ns2: add support for frame relay

Add support for frame relay over dahdi hdlc device.
It's supporting lmi by q933 and supports both
SGSN and BSS.

Change-Id: Id3b49f93d33c271f77cd9c9db03cde6b727a4d30

10 files changed, 1813 insertions, 23 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index 44ff3789..31732907 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -60,6 +60,7 @@ nobase_include_HEADERS = \
 		       osmocom/ctrl/control_cmd.h \
 		       osmocom/ctrl/control_if.h \
 		       osmocom/ctrl/ports.h \
+                       osmocom/gprs/frame_relay.h \
                        osmocom/gprs/gprs_bssgp.h \
                        osmocom/gprs/gprs_bssgp_bss.h \
                        osmocom/gprs/gprs_msgb.h \
diff --git a/include/osmocom/gprs/frame_relay.h b/include/osmocom/gprs/frame_relay.h
new file mode 100644
index 00000000..b382ea86
--- /dev/null
+++ b/include/osmocom/gprs/frame_relay.h
@@ -0,0 +1,136 @@
+/*! \file frame_relay.h */
+
+/* (C) 2020 Harald Welte <laforge@gnumonks.org>
+ * (C) 2020 sysmocom - s.f.m.c. GmbH
+ * Author: Alexander Couzens <lynxis@fe80.eu>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/utils.h>
+
+#include <stdint.h>
+
+struct osmo_tdef;
+struct msgb;
+
+enum osmo_fr_role {
+	FR_ROLE_USER_EQUIPMENT,
+	FR_ROLE_NETWORK_EQUIPMENT,
+};
+
+extern const struct value_string osmo_fr_role_names[];
+
+static inline const char *osmo_fr_role_str(enum osmo_fr_role role) {
+	return get_value_string(osmo_fr_role_names, role);
+}
+
+struct osmo_fr_network {
+	struct llist_head links;
+
+	unsigned int n391; 		/* full status polling counter */
+	unsigned int n392;		/* error threshold */
+	unsigned int n393;		/* monitored events count */
+
+	struct osmo_tdef *T_defs;	/* T391, T392 */
+};
+
+struct osmo_fr_dlc;
+
+/* Frame Relay Link */
+struct osmo_fr_link {
+	/* list in osmo_fr_network.links */
+	struct llist_head list;
+	struct osmo_fr_network *net;
+	enum osmo_fr_role role;
+	/* human-readable name */
+	const char *name;
+
+	/* value of the last received send sequence number field in the
+	 * link integrity verification information element */
+	uint8_t last_rx_seq;
+
+	/* value of the send sequence number field of the last link
+	 * integrity verification information element sent */
+	uint8_t last_tx_seq;
+
+	struct osmo_timer_list t391;
+	struct osmo_timer_list t392;
+
+	unsigned int polling_count;
+	unsigned int err_count;
+	unsigned int succeed;
+	/* the type of the last status enquiry */
+	uint8_t expected_rep;
+	bool state;
+
+	/* list of data link connections at this link */
+	struct llist_head dlc_list;
+
+	int (*unknown_dlc_rx_cb)(void *cb_data, struct msgb *msg);
+	void *unknown_dlc_rx_cb_data;
+
+	int (*tx_cb)(void *data, struct msgb *msg);
+	void *tx_cb_data;
+};
+
+/* Frame Relay Data Link Connection */
+struct osmo_fr_dlc {
+	/* entry in fr_link.dlc_list */
+	struct llist_head list;
+	struct osmo_fr_link *link;
+
+	uint16_t dlci;
+
+	/* is this DLC marked active for traffic? */
+	bool active;
+	/* was this DLC newly added? */
+	bool add;
+	/* is this DLC about to be destroyed */
+	bool del;
+
+	/* the local state needs to be transfered to the
+	 * UE. The NET must wait until the UE confirms it implicited by a seq number check */
+	bool state_send;
+
+	int (*rx_cb)(void *cb_data, struct msgb *msg);
+	void *rx_cb_data;
+};
+
+/* allocate a frame relay network */
+struct osmo_fr_network *osmo_fr_network_alloc(void *ctx);
+
+/* allocate a frame relay link in a given network */
+struct osmo_fr_link *osmo_fr_link_alloc(struct osmo_fr_network *net, enum osmo_fr_role role, const char *name);
+
+/* free a frame link in a given network */
+void osmo_fr_link_free(struct osmo_fr_link *link);
+
+/* allocate a data link connectoin on a given framerelay link */
+struct osmo_fr_dlc *osmo_fr_dlc_alloc(struct osmo_fr_link *link, uint16_t dlci);
