http://www.rfc-editor.org/rfc/rfc0838.txt
RFC 0838: Who talks TCP?, D. Smallberg1983-01-01T23:00:00-00:00This 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 31-Dec-82. The tests were run on 18-Jan-83.