Instruction manual

GLOSSARY
Bearer Capability Class (BCC)
The Bearer Capability Class (BCC) identifies the type of a call, for example, voice and
different types of data. Determination of BCC is based on the call originator’s charac-
teristics for non-ISDN endpoints and on signaling in the D-channel for ISDN endpoints.
There are five Bearer Capability Classes (0-4), based on voice and data Modes 0, 1, 2, 3
capabilities.
Bit (Binary Digit)
One unit of information in binary notation (having two possible states or values, 0 or 1 ).
Bridge (Bridging)
The appearance of a voice terminal’s extension at one or more other voice terminals.
Bridged Appearance
A call appearance on a voice terminal that matches a call appearance on another voice
terminal for the duration of a call.
Buffer
A circuit or component that isolates one electrical circuit from another.
holds data from one circuit or process until another circuit or process
the data.
Typically, a buffer
is ready to accept
Bus
A multiconductor electrical path used to transfer information over a common connection
from any of several sources to any of several destinations.
Bus, Time Division Multiplex
See Time Division Multiplex Bus.
Business Communications Terminals
An advanced series of semi-intelligent terminals.
Bypass Tie Trunks
One-way, outgoing tie trunks from a tandem switch to a main switch in an ETN. These
trunks, provided in limited quantities, are used as a “last-choice” route when all trunks to
another tandem switch are busy. Bypass tie trunks are used only if all applicable inter-
tandem trunks are busy.
Byte
A sequence of bits, 8 bits long, that is usually shorter than a word. A word is 16 bits
long.
G-5