+void osmo_fr_dlc_free(struct osmo_fr_dlc *dlc);
+
+struct osmo_fr_dlc *osmo_fr_dlc_by_dlci(struct osmo_fr_link *link, uint16_t dlci);
+
+int osmo_fr_rx(struct msgb *msg);
+int osmo_fr_tx_dlc(struct msgb *msg);
diff --git a/include/osmocom/gprs/gprs_ns2.h b/include/osmocom/gprs/gprs_ns2.h
index 3b47b3c0..dd4f4d5a 100644
--- a/include/osmocom/gprs/gprs_ns2.h
+++ b/include/osmocom/gprs/gprs_ns2.h
@@ -8,9 +8,11 @@
 
 #include <osmocom/core/prim.h>
 #include <osmocom/gprs/protocol/gsm_08_16.h>
+#include <osmocom/gprs/frame_relay.h>
 
 struct osmo_sockaddr;
 struct osmo_sockaddr_str;
+struct osmo_fr_network;
 
 struct gprs_ns2_inst;
 struct gprs_ns2_nse;
@@ -146,6 +148,23 @@ struct gprs_ns2_vc_bind *gprs_ns2_ip_bind_by_sockaddr(struct gprs_ns2_inst *nsi,
 						      const struct osmo_sockaddr *sockaddr);
 void gprs_ns2_bind_set_mode(struct gprs_ns2_vc_bind *bind, enum gprs_ns2_vc_mode mode);
 
+/* FR VL driver */
+struct gprs_ns2_vc_bind *gprs_ns2_fr_bind_by_netif(
+		struct gprs_ns2_inst *nsi,
+		const char *netif);
+const char *gprs_ns2_fr_bind_netif(struct gprs_ns2_vc_bind *bind);
+int gprs_ns2_fr_bind(struct gprs_ns2_inst *nsi,
+		     const char *netif,
+		     struct osmo_fr_network *fr_network,
+		     enum osmo_fr_role fr_role,
+		     struct gprs_ns2_vc_bind **result);
+int gprs_ns2_is_fr_bind(struct gprs_ns2_vc_bind *bind);
+struct gprs_ns2_vc *gprs_ns2_fr_nsvc_by_dlci(struct gprs_ns2_vc_bind *bind, uint16_t dlci);
+struct gprs_ns2_vc *gprs_ns2_fr_connect(struct gprs_ns2_vc_bind *bind,
+					uint16_t nsei,
+					uint16_t nsvci,
+					uint16_t dlci);
+
 /* create a VC connection */
 struct gprs_ns2_vc *gprs_ns2_ip_connect(struct gprs_ns2_vc_bind *bind,
 					const struct osmo_sockaddr *remote,
@@ -188,6 +207,7 @@ int gprs_ns2_frgre_bind(struct gprs_ns2_inst *nsi,
 			int dscp,
 			struct gprs_ns2_vc_bind **result);
 int gprs_ns2_is_frgre_bind(struct gprs_ns2_vc_bind *bind);
+uint16_t gprs_ns2_fr_nsvc_dlci(struct gprs_ns2_vc *nsvc);
 
 struct gprs_ns2_vc *gprs_ns2_nsvc_by_sockaddr_nse(
 		struct gprs_ns2_nse *nse,
diff --git a/src/gb/Makefile.am b/src/gb/Makefile.am
index 65c35529..41b6c6db 100644
--- a/src/gb/Makefile.am
+++ b/src/gb/Makefile.am
@@ -21,9 +21,9 @@ libosmogb_la_LIBADD = $(TALLOC_LIBS) \
 libosmogb_la_SOURCES = gprs_ns.c gprs_ns_frgre.c gprs_ns_vty.c gprs_ns_sns.c \
 		  gprs_bssgp.c gprs_bssgp_util.c gprs_bssgp_vty.c \
 		  gprs_bssgp_bss.c \
-		  gprs_ns2.c gprs_ns2_udp.c gprs_ns2_frgre.c gprs_ns2_vc_fsm.c gprs_ns2_sns.c \
+		  gprs_ns2.c gprs_ns2_udp.c gprs_ns2_frgre.c gprs_ns2_fr.c gprs_ns2_vc_fsm.c gprs_ns2_sns.c \
 		  gprs_ns2_message.c gprs_ns2_vty.c \
-		  common_vty.c
+		  common_vty.c frame_relay.c
 endif
 
 EXTRA_DIST = libosmogb.map
diff --git a/src/gb/frame_relay.c b/src/gb/frame_relay.c
new file mode 100644
index 00000000..f8902095
--- /dev/null
+++ b/src/gb/frame_relay.c
@@ -0,0 +1,966 @@
+/*! \file frame_relay.c
+ * Implement frame relay/PVC by Q.933
+ */
+/* (C) 2020 Harald Welte <laforge@gnumonks.org>
+ * (C) 2020 sysmocom - s.f.m.c. GmbH
+ * Author: Alexander Couzens <lynxis@fe80.eu>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include <osmocom/gprs/frame_relay.h>
+#include <osmocom/core/endian.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/tdef.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/msgb.h>
+
+#include <osmocom/gsm/tlv.h>
+
+#define LOGPFRL(frl, lvl, fmt, args ...) \
+	LOGP(DFR, lvl, "%s: " fmt, (frl)->name, ## args)
+
+#define DFR DLNS
+
+/* Table 4-2/Q.931 */
+enum q931_msgtype {
+	/* Call establishment message */
+	Q931_MSGT_ALERTING		= 0x01,
+	Q931_MSGT_CALL_PROCEEDING	= 0x02,
+	Q931_MSGT_CONNECT		= 0x07,
+	Q931_MSGT_CONNECT_ACK		= 0x0f,
+	Q931_MSGT_PROGRESS		= 0x03,
+	Q931_MSGT_SETUP			= 0x05,
+	Q931_MSGT_SETUP_ACK		= 0x0d,
+	/* Call information phase message */
