ADTRAN 4200659L1 - Manual (Page 177)

Appendix D. Glossary
61200659L1-1 MX2800 STS-1 User Manual D-3
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 chan-
nel, thereby transmitting framing information so that time slots allocated to each
channel can be identified by the receiver.
channel service unit
See CSU.