ADTRAN 25 manual

Loop-Start Trunk

Simplest type of central office (CO) trunk. Calls are originated by providing a dc path between the tip and ring leads. The CO detects the loop current thus drawn and returns dial tone. Incoming calls are signaled by the CO placing an ac ringing voltage between the tip and ring leads. (The port circuit pack detects this signal.)

Modem

A device that modulates and demodulates signals transmitted over a communications path. Used to connect Data Terminal Equipment to the system’s analog ports. The system (optionally) provides a 212A compatible conversion resource.

Modem Pooling

Provides shared-use conversion resources that eliminate the need for dedicated modems.

Multiline Voice Terminal

A terminal equipped with several call appearance buttons for the same extension number. Allows the user to handle more than one call at the same time.

Multiplexed

The simultaneous transmission of two or more signals over a common transmission medium.

N e t w o r k

An arrangement of inter- and/or intra-location circuits designed to perform specific functions.

Network Interface

Provided by the telephone company in three forms:

(1)RJ21X for trunk facilities other than tie trunks.

(2)RJ2GX for tie trunk facilities.

(3)RJ48X or RJ48G for DS1 Tie Trunk facilities.

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