AT&T MERLIN LEGEND Data Manual page 139

Glossary
D4 framing format
A framing format consisting of a sequence of individual frames of 24 eight-bit slots and 1 signal bit (193 bits) in a 12-frame
superframe. See also extended superframe format.
data communications equipment (DCE)
Equipment such as modems or data modules used to establish, maintain, and terminate a connection between the
communications system and data terminal equipment (DTE), such as printers, host computers, or workstations.
data hunt group (DHG)
A group of analog or digital data stations that share a common access code. Calls are connected in a round-robin fashion to
the first available data station in the group.
data rate
See bit rate.
data terminal
An input/output (I/O) device that can be connected to the communications system control unit via an interface.
data terminal equipment (DTE)
The equipment that makes up the endpoints in a connection over a data circuit — forexample, a data terminal, host
computer, or printer.
dedicated feature buttons
The imprinted feature buttons on a telephone: Conf or Conference, Drop, HFAI (Hands Free Answer on Intercom), Hold, Mute
or Microphone, Speaker or Speakerphone, Transfer, Message, and Recall.
delay-dial-start tie trunk
A type of tie trunk on which the originating end of the tie trunk transmits an off-hook signal to the receiving end and waits for
the receiving end to send an off-hook signal followed by an on-hook signal. Also called a dial-repeating tie trunk.
dial access
See feature code.
Dialed Number Identification Service (DNIS)
A service provided by the AT&T Switched Network that routes incoming 800 or 900 calls according to customer-selected
parameters, such as area code, state, or time of call.
dial-out code
A code (usually a 9) dialed by single-line telephone users and multiline telephone users with System Access (SA) buttons to
get an outside line.
DID (direct inward dialing) trunk
An incoming trunk that receives dialed digits from the local exchange, allowing the communications system to connect
directly to a station without assistance from the system operator.
digital
The representation of information in discrete elements such as off and on or 0 and 1. See also analog transmission.
Digital Communications Protocol (DCP)
An AT&T proprietary protocol to transmit both digitized voice and data over the same communications link. A DCP link is
made up of two 64-kbps information (I) channels and one signaling (S) channel similar to the B and D channels used in an
Integrated Services Digital Network (lSDN).
digital switch element (DSE)
A device in each jack on each module in the communications system control unit that interfaces with the TDM (time-division
multiplex) bus.
digital transmission
A mode of transmission in which the information to be transmitted is first converted to digital form and then transmitted as a
serial stream of pulses. See also analog transmission.
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