diff --git a/library/NS_Emulation.ttcn b/library/NS_Emulation.ttcn
index 27acae2..d43d15c 100644
--- a/library/NS_Emulation.ttcn
+++ b/library/NS_Emulation.ttcn
@@ -81,6 +81,10 @@
 		var Result res;
 		/* Connect the UDP socket */
 		res := f_IPL4_connect(NSCP, mp_remote_ip, mp_remote_udp_port, mp_local_ip, mp_local_udp_port, 0, { udp := {}});
+		if (not ispresent(res.connId)) {
+			setverdict(fail, "Could not connect NS UDP socket, check your configuration");
+			self.stop;
+		}
 		g_conn_id := res.connId;
 		f_change_state(NSE_S_DEAD_BLOCKED);
 		/* Send the first NS-ALIVE to test the connection */