John Day provided a fundamental theory of reliable transport in 1981 whereby connection management requires only timers bounded by a small factor of the Maximum Packet Lifetime and developed the Delta-1 protocol which allows a connection's state to be determined simply by bounding three timers, with no handshaking.
Richard Watson in 1981 provided a fundamental theory of reliable transport whereby connection management requires only timers bounded by a small factor of the Maximum Packet Lifetime (MPL). 
