[Twisted-Python] PB and unstable network

I use PB in unstable network. The server remembers the last answer. Client detection disconnected, connected again, makes entry into the system and calls the function returns the last response (get_last_response). The answer, it returns a deferred saved earlier. If somewhere an error cycle repeats. All of this works until the lost communication does not happen at a time when Twisted sends data to a server. As the server in this situation does not receive a first request, and when you call get_last_response client receives the data that has already received. How can I check if an error in the client arrived data to the server or not?