Zoom Vo IP 5801-72-11F Phone Adapter 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 Model 5801 is a Voice over IP Telephone Adapter, which allows standard analog telephones to make & receive calls over a cable or ADSL Internet connection. A conventional phone or cordless phone is plugged into the adapter & then the adapter is plugged into a broadband connected router or Internet gateway. A minimum of five attached phones can be rung simultaneously using the built-in ring generator. The model supports industry-standard Session Initiation Protocol (SIPv 2) & works with a wide range of service providers & SIP-based Vo IP equipment. The Model 5801 also supports G.711 & i LBC Codecs.