ADTRAN T3SU 300 user manual clocking, control port

Appendix D. Glossary

channel service unit See CSU.

clocking

An oscillator-generated signal that provides a timing reference for a transmis- sion link. A clock provides 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.

control port

The electrical interface between the T3SU 300 and the control terminal. The con- trol terminal is used to communicate commands to the unit.

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 tele- phones.

CSU

channel service unit. A device used to connect a digital phone line coming in from the phone company to either a multiplexer, channel bank, or directly to another device producing a digital signal; for example, a digital PBX, a PC, or data communications device. A CSU performs certain line-conditioning and equalization functions, and responds to loopback commands sent from the cen- tral office. A CSU regenerates digital signals. It monitors them for problems and provides a way of testing the digital circuit.

CTS

clear to send. A signal on the DTE interface indicating that the DCE is clear to send data.

data communications equipment See DCE.

data service unit See DSU.

dB

decibel. A unit of measure of signal strength; usually the relation between a transmitted signal and a standard signal source.

D-4 T3SU 300 User Manual 61200217L1-1