ADTRAN Atlas 550 - Manual (Page 242)

Appendix G. Glossary
G-2 ATLAS 550 User Manual 61200305L1-1
B8ZS
Bipolar eight zero substitution. In a T1 carrier system, a specific eight bit pattern containing two delib-
erate bipolar violations which replaces eight consecutive customer zero bits.
bandwidth
The transmission capacity of a communications channel, stated in megabits per second (Mbps).
BECN
Backward Explicit Congestion Notification. Sent to the device generating excessive frame relay traffic
as a means to slow down the flow of data to the network. Compare with FECN.
bit
Bit is a contraction of the term binary digit. It is the smallest unit of information a computer can pro-
cess representing either high or low, yes or no, or 1 or 0. It is the basic unit in data communications. A
bit can have a value of zero (a mark) or one (a space).
bps
Bits per second. A measure of the speed of data communications.
BRI
Basic Rate ISDN. An ISDN service that offers two bearer (B) channels. One channel (64 kbps) is used
for data transfer and as a data-link. The second channel (16 kbps) is used for signaling and control
information.
Burst
A sporadic increase in a transmission.
Bursty traffic
Traffic that alternates between steady transmission and short bursts of high transmission.
byte
Eight bits of information composed of zeros or ones, one of which may include a parity bit.
CIR
Committed Information Rate. The guaranteed bandwidth available for customer data under normal
circumstances.
Companding
The process of compressing and expanding a signal.
clocking
An oscillator-generated signal that provides a timing reference for a transmission link. A clock pro-
vides signals used in a transmission system to control the timing of certain functions. The clock has
two functions, (1) to generate periodic signals for synchronization and (2) to provide a time base.
CPE
Customer premise equipment. All telecommunications terminal equipment located on the customer
premises, including telephone sets, private branch exchanges (PBXs), data terminals, and customer-
owned coin-operated telephones.
CS
See CTS.