digraph G {
        rankdir=LR;
        UE0 [label="UE"];
        UE1 [label="UE"];
        UE2 [label="UE"];
        UE3 [label="UE"];
        HNB0 [label="hNodeB"];
        HNB1 [label="hNodeB"];
        HNBGW [label="OsmoHNBGW"];
        MSC [label="OsmoMSC"];
        SGSN [label="OsmoSGSN"];
        STP [label="OsmoSTP"];

	UE0 -> HNB0;
	UE1 -> HNB0;
	UE2 -> HNB1;
	UE3 -> HNB1;
	HNB0 -> HNBGW [label="Iuh (RUA)"];
	HNB1 -> HNBGW [label="Iuh (RUA)"];
	HNBGW -> STP [label="Iu (SCCP/M3UA)"];
	STP -> MSC [label="Iu (SCCP/M3UA)", dir="back"];
	STP -> SGSN [label="Iu (SCCP/M3UA)", dir="back"];
}