Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 133)

Acronyms and Definitions
Verilink Access System 2000: Basics Glossary-13
D
D4 See Superframe (SF/D4) .
DACS Digital Access and Cross-connect
System—a digital switching device
for routing and switching T1/E1
lines, and DS0 portions of lines
among multiple T1/E1 ports. Used
within the network backbone.
data Digitally represented information
(1’s or 0’s) falling into one of four
groups: voice, text, facsimile, and
video.
data carrier detect (DCD) Control lead used to indicate data
circuit- terminating equipment
(DCE) is receiving a valid framed
signal.
data channel A portion of bandwidth of a
communications channel which is
configured to support a
synchronous serial interface.
data circuit- terminating equipment
(DCE)
In a digital communications link,
equipment at which a network
circuit terminates; either at the end
user’s site or within the network.
Examples include DSUs, CSUs.
Data Interface Unit (DIU) A high speed device that interfaces
data equipment ports with a CSU
(Verilink’s name for a Data
Service Unit (DSU) .
data link A general term referring to the
transmission of data from one
location to another using
predetermined hardware, and
protocols. Data links can be
attained using telephone lines,
coaxial cables, radio and/or
microwave signals, or fiber-optic
cables and lasers.
data port AS2000 interface to data terminal
equipment (DTE) , mounted at the
connector interface modules
(CIM) .
Data Service Unit (DSU) Converts a
synchronous / asynchronous
serial data interface into the
formatted data stream required by
a digital service. Signal is then
passed to a Channel Service
Unit (CSU) for transmission to the
network.
data set ready Control lead indicating the data
circuit- terminating equipment
(DCE) is ready to operate.