+	Q931_MSGT_RESUME		= 0x26,
+	Q931_MSGT_RESUME_ACK		= 0x2e,
+	Q931_MSGT_RESUME_REJ		= 0x22,
+	Q931_MSGT_SUSPEND		= 0x25,
+	Q931_MSGT_SUSPEND_ACK		= 0x2d,
+	Q931_MSGT_USER_INFO		= 0x20,
+	/* Call clearing message */
+	Q931_MSGT_DISCONNECT		= 0x45,
+	Q931_MSGT_RELEASE		= 0x4d,
+	Q931_MSGT_RELEASE_COMPLETE	= 0x5a,
+	Q931_MSGT_RESTART		= 0x46,
+	Q931_MSGT_RESTART_ACK		= 0x4e,
+	/* Miscellaneous messages */
+	Q931_MSGT_SEGMENT		= 0x60,
+	Q931_MSGT_CONGESTION_CONTROL	= 0x79,
+	Q931_MSGT_IFORMATION		= 0x7b,
+	Q931_MSGT_NOTIFY		= 0x6e,
+	Q931_MSGT_STATUS		= 0x7d,
+	Q931_MSGT_STATUS_ENQUIRY	= 0x75,
+};
+
+
+/* Figure A.1/Q.933 Report type information element */
+enum q933_type_of_report {
+	Q933_REPT_FULL_STATUS		= 0x00,
+	Q933_REPT_LINK_INTEGRITY_VERIF	= 0x01,
+	Q933_REPT_SINGLE_PVC_ASYNC_STS	= 0x02,
+};
+
+/* Q.933 Section A.3 */
+enum q933_iei {
+	Q933_IEI_REPORT_TYPE		= 0x51,
+	Q933_IEI_LINK_INT_VERIF		= 0x53,
+	Q933_IEI_PVC_STATUS		= 0x57,
+};
+
+/* Q.933 Section A.3.3 */
+enum q933_pvc_status {
+	Q933_PVC_STATUS_DLC_ACTIVE = 0x02,
+	Q933_PVC_STATUS_DLC_DELETE = 0x04,
+	Q933_PVC_STATUS_DLC_NEW = 0x08,
+};
+
+
+
+#define LAPF_UI			0x03	/* UI control word */
+#define Q931_PDISC_CC		0x08	/* protocol discriminator */
+#define LMI_Q933A_CALLREF	0x00	/* NULL call-ref */
+
+/* LMI DLCI values */
+#define LMI_Q933A_DLCI		0	/* Q.933A DLCI */
+#define LMI_CISCO_DLCI		1023	/* Cisco DLCI */
+
+/* maximum of supported */
+#define MAX_SUPPORTED_PVC	10
+
+/* TODO: add counters since good connection */
+
+/* Message header of the L3 payload of a Q.933 Annex A message */
+struct q933_a_hdr {
+	uint8_t prot_disc;
+	uint8_t call_ref;
+	uint8_t msg_type;
+} __attribute__((packed));
+
+/* Value part of the Q.933 Annex A.3.3 IE */
+struct q933_a_pvc_sts {
+	uint8_t dlci_msb:6,
+		spare:1,
+		ext0:1;
+	uint8_t space1:3,
+		dlci_lsb:4,
+		ext1:1;
+	uint8_t reserved:1,
+		active:1,
+		delete:1,
+		new:1,
+		spare2:3,
+		ext2:1;
+
+} __attribute__((packed));
+
+/* RX Message: 14 [ 00 01 03 08 00 75  95 01 01 00 03 02 01 00 ] */
+/* RX Message: 13 [ 00 01 03 08 00 75  51 01 00  53 02 01 00 ] */
+
+const struct value_string osmo_fr_role_names[] = {
+	{ FR_ROLE_USER_EQUIPMENT,	"USER" },
+	{ FR_ROLE_NETWORK_EQUIPMENT,	"NETWORK" },
+	{ 0, NULL }
+};
+
+/* Table A.4/Q.933 */
+struct osmo_tdef fr_tdefs[] = {
+	{
+		.T=391,
+		.default_val = 10,
+		.min_val = 5,
+		.max_val = 30,
+		.desc = "Link integrity verification polling timer",
+			.unit =  OSMO_TDEF_S,
+	}, {
+		.T=392,
+		.default_val = 15,
+		.min_val = 5,
+		.max_val = 30,
+		.desc = "Polling verification timer",
+				.unit =  OSMO_TDEF_S,
+	},
+	{}
+};
+
+static const struct tlv_definition q933_att_tlvdef = {
+	.def = {
+		[Q933_IEI_REPORT_TYPE] = { TLV_TYPE_TLV },
+		[Q933_IEI_LINK_INT_VERIF] = { TLV_TYPE_TLV },
+		[Q933_IEI_PVC_STATUS] = { TLV_TYPE_TLV },
+	},
+};
+
+static void check_link_state(struct osmo_fr_link *link, bool valid);
+
+static inline uint16_t q922_to_dlci(const uint8_t *hdr)
+{
+	return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
+}
+
+
+static inline void dlci_to_q922(uint8_t *hdr, uint16_t dlci)
+{
+	hdr[0] = (dlci >> 2) & 0xFC;
+	hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
+}
+
+/* allocate a message buffer and put Q.933 Annex A headers (L2 + L3) */
+static struct msgb *q933_msgb_alloc(uint16_t dlci, uint8_t prot_disc, uint8_t msg_type)
+{
+	struct msgb *msg = msgb_alloc_headroom(1600+64, 64, "FR Q.933 Tx");
+	struct q933_a_hdr *qh;
+
+	if (!msg)
+		return NULL;
+
+	msg->l1h = msgb_put(msg, 2);
+	dlci_to_q922(msg->l1h, dlci);
+
+	/* LAPF UI control */
+	msg->l2h = msgb_put(msg, 1);
+	*msg->l2h = LAPF_UI;
+
+	msg->l3h = msgb_put(msg, sizeof(*qh));
+	qh = (struct q933_a_hdr *) msg->l3h;
+	qh->prot_disc = prot_disc;
+	qh->call_ref = LMI_Q933A_CALLREF;
+	qh->msg_type = msg_type;
