diff --git a/openbsc/src/gb_proxy.c b/openbsc/src/gb_proxy.c
index f04d057..a4b432e 100644
--- a/openbsc/src/gb_proxy.c
+++ b/openbsc/src/gb_proxy.c
@@ -155,7 +155,7 @@
 static int gbprox_relay2sgsn(struct msgb *msg, uint16_t ns_bvci)
 {
 	DEBUGP(DGPRS, "NSEI=%u proxying to SGSN (NS_BVCI=%u, NSEI=%u)\n",
-		ns_bvci, gbcfg.nsip_sgsn_nsei);
+		msgb_nsei(msg), ns_bvci, gbcfg.nsip_sgsn_nsei);
 
 	msgb_bvci(msg) = ns_bvci;
 	msgb_nsei(msg) = gbcfg.nsip_sgsn_nsei;
@@ -170,7 +170,7 @@
 			  uint16_t ns_bvci)
 {
 	DEBUGP(DGPRS, "NSEI=%u proxying to to BSS (NS_BVCI=%u, NSEI=%u)\n",
-		ns_bvci, peer->nsvc->nsei);
+		msgb_nsei(msg), ns_bvci, peer->nsvc->nsei);
 
 	msgb_bvci(msg) = ns_bvci;
 	msgb_nsei(msg) = peer->nsvc->nsei;
diff --git a/openbsc/src/gprs_sndcp.c b/openbsc/src/gprs_sndcp.c
new file mode 100644
index 0000000..0d1a390
--- /dev/null
+++ b/openbsc/src/gprs_sndcp.c
@@ -0,0 +1,70 @@
+/* GPRS SNDCP protocol implementation as per 3GPP TS 04.65 */
+
+/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 <errno.h>
+#include <stdint.h>
+
+#include <osmocore/msgb.h>
+#include <osmocore/linuxlist.h>
+#include <osmocore/timer.h>
+#include <osmocore/talloc.h>
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/debug.h>
+#include <openbsc/gprs_bssgp.h>
+#include <openbsc/gprs_llc.h>
+
+/* Chapter 7.2: SN-PDU Formats */
+struct sndcp_common_hdr {
+	/* octet 1 */
+	uint8_t nsapi:4;
+	uint8_t more:1;
+	uint8_t type:1;
+	uint8_t first:1;
+	uint8_t spare:1;
+	/* octet 2 */
+	uint8_t pcomp;
+	uint8_t dcomp;
+};
+
+struct sndcp_udata_hdr {
+	/* octet 3 */
+	uint8_t npdu_high:4;
+	uint8_t seg_nr:4;
+	/* octet 4 */
+	uint8_t npdu_low;
+};
+
+/* Entry point for the LL-UNITDATA.indication */
+int sndcp_unitdata_ind(struct msgb *msg, uint8_t sapi, uint8_t *hdr, uint8_t len)
+{
+	struct sndcp_udata_hdr *suh;
+	uint16_t npdu;
+
+	if (suh->type == 0) {
+		LOGP(DGPRS, LOGL_ERROR, "SN-DATA PDU at unitdata_ind() function\n");
+		return -EINVAL;
+	}
+
+	npdu = (suh->npdu_high << 8) | suh->npdu_low;
+}
+