title: Finite State Machine of concurrent system
body: <p>I devise a new algorithm to use flow analysis technique to detect unreachability faults in concurrent systems. I need to find some finite state machine of large concurrent system (probably with hundreds of states) such as network protocols to do experiments. However, I can't find it on the web. Can anyone give me some clue?</p>
  
  <p>I need state machines that the transitions between them should be synchronized.</p>
  
  <p>Thanks in advance.</p>