msc {
	hscale="2";
	ue [label="eUE"], nodeb [label="eNodeB"], mme [label="MME"], cbc [label="CBC"], cbe [label="CBE"];

	cbc <= cbe [label="New message (duration, geographic scope)"];

	cbc box cbc [label="Determine list of MMEs in scope"];
	mme <= cbc [label="SBc-AP WRITE-REPLACE WARNING MSG"];

	mme box mme [label="Determine list of eNodeBs in scope"];
	nodeb <= mme [label="S1-AP Write-Replace Warning Req"];
	nodeb => mme [label="S1-AP Write-Replace Warning Resp"];
	mme => cbc [label="SBc-AP Write-Replace Warning Ind"];

	ue <= nodeb [label="SIB Warning"];
}