diff --git a/include/osmocom/msc/mncc.h b/include/osmocom/msc/mncc.h
index c8f3bfd6b..2beeb278f 100644
--- a/include/osmocom/msc/mncc.h
+++ b/include/osmocom/msc/mncc.h
@@ -110,24 +110,26 @@ struct gsm_call {
 #define GSM_MAX_SSVERSION	128
 #define GSM_MAX_USERUSER	128
 
-#define	MNCC_F_BEARER_CAP	0x0001
-#define MNCC_F_CALLED		0x0002
-#define MNCC_F_CALLING		0x0004
-#define MNCC_F_REDIRECTING	0x0008
-#define MNCC_F_CONNECTED	0x0010
-#define MNCC_F_CAUSE		0x0020
-#define MNCC_F_USERUSER		0x0040
-#define MNCC_F_PROGRESS		0x0080
-#define MNCC_F_EMERGENCY	0x0100
-#define MNCC_F_FACILITY		0x0200
-#define MNCC_F_SSVERSION	0x0400
-#define MNCC_F_CCCAP		0x0800
-#define MNCC_F_KEYPAD		0x1000
-#define MNCC_F_SIGNAL		0x2000
-#define MNCC_F_GCR		0x4000
+#define	MNCC_F_BEARER_CAP	0x00000001
+#define MNCC_F_CALLED		0x00000002
+#define MNCC_F_CALLING		0x00000004
+#define MNCC_F_REDIRECTING	0x00000008
+#define MNCC_F_CONNECTED	0x00000010
+#define MNCC_F_CAUSE		0x00000020
+#define MNCC_F_USERUSER		0x00000040
+#define MNCC_F_PROGRESS		0x00000080
+#define MNCC_F_EMERGENCY	0x00000100
+#define MNCC_F_FACILITY		0x00000200
+#define MNCC_F_SSVERSION	0x00000400
+#define MNCC_F_CCCAP		0x00000800
+#define MNCC_F_KEYPAD		0x00001000
+#define MNCC_F_SIGNAL		0x00002000
+#define MNCC_F_GCR		0x00004000
+#define MNCC_F_HIGHL_COMPAT	0x00008000
+#define MNCC_F_LOWL_COMPAT	0x00010000
 
 /* UPDATEME when adding new MNCC_F_* entries above */
-#define MNCC_F_ALL		0x7fff
+#define MNCC_F_ALL		0x0001ffff
 
 struct gsm_mncc {
 	/* context based information */
@@ -170,6 +172,10 @@ struct gsm_mncc {
 
 	/* A buffer to contain SDP ('\0' terminated) */
 	char		sdp[1024];
+
+	/* Additional information that extends current socket interface version. */
+	struct gsm_mncc_highl_compat	hlc;
+	struct gsm_mncc_lowl_compat	llc;
 };
 
 struct gsm_data_frame {