+
+	return msg;
+}
+
+/* obtain the [next] transmit sequence number */
+static uint8_t link_get_tx_seq(struct osmo_fr_link *link)
+{
+	/* The {user equipment, network} increments the send sequence
+	 * counter using modulo 256. The value zero is skipped. */
+	link->last_tx_seq++;
+	if (link->last_tx_seq == 0)
+		link->last_tx_seq++;
+
+	return link->last_tx_seq;
+}
+
+/* Append PVC Status IE according to Q.933 A.3.2 */
+static void msgb_put_link_int_verif(struct msgb *msg, struct osmo_fr_link *link)
+{
+	uint8_t link_int_tx[2];
+	link_int_tx[0] = link_get_tx_seq(link);
+	link_int_tx[1] = link->last_rx_seq;
+	msgb_tlv_put(msg, Q933_IEI_LINK_INT_VERIF, 2, link_int_tx);
+}
+
+static void dlc_destroy(struct osmo_fr_dlc *dlc)
+{
+	llist_del(&dlc->list);
+	talloc_free(dlc);
+}
+
+/* Append PVC Status IE according to Q.933 A.3.3 */
+static void msgb_put_pvc_status(struct msgb *msg, struct osmo_fr_dlc *dlc)
+{
+	uint8_t ie[3];
+
+	ie[0] = (dlc->dlci >> 4) & 0x3f;
+	/* extension bits */
+	ie[1] = 0x80 | ((dlc->dlci & 0xf) << 3);
+	/* extension bits */
+	ie[2] = 0x80;
+
+	/* FIXME: validate: this status should be added as long it's not yet acked by the remote */
+	if (dlc->active)
+		ie[2] |= Q933_PVC_STATUS_DLC_ACTIVE;
+
+	if (dlc->add) {
+		ie[2] |= Q933_PVC_STATUS_DLC_NEW;
+		/* we've reported it as new once, reset the status */
+	}
+
+	if (dlc->del) {
+		ie[2] |= Q933_PVC_STATUS_DLC_DELETE;
+		/* we've reported it as deleted once, destroy it */
+		dlc_destroy(dlc);
+	}
+
+	msgb_tlv_put(msg, Q933_IEI_PVC_STATUS, 3, ie);
+}
+
+/* Send a Q.933 STATUS ENQUIRY given type over given link */
+static int tx_lmi_q933_status_enq(struct osmo_fr_link *link, uint8_t rep_type)
+{
+	struct msgb *resp;
+
+	resp = q933_msgb_alloc(0, Q931_PDISC_CC, Q931_MSGT_STATUS_ENQUIRY);
+	if (!resp)
+		return -1;
+	resp->dst = link;
+	link->expected_rep = rep_type;
+
+	/* Table A.2/Q.933 */
+	msgb_tlv_put(resp, Q933_IEI_REPORT_TYPE, 1, &rep_type);
+	msgb_put_link_int_verif(resp, link);
+
+	return link->tx_cb(link->tx_cb_data, resp);
+}
+
+/* Send a Q.933 STATUS of given type over given link */
+static int tx_lmi_q933_status(struct osmo_fr_link *link, uint8_t rep_type)
+{
+	struct osmo_fr_dlc *dlc;
+	struct msgb *resp;
+
+	resp = q933_msgb_alloc(0, Q931_PDISC_CC, Q931_MSGT_STATUS);
+	if (!resp)
+		return -1;
+
+	resp->dst = link;
+
+	/* Table A.1/Q.933 */
+	msgb_tlv_put(resp, Q933_IEI_REPORT_TYPE, 1, &rep_type);
+	switch (rep_type) {
+	case Q933_REPT_FULL_STATUS:
+		msgb_put_link_int_verif(resp, link);
+		llist_for_each_entry(dlc, &link->dlc_list, list) {
+			if (dlc->add || dlc->del)
+				dlc->state_send = true;
+
+			msgb_put_pvc_status(resp, dlc);
+		}
+		break;
+	case Q933_REPT_LINK_INTEGRITY_VERIF:
+		msgb_put_link_int_verif(resp, link);
+		llist_for_each_entry(dlc, &link->dlc_list, list) {
+			if (dlc->add || dlc->del) {
+				msgb_put_pvc_status(resp, dlc);
+				dlc->state_send = true;
+			}
+		}
+		break;
+	case Q933_REPT_SINGLE_PVC_ASYNC_STS:
+		llist_for_each_entry(dlc, &link->dlc_list, list)
+			msgb_put_pvc_status(resp, dlc);
+		break;
+	}
+
+	return link->tx_cb(link->tx_cb_data, resp);
+}
+
+
+/* Q.933 */
+static int rx_lmi_q933_status_enq(struct msgb *msg, struct tlv_parsed *tp)
+{
+	struct osmo_fr_link *link = msg->dst;
+	struct osmo_fr_dlc *dlc;
+	const uint8_t *link_int_rx;
+	uint8_t rep_type;
+
+	OSMO_ASSERT(link);
+
+	if (link->role == FR_ROLE_USER_EQUIPMENT) {
+		LOGPFRL(link, LOGL_ERROR, "STATUS-ENQ are not support for role user\n");
+		return -1;
+	}
+
+	/* check for mandatory IEs */
+	if (!TLVP_PRES_LEN(tp, Q933_IEI_REPORT_TYPE, 1) ||
+	    !TLVP_PRES_LEN(tp, Q933_IEI_LINK_INT_VERIF, 2))
+		return -1;
+
+	rep_type = *TLVP_VAL(tp, Q933_IEI_REPORT_TYPE);
+
+	link_int_rx = TLVP_VAL(tp, Q933_IEI_LINK_INT_VERIF);
+	link->last_rx_seq = link_int_rx[0];
+
