Lucent Technologies MERLIN LEGEND Release 6.0 Network Reference Manual page 44

MERLIN LEGEND Communications System Release 6.0
Network Reference 555-660-150
1 Introduction
Networking Concepts
communications. For users of the MERLIN LEGEND
Release 6.0 introduces the ability to realize significant cost and convenience
benefits through the networking of geographically separate locations in private
communications networks.
Briefly, a private communications network is an interconnected group of
communications systems, which may consist of MERLIN LEGEND
Communications Systems (all must be Release 6.0 or later), DEFINITY
Enterprise Communications Servers (ECS), and/or DEFINITY ProLogix Solutions.
People within each system, called local users , can exchange voice and data with
other individuals at communications systems in the network, called non-local
users . The systems in a private network may be located on the same campus, or
they may be separated by thousands of miles.
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 network, correct operation requires that planning be coordinated for all
systems. If a 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 network, a coordinating system manager
should be appointed. This person should keep copies of all system forms for all
systems in the 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 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.
February 1998
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Communications System,
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Issue 1
Page 1-2