AT&T 7500 series, 7100 series manual DIMENSION, System 85, and Generic 2 Multipremises Package

2-6COMMUNICATION SYSTEM NETWORKING — AN OVERVIEW

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switch for processing.

DIMENSION, System 85, and Generic 2 Multipremises Package

The set of software capabilities that enable a DIMENSION, System 85, or Generic 2 communications system to function as a node in a MS/T network are provided through the Multipremises package.

The Multipremises package uses extension number steering to route a call through the network. With extension number steering, the caller dials the destination extension number. The switch matches the extension number to a dial access code. It sends calls to terminals on other switches over the trunk group that the dial access code designates.

In addition to extension number steering, the DIMENSION, System 85, and Generic 2 Multipremises package includes the Extended Trunk Access (ETA) feature. ETA is a capability used only in a satellite or tributary switch. With ETA, instead of entering all network extensions and their switch locations on the satellite, the administrator enters only satellite or tributary extensions there. Calls originating on the satellite to extensions not on the satellite database are sent to the main for processing. For ETA to function properly, the trunk group that connects the satellite or tributary switch to the main switch must be identified through administration. In addition, the satellite flag must be set for ETA operation.

Electronic Tandem Network Software — The PNA and ETN (Standard Network) Packages

The Private Network Access (PNA) package enables a System 75 or Generic 1 communications system to perform as a tandem in an electronic tandem network. Similarly, the ETN (Standard Network) package allows a DIMENSION, System 85, or Generic 2 communications system to perform in the same capacity.

The capabilities offered by both the PNA and ETN (Standard Network) packages are provided through Automatic Alternate Routing (AAR). AAR is a feature that ensures least-cost routing for private network calls. (See Network Call Processing later in this chapter for more details.)

System 75 and Generic 1 PNA Package

For a System 75 or Generic 1 communications system to function as a tandem in an ETN, the PNA package must be activated there. The PNA package provides the same features as the UDP package, plus it provides access to AAR through feature-access-code dialing.

DIMENSION, System 85, and Generic 2 ETN (Standard Network) Package

The ETN (Standard Network) package is totally unrelated to the Multipremises software that is used to enable a DIMENSION, System 85, or Generic 2 communications system as a node in a MS/T network. With the ETN (Standard Network) package, to reach the destination terminal the caller may dial either the extension number (which points either to an RNX or to a node number), or the AAR feature access code (usually an 8), followed by the RNX and the extension number.

When a System 85 or Generic 2 communications system is administered so that the caller may dial the extension number only, either of two dialing conventions are in operation: