ADTRAN 1200214L1 - Manual (Page 148)

124 IQ Probe User Manual 61200214L1-1
Glossary
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.
dB
The standard abbreviation for decibel. A decibel is a unit of measure for signal. A
decibel is usually the relation between a transmitted signal and a standard signal
source. Therefore, 6 dB of loss would mean that there is a 6 dB difference
between what arrives down a communications circuit and what was transmitted
by a standard signal generator.
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.
DDS
digital data service. AT&T private line service for transmitting data over a digital
system. The digital transmission system transmits electrical signals directly,
instead of translating the signals into tone of varied frequencies as with
traditional analog transmission systems. Digital techniques provide more
efficient use of transmission facilities, resulting in lower error rates and costs
than analog systems.
DE
discard eligibility. A user-set bit indicating that a frame may be discarded in
preference to other frames if congestion occurs, to maintain the committed
quality of service within the network. Frames with the DE bit set are considered
Be excess data.
DLCI
data link connection identifier. A unique number assigned to a PVC end point in
a frame relay network. Identifies a particular PVC endpoint within a user's
access channel in a frame relay network and has local significance only to that
channel.