anchor.diff:      ok;
   buffer_size_client(Server, IP, Port, 
   		   Socket, Cnt, [Opts|T]) when is_list(Opts) ->
  -    io:format("buffer_size_client Cnt=~w setopts ~p.~n", [Cnt,Opts]),
  +    ?P("buffer_size_client Cnt=~w setopts ~p", [Cnt, Opts]),
       ok = inet:setopts(Socket, Opts),
       Server ! {self(),setopts,Cnt},
       receive {Server,setopts,Cnt} -> ok end,
       buffer_size_client(Server, IP, Port, Socket, Cnt+1, T);
   buffer_size_client(Server, IP, Port, 
   		   Socket, Cnt, [{B,Replies}|T]=Opts) when is_binary(B) ->
  -    io:format(
  -      "buffer_size_client Cnt=~w send size ~w expecting ~p.~n",
  -      [Cnt,size(B),Replies]),
  -    ok = gen_udp:send(Socket, IP, Port, <<Cnt,B/binary>>),
  -    receive
  -	{Server,Cnt,Reply} ->
  -	    Tag =
  -		if
  -		    is_tuple(Reply) ->
  -			element(1, Reply);
  -		    is_atom(Reply) ->
  -			Reply
  -		end,
  -	    case lists:member(Tag, Replies) of
  -		true -> ok;
  -		false ->
  -		    ct:fail({reply_mismatch,Cnt,Reply,Replies,
  -			     byte_size(B),
  -			     inet:getopts(Socket,
  -					  [sndbuf,recbuf])})
  -	    end,
  -	    buffer_size_client(Server, IP, Port, Socket, Cnt+1, T)
  -    after 1313 ->
  -	    buffer_size_client(Server, IP, Port, Socket, Cnt, Opts)
  +    ?P("buffer_size_client Cnt=~w send size ~w expecting ~p",
  +       [Cnt, size(B), Replies]),
  +    case gen_udp:send(Socket, IP, Port, <<Cnt,B/binary>>) of
  +	ok ->
  +	    receive
  +		{Server,Cnt,Reply} ->
  +		    Tag =
  +			if
  +			    is_tuple(Reply) ->
  +				element(1, Reply);
  +			    is_atom(Reply) ->
  +				Reply
  +			end,
  +		    case lists:member(Tag, Replies) of
  +			true -> ok;
  +			false ->
  +			    ct:fail({reply_mismatch,Cnt,Reply,Replies,
  +				     byte_size(B),
  +				     inet:getopts(Socket,
  +						  [sndbuf,recbuf])})
  +		    end,
  +		    buffer_size_client(Server, IP, Port, Socket, Cnt+1, T)
  +	    after 1313 ->
  +		    buffer_size_client(Server, IP, Port, Socket, Cnt, Opts)
  +	    end;
  +	{error, Reason} ->
  +	    ?P("<ERROR> Failed sending data ~w bytes of data: "
  +	       "~n   SndBuf: ~p"
  +	       "~n   Reason: ~p",
  +	       [size(B), inet:getopts(Socket, [sndbuf]), Reason]),
  +	    ct:fail(Reason)
       end.
   
   buffer_size_server(_, _, _, _, _, []) -> 
  
positive.code: 			 {unexpected,D}
  		 end;
  	     Error ->
  		 io:format(
  		   "buffer_size_server Cnt=~w received error ~w.~n",
  		   [Cnt,Error]),
  		 Error
  	 end},
      buffer_size_server(Client, IP, Port, Socket, Cnt+1, T).
  
negative.code: buffer_size_server(Client, IP, Port, 
  		   Socket, Cnt, [Opts|T]) when is_list(Opts) ->
      receive {Client,setopts,Cnt} -> ok end,
      ?P("buffer_size_server Cnt=~w setopts ~p", [Cnt, Opts]),
      ok = inet:setopts(Socket, Opts),
      Client ! {self(),setopts,Cnt},
      buffer_size_server(Client, IP, Port, Socket, Cnt+1, T);
  buffer_size_server(Client, IP, Port, 
  		   Socket, Cnt, [{B,_}|T]) when is_binary(B) ->
      ?P("buffer_size_server Cnt=~w expecting size ~w", [Cnt, size(B)]),
      Client ! 
  	{self(),Cnt,
  	 case buffer_size_server_recv(Socket, IP, Port, Cnt) of
  	     D when is_binary(D) ->
  		 SizeD = byte_size(D),
  		 ?P("buffer_size_server Cnt=~w received size ~w", [Cnt, SizeD]),
  		 case B of
  		     D ->
  			 correct;
  