http://www.rfc-editor.org/rfc/rfc1221.txt
RFC 1221: Host Access Protocol (HAP) specification: Version 2, W. Edmond1991-04-01T23:00:00-00:00This memo describes the Host Access Protocol implemented in the Terrestrial Wideband Network (TWBNET). This memo provides information for the Internet community. It does not specify an Internet standard.