msc {
	hscale = 2;

	chan [label="Channel"], rc [label="Radio Carrier"], bts [label="BTS"], bsc [label="BSC"];

	...;
	rc <= bsc   [label="(RC) SW Activate Req Ack"];
	rc <= bsc   [label="(RC) Activate SW"];
	rc => bsc   [label="(RC) Activate SW Ack"];
	rc => bsc   [label="(RC) STATE CHG REP (Disabled/Offline)"];
	rc => bsc   [label="(RC) SW Activated Report"];
	rc <= bsc   [label="(TRANSC) IPA RSL Connect"];
	rc => bsc   [label="(TRANSC) IPA RSL Connect Ack"];
	rc <= bsc   [label="(TRANSC) OPSTART"];
	rc => bsc   [label="(TRANSC) OPSTART Ack"];
	rc <= bsc   [label="(TRANSC) Change Adm State (Unlocked)"];
	rc => bsc   [label="(TRANSC) Change Adm State Ack (Unlocked)"];
	rc => bsc   [label="(TRANSC) STATE CHG REP (Disabled/Dependency/Unlocked)"];
	|||;
	chan <= bsc [label="(CHAN 0) Set Channel Attributes"];
	chan => bsc [label="(CHAN 0) Set Channel Attributes Ack"];
	chan <= bsc [label="(CHAN 0) OPSTART"];
	chan => bsc [label="(CHAN 0) OPSTART Ack"];
	chan <= bsc [label="(CHAN 0) Change Adm State (Unlocked)"];
	chan => bsc [label="(CHAN 0) Change Adm State Ack (Unlocked)"];
	chan => bsc [label="(CHAN 0) STATE CHG REP (Disabled/Dependency/Unlocked)"];
	...;
	chan <= bsc [label="(CHAN 7) Set Channel Attributes"];
	chan => bsc [label="(CHAN 7) Set Channel Attributes Ack"];
	chan <= bsc [label="(CHAN 7) OPSTART"];
	chan => bsc [label="(CHAN 7) OPSTART Ack"];
	chan <= bsc [label="(CHAN 7) Change Adm State (Unlocked)"];
	chan => bsc [label="(CHAN 7) Change Adm State Ack (Unlocked)"];
	chan => bsc [label="(CHAN 7) STATE CHG REP (Disabled/Dependency/Unlocked)"];
	|||;
	rc <= bsc   [label="(RC) Set Radio Carrier Attributes"];
	rc => bsc   [label="(RC) Set Radio Carrier Attributes Ack"];
	rc <= bsc   [label="(RC) OPSTART"];
	rc => bsc   [label="(RC) OPSTART Ack"];
	rc <= bsc   [label="(RC) Change Adm State (Unlocked)"];
	rc => bsc   [label="(RC) Change Adm State Ack (Unlocked)"];
	rc => bsc   [label="(RC) STATE CHG REP (Disabled/OK/Unlocked)"];
	rc => bsc   [label="(RC) STATE CHG REP (Enabled)"];
	rc => bsc   [label="(TRANSC) STATE CHG REP (Disabled/Offline)"];
	rc => bsc   [label="(TRANSC) STATE CHG REP (Enabled/OK)"];
	|||;
	chan => bsc [label="(CHAN 0) STATE CHG REP (Disabled/Offline)"];
	chan => bsc [label="(CHAN 0) STATE CHG REP (Enabled/OK)"];
	|||;
	bts => bsc  [label="(BTS) STATE CHG REP (Enabled/OK)"];
}