FXS/ FXO Gateway| VoIP FXS Gateway

Difference between FXS / FXO Gateway

FXS stands for Foreign Exchange Subscriber that delivers the analog lines to the Subscriber/PBX/system. FXO stands for Foreign Exchange Office that is used to receives the input via subscriber/System.

FXS and FXO are the names of the ports used by analog phone lines (also known as POTS – Plain Old Telephone Service) or phones. The expression “POTS” was initially intended as a joke but is now used as a common expression in the telecommunications industry.

FXS (Foreign Exchange Subscriber) is the port that delivers the analog line to the subscriber. In other words, it is the “plug in the wall” that delivers a dial tone, battery current and ring voltage. This is the jack or interface to the phone system which FXO devices can be connected to.

FXO Gateway

FXO (Foreign Exchange Office) is the port that receives the analog line. It is the plug on the phone or fax machine or the plug(s) on your analog phone system. It delivers an on-hook/off-hook indication (loop closure). Since the FXO port is attached to a device, such as a fax or a phone, the device is often called the “FXO device.” This port establishes the connection to the analog line (FXS).

To connect analog phone lines to an IP phone system you need an FXO gateway. This allows you to connect the FXS port to the FXO port of the gateway, which then translates the analog phone line to a VoIP call.