http://www.rfc-editor.org/rfc/rfc0833.txt
RFC 0833: Who talks TCP?, D. Smallberg1982-12-01T23:00:00-00:00This RFC is a survey of hosts to identify the implementation status of Telnet, FTP, and Mail on TCP. The list of hosts was taken from the NIC hostname table of 2-Dec-82. The tests were run on 14-Dec-82.