http://www.rfc-editor.org/rfc/rfc0907.txt
RFC 0907: Host Access Protocol specification, 1984-07-01T23:00:00-00:00This document specifies the Host Access Protocol (HAP). Although HAP was originally designed as the network-access level protocol for the DARPA/DCA sponsored Wideband Packet Satellite Network, it is intended that it evolve into a standard interface SATNET and TACNET (aka MATNET) as well as the Wideband Network. HAP is an experimental protocol, and will undergo further revision as new capabilities are added and/or different satellite networks are suported. Implementations of HAP should be performed in coordination with satellite network development and operations personnel.