ADTRAN 1200214L1 Spezifikationen PDF herunterladen (Seite 162)

Appendix D. Glossary

D-4 IQ Probe User Manual 61200214L1-20

CRC

Cyclic redundancy check. A computational means to ensure the

accuracy of frames transmitted between devices in a frame relay net-

work. The mathematical function is computed, before the frame is

transmitted, at the originating device. Its numerical value is com-

puted based on the content of the frame. This value is compared with

a recomputed value of the function at the destination device.

See CTS.

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 central 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.

The standard abbreviation for decibel. A decibel is a unit of measure

for signal. A decibel is usually the relation between a transmitted sig-

nal and a standard signal source. Therefore, 6 dB of loss would mean

that there is a 6 dB difference between what arrives down a commu-

nications circuit and what was transmitted by a standard signal gen-

erator.

DCE

Data communications equipment. A device that provides all the

functions required for connection to telephone company lines and for

converting signals between telephone lines and DTE. Also see DTE.

1 2 ... 157 158 159 160 161 162 163 164 165 166 167 ... 175 176

Keine Kommentare

ADTRAN 1200214L1 Spezifikationen Seite 162