19 Introduction
This section describes configuration of the Gateway applications. The Gateway application
refers to IP-to-Tel call routing and vice versa.
Notes:
• In some areas of the Web interface, the term "GW" application refers to
the Gateway applications, respectively.
• The terms IP-to-Tel and Tel-to-IP refer to the direction of the call relative
to the device. IP-to-Tel refers to calls received from the IP network and
destined to the PBX (i.e., telephone connected directly or indirectly to the
device); Tel-to-IP refers to calls received from telephones connected
directly to the device's FXS ports or from the PBX, and destined for the
IP network.
• FXO (Foreign Exchange Office) is the interface replacing the analog
telephone and connects to a Public Switched Telephone Network (PSTN)
line from the Central Office (CO) or to a Private Branch Exchange (PBX).
The FXO is designed to receive line voltage and ringing current, supplied
from the CO or the PBX (just like an analog telephone). An FXO VoIP
device interfaces between the CO/PBX line and the Internet.
• FXS (Foreign Exchange Station) is the interface replacing the Exchange
(i.e., the CO or the PBX) and connects to analog telephones, dial-up
modems, and fax machines. The FXS is designed to supply line voltage
and ringing current to these telephone devices. An FXS VoIP device
interfaces between the analog telephone devices and the Internet.