Instruction manual

Glossary
DIP switch
direct facility
termination
Direct Inward
Dialing
Direct-Line
Console
Direct Station
Selector
display buttons
DLC
DNIS
door answering
unit
DOS
DS0
DS1
DSE
DSS
DTE
DTMF signaling
(Dual in-line package) A switch on a 400EM module used to
select the signaling format for tie-line transmission. DIP
switches are also used on other equipment for setting
hardware options.
(DFT) See Personal Line.
See DID.
See DLC.
See DSS.
The buttons on an MLX display telephone used to access
the telephone’s display.
(Direct-Line Console) A telephone used by a system
operator to answer outside calls (not directed to an
individual or a group) and inside calls, transfer calls, make
outside calls for users with outward calling restrictions, set
up conference calls, and monitor system operation.
(Dialed Number Identification Service) 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.
A device that is connected to a basic telephone jack and
used at an unattended station or front desk.
Disk operating system.
(Digital Signal 0) A single 64-kbps voice or data channel.
(Digital Signal 1) A bit-oriented signaling interface that
multiplexes twenty-four 64-kbps channels into a single
1.544-Mbps stream.
(Digital switch element) A device in each jack on each
module in the communications system control unit that
interfaces with the TDM (time-division multiplex) bus.
(Direct Station Selector) A 60-button adjunct that enhances
the call-handling capabilities of an MLX-20L or MLX-28D
telephone used as an operator console.
(Data terminal equipment) The equipment that makes the
endpoints in a connection over a data circuit — for
example, a data terminal, host computer, or printer.
(Dual-tone multifrequency signaling) Touch-tone signaling
from telephones using the voice transmission path. DTMF
signaling provides 12 distinct signals, each representing a
Glossary GL-9