A VoIP analog adapter or analog telephone adapter (ATA) is a piece of VoIP equipment that allows individuals using a VoIP service to leverage their existing telephone to send and receive calls. A Voice over IP adapter connects to a regular telephone through an FXS (Foreign eXchange Station) port and to your cable modem or switch via an Ethernet port. Some VoIP adapters also have a FXO (Foreign eXchange Office) port that allows you to connect a POTS (Plain Old Telephone Service) line as well as a second Ethernet port.
