diff --git a/library/RTP_Emulation.ttcn b/library/RTP_Emulation.ttcn
index a3a0509..20e4299 100644
--- a/library/RTP_Emulation.ttcn
+++ b/library/RTP_Emulation.ttcn
@@ -264,10 +264,18 @@
 			}
 			res := RTP_CodecPort_CtrlFunct.f_IPL4_listen(RTP, g_local_host,
 								g_local_port, {udp:={}});
+			if (not ispresent(res.connId)) {
+				setverdict(fail, "Could not listen on RTP socket, check your configuration");
+				self.stop;
+			}
 			g_rtp_conn_id := res.connId;
 			tr_rtp.connId := g_rtp_conn_id;
 			res := RTP_CodecPort_CtrlFunct.f_IPL4_listen(RTCP, g_local_host,
 								g_local_port+1, {udp:={}});
+			if (not ispresent(res.connId)) {
+				setverdict(fail, "Could not listen on RTCP socket, check your configuration");
+				self.stop;
+			}
 			g_rtcp_conn_id := res.connId;
 			tr_rtcp.connId := g_rtcp_conn_id;
 			CTRL.reply(RTPEM_bind:{g_local_host, g_local_port});
@@ -282,10 +290,18 @@
 								g_remote_port,
 								g_local_host, g_local_port,
 								g_rtp_conn_id, {udp:={}});
+			if (not ispresent(res.connId)) {
+				setverdict(fail, "Could not connect to RTP socket, check your configuration");
+				self.stop;
+			}
 			res := RTP_CodecPort_CtrlFunct.f_IPL4_connect(RTCP, g_remote_host,
 								g_remote_port+1,
 								g_local_host, g_local_port+1,
 								g_rtcp_conn_id, {udp:={}});
+			if (not ispresent(res.connId)) {
+				setverdict(fail, "Could not connect to RTCP socket, check your configuration");
+				self.stop;
+			}
 			CTRL.reply(RTPEM_connect:{g_remote_host, g_remote_port});
 		}
 		[] CTRL.getcall(RTPEM_mode:{RTPEM_MODE_NONE}) {