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Tandem Switching Feature

Description

Automatic Route Selection (ARS), Uniform Dial Plan Routing, and Remote Access

Tandem switching allows network system users to use ARS calls that are carried on private network trunks to non-local systems where they are routed out over public switched telephone network facilities. At the non-local systems to which or through which calls are routed, the calls are received as Remote Access calls, even though the callers dial normally without using a Remote Access code. When an ARS call arrives at a networked system, ARS routes the call cost-effectively either over local lines/trunks accessing the public switched telephone network or over tandem trunks that connect to another networked system.

For example, an organization might have a main office in Boston and subsidiary offices in New Jersey and New York, connected by networked private tandem trunks that link three MERLIN MAGIX Integrated Systems. A user in the New Jersey office who wishes to make an outside call to the 617 area code (Boston) can do so through a line/trunk connected to the system in Boston. To accomplish this, ARS routes the call from New Jersey over tandem trunks, first to the New York system and then to the Boston system. Remote Access features are used at the New York system, through which the call is routed, and at the Boston system, where the outgoing call is sent to the public switched telephone network. The caller does not dial a Remote Access code. For example, a user might dial, 916175551211.

This section discusses the general steps for setting up ARS and Remote Access at the system where calls originate, at any intervening systems, and at the system where the calls are connected to the public switched telephone network. It includes the following two topics:

• Local Calls Routed to Other Systems. This topic explains the factors that you must consider when you set up your local system so that your users can make ARS calls via public switched telephone network trunks connected to another networked system.
  
  
• Network Calls Routed via the Local System. This topic explains the factors that you must consider when remote users, calling via ARS from a networked system, use public switched telephone network facilities connected to your own local system and/or have calls routed through your system to another system where they are sent to the PSTN.

Automatic Route Selection and Remote Access provide additional general information about these features.

Topics
	Description
	Switch Identifiers ARS, UDP Routing and Remote Access Local Calls Routed to Other Systems Network Calls Routed via the Local System
	At a Glance
	System Programming
	Feature Interactions