A multi-level approach has been proposed for generating test sequences for the control portion of communication protocols, given the specification. Test sequences generated using this approach have a high degree of fault coverage and the capability to recover from errors. The method does not assume the existence of an error-free reset input to move a protocol Finite State Machine (FSM) from any state to an initial state, unlike many other methods. The multi-level approach, thus, can be used to generate test sequences for real-world protocols. The methodology has been used to generate test sequences for a subset of the OSI Class 4 Transport Protocol and results are presented. © 1995.