diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index 98452ce..5df3577 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -258,6 +258,7 @@
 	len = snprintf(sdp_record, size,
 			"v=0\r\n"
 			"o=- %u 23 IN IP4 %s\r\n"
+			"s=-\r\n"
 			"c=IN IP4 %s\r\n"
 			"t=0 0\r\n",
 			endp->ci, addr, addr);
diff --git a/openbsc/tests/mgcp/mgcp_test.c b/openbsc/tests/mgcp/mgcp_test.c
index 0a3c47a..0f0e06c 100644
--- a/openbsc/tests/mgcp/mgcp_test.c
+++ b/openbsc/tests/mgcp/mgcp_test.c
@@ -84,6 +84,7 @@
 		 "\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 0 RTP/AVP 126\r\n"	\
@@ -94,6 +95,7 @@
 		 "\n"				\
 		 "v=0\r\n"			\
 		 "o=- 3 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 0 RTP/AVP 126\r\n"	\
@@ -118,6 +120,7 @@
 		 "\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 0 RTP/AVP 126\r\n"	\
@@ -209,6 +212,7 @@
 		 "\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 0 RTP/AVP 126\r\n"	\
@@ -220,6 +224,7 @@
 		 "\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 0 RTP/AVP 126\r\n"	\
@@ -230,6 +235,7 @@
 		 "\n"				\
 		 "v=0\r\n"			\
 		 "o=- 3 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 0 RTP/AVP 126\r\n"	\
@@ -250,6 +256,7 @@
 		 "\n"				\
 		 "v=0\r\n"			\
 		 "o=- 2 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 0 RTP/AVP 126\r\n"	\