digraph G {
	rankdir=LR;

	HSS [label="HSS/HLR"];

	{ rank=same; MME; MSC; }

	SGW [label="S-GW"];
	PGW [label="P-GW"];

	UE -> eNodeB [label="Radio"];
	eNodeB -> MME [label="S1-MME\nControl Plane"];
	eNodeB -> SGW [label="S1-U\nUser Plane"];
	MME -> HSS [label="S6a\nDIAMETER"];
	MME -> SGW [label="S11"];
	SGW -> PGW [label="S5/S8\nGTP"];
	PGW -> Internet [label="SGi"];

	UE -> GERAN [label="Um"];
	UE -> UTRAN [label="Uu"];
	GERAN-> MSC [label="A"];
	UTRAN-> MSC [label="IuCS"];

	MME -> MSC [label="SGs"];

	MSC -> HSS [label="MAP"];
	MSC -> SMSC [label="MAP"];
}