A telephone network constructed according to the present invention includes call redirection functions that redirect calls intended for a toll-free-number or central number of an Internet Service Provider (ISP) to one of a plurality of available Internet Protocol (IP) gateways operated by the ISP. Call...http://www.google.fr/patents/US6459783?utm_source=gb-gplus-shareBrevet US6459783 - Internet service provider call redirection
