diff --git a/openbsc/src/nat/bsc_sccp.c b/openbsc/src/nat/bsc_sccp.c
new file mode 100644
index 0000000..8c14aa8
--- /dev/null
+++ b/openbsc/src/nat/bsc_sccp.c
@@ -0,0 +1,151 @@
+/* SCCP patching and handling routines */
+/*
+ * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2010 by On-Waves
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <openbsc/debug.h>
+#include <openbsc/bsc_nat.h>
+
+#include <osmocore/talloc.h>
+
+#include <string.h>
+
+/*
+ * SCCP patching below
+ */
+
+/* check if we are using this ref for patched already */
+static int sccp_ref_is_free(struct sccp_source_reference *ref, struct bsc_nat *nat)
+{
+	struct sccp_connections *conn;
+
+	llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+		if (memcmp(ref, &conn->patched_ref, sizeof(*ref)) == 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+/* copied from sccp.c */
+static int assign_src_local_reference(struct sccp_source_reference *ref, struct bsc_nat *nat)
+{
+	static u_int32_t last_ref = 0x50000;
+	int wrapped = 0;
+
+	do {
+		struct sccp_source_reference reference;
+		reference.octet1 = (last_ref >>  0) & 0xff;
+		reference.octet2 = (last_ref >>  8) & 0xff;
+		reference.octet3 = (last_ref >> 16) & 0xff;
+
+		++last_ref;
+		/* do not use the reversed word and wrap around */
+		if ((last_ref & 0x00FFFFFF) == 0x00FFFFFF) {
+			LOGP(DNAT, LOGL_NOTICE, "Wrapped searching for a free code\n");
+			last_ref = 0;
+			++wrapped;
+		}
+
+		if (sccp_ref_is_free(&reference, nat) == 0) {
+			*ref = reference;
+			return 0;
+		}
+	} while (wrapped != 2);
+
+	LOGP(DNAT, LOGL_ERROR, "Finding a free reference failed\n");
+	return -1;
+}
+
+int create_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
+{
+	struct sccp_connections *conn;
+
+	conn = talloc_zero(bsc->nat, struct sccp_connections);
+	if (!conn) {
+		LOGP(DNAT, LOGL_ERROR, "Memory allocation failure.\n");
+		return -1;
+	}
+
+	conn->real_ref = *parsed->src_local_ref;
+	if (assign_src_local_reference(&conn->patched_ref, bsc->nat) != 0) {
+		LOGP(DNAT, LOGL_ERROR, "Failed to assign a ref.\n");
+		talloc_free(conn);
+		return -1;
+	}
+
+	return 0;
+}
+
+void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
+{
+	struct sccp_connections *conn;
+
+	llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
+		if (memcmp(parsed->src_local_ref,
+			   &conn->real_ref, sizeof(conn->real_ref)) == 0) {
+			if (bsc != conn->bsc) {
+				LOGP(DNAT, LOGL_ERROR, "Someone else...\n");
+				continue;
+			}
+
+
+			llist_del(&conn->list_entry);
+			talloc_free(conn);
+			return;
+		}
+	}
+
+	LOGP(DNAT, LOGL_ERROR, "Unknown connection.\n");
+}
+
+struct bsc_connection *patch_sccp_src_ref_to_bsc(struct msgb *msg,
+						 struct bsc_nat_parsed *parsed,
+						 struct bsc_nat *nat)
+{
+	struct sccp_connections *conn;
+	llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+		if (memcmp(parsed->dest_local_ref,
+			   &conn->real_ref, sizeof(*parsed->dest_local_ref)) == 0) {
+			memcpy(parsed->dest_local_ref,
+			       &conn->patched_ref, sizeof(*parsed->dest_local_ref));
+			return conn->bsc;
+		}
+	}
+
+	return NULL;
+}
+
+struct bsc_connection *patch_sccp_src_ref_to_msc(struct msgb *msg,
+						 struct bsc_nat_parsed *parsed,
+						 struct bsc_nat *nat)
+{
+	struct sccp_connections *conn;
+	llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
+		if (memcmp(parsed->src_local_ref,
+			   &conn->real_ref, sizeof(*parsed->src_local_ref)) == 0) {
+			memcpy(parsed->src_local_ref,
+			       &conn->patched_ref, sizeof(*parsed->src_local_ref));
+			return conn->bsc;
+		}
+	}
+
+	return NULL;
+}