AT&T 3.0 manual Did

Glossary

Dialed Number	See DNIS.
identification Service
dial-out code	Digit (usually a 9) or digits dialed by telephone users to
	get an outside line.
dial plan	Numbering scheme for system extensions, lines, and
	trunks.
dial-repeating tie	Tie trunk on which the originating end of the tie trunk
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 “delay dial start tie
	trunk.”
DID	(Direct Inward Dialing) Service that transmits from the
	telephone company central office and routes incoming
	calls directly to the called extension, calling group, or
	outgoing trunk pool, bypassing the system operator.
DID trunk	Incoming trunk that receives dialed digits from the local
	exchange, allowing the system to connect directly to an
	extension without assistance from the system operator.
digital	Representation of information in discrete elements such as
	off and on or zero and one. See also analog transmission.
Digital	See DCP.
Communications
Protocol
digital data station	See 7500B data station.
Digital Signal 0	See DS0.
Digital Signal 1	See DS1.
digital switch	See DSE.
element

Maintenance and Troubleshooting GL–11