anchor.diff:      [Bin];
   
   %% sent request
  -message(ack, <<_:32, 1, _/bits>>, _) ->
  +message(ack, <<_:32, 1:1, _/bits>>, _) ->
       [];
   
   %% sent answer or discarded request
   message(ack, _, N) ->
  -    [0 =< N, fun ?MODULE:message/3, N+1].
  +    [N =< 16, fun ?MODULE:message/3, N-1].
   
   %% ------------------------------------------------------------------------
   
  
positive.code:     message(Dir, Bin, N);
  
  %% incoming request
  message(recv, <<_:32, 1, _/bits>> = Bin, N) ->
      [Bin, 1 < N, fun ?MODULE:message/3, N-1];
  
  %% incoming answer
  message(recv, Bin, _) ->
  
negative.code:     LRef = ?util:listen(SN,
                          [T,
                           {sender, SS},
                           {message_cb, ST andalso {?MODULE, message, [0]}}
                           | [{packet, hd(?util:scramble([false, raw]))}
                              || T == sctp andalso CS]],
                          [{capabilities_cb, fun capx/2},
  