AT&T DS1/DMi/ISDN-PRI manual Dte

	GLOSSARY	GL-7
D4 framing	A format containing 12 frames. See also extended frame and frame.
format
D-channel	The 16K-bps or 64K-bps packet-switched channel on an Integrated Services
	Digital Network basic rate interface (ISDN-BRI) or 64K-bps on an Integrated
	Services Digital Network primary rate interface (ISDN-PRI) packet-switched
	channel that carries signaling messages and packet-switched user data. A D-
	channel is the (ISDN-PRI) Q.931 signaling channel. (A D-channel can also
	carry data, but this capability is not used on a DEFINITY Communications
	System Generic 2.) See also B-channel, Q.930 and Q.931.
DACS	See digital-access and cross-connect system.
data module	An interconnection device between a basic rate interface (BRI) or Digital
	Communications Protocol (DCP) interface of System 75 and System 85 and data
	terminal equipment (DTE) or data circuit-terminating equipment (DCE).
data set	See modem.
data service	A device designed to transmit digital data on transmission facilities. See also
unit (DSU)	network channel-terminating equipment.
data terminal	The equipment that makes up the endpoints in a connection over a data circuit.
equipment	For example, in a connection between a data terminal and a host, the terminal,
(DTE)	the host, and their associated modems or data modules make up the DTE. DTE
	usually consists of the following functional units: control logic, buffer store, and
	one or more input or output devices or computers. DTE can also contain error
	control, synchronization, and telephone-identification capabilities.
dB	See decibel.
DCP	See Digital Communications Protocol.
decibel (dB)	A relative unit of measure that converts the power or voltage ratio for acoustic or
	electrical energy at each of two points to a useful and comparative form. For
	example, a 3-dB loss implies a loss ratio of one half and a 6-dB loss implies a
	ratio of one fourth.
dialed-number	A display provided to the answering agent of a service or project, or of the
identification	number called by the caller, so that agents grouped in one split can answer calls
service (DNIS)	appropriately for different services. DNIS can also be sent to a host computer or
	other adjunct.
dial pulse	Regular momentary interruptions by the sending end of a direct- or alternating-
	current path. The number of interruptions corresponds to the value of a digit or
	character. Also called dial-pulse addressing.
dial-pulse	See dial pulse.
addressing

DID

digital-access and cross- connect system (DACS)

See Direct Inward Dialing.

Areconfigurable, central-office (CO) system used to cross-connect digital signal level 1s (DS1s). A DACS takes DS1s as inputs and also outputs DS1s.