Instruction manual

Glossary
Behind Switch
mode
binary code
bipolar 8 zero
substitution
bipolar signal
bipolar violation
BIS
bit
bit rate
blocking
BMI
bps
BRI
broadband
bus
button
One of three modes of system operation, in which the
communications system control unit is connected to (is
“behind”) another telephone switching system, which
provides features and services to telephone users. See
also Hybrid/PBX mode and Key mode.
An electrical representation of quantities or symbols
expressed in the base-2 number system.
See B8ZS.
A digital signal in which pulses (1s) alternate between
positive and negative. See also AMI, alternate space
inversion, B8ZS, and bipolar violation.
A condition that occurs when two positive or two negative
pulses are received in succession. See also AMI, alternate
space inversion, B8ZS, and bipolar signal.
Part of the model name for some analog multiline
telephones, standing for built-in speakerphone.
(Binary digit) One unit of information in binary notation,
having two possible values: zero or one.
The speed at which bits are transmitted, usually expressed
in bps. Also called data rate. See also baud and bps.
A condition in which end-to-end connections cannot be
made on calls because of a full load on all possible services
and facilities.
Broadcast Music Incorporated.
(Bits per second) A measure of digital transmission speed.
(Basic Rate Interface) A standard ISDN frame format that
specifies the protocol used between the communications
system and a terminal. BRI runs at 192 kbps and provides
two 64-kbps voice or B-channels and one 16-kbps signaling
or D-channel per port. The remaining 48 kbps are used for
framing and D-channel contention.
A transmission path having a bandwidth greater than a
voice-grade channel.
A multiconductor electrical path used to transfer information
over a common connection from any of several sources to
any of several destinations.
A key on the face of a telephone that is used to access a
line, activate a feature, or enter a code on a
communications system.
GL-4 Glossary