Instruction manual

GLOSSARY
Data Endpoint
Two general groups: those having a DTE-type interface, which encompasses almost all of
the data terminal devices; and the group of DCE interface devices which are primarily
modems. However, it must be noted that within each category, control interfaces may also
vary. Refer to Analog Data Endpoint and Digital Data Endpoints for additional information.
Data Module
A data interface device (i.e.,
Asynchronous Data Unit) providing a standard interface
between customer-provided data equipment and a data port on the switch.
Data Terminal Equipment (DTE)
DTE refers to a specific RS-232C connector termination designed to connect directly to a
DCE-type connection. Typically associated with video display terminals, printers, and
computers which either originate or terminate a data transmission path.
Data Terminals
Refers to RS-232C-compatible Data Terminal Equipment.
Delay-Dial Tie Trunk
After a request for service (called a seizure) is detected on an incoming trunk, the system
sends a momentary signal followed by a steady tone over the trunk. This informs the calling
party that dialing can start. This type of trunk allows dialing directly into the system. That is,
the digits are received as they are dialed.
Digital Data Endpoints
In System 25, digital data endpoints include any digital device providing an RS-232C
connection interface to the switch. The connection is via Asynchronous Data Units (ADUs)
to the switch.
Direct Extension Selector (DXS) Console
An option at the attendant console that allows an attendant direct access to voice terminals
by pressing a Group Select button and a DXS button.
EIA: (Electronics Industries Association)
ESF
Extended Super Frame (ESF) is the successor to D4 framing.
Emergency Transfer Unit
Provides direct connection of designated Power Failure Transfer (PFT) registered voice
terminals to the CO during a power failure or other service interruption.
Equal Access
Provides access to any Interexchange Carrier (IXC).
9-6
November 1995