What does FXO Stand for? FXO is a shortening of the phrase for foreign exchange office. Foreign exchange office or FXO designates a telecomunication signaling interface or port that receives POTS, or plain old telephone service. It generates the off-hook and on-hook indications. If you are looking for a card or gateway that you can plug your Analog telephone lines in to you will need to have FXO ports.
What does PRI stand for? PRI stands for Primary Rate Interface. A PRI is a service in the Integrated Services Digital Network specification for carrying multiple T1 voice and data transmissions between a network and a user.