Lucent Technologies 555-661-150 manual Tandem Trunking and Tandem Switching

MERLIN LEGEND Communications System Release 6.1	Issue 1
Network Reference 555-661-150	August 1998
1 Introduction
Tandem Trunking and Tandem Switching	Page 1-15

In Figure 1–5, the 3-system star configuration that we saw earlier has been modified to bring out some additional possibilities for private network configurations. Consider the following points as you review this graphic:

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All three systems are Release 6.1 or later systems and enjoy the advantages of tandem PRI trunks, including MLX telephone display capabilities and high-speed data communications among networked systems.

System B is a corporate data-processing center with no facilities connected to the PSTN. It is located in the same building as System A. Outside calls for System B arrive at System A. All intersystem calls pass through System A, the hub system.

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!CAUTION:

Unless networked systems are co-located, each system should have at least one loop-start line connected to the PSTN. The line is required to allow connection of a power-failure telephone to the Power-Failure Transfer (PFT) jack on a module as a power outage backup and for correct routing of emergency and other N11 (911, 411, etc.) calls. To ensure that the correct services are reached, if the loop-start line is used for emergency or other N11 calls, it should be assigned to the main pool. In this case, inter-exchange (IXC) calls determine the number of loop-starts required. Refer to Feature Reference guide for details on the PFT feature.

PRI dial-plan routed calls arrive at System C, where they are routed to a telemarketing calling group on System A. These agents primarily use the outside PRI facility connected to their system to return customer calls.

Both System B and System C share the voice mail/automated attendant application connected to System A. Calls are routed from the automated attendant to users on all these systems.

NOTE:

For Release 6.0 networks, Centralized Voice Mail is not available. Each system must have its own voice mail application for voice mail coverage. However, with Release 6.0 Version 11 and later systems, calls can be routed over the private network from a centralized automated attendant.