(ARPANET) A pioneering longhaul wide area network funded by DARPA (when it was still called "ARPA"?). It became operational in 1968 and served as the basis for early networking research, as well as a central backbone during the development of the Internet. The ARPANET consisted of individual packet switching computers interconnected by leased lines. Protocols used include FTP and telnet. It has now been replaced by NSFnet.