A Foreign Exchange Office, or FXO, is a telephone interface that receives POTS, or Plain old telephone service. It generates the on-hook and off-hook indicators used to signal a loop closure at the FXO's end of the circuit. Analog telephone handsets, fax machines and (analogue) modems are FXO devices. FXO interfaces are also available for computers and networking equipment to allow these to interact directly with POTS systems. These are commonly found in devices acting as gateways between VoIP systems and the PSTN. The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device which is used to transmit and receive sound (most commonly voice and speech) across distance. ... Plain old telephone service, or POTS, are the services available from analogue telephones prior to the introduction of electronic telephone exchanges into the public switched telephone network. ... A transceiver is a device that has a transmitter and receiver which is combined into a one unit. ... A modem (a portmanteau word constructed from modulator and demodulator) is a device that modulates a carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. ... IP Telephony, also called Internet telephony, is the technology that makes it possible to have a telephone conversation over the Internet or a dedicated Internet Protocol (IP) network instead of dedicated voice transmission lines. ... The public switched telephone network (PSTN) is the concatenation of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the concatenation of the worlds public IP-based packet-switched networks. ...

The FXO must be connected to the Foreign exchange station interface, or FXS interface. The FXS interface delivers the familiar dial tone and ring tone to the FXO and supplies the power for the FXO device to work. A Foreign Exchange Station, or FXS, is a telephone interface which provides battery power, sends dialtone, and generates ringing voltage. ...

In a nutshell

FXO is any device that, from the point of view of a telephone exchange, seems to be a regular telephone. As such, it should be able to accept ring signals, go on-hook and off-hook, and send and receive voice signals.

See also

• Foreign exchange station (FXS)

A Foreign Exchange Station, or FXS, is a telephone interface which provides battery power, sends dialtone, and generates ringing voltage. ...

External links

• More Info- VoIP Wiki