diff --git a/mgw/MGCP_Test.ttcn b/mgw/MGCP_Test.ttcn
index 3decaed..844980f 100644
--- a/mgw/MGCP_Test.ttcn
+++ b/mgw/MGCP_Test.ttcn
@@ -135,12 +135,21 @@
 		sdp := sdp
 	}
 
-	template MgcpCommand ts_DLCX(MgcpTransId trans_id, charstring ep,  MgcpCallId call_id) := {
-		line := t_MgcpCmdLine("DLCX", trans_id, ep),
-		params := {
-			ts_MgcpParCallId(call_id)
-		},
-		sdp := omit
+	/* have a function that generates a template, rather than a template in order to handle
+	 * optional parameters */
+	function ts_DLCX(MgcpTransId trans_id, charstring ep, template MgcpCallId call_id := omit,
+			 template MgcpConnectionId conn_id := omit) return template MgcpCommand {
+		var template MgcpCommand cmd;
+		cmd.line := t_MgcpCmdLine("DLCX", trans_id, ep);
+		cmd.params := {};
+		cmd.sdp := omit;
+		if (isvalue(call_id)) {
+			f_mgcp_par_append(cmd.params, ts_MgcpParCallId(valueof(call_id)));
+			if (isvalue(conn_id)) {
+				f_mgcp_par_append(cmd.params, ts_MgcpParConnectionId(valueof(conn_id)));
+			}
+		}
+		return cmd;
 	}
 
 	/* SDP Templates */
@@ -347,7 +356,7 @@
 	}
 
 	/* Send DLCX and expect OK response */
-	function f_dlcx_ok(MgcpEndpoint ep, MgcpCallId call_id,
+	function f_dlcx_ok(MgcpEndpoint ep, template MgcpCallId call_id := omit,
 			   template MgcpConnectionId conn_id := omit) runs on dummy_CT {
 		var template MgcpCommand cmd;
 		var MgcpResponse resp;
@@ -359,13 +368,12 @@
 			params := *,
 			sdp := *
 		};
-		cmd := ts_DLCX(get_next_trans_id(), ep, call_id);
-		/* FIXME: add conn_id if present */
+		cmd := ts_DLCX(get_next_trans_id(), ep, call_id, conn_id);
 		resp := mgcp_transceive_mgw(cmd, rtmpl);
 	}
 
 	/* Send DLCX and accept any response */
-	function f_dlcx_ignore(MgcpEndpoint ep, MgcpCallId call_id,
+	function f_dlcx_ignore(MgcpEndpoint ep, template MgcpCallId call_id := omit,
 				template MgcpConnectionId conn_id := omit) runs on dummy_CT {
 		var template MgcpCommand cmd;
 		var MgcpResponse resp;
@@ -377,8 +385,7 @@
 			params := *,
 			sdp := *
 		};
-		cmd := ts_DLCX(get_next_trans_id(), ep, call_id);
-		/* FIXME: add conn_id if present */
+		cmd := ts_DLCX(get_next_trans_id(), ep, call_id, conn_id);
 		resp := mgcp_transceive_mgw(cmd, rtmpl);
 	}