A telephone gateway device that operates in a manner transparent to calling and called parties is provided. The gateway includes a port for connecting one or more POTS devices, a port for connecting to a local PSTN, a modem, and a network interface. The gateway selectively routes toll calls made on an...http://www.google.fr/patents/US20020114439?utm_source=gb-gplus-shareBrevet US20020114439 - User transparent internet telephony device and method
User transparent internet telephony device and method
