digraph G {
	rankdir=LR
	labelloc=t; label="OsmoBSC MSC-pool conn (re)direction"

	subgraph cluster_msc_usable {
		style=dotted; label="MSC usable\n(successful BSSMAP RESET)"

		allowed [label="MSC\nallow-attach"]
		notallowed [label="MSC\nno allow-attach\n(MSC should respond\nwith null-NRI)"]
	}

	subgraph cluster_msc_unusable {
		style=dotted; label="MSC unusable\n(no link)"
		allowed_unusable [label="MSC\nallow-attach"]
		notallowed_unusable [label="MSC\nno allow-attach"]
	}

	TMSI_unknown_NRI [label="TMSI, NRI unknown"]
	TMSI_null_NRI [label="TMSI, null-NRI"]
	TMSI_known_NRI [label="TMSI, NRI known"]

	IMSI -> allowed
	TMSI_unknown_NRI -> allowed
	TMSI_null_NRI -> allowed
	TMSI_known_NRI -> allowed
	TMSI_known_NRI -> notallowed

	never [style=dotted]
	never -> {allowed_unusable, notallowed_unusable} [style=dotted]
}