ADTRAN Atlas 800 Plus, User Manual

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Appendix E. Glossary
E-4 ATLAS 800
PLUS
User Manual 61200226L1-1
LAN
local area network. Group of computers and peripheral devices connected by a communications chan-
nel, limited by distance.
LCD
liquid crystal display. Alphanumeric characters that appear in a display area as a result of light reflect-
ing off a special crystalline substance.
leased line
A telecommunication facility or link reserved for the exclusive use of one customer. Also called a ded-
icated line.
local loop
In telephony the wire pair that connects a subscriber to a phone company end office, typically contain-
ing two wires. Four-wire local loops are common, however, especially with leased voice grade circuits.
loopback
A diagnostic procedure where data is sent to the device being tested, and the output of the device is
fed directly back to its input, looped around, and the returning data is checked against that which was
sent.
LED
light emitting diode. Alphanumeric characters that glow when supplied with a specified voltage.
Mbps
Mega bits per second. A measure of the amount of information travelling across a network or commu-
nications link.
MIB
management information base. The MIB is an index to the organized data stored within a network
device.
Modem 16 Module
One of the ATLAS 800 option modules. The Modem 16 Module supports sixteen 56Kflex modem (ana-
log) calls or sixteen ISDN connections.
multiplexer
(mux) A device that takes several low-speed channels and merges them into one high-speed channel
at one end of a link. Another multiplexer at the other end of the link reverses this process.
NT1
Network termination 1. A unit that provides physical and electromagnetic termination of the U-inter-
face, 2-wire transmission line; converts between Layer 1 formats used at the U- and T- reference points;
and performs some maintenance functions.
nonvolatile memory
Any form of memory that retains its contents when power is removed (for example, ROM, EPROM,
etc.)
Octal BRI/U Module
One of the ATLAS 800 option modules. The Octal BRI/U Module provides eight basic rate ISDN U
interfaces, each capable of operating in NT or LT mode.