+	/* the network checks the receive sequence number received from
+	 * the user equipment against its send sequence counter */
+	if (link_int_rx[1] != link->last_tx_seq) {
+		check_link_state(link, false);
+		link->err_count++;
+	} else {
+		check_link_state(link, true);
+		/* confirm DLC state changes */
+		llist_for_each_entry(dlc, &link->dlc_list, list) {
+			if (!dlc->state_send)
+				continue;
+
+			if (dlc->add) {
+				dlc->active = link->state;
+				dlc->add = false;
+			}
+
+			if (dlc->del) {
+				dlc->del = false;
+			}
+
+			dlc->state_send = false;
+		}
+	}
+
+
+	/* The network responds to each STATUS ENQUIRY message with a
+	 * STATUS message and resets the T392 timer */
+	osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
+
+	return tx_lmi_q933_status(link, rep_type);
+}
+
+/* check if the link become active.
+ * The link becomes active when enough times a STATUS/STATUS ENQUIRY arrives without any loss.
+ * Look at the last N393 STATUS/STATUS ENQUIRY PDUs. The link is valid if at least N392
+ * got received.
+ * param[in] valid contains the status of the last packet */
+static void check_link_state(struct osmo_fr_link *link, bool valid)
+{
+	unsigned int last, i;
+	unsigned int carry = 0;
+	struct osmo_fr_dlc *dlc;
+
+	link->succeed <<= 1;
+	if (valid)
+		link->succeed |= 1;
+
+	/* count the bits */
+	last = link->succeed & ((1 << link->net->n393) - 1);
+	for (i = 0; i < link->net->n393; i++)
+		if (last & (1 << i))
+			carry++;
+
+	if (link->net->n393 - carry >= link->net->n392) {
+		/* failing link */
+		if (!link->state)
+			return;
+
+		LOGPFRL(link, LOGL_NOTICE, "Link failed\n");
+		link->state = false;
+		if (link->role == FR_ROLE_USER_EQUIPMENT)
+			return;
+
+		llist_for_each_entry(dlc, &link->dlc_list, list) {
+			dlc->active = false;
+		}
+	} else {
+		/* good link */
+		if (link->state)
+			return;
+
+		LOGPFRL(link, LOGL_NOTICE, "Link recovered\n");
+		link->state = true;
+		if (link->role == FR_ROLE_USER_EQUIPMENT)
+			return;
+
+		llist_for_each_entry(dlc, &link->dlc_list, list) {
+			if (!dlc->add && !dlc->del)
+				dlc->active = true;
+		}
+	}
+}
+
+static int validate_pvc_status(struct tlv_parsed *tp, size_t tp_len)
+{
+	size_t i;
+	uint16_t len = 0;
+
+	for (i = 0; i < tp_len; i++) {
+		if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
+			continue;
+
+		/* PVC status can be 2 or 3 bytes. If the PVC is bigger
+		 * ignore this to be compatible to future extensions. */
+		len = TLVP_LEN(&tp[i], Q933_IEI_PVC_STATUS);
+		if (len <= 1) {
+			return -EINVAL;
+		}
+		/* FIXME: validate correct flags: are some flags invalid at the same time? */
+	}
+
+	return 0;
+}
+
+static int parse_full_pvc_status(struct osmo_fr_link *link, struct tlv_parsed *tp, size_t tp_len)
+{
+	size_t i;
+	int err = 0;
+	struct osmo_fr_dlc *dlc, *tmp;
+	struct q933_a_pvc_sts *pvc;
+	uint16_t dlci = 0;
+	uint16_t *dlcis = talloc_zero_array(link, uint16_t, tp_len);
+	if (!dlcis)
+		return -ENOMEM;
+
+	/* first run validate all PVCs */
+	err = validate_pvc_status(tp, tp_len);
+	if (err < 0)
+		goto out;
+
+	for (i = 0; i < tp_len; i++) {
+		if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
+			continue;
+
+		/* parse only 3 byte PVCs */
+		pvc = (struct q933_a_pvc_sts *) TLVP_VAL_MINLEN(
+					&tp[i],
+					Q933_IEI_PVC_STATUS,
+					sizeof(struct q933_a_pvc_sts));
+		if (!pvc)
+			continue;
+
+		dlci = ((pvc->dlci_msb & 0x3f) << 4) | (pvc->dlci_lsb & 0xf);
+		dlcis[i] = dlci;
+		dlc = osmo_fr_dlc_by_dlci(link, dlci);
+		if (!dlc) {
+			dlc = osmo_fr_dlc_alloc(link, dlci);
+			if (!dlc) {
+				LOGPFRL(link, LOGL_ERROR, "Could not create DLC %d\n", dlci);
+				continue;
+			}
+		}
+
+		/* Figure A.3/Q.933: The delete bit is only applicable for timely notification
+		 *                   using the optional single PVC asynchronous status report.
