digraph {
	rankdir=LR;
	SIM [shape=rect];
	Reader [shape=rect];
	Computer [shape=rect];
	ComputerB [shape=rect];
	SIMtrace [shape=rect];
	Phone [shape=rect];

	SIM -> Reader [label="ISO-7816-2/3",dir=both];
	Reader -> Computer [label="USB CCID",dir=both];
	Computer -> ComputerB [label="IP based transport",dir=both];
	ComputerB -> SIMtrace [label="USB",dir=both];
	SIMtrace -> Phone [label="ISO-7816-2/3",dir=both];
}