public static void RegisterFactory(SocketOpenDelegate doOpen, SocketCloseDelegate doClose,
                                    SocketWriteDelegateManaged doWrite, SocketCompletedReceiveDelegateManaged doCompleteReceive)
 {
     _externalOpen             = doOpen;
     _externalClose            = doClose;
     _externalWrite            = doWrite;
     _externalCompletedReceive = doCompleteReceive;
 }