In 1987, the networking community became well aware of IP fragmentation's problems, and Richard Watson 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.
Based on this theory, Watson et al. developed the Delta-t protocol which allows a connection's state to be determined simply by bounding three timers, with no handshaking. 
