# MO Call on a classic E1 Abis BTS with classic E1 A BSC
# not actually supported by OsmoBSC (nor planned), for reference only
msc {
	hscale=2;
	ms [label="MS"], bts [label="E1 BTS"], bsc[label="OsmoBSC"], trau[label="TRAU"], m_sc[label="MSC"]; 

	ms box m_sc	[label="We assume a SDCCH is already established"];
	...;

	ms -> m_sc	[label="DTAP CC SETUP"];
	ms <- m_sc	[label="DTAP CC CALL PROCEEDING"];

	bsc <- m_sc 	[label="BSSAP ASSGN REQ"];
	bsc box m_sc	[label="E1 TS for PCM specified by CIC"];
	bts <- bsc 	[label="RSL CHAN ACT"];
	bts -> bsc 	[label="RSL CHAN ACT ACK"];
	bts box bsc	[label="E1 TS + 16k sub-slot configured for given lchan"];
	ms <-> bsc	[label="Assignment"];
	bsc -> m_sc	[label="BSSAP ASSGN CMPL"];

	...;
	trau <- m_sc	[label="PCM Audio in full E1 slot"];
	bts <- trau	[label="A-bis TRAU frames on 16k sub-slot"];

	...;
	ms <- m_sc	[label="DTAP CC CONNECT"];
	ms -> m_sc	[label="DTAP CC CONNECT ACK"];
	trau <-> m_sc	[label="PCM Audio in full E1 slot"];
	bts <-> trau	[label="A-bis TRAU frames on 16k sub-slot"];
	---		[label="Voice Call in Progress"];
	ms <- m_sc	[label="DTAP CC DISCONNET"];
	ms <- m_sc	[label="DTAP CC RELEASE"];
	ms <- m_sc	[label="DTAP CC RELEASE COMPL"];
	...;
	bsc <- m_sc	[label="BSSMAP CLEAR CMD"];
	bsc -> m_sc	[label="BSSMAP CLEAR COMPL"];
	bsc <- m_sc	[label="SCCP RLSD"];
	bsc -> m_sc	[label="SCCP RLC"];
}
