To verify the logical correctness of communication protocols, protocol
verification should be invoked in the design phase. In this paper, we
propose a new communicating finite state machine (CFSM)-based verific
ation method, which is called reverse protocol verification. By analyz
ing the properties of deadlock error, unspecified reception error and
channel overflow error, some candidate erroneous global states are gen
erated. Then, each candidate global state is checked whether there is
a path, i.e. a global state sequence, which can connect to the origina
l initial global state. If there is a path, then the candidate global
state is really an erroneous global state and the protocol under desig
ning does have some logical errors; alternatively, if there is no cand
idate global state or none of the candidate global states has a path,
then the protocol is error free. Based on the reverse method, an incre
mental protocol specification system (IPSS) has been developed on SUN
SPARC workstations. Usage and applications of IPSS are also presented
in this paper.