AT&T DS1/DMi/ISDN-PRI manual Dmi-Mos, Dnis

GL-8	GLOSSARY
Digital		An AT&T proprietary protocol used to transmit both digitized voice and
Communication		digitized data over the same communications link. A DCP link is made up of
Protocol (DCP)		two information (I-) channels and one signaling (S-) channel.
digital		The representation of information in discrete elements such as off and on or 0
		and 1.
digital data		See digital.
digital		An interface that provides connectivity between a communications system and a
multiplexed		host computer or between two communications systems using digital signal level
interface (DMI)		1 (DS1) 24th-channel signaling. DMI provides 23 64K-bps data channels and 1
		common signaling channel over a twisted-pair connection. DMI is offered
		through two capabilities: bit-oriented signaling (DMI-BOS) and message-oriented
		signaling (DMI-MOS).

digital multiplexed interface with bit-oriented signaling (DMI-BOS)

DMI signaling in which the signaling in the 24th channel is based on the definitions of single bits. For example, a bit may indicate an on-hook/off-hook condition.

digital	DMI signaling in which the signaling in the 24th channel is based on the
multiplexed	definitions of strings of bits that form messages. DMI-MOS is similar to the
interface with	Integrated Services Digital Network primary rate interface (ISDN-PRI).
message-
oriented
signaling
(DMI-MOS)

digital signal level 1 (DS1)

A bit-oriented signaling (BOS) interface that multiplexes 24 channels into a single 1.544M bps stream. DS1 can be used for pulse-code modulation (PCM) for voice or voice-grade data and for mode-0, -1, -2, and -3 data protocols as well as for other voice or data transmission protocols.

Direct Inward	A feature that allows an incoming call from the public network (not FX or
Dialing (DID)	WATS) to reach a specific telephone without attendant assistance. DID calls to
	DID-restricted telephone lines are routed to an attendant or recorded
	announcement, depending on the option selected.
DNIS	See dialed-number identification service.
DS1	See digital signal level 1.
DS1 robbed-bit	See robbed-bit signaling.
signaling
DSX-1	1. A cross-connect field for digits signal level 1s (DS1s).
	2. A specification that defines the signal shape and power level of the DS1
	signal at a virtual or real point.
DTE	See data terminal equipment.
E&M	Ear and mouth.