ADTRAN 25 manual Glossary

GLOSSARY

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 DTE or DCE with an RS-232C interface to the switch connected through Asynchronous Data Units.

Digital Tape Unit (DTU)

The RS-232C peripheral DTE used to store and reload system translations.

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 D X S b u t t o n .

Direct Group Call (DGC)

An incoming call that arrives on a loop-start, ground-start, or tie trunk and is routed to a predetermined group of stations (for example, sales department and service department).

Direct Inward Dialing (DID)

A service whereby the called extension (station) number is transmitted to a PBX by the central office (CO) and incoming calls are routed directly to the called station, bypassing the attendant.

D S n

Generally, Digital Signal (DS) level n refers to the logical organization or division of the bandwith available on T carriers. DSO is a single

64 Kbps channel. Twenty-four DS0 channels combine to form a DS1 channel. Four DS1 channels combine to form a DS2 channel. Twenty-eight DS1 channels combine to form a DS3 channel.

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