Vo IP ATAs (Analogue Telephone Adapters) bridge the technical gap between analogue telephones & fax machines in homes & businesses with making Vo IP calls over the Internet. By connecting an ordinary analogue telephone that is already in your house to a Vo IP Adaptor, you can benefit from making cheap, crystal clear Vo IP calls via a router which is connected to the Internet (and you dont need to turn on your PC). The Zoom Model 5821 Vo IP ATA (2 FXS + G.729) allows standard analog telephones to make & receive calls over a broadband internet connection. This model has 2 FXS ports to allow two Vo IP channels. Simply plug one or two conventional or cordless telephone into the adapter & then plug the telephone adapter into a broadband connected router or internet gateway. A minimum of 5 & often more attached phones to each port can be rung simultaniously using the built in ring generater. * Provides a FREE second & third phone line (2 FXS) * Supports Qo S * Supports auto provisioning by service providers * Call bridging allows your internet phone calls to be forwarded to a conventional phone number & gives remote access to internet calling services * 2 Year Warranty