David D. Clark

Internet telephony is the integration and convergence of voice and data networks, services, and applications. The rapidly developing technology can convert analog voice input to digital data, send it over available networked channels, and then convert it back to voice output. Traditional circuit-switching networks such as telephone lines can be used together with packet-switching networks such as the Internet, thereby merging communication modes such as email, voice mail, fax, pager, real-time human speech, and multimedia videoconferencing into a single integrated system.