System Telephony Networking Overview; Basic System Configurations - Nortel BCM50 Configuration Manual

Chapter 2

System telephony networking overview

The system supports both public and private networking for telephony traffic.
• The public network is created by PSTN trunk connections from a Central Office terminating
on a telephone system such as the BCM.
• A private network is created when the system is connected through dedicated PSTN lines or
VoIP trunks to other systems. This system may take several forms. At the simplest level, your
system may be behind a private PBX, which connects directly to the Central Office. A more
complicated system may be a node in a network of systems of various types, where calls not
only terminate at the system, but calls may need to be passed through the system to other
nodes unconnected to the originating node.
Refer to the following information:
•

"Basic system configurations"

• "Private network parameters" on page 37
Basic system configurations
In the most basic application, your system can provide support for system telephones to make and
receive calls over public network (PSTN) lines.
Two basic system telephony configurations
The following provides a broad overview of the telephony setup for two of the most common
office-telephone configurations.
PBX system
This setup is for larger offices which have fewer CO lines than telephones. In this case the lines are
pooled, and the line pool access is assigned to all DNs. There may also be a designated attendant
with a telephone that has all lines individually assigned.
Networking Configuration Guide
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