Instruction manual

GLOSSARY

Secondary Reference

The secondary reference is a backup DS1 facility used as a clock timing reference for

synchronization in case the primary reference fails or has too many slips.

Service Observing

Service observing allows users to monitor calls. Once the feature is activated and a sta-

tion call is being monitored, the activating user has the capability to toggle back and forth

between a listen-only connection and a listen/talk connection on the call. Subsequent

calls at the station can be monitored without having to reactivate the feature.

Signaling Groups

Refers to a group of B-Channels for which a given D-Channel (or D-Channel Pair) will

carry the signaling information.

Single-Line Voice Terminals

Voice terminals served by a single-line tip and ring circuit (for example, Models 500,

2500, 7101A, and 7103A).

Software

A set of computer programs that accomplish one or more tasks.

Special Information Tones (SIT)

Tones that precede certain recorded announcements provided by the network. Such

announcements are used when the caller encounters a condition that requires an expla-

nation (for example, “no such number’).

Split

A condition whereby a caller is temporarily separated from

dant. This split condition automatically occurs when the

presses the Start button.

Status Lamp

a connection with the atten-

attendant, active on a call,

A green lamp that shows the status of a call appearance or a feature button by the state

of the lamp (lighted, flashing, fluttering, broken flutter, or dark).

Stratum 3 Clock

This is the most accurate clock supported by the system; it is duplicated and has a hold-

over of 24 hours. The implementation requires external hardware to provide timing to the

TN780 Tone/Clock circuit pack.

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