Glossary

Kbps (Kilobits per second)

KBps (Kilobytes per second)

LAN (Local Area Network) A data communications system designed to operate over a limited geographic distance, such as a single building.

LAP-D (Link Access Procedure-D) A Data Link layer procedure using D channel communications, typical of ISDN.

LATA (Local Area Transport Area) This is the territory covered by an individual local telephone operating company.

LEC (Local Exchange Carrier) The local phone company – either a Regional Bell Operating Company (RBOC) or an independent phone company – that provides local transmission services.

LED Light Emitting Diode

LLC (Logical Link Control) The upper half of the Data Link layer in LANs. Performs error control, broadcasting, multiplexing, and flow control functions. See also MAC (Medium Access Control).

LLC/SNAP (Logical Link Control/SubNetwork Attachment Point)

local ♦ Describes files and devices, such as disk drives, that are attached to, or on, your machine.

Loop Qualification This is a test done by the phone company to make sure the customer is within the maximum distance of 18,000 feet from the central office that serves that customer. (ISDN service could be available at a longer distance than that with a repeater.)

LOS (Loss Of Signal) PRI alarm.

LT (Line termination) The equivalent of the NT1 function at the Central Office.

MAC (Medium Access Control) ♦ A set of protocols that are the lower part of the Data Link layer and comprise the basis of the IEEE LAN specifications. In general, MAC determines the way devices can transmit in a broadcast network. See also LLC (Logical Link Control).

Mbps (Megabits per second) Transmission speed or rate of one million bits per second.

MBps (Megabytes per second) Transmission speed or rate of one million bytes per second or 8 Mbps.

iSPAN PRI PCI ISDN Users Guide

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