ADTRAN 1200218L1, User Manual

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Appendix D. Glossary
61200663L1-1 OSU 300 User Manual D-3
intentional (B8ZS) are counted as errors. Could also be the presence of two con-
secutive 1 bits of the same polarity on the T-carrier line.
bridge
A data communications device that connects two or more networks and for-
wards packets between them.
byte
Generally, an 8-bit quantity of information. This term is used mainly in referring
to parallel data transfer, semiconductor capacity, and data storage.
carrier
The provider of the telecommunication services to the customer site. Carriers
can be local telephone companies, regional telephone companies, or any inter-
exchange carrier such as AT&T, Sprint, or MCI.
C-bit
An overhead bit in the DS3 string not used for framing, parity, or alarm indica-
tion.
CCITT
Consultive Committee for International Telephony and Telegraphy. A standards
organization that devises and proposes recommendations for international com-
munications. See also ANSI.
CD
carrier detect. A signal generated by a modem or DSU/CSU indicating the pres-
ence of a carrier signal on a communications link.
channel
A transmission path between two or more termination points; also called a cir-
cuit, facility, line, link, or path.
channel bank
Equipment in a telephone central office or customer premises that performs mul-
tiplexing of lower speed digital channels into a higher speed composite channel.
The channel bank also detects and transmits signaling information for each
channel, thereby transmitting framing information so that time slots allocated to
each channel can be identified by the receiver.