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ITG User’s Guide
Chapter 6 Application Samples
This section discusses the various environments and situations where you can use the Internet
Telephony Gateway.
6.1 Module Configuration
Internet Telephony Gateway supports FXS and FXO modules.
FXS (Foreign Exchange Station)
FXS provides power and ringing signals to its interfacing equipment. It is
not intended for
connection to the Public Switched Telephone Network. It is a station loop start operation that
provides a connection to:
1. a standard, single-line analog telephone system
2. the line circuit of a key telephone system
3. a loop start trunk circuit of a Private Branch Exchange (PBX) that normally connects to
incoming Central Office circuits
FXO (Foreign Exchange Office)
FXO recognizes signals and draws current to indicate an active state. It is a trunk loop start
operation that emulates a single-line telephone to:
1. Central Office lines
2. PBX station
There are three basic environments that the ITG can be applied to. They are described in the
following sections.
Troubleshooting Tips 47