diff --git a/library/RAN_Adapter.ttcnpp b/library/RAN_Adapter.ttcnpp
index 68e1e60..c90ffce 100644
--- a/library/RAN_Adapter.ttcnpp
+++ b/library/RAN_Adapter.ttcnpp
@@ -100,11 +100,17 @@
 	}
 	select (cfg.transport) {
 	case (BSSAP_TRANSPORT_AoIP, RANAP_TRANSPORT_IuCS) {
+		var template (omit) integer rctx;
+		if (not ispresent(cfg.rctx)) {
+			rctx := omit;
+		} else {
+			rctx := cfg.rctx;
+		}
 		ba.vc_M3UA := M3UA_CT.create(id & "-M3UA");
 		map(ba.vc_M3UA:SCTP_PORT, system:sctp);
 		/* connect MTP3 service provider (M3UA) to lower side of SCCP */
 		connect(ba.vc_M3UA:MTP3_SP_PORT, ba.vc_SCCP:MTP3_SCCP_PORT);
-		ba.vc_M3UA.start(f_M3UA_Emulation(cfg.sctp_addr, cfg.rctx));
+		ba.vc_M3UA.start(f_M3UA_Emulation(cfg.sctp_addr, rctx));
 		}
 #ifdef IPA_EMULATION_SCCP
 	case (BSSAP_TRANSPORT_SCCPlite_SERVER) {