.

LINEAR-BUS

A network topology consisting of connections strung over the length of a cable segment. Linear-bus topology can be used in Ethernet and ARCnet LANs.

LINK

Only an object's presentation data and a reference (or pointer) to its native data are placed in a document. More efficient, since it requires less "overhead". Linked objects cannot travel with documents outside the local file system.

LINK ACCESS PROCEDURE FOR MODEMS

LAPM is an error control protocol specified by CCITT V.42. LAPM provides error control when your modem is communicating with another modem that supports LAPM.

LINK RESPONSE TIME

The elapsed time from when a message is ready for processing by the transmitting station, to when the receiving station has completed processing.

LINK SERVICES LAYER

See Link Support Layer.

LINK STATE DATABASE

A database in IP and OSI that collects reachability information about ESs and ISs and calculates routes based on the shortest path.

LINK STATE PACKET

In OSI and IP, the LSP contains reachability information about systems and areas that the router knows about. This packet is flooded across the network to other routers for the purpose of maintaining the link state database on each router.

LINK STATE UPDATE

The process that is responsible for building the LSP.

LINK SUPPORT LAYER

(LSL) Routes packets between LAN boards with their multiple link interface drivers (MLIDs) and protocol stacks. The LSL maintains LAN board, protocol stack, and packet buffer information. The LSL is the technological factor that allows a single driver to support multiple protocols and for a protocol to use multiple drivers. When the LSL receives a packet of data from the MLID, the LSL acts as a switchboard by determining which protocol stack should receive the packet. This "traffic cop" functionality eliminates the need to write separate drivers for each frame/protocol combination, thereby dramatically reducing the number of drivers a developer has to write and a customer has to install. LSL provides a foundation for network adapter card drivers to communicate with multiple protocol drivers, and for protocol drivers to communicate with multiple network adapter card drivers. See MLID and ODI.

LINK TURNAROUND TIME

The time between the end of a frame transmitted by one station to the start of the next frame transmitted by another station, as referenced by the signals on the bus. For example, from the last bit of an end flag to the first bit of a start flag.

LINK-LEVEL ACKNOWLEDGE

An immediate response transmission from a station after receiving a transmission, without requiring the station to acquire the token. Reception of a positive acknowledgment indicates successful reception of the original transmission; absence of a positive acknowledgment, or reception of a negative acknowledgment, indicates failure of the original transmission and a need for some recovery procedure.

LINK-LEVEL REPLY

A reply message that is immediate because the message data is available at the link level.

LINT

A C program verifier.

LITTLE-ENDIAN

A format for storage or transmission of binary data in which the least significant byte (bit) comes first. See big-endian.

LLAP

LocalTalk Link Access Protocol

LLC

Logical Link Control

National Semiconductor part prefix that indicates the device is in device family: Linear (Monolithic)

IC part number prefix indicating National Semiconductor Corp.

LMC

National Semiconductor part prefix that indicates the device is in device family: Linear CMOS

LMF

National Semiconductor part prefix that indicates the device is in device family: Linear Monolithic Filter

LMMP

LAN/MAN Management Protocol

LMMS

LAN/MAN Management Service

LMOS

Loop Maintenance Operations System

LMR

Land Mobile Radio

LNI

See Local Network Interconnect.

LOAD BALANCING

Shifting a user job from a more heavily loaded resource to a less loaded resource.

LOC-SRV

Location Service

LOCAL ACCESS AND TRANSPORT AREA

A geographic territory used primarily by local telephone companies to determine charges for intrastate calls. As a result of the Bell divestiture, switched calls that both begin and end at points within the LATA (intraLATA) are generally the sole responsibility of the local telephone company, while calls that cross outside the LATA (interLATA) are passed on to an Inter eXchange Carrier (IXC). One of 161 USA geographical subdivisions used to define local (vs. long distance) telephone service.

LOCAL AREA NETWORK

(LAN) A limited-distance, multipoint physical connectivity medium consisting of network interface cards, media, and repeating devices designed to transport frames of data between host computers at high speeds with low error rates. A LAN is a subsystem that is part of a network. At times, the term 'LAN' is used differently from the way Novell uses the term in much of its training and documentation, but fully consistent with the way the term is used in operating system messages and screens. The use of the LAN in this manner is also in full compliance with IEEE and ANSI standards, which specifically discuss technical aspects of LANs. The term LAN is commonly used to refer to an entire network of computers; however, in some cases, the term LAN refers specifically to a single Ethernet, Token Ring, or other type of LAN. It is important to accurately describe each LAN as a separate entity in a network where routable protocols are used, as is the case in a NetWare IPX network. (See network, network architecture, routable protocols, IPX, UNA, and OSI Model.)Two or more computing units connected for local resource sharing, or a network in which communications are limited to an area such as a single office building and do not extend across public rights-of-way. A LAN allows PCs to have access to common data and peripherals, and it typically consists of PCs with adapter cards, file servers, printers, gateways to departmental or corporate computers, and network software to integrate these components. More sophisticated LANs permit sharing of computing resources, along with sharing printers and file storage facilities. For example, networks equipped with MS LAN Manager support client/server computing. A network comprising two or more units physically connected for the purpose of local resource sharing. The network is generally limited to a moderate-sized geographic area, such as a single office building or campus.

LOCAL AREA TRANSPORT

A Digital Equipment Corporation proprietary network communication protocol. Based on the idea of a relatively small, known number of hosts on a local network sending small network packets at regular intervals. LAT will not work on a WAN scale, as TCP/IP does.

