anchor.diff:      M = if SslOpts -> ssl; true -> Mod end,
       setopts(M, Sock),
       putr(?REF_KEY, Ref),
  -    infinity == Tmo orelse erlang:start_timer(Tmo, self(), flush),
       #transport{parent = Pid,
                  module = M,
                  socket = Sock,
  
positive.code:             S#transport{frag = B};
          Frag ->
              setopts(M, Sock),
              S#transport{frag = Frag}
      end;
  
  %% Incoming message.
  
negative.code:   when P == tcp, not B;
         P == ssl, B ->
      setopts(M, Sock),
      start_fragment_timer(recv(Bin, S));
  
  %% Capabilties exchange has decided on whether or not to run over TLS.
  transition({diameter, {tls, Ref, Type, B}}, #transport{parent = Pid}
  