Instruction manual

Glossary
Automatic Route
Selection
See
ARS .
auxiliary power unit
Device that provides additional power to the system.
B
backup
Procedure for saving a copy of system programming onto
a floppy disk or
memory card . See also restore.
barrier code
Password used to limit access to the
Remote Access
feature of the system.
basic carrier
Hardware that holds and connects the
processor module ,
power supply module , and up to five other modules in the
system. See also
expansion carrier .
B-channel
(Bearer-channel) 64- or 56-kbps channel that carries a
variety of digital information streams, such as voice at 64
kbps, data at up to 64 kbps, wideband voice encoded at
64 kbps, and voice at less than 64 kbps, alone or
combined
.
Basic Rate Interface
See
BRI .
Bearer-channel
See
B-channel .
Behind Switch
mode
One of three modes of system operation, in which the
control unit is connected to (behind) another telephone
switching system, such as
Centrex or DEFINITY, which
provides features and services to telephone users. See
also
Hybrid/PBX mode and Key mode .
BIS
(Built-In Speakerphone) Part of the model name of some
analog multiline telephones.
bit
(binary digit) One unit of information in binary notation; it
can have one of two values, zero or one.
bit rate
Speed at which bits are transmitted, usually expressed in
bps . Also called “data rate.”
BMI
(Broadcast Music Incorporated)
board
A module, for example, 100D or 408 MLX GS/LS, that
allows you to connect lines/trunks and extensions to the
communication system.
board assignment
System Programming and Maintenance (SPM) procedure
for assigning line/trunk and extension modules to slots on
the control unit.
System Manager's Guide
GL–
3