AT&T 3.0 manual Bis

Glossary

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.

binary code

bipolar 8 zero substitution

bipolar signal

Electrical representation of quantities or symbols expressed in the base-2 number system, which includes zeros and ones.

See B8ZS.

Digital signal in which pulses (ones) alternate between positive and negative. See also AMI, B8ZS, and bipolar violation.

bipolar violation

BIS

Condition occurring when two positive or two negative pulses are received in succession. See also AMI and B8ZS.

(Built-in Speakerphone) Part of the model name of some analog multiline telephones.

bit

bit rate

blocking

(binary digit) One unit of information in binary notation; it can have one of two values, zero or one.

Speed at which bits are transmitted, usually expressed in bps. Also called “data rate.” See alsobaud rate.

Condition in which end-to-end connections cannot be made on calls because of a full load on all possible services and facilities. See also glare.

BMI board

(Broadcast Music Incorporated)

A module, for example, 100D or 408 MLX GS/LS, that allows you to connect lines/trunks and extensions to the communications system or holds the processor or power supply*

Maintenance and Troubleshooting GL-5