Instruction manual

Glossary
DNIS
(Dialed Number Identification Service) Service provided
by the AT&T Switched Network (
ASN ); it routes incoming
800 or 900 calls according to customer-selected
parameters, such as area code, state, or time of call.
door answering unit
Device connected to a basic telephone jack and used at
an unattended extension or front desk.
DOS
(disk operating system)
DS0
(Digital Signal 0) Single 64-kbps voice or data channel.
DS1
(Digital Signal 1)
Bit -oriented signaling interface that
multiplexes twenty-four 64-kbps channels into a single
1.544-Mbps stream.
DSL
(digital subscriber line) A digital
facility that supports T1
Switched 56 service
.
DSS
(Direct Station Selector) 60-button
adjunct that enhances
the call-handling capabilities of an MLX-20L or MLX-28D
telephone used as an operator console.
DTE
(data terminal equipment) Equipment that makes the
endpoints in a connection over a data connection; for
example, a data terminal, personal computer, host
computer, or printer.
DTMF signaling
(dual-tone multifrequency signaling) Touch-tone signaling
from telephones using the voice transmission path. DTMF
signaling provides 12 distinct signals, each representing a
dialed digit or character, and each composed of two
voiceband frequencies.
E
EIA
(Electronic Industries Association)
Electronic
Switching System
See
ESS .
endpoint
Final destination in the path of an electrical or
telecommunications signal.
ESS
(Electronic Switching System) Class of central office ( CO )
switching systems developed by AT&T in which the control
functions are performed principally by electronic data
processors operating under the direction of a stored
program.
GL–8 System Manager's Guide