digraph G {
	rankdir=LR;
	edge [arrowhead=none];
	scale=2;

	bts2 [label="bts"]
	bts2 -> "osmo-bsc-sccplite" [label="Abis"]
	"osmo-bsc-sccplite" -> "3rd party MSC" [label="SCCPlite"]

	subgraph cluster_msc {
		label="osmo-msc";
		msc -> {vlr, smsc}
	}

	subgraph cluster_bts {
		bts
		pcu
	}

	bsc [label="osmo-bsc"]
	bts -> bsc [label="Abis"]

	sgsn [label="osmo-sgsn"]
	pcu -> sgsn
	{vlr,sgsn} -> "osmo-hlr" [label="GSUP"]

	hnb -> msc [label="IuCS"]
	hnb -> sgsn [label="IuPS"]

	bsc -> msc [label="A"]
}