msc-test: improve error log on Assignment RTP port mismatch

Before this, if an Assignment Request contains an unexpected Transport Layer
Address, the test completely rejects the Assignment Request.

Instead, accept any tla in the Assignment, and compare the expected tla in the
Assignment's interleave action. Thus we directly get logging hinting at the tla
instead of a T_guard timeout.

Change-Id: I04847c10d6c3bf9e04cfda6e343dfd4a65be71a5
diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index fb2d888..5b0a125 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -1044,12 +1044,19 @@
 		}
 
 	//[g_pars.ran_is_geran] BSSAP.receive(tr_BSSMAP_AssignmentReq(omit, tla_ass)) -> value bssap {
-	[] BSSAP.receive(tr_BSSMAP_AssignmentReq(omit, tla_ass)) -> value bssap {
+	[] BSSAP.receive(tr_BSSMAP_AssignmentReq(omit)) -> value bssap {
 		log("f_mo_call_establish 4: rx Assignment Request");
 		var BSSMAP_IE_AoIP_TransportLayerAddress tla;
 		var BSSMAP_IE_SpeechCodec codec;
 		var BSSMAP_IE_Osmo_OsmuxCID osmuxCID;
 
+		if (tla_ass != bssap.pdu.bssmap.assignmentRequest.aoIPTransportLayer) {
+			log("Expected:", tla_ass);
+			log("Got:", bssap.pdu.bssmap.assignmentRequest.aoIPTransportLayer);
+			setverdict(fail, "MSC sent Assignment Request with unexpected AoIP Transport Layer IE");
+			mtc.stop;
+		}
+
 		tla := valueof(ts_BSSMAP_IE_AoIP_TLA4(f_inet_addr(cpars.bss_rtp_ip), cpars.bss_rtp_port));
 		codec := valueof(ts_BSSMAP_IE_SpeechCodec({ts_CodecFR}));
 		if (cpars.use_osmux) {