I have a very simple application that try to open a connection on a port on the local computer and if it has no program listening, it execute a program file, else if it find a answer program, it send a string ( about 50/80 characters ). After the upgrade to 2.0.x, it don't want to work well, because if it has no response, it open the program correctly, but if it has response, it send the message, but the message don't arrive to the listener. After some tries, I see that into my code, I call reactor.stop before, I think, reactor has ended to send my message. I resolve this with a simple code: reactor.callLater(1, reactor.stop). My question is: when I call reactor.stop, it close all, also if there are some communication in progress? Is there another method to close the communication (and in my case the program) when I'm sure that all the works are ended? Thanks, Michele My code: class ConneExist(protocol.Protocol): #The server is listening def connectionMade(self): self.transport.write(file_name_path) out() def out(): # reactor.stop() <- here is a problem reactor.callLater(1, reactor.stop)