ADTRAN 1203086L1, Manual

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61203086L1-1 ISU 512e User Manual Glossary-1
Glossary
2 B+D
The basic rate interface (BRI) in ISDN. A single ISDN circuit di-
vided into two 64 kbps digital channels for voice or data and one
16 kbps channel for low speed data (up to 9,600 baud) and signal-
ing. 2B+D is carried on one or two pairs of wires depending on
the interface, the same wire pairs that today bring a single voice
circuit into your home or office. See ISDN.
2B1Q
Two binary, one quarternary. An ISDN line encoding technique
which uses two bits to represent four variations in amplitude and
polarity.
10BaseT
IEEE 802.3 specification, using unshielded twisted-pair cabling
and running at 10 Mbps.
asynchronous transmission
Not synchronous. A method of data transmission which allows
characters to be sent at irregular intervals by preceding each char-
acter with a start bit and following it with a stop bit. The timing of
the transmission is not determined by the timing of a previous
character. Applications include communication between most
small computers (especially PCs) and mainframes, lower speed
transmission, and less expensive computer transmission systems.
See synchronous.
B channel
64 kbps bearer channel used for voice, circuit, or packet switched
data.
bearer service
As defined by CCITT standards, a type of telecommunication ser-
vice that provides the capability for the transmission of informa-
tion between user-to-network interfaces. Bearer services defined
for ISDN are circuit mode and packet mode.
BONDING protocol
Industry standard B channel aggregation protocol. Developed by
the Bandwidth on Demand Interoperability Group.