ADTRAN 1200657L2, 4200659L1 byte, carrier, C-bit, Ccitt, channel bank, channel service unit

Appendix D. Glossary

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.

61200659L1-1 MX2800 STS-1 User Manual D-3