B

B channel

A bearer channel that is a fundamental component of ISDN interfaces. It carries 64,000 bits per second (bps) in both directions, is circuit-switched, and is able to carry either voice or data. For additional information, see Bearer Mode. See also D channel, Integrated Services Digital Network (ISDN).

band

The range of frequencies between two defined points.

bandwidth

In communications, the difference between the highest and lowest frequencies in a given range. For example, a telephone accommodates a bandwidth of 3000 Hz, the difference between the lowest (300 Hz) and highest (3300 Hz) frequencies it can carry.

Bandwidth Allocation Control Protocol (BACP)

The set of rules that manage bandwidth over dynamic multi-link PPP connections. See also multi-link PPP, point-to-point protocol (PPP).

Basic Rate Interface (BRI-ISDN)

The standard ISDN line, consisting of two B channels and one D channel. See also Integrated Services Digital Network (ISDN), Primary Rate Interface (PRI-ISDN).

Basic Telephony

An elementary level of telephony service, with a minimal subset of features, that provides a minimum set of functions that corresponds to Plain Old Telephone Service (POTS). TAPI service providers are required to support all Basic Telephony functions. See also Assisted Telephony, Extended Telephony, Supplementary Telephony.

BRI-ISDN

See Basic Rate Interface (BRI-ISDN).

bps

See bits per second (bps).

bits per second (bps)

Transfer-rate measurement indicating how many bits of computer data are sent in a one-second period through a modem over a telephone line.