BSC_Tests: parametrize f_mo_l3_transceive()

Change-Id: I617a103e9dae8f16e3f3996c89e53ace49f7bfa8
Related: OS#3716
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 2efe2fd..544e79b 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -4464,17 +4464,18 @@
 	f_shutdown_helper();
 }
 
-private function f_mo_l3_transceive() runs on MSC_ConnHdlr
-{
+private function f_mo_l3_transceive(template (value) RslLinkId link_id := ts_RslLinkID_DCCH(0),
+				    template (present) OCT1 dlci := '00'O,
+				    octetstring l3 := '0123456789'O)
+runs on MSC_ConnHdlr {
 	/* The old lchan and conn should still be active. See that arbitrary L3
 	 * is still going through. */
-	var octetstring l3 := '0123456789'O;
-	RSL.send(ts_RSL_DATA_IND(g_chan_nr, valueof(ts_RslLinkID_DCCH(0)), l3));
+	RSL.send(ts_RSL_DATA_IND(g_chan_nr, link_id, l3));
 	var template PDU_BSSAP exp_data := {
 		    discriminator := '1'B,
 		    spare := '0000000'B,
-		    dlci := '00'O,
-		    lengthIndicator := 5,
+		    dlci := dlci,
+		    lengthIndicator := lengthof(l3),
 		    pdu := {
 			dtap := l3
 		    }