<P> In 1983, TCP / IP protocols replaced NCP as the ARPANET's principal protocol, and the ARPANET then became one component of the early Internet . </P> <P> NCP provided a standard set of network services that could be shared by several applications running on a single host computer . This led to the evolution of application protocols that operated, more or less, independently of the underlying network service, and permitted independent advances in the underlying protocols . </P> <P> In 1971, Ray Tomlinson, of BBN sent the first network e-mail (RFC 524, RFC 561). By 1973, e-mail constituted 75 percent of ARPANET traffic . </P> <P> By 1973, the File Transfer Protocol (FTP) specification had been defined (RFC 354) and implemented, enabling file transfers over the ARPANET . </P>

When did arpanet connect for the first time