Instruction manual

Glossary
L
LAN
(local area network) Arrangement of interconnected
personal computers or terminals, sometimes accessing a
host computer, sometimes sharing resources such as files
and printers.
LDN
(Listed Directory Number)
LED
(light-emitting diode) Semiconductor device that produces
light when voltage is applied; light on a telephone.
line
Connection between extensions within the
communications system; often, however, used
synonymously with
trunk .
line and trunk
assignment
Assignment of lines and trunks connected to the system
control unit to specific buttons on each telephone.
line/trunk
Refers to inside system lines and outside trunks in general
terms. See also line and trunk .
line/trunk jack
Physical interface on a module in the control unit for
connecting an outside trunk to the communications
system. Also called “trunk jack.”
line/trunk and
extension module
Module on which the jacks for connecting central office
lines/trunks and/or the jacks for connecting the extensions
are located.
local host computer
access
A method for connecting an extension jack to an on-site
computer for data-only calls through a
modem or data
module
.
local loop
The two-way connection between a customer premises
and the central office (CO).
logical ID
Unique numeric identifier for each
extension and line/trunk
jack
in the system control unit.
loop-start trunk
Trunk on which a closure between the tip and ring leads is
used to originate or answer a call. High-voltage 20-Hz AC
ringing current from the central office signals an incoming
call.
System Manager's Guide
GL–13