diff --git a/mgw/RTP_Endpoint.ttcn b/mgw/RTP_Endpoint.ttcn
index d33423a..3c939a2 100644
--- a/mgw/RTP_Endpoint.ttcn
+++ b/mgw/RTP_Endpoint.ttcn
@@ -109,8 +109,10 @@
 
 		res := f_IPL4_connect(RTP, sub.remote_name, sub.remote_port,
 					sub.local_name, sub.local_port, sub.connection_id, { udp := {} });
-		/* FIXME: Check for success (no res.errorCode) */
-
+		if (not ispresent(res.connId)) {
+			setverdict(fail, "Could not connect RTP, check your configuration");
+			self.stop;
+		}
 		/* connect without previous bind: save conenction id allocated by IPL4asp */
 		if (sub.connection_id == -1) {
 			sub.connection_id := res.connId;
@@ -132,7 +134,10 @@
 		var Result res;
 		rtp_endpoint_sub_close(RTP, sub);
 		res := f_IPL4_listen(RTP, sub.local_name, sub.local_port, { udp := {} });
-		/* FIXME: Check for success (no res.errorCode) */
+		if (not ispresent(res.connId)) {
+			setverdict(fail, "Could not listen to RTP, check your configuration");
+			self.stop;
+		}
 		sub.connection_id := res.connId;
 	}