AT&T 3.0 manual Terms and Conventions Used, Lines, Trunks and Facilities

Terms and Conventions Used

Terms and Conventions Used

In this document, the terms in the following list are used in preference to other, equally acceptable terms for describing communications systems.

Lines, Trunks and Facilities

Facility is a general term that designates a communications path between a telephone system and the telephone company central office. Technically a trunk connects a switch to a switch, for example the MERLIN LEGEND Communications System to the central office. Technically, a line is a loop- start facility or a communications path that does not connect two switches (for example, an intercom line or a Centrex line). However, in actual usage, the terms line and trunk are often applied interchangeably. In this book, we use line/trunk and lines/trunks to refer to facilities in general. Specifically, we refer to digital facilities. We also use terms such as personal line, ground- start trunk, Direct Inward Dialing (DID) trunk, and so on. When you talk to your local telephone company central office, ask them what terms they use for the specific facilities they connect to your system.

Some older terms have been replaced with newer terms. The following list shows the old term on the left and the new term on the right:

trunk module trunk jack station station jack analog data station digital data station

analog voice and analog data station

digital voice and analog data station

analog data only station digital data only station

digital voice and digital data station

line/trunk module line/trunk jack extension extension jack modem data station 7500B data station

analog voice and modem data station

MLX voice and modem data station

modem data-only station 7500B data-only station MLX voice and 7500B data

station

Installation xxi