LOCAL AREA VAXCLUSTER

(LAVC) A local area network of up to 64 nodes that consists of a host, or boot server, (any MicroVAX or VAXserver system with sufficient power and storage) and MicroVAX satellite members. Local Area VAXclusters use Ethernet as the common interconnect, and offer the advantages of shared resources, high data availability, and abundant, expandable data-storage capacity for local work groups.

LOCAL EXCHANGE CARRIER

The local phone companies - either a Regional Bell Operating Company (RBOC) or an independent phone company (e.g. GTE) -- that provide local transmission services. See also RBOC.

LOCAL HEAP

A memory storage area limited to 64K in size.

LOCAL LOOP

The physical wires that run from the subscriber's telephone equipment to the switching system in the telephone company's central office.

LOCAL LOOP QUALIFICATION.

This is the process of checking the local loop distance-the distance between the customer's telephone equipment and the central office switch. If this distance exceeds 18,000 feet, additional equipment, such as repeaters, are added to the line to boost or enhance the signal. See also REPEATER.

LOCAL NETWORK INTERCONNECT

(LNI) A Port Multiplier, or concentrator supporting multiple active devices or communications controllers, either used standalone or attached to standard Ethernet cable.

LOCALTALK

A proprietary type of LAN developed by Apple Computer for Macintosh computers. LocalTalk uses flat telephone wire and AppleTalk network architecture for peer-to-peer access between nodes. LocalTalk is not used extensively with NetWare because of its limited bandwidth (230 Kbps). It uses the CSMA/CD access method over unshieled twisted pair wire. See LAN, network, and OSI Model.

LOD

Legion of Doom

LOGGING ON

The procedure that links a user to a network.

LOGIC BOMB

A method for releasing a system attack of some kind. It s triggered when a particular condition (e.g., a certain date or system operation) occurs.

LOGIC BOMB

See Bomb.

LOGICAL ADAPTER NETWORK ADDRESS

A unique identifier for a workstation or resource participating in a LAN Distance wide area network. The LAN Distance product uses this address to accomplish LAN traffic filtering and routing.

LOGICAL HOP

The number of hops across routers. A router detects logical hops based on how many routers a packet must traverse to reach its destination. If bridges exist, they constitute a physical hop, but no logical hop is detected because bridges do not work at the network protocol layer.

LOGICAL LINK

The top sublayer of the data link layer. This sublayer control passes data to higher layers; the protocol differs (LLC) according to the network.

LOGICAL LINK CONTROL (LLC)

IEEE LLC (802.2) layer defines protocol, frame header information, and methods of bridging similar and dissimilar types of LANs together. LLC includes spanning-tree and source-routing protocols and uses DSAP and SSAP addressing to determine specific bridge routes through an internetwork connected with LLC bridges. Also see DSAP, SSAP, Spanning-Tree Protocol, Source-Routing Protocol, and Translating Bridges.

LOGICAL PARTITION

The remaining usable Data Area of a NetWare partition, after the Redirection Area has been allocated. No more than one NetWare logical partition can exist on a physical disk drive.

LOGICAL UNIT

A software component of an SNA network that allows a person or application to access the network; also called an LU. To the network, each user (whether a person or an application) is an LU.

LOGICAL UNIT TYPE 6.2

In SNA networks, the logical unit that implements distributed processing and peer-to-peer communications.

LOGIN

LOGIN ADDRESS

A NetWare term that refers to the combination of the network address and node address. The login address is used by IPX, routers, and NetWare file servers to determine exactly where each node is located on a NetWare network or internetwork.

LONGITUDINAL REDUNDANCY CHECK

(LRC) An error-checking technique based on an accumulated exclusive-OR of transmitted characters. An LRC character is accumulated at both the sending and receiving stations (similar to CRC).

LOOP QUAL

See Local Loop Qualification.

LOOPBACK

Directing signals back towards a source along a communications path.

LOOPBACK TEST

Diagnostic test where characters that are sent to the modem are immediately sent back from the modem so the computer can compare the characters sent with the characters received.

LOSSLESS COMPRESSION

Ensures that the original data is exactly recoverable with no loss in image quality.

LOSSY COMPRESSION

The original data is not completely recoverable. Although image quality may suffer, many experts believe that up to 95 percent of the data in a typical image may be discarded without a noticeable loss in apparent resolution.

LOW BYTE

The 8 least-significant bits of a 16-bit word.

LOW MAINTENANCE

Impossible to fix if broken.

LOW NIBBLE

The 4 least-significant bits of a byte.

LOW-ACCESS LATENCY

See Peripheral Component Interconnect bus.

National Semiconductor part prefix that indicates the device is in device family: Linear (Low Power)

LPD

See Line Printer Daemon

LPQ

Spool queue examination program (who is printing and where)

LPR

Command used to queue print jobs on Berkeley queuing systems.

LRC

See Longitudinal Redundancy Check.

LSBYTE

See Least-Significant Byte.

LSL

Link Support Layer OR Link Services Layer

LSP

See Link State Packet.

LSU

See Link State Update.

See logical unit.

LU 6.2

See Logical unit type 6.2.

LUMINANCE

Brightness; one of the three image characteristics coded in composite television (represented by the letter Y). May be measured in lux or foot-candles.

LUT

Look-Up Table

LVAC

See Local Area VAXcluster.