An Internet communication system is disclosed, that comprises a plurality of ISDN (Integrated Services Digital network) lines, an Internet network connected to the ISDN lines using IP (Internet Protocol) as a common protocol, at least one button telephone apparatus connected to the ISDN lines, and at...http://www.google.ca/patents/US6707793?utm_source=gb-gplus-sharePatent US6707793 - Button telephone apparatus and internet communication system
