anchor.diff:      end,
       {ok, Remote} = gen_tcp:connect(Address,
                                      Port,
  -                                   [{active, false}, binary],
  +                                   [{active, false}, binary, {nodelay, true}],
                                      ?CONNECT_TIMEOUT),
       {ok, Remote}.
   
  
positive.code:     {ok, Socket} = gen_tcp:listen(BackPort, [{reuseaddr, true},
                                               {active, false},
                                               {ifaddr, BackAddress},
                                               binary]),
      back_accept(Socket).
  
  
negative.code:     ?LOG("connect to back.~n", []),
      {ok, Back} = gen_tcp:connect(BackAddress,
                                   BackPort,
                                   [{active, false}, binary, {nodelay, true}],
                                   ?CONNECT_TIMEOUT),
      ok = flip_send(Back, <<?PASSWORD>>),
      {ok, Back}.
  