+		 * Ignoring the delete. */
+		dlc->add = pvc->new;
+		dlc->active = pvc->active;
+		dlc->del = 0;
+	}
+
+	/* check if all dlc are present in PVC Status */
+	llist_for_each_entry_safe(dlc, tmp, &link->dlc_list, list) {
+		bool found = false;
+		for (i = 0; i < tp_len; i++) {
+			if (dlcis[i] == dlc->dlci) {
+				found = true;
+				break;
+			}
+		}
+
+		if (!found) {
+			dlc->active = false;
+			dlc->del = true;
+		}
+	}
+
+	return 0;
+out:
+	talloc_free(dlcis);
+	return err;
+}
+
+static int parse_link_pvc_status(struct osmo_fr_link *link, struct tlv_parsed *tp, size_t tp_len)
+{
+	int err;
+	size_t i;
+	struct q933_a_pvc_sts *pvc;
+	struct osmo_fr_dlc *dlc;
+	uint16_t dlci = 0;
+
+	err = validate_pvc_status(tp, tp_len);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < tp_len; i++) {
+		if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
+			continue;
+
+		/* parse only 3 byte PVCs */
+		pvc = (struct q933_a_pvc_sts *) TLVP_VAL_MINLEN(
+					&tp[i],
+					Q933_IEI_PVC_STATUS,
+					sizeof(struct q933_a_pvc_sts));
+		if (!pvc)
+			continue;
+
+		dlci = ((pvc->dlci_msb & 0x3f) << 4) | (pvc->dlci_lsb & 0xf);
+		dlc = osmo_fr_dlc_by_dlci(link, dlci);
+		if (!dlc) {
+			/* don't create dlc's for the ones which are about to be deleted. */
+			if (dlc->del)
+				continue;
+
+			dlc = osmo_fr_dlc_alloc(link, dlci);
+			if (!dlc) {
+				LOGPFRL(link, LOGL_ERROR, "Rx STATUS: Could not create DLC %d\n", dlci);
+			}
+		}
+
+		if (pvc->delete) {
+			dlc->del = 1;
+		} else {
+			dlc->add = pvc->new;
+			dlc->active = pvc->active;
+			dlc->del = 0;
+		}
+	}
+
+	return 0;
+}
+
+static size_t count_pvc_status(struct tlv_parsed *tp, size_t tp_len)
+{
+	size_t i, count = 0;
+	for (i = 0; i < tp_len; i++) {
+		if (!TLVP_PRESENT(&tp[i], Q933_IEI_PVC_STATUS))
+			continue;
+		count++;
+	}
+
+	return count;
+}
+
+static int rx_lmi_q933_status(struct msgb *msg, struct tlv_parsed *tp)
+{
+	struct osmo_fr_link *link = msg->dst;
+	const uint8_t *link_int_rx;
+	uint8_t rep_type;
+
+	OSMO_ASSERT(link);
+
+	if (link->role == FR_ROLE_NETWORK_EQUIPMENT) {
+		LOGPFRL(link, LOGL_ERROR, "Rx STATUS: STATUS aren't support for role network\n");
+		return -1;
+	}
+
+	/* check for mandatory IEs */
+	if (!TLVP_PRES_LEN(tp, Q933_IEI_REPORT_TYPE, 1)) {
+		LOGPFRL(link, LOGL_NOTICE, "Rx STATUSL: Missing TLV Q933 Report Type\n");
+		return -1;
+	}
+
+	rep_type = *TLVP_VAL(tp, Q933_IEI_REPORT_TYPE);
+
+	switch (rep_type) {
+	case Q933_REPT_FULL_STATUS:
+	case Q933_REPT_LINK_INTEGRITY_VERIF:
+		if (rep_type != link->expected_rep) {
+			LOGPFRL(link, LOGL_NOTICE, "Rx STATUS: Unexpected Q933 report type (got 0x%x != exp 0x%x)\n",
+			     rep_type, link->expected_rep);
+			return -1;
+		}
+
+		if (!TLVP_PRES_LEN(tp, Q933_IEI_LINK_INT_VERIF, 2)) {
+			LOGPFRL(link, LOGL_NOTICE, "Rx STATUS: Missing TLV Q933 Link Integrety Verification\n");
+			return -1;
+		}
+		link_int_rx = TLVP_VAL(tp, Q933_IEI_LINK_INT_VERIF);
+		link->last_rx_seq = link_int_rx[0];
+		/* The received receive sequence number is not valid if
+		 * it is not equal to the last transmitted send sequence
+		 * number. Ignore messages containing this error. As a
+		 * result, timer T391 expires and the user then
+		 * increments the error count. */
