anchor.diff:  send(SipSocket, Proto, _Host, _Port, _Message)
     when is_record(SipSocket, sipsocket), SipSocket#sipsocket.proto /= Proto ->
       {error, "Protocol mismatch"};
  -send(SipSocket, Proto, Host, Port, Message) when is_record(SipSocket, sipsocket), 
  +send(SipSocket, Proto, Host, Port, Message) when is_record(SipSocket, sipsocket),
   						 is_integer(Port), is_atom(Proto),
   						 Proto == udp; Proto == udp6 ->
       Pid = SipSocket#sipsocket.pid,
  
positive.code: 	{ok, Socket} ->
  	    Local = get_localaddr(Socket, "0.0.0.0"),
  	    SipSocket = #sipsocket{module=sipsocket_udp, proto=udp, pid=self(), data={Local, none}},
  	    NewSocketList = socketlist:add({listener, udp, Port}, self(), udp, Local, none, SipSocket, 
  					   0, State#state.socketlist),
  	    start_listening(T, Port, State#state{socket=Socket, socketlist=NewSocketList});
  	{error, Reason} ->
  
negative.code: %%           Port  = integer()
  %% Descrip.: Get a socket for a certain protocol (Proto).
  %%           sipsocket_udp is currently not multi-socket, we just have
  %%           a single UDP socket for each protocol and that is
  %%           'listener'. Locate and return it.
  %% Returns : {reply, Reply, State}
  %%           Reply = {ok, SipSocket} |
  