diff --git a/mgw/MGCP_Test.ttcn b/mgw/MGCP_Test.ttcn
index 53cc94c..5a83b3b 100644
--- a/mgw/MGCP_Test.ttcn
+++ b/mgw/MGCP_Test.ttcn
@@ -26,6 +26,7 @@
 						"\n" &
 						"v=0\r\n" &
 						"o=- 1 23 IN IP4 0.0.0.0\r\n" &
+						"s=-\r\n" &
 						"c=IN IP4 0.0.0.0\r\n" &
 						"t=0 0\r\n" &
 						"m=audio 4441 RTP/AVP 99\r\n" &