+		if (link_int_rx[1] != link->last_tx_seq)
+			return 0;
+		break;
+	case Q933_REPT_SINGLE_PVC_ASYNC_STS:
+	default:
+		return -1;
+	}
+
+	check_link_state(link, true);
+	if (count_pvc_status(tp, MAX_SUPPORTED_PVC + 1) > MAX_SUPPORTED_PVC) {
+		LOGPFRL(link, LOGL_ERROR, "Rx STATUS: Too many PVC! Only %d are supported!\n", MAX_SUPPORTED_PVC);
+	}
+
+	switch (rep_type) {
+	case Q933_REPT_FULL_STATUS:
+		parse_full_pvc_status(link, tp, MAX_SUPPORTED_PVC);
+		break;
+	case Q933_REPT_LINK_INTEGRITY_VERIF:
+		parse_link_pvc_status(link, tp, MAX_SUPPORTED_PVC);
+		break;
+	default:
+		break;
+	}
+
+	/* The network responds to each STATUS ENQUIRY message with a
+	 * STATUS message and resets the T392 timer */
+	osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
+
+	return 0;
+}
+
+static int rx_lmi_q922(struct msgb *msg)
+{
+	struct osmo_fr_link *link = msg->dst;
+	struct q933_a_hdr *qh;
+	/* the + 1 is used to detect more than MAX_SUPPORTED_PVC */
+	struct tlv_parsed tp[MAX_SUPPORTED_PVC + 1];
+	uint8_t *lapf;
+	int rc;
+
+	OSMO_ASSERT(link);
+
+	if (msgb_l2len(msg) < 1)
+		return -1;
+	lapf = msgb_l2(msg);
+
+	/* we only support LAPF UI frames */
+	if (lapf[0] != LAPF_UI)
+		return -1;
+
+	msg->l3h = msg->l2h + 1;
+	if (msgb_l3len(msg) < 3)
+		return -1;
+
+	qh = (struct q933_a_hdr *) msgb_l3(msg);
+	if (qh->prot_disc != Q931_PDISC_CC) {
+		LOGPFRL(link, LOGL_NOTICE,
+			"Rx unsupported LMI protocol discriminator %u\n", qh->prot_disc);
+		return -1;
+	}
+
+	rc = tlv_parse2(tp, MAX_SUPPORTED_PVC + 1, &q933_att_tlvdef,
+			msgb_l3(msg) + sizeof(*qh),
+			msgb_l3len(msg) - sizeof(*qh), 0, 0);
+	if (rc < 0) {
+		LOGPFRL(link, LOGL_NOTICE,
+			"Failed to parse TLVs in LMI message type %u\n", qh->msg_type);
+		return rc;
+	}
+
+	switch (qh->msg_type) {
+	case Q931_MSGT_STATUS_ENQUIRY:
+		rc = rx_lmi_q933_status_enq(msg, tp);
+		break;
+	case Q931_MSGT_STATUS:
+		rc = rx_lmi_q933_status(msg, tp);
+		break;
+	default:
+		LOGPFRL(link, LOGL_NOTICE,
+			"Rx unsupported LMI message type %u\n", qh->msg_type);
+		rc = -1;
+		break;
+	}
+	msgb_free(msg);
+
+	return rc;
+}
+
+int osmo_fr_rx(struct msgb *msg)
+{
+	int rc = 0;
+	uint8_t *frh;
+	uint16_t dlci;
+	struct osmo_fr_dlc *dlc;
+	struct osmo_fr_link *link = msg->dst;
+
+	OSMO_ASSERT(link);
+
+	if (msgb_length(msg) < 2) {
+		LOGPFRL(link, LOGL_ERROR, "Rx short FR header: %u bytes\n", msgb_length(msg));
+		rc = -1;
+		goto out;
+	}
+
+	frh = msg->l1h = msgb_data(msg);
+	if (frh[0] & 0x01) {
+		LOGPFRL(link, LOGL_NOTICE, "Rx Unsupported single-byte FR address\n");
+		rc = -1;
+		goto out;
+	}
+	if ((frh[1] & 0x0f) != 0x01) {
+		LOGPFRL(link, LOGL_NOTICE, "Rx Unknown second FR octet 0x%02x\n", frh[1]);
+		rc = -1;
+		goto out;
+	}
+	dlci = q922_to_dlci(frh);
+	msg->l2h = frh + 2;
+
+	switch (dlci) {
+	case LMI_Q933A_DLCI:
+		return rx_lmi_q922(msg);
+	case LMI_CISCO_DLCI:
+		LOGPFRL(link, LOGL_ERROR, "Rx Unsupported FR DLCI %u\n", dlci);
+		goto out;
+	}
+
+	if (!link->state) {
+		LOGPFRL(link, LOGL_NOTICE, "Link is not reliable. Discarding Rx PDU on DLCI %d\n", dlci);
+		goto out;
+	}
+
+	llist_for_each_entry(dlc, &link->dlc_list, list) {
+		if (dlc->dlci == dlci) {
+			/* dispatch to handler of respective DLC */
+			msg->dst = dlc;
