Lucent Technologies 555-661-150 manual Merlin Legend Communications System Release

MERLIN LEGEND Communications System Release 6.1	Issue 1
Network Reference 555-661-150	August 1998
1 Introduction
Networking Concepts	Page 1-3

Communications systems are linked by special facilities called tandem trunks. These lines/trunks may be analog tandem tie trunks, T1-emulated tie trunks, or tandem Primary Rate Interface (PRI) trunks. As a group, they can be referred to as private network trunks, because they enable private networks.

Private networks are distinct from the public switched telephone network (PSTN) of facilities that link customers with central office (CO) service providers across the nation and the world. PSTN lines and trunks allow you to communicate with local and long-distance parties outside your organization.

Private communications networks are not simply communications systems chained together by tandem trunks. They also allow tandem switching, which permits a communications system to route a call from outside a local system to an outside facility on a non-local system. In addition, a MERLIN LEGEND Communications System can route calls from a tandem trunk to a local extension.

NOTE:

In this guide, switch is often used to mean communications system. For the purposes of this guide, a private network denotes a network with tandem trunks and tandem switching.

In a private network, correct operation requires that planning be coordinated for all systems. If a private network includes only two systems, this may simply mean that the system managers get together to assure that the correct programming is performed initially, that each manager has a copy of the system forms for the other system, and that the system managers discuss and agree upon any subsequent modifications. In a larger private network, a coordinating system manager should be appointed. This person should keep copies of all system forms for all systems in the private network. When a change must be made at a local system, it should be cleared through the coordinating system manager, who assesses the change as it affects the private network as a whole. If a change in one system requires modifications in other networked systems, the coordinating system manager ensures that these changes are made.

If these terms and concepts are new to you, do not be alarmed. There is no need to comprehend them immediately. You will gain a better understanding as you learn the practical applications of these concepts.