+			return dlc->rx_cb(dlc->rx_cb_data, msg);
+		}
+	}
+
+	if (link->unknown_dlc_rx_cb)
+		return link->unknown_dlc_rx_cb(link->unknown_dlc_rx_cb_data, msg);
+	else
+		LOGPFRL(link, LOGL_NOTICE, "DLCI %u doesn't exist, discarding\n", dlci);
+
+out:
+	msgb_free(msg);
+
+	return rc;
+}
+
+int osmo_fr_tx_dlc(struct msgb *msg)
+{
+	uint8_t *frh;
+	struct osmo_fr_dlc *dlc = msg->dst;
+	struct osmo_fr_link *link = dlc->link;
+
+	OSMO_ASSERT(dlc);
+	OSMO_ASSERT(link);
+
+	if (!link->state) {
+		LOGPFRL(link, LOGL_NOTICE, "Link is not reliable (yet), discarding Tx\n");
+		msgb_free(msg);
+		return -1;
+	}
+	if (!dlc->active) {
+		LOGPFRL(link, LOGL_NOTICE, "DLCI %u is not active (yet), discarding Tx\n", dlc->dlci);
+		msgb_free(msg);
+		return -1;
+	}
+	LOGPFRL(link, LOGL_DEBUG, "DLCI %u is active, sending message\n", dlc->dlci);
+
+	if (msgb_headroom(msg) < 2) {
+		msgb_free(msg);
+		return -ENOSPC;
+	}
+
+	frh = msgb_push(msg, 2);
+	dlci_to_q922(frh, dlc->dlci);
+
+	msg->dst = link;
+	return link->tx_cb(link->tx_cb_data, msg);
+}
+
+/* Every T391 seconds, the user equipment sends a STATUS ENQUIRY
+ * message to the network and resets its polling timer (T391). */
+static void fr_t391_cb(void *data)
+{
+	struct osmo_fr_link *link = data;
+
+	OSMO_ASSERT(link);
+
+	if (link->polling_count % link->net->n391 == 0)
+		tx_lmi_q933_status_enq(link, Q933_REPT_FULL_STATUS);
+	else
+		tx_lmi_q933_status_enq(link, Q933_REPT_LINK_INTEGRITY_VERIF);
+	link->polling_count++;
+	osmo_timer_schedule(&link->t391, osmo_tdef_get(link->net->T_defs, 391, OSMO_TDEF_S, 10), 0);
+}
+
+static void fr_t392_cb(void *data)
+{
+	struct osmo_fr_link *link = data;
+
+	OSMO_ASSERT(link);
+
+	/* A.5 The network increments the error count .. Non-receipt of
+	 * a STATUS ENQUIRY within T392, which results in restarting
+	 * T392 */
+	link->err_count++;
+	check_link_state(link, false);
+	osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
+}
+
+/* allocate a frame relay network */
+struct osmo_fr_network *osmo_fr_network_alloc(void *ctx)
+{
+	struct osmo_fr_network *net = talloc_zero(ctx, struct osmo_fr_network);
+
+	INIT_LLIST_HEAD(&net->links);
+	net->T_defs = fr_tdefs;
+	osmo_tdefs_reset(net->T_defs);
+	net->n391 = 6;
+	net->n392 = 3;
+	net->n393 = 4;
+
+	return net;
+}
+
+void osmo_fr_network_free(struct osmo_fr_network *net)
+{
+	struct osmo_fr_link *link, *tmp;
+
+	if (!net)
+		return;
+
+	llist_for_each_entry_safe(link, tmp, &net->links, list) {
+		osmo_fr_link_free(link);
+	}
+}
+
+/* allocate a frame relay link in a given network */
+struct osmo_fr_link *osmo_fr_link_alloc(struct osmo_fr_network *net, enum osmo_fr_role role, const char *name)
+{
+	struct osmo_fr_link *link = talloc_zero(net, struct osmo_fr_link);
+	if (!link)
+		return NULL;
+
+	LOGPFRL(link, LOGL_INFO, "Creating frame relay link with role %s\n", osmo_fr_role_str(role));
+
+	link->role = role;
+	link->net = net;
+	link->name = talloc_strdup(link, name);
+	INIT_LLIST_HEAD(&link->dlc_list);
+	llist_add_tail(&link->list, &net->links);
+
+	osmo_timer_setup(&link->t391, fr_t391_cb, link);
+	osmo_timer_setup(&link->t392, fr_t392_cb, link);
+
+	switch (role) {
+	case FR_ROLE_USER_EQUIPMENT:
+		osmo_timer_schedule(&link->t391, osmo_tdef_get(link->net->T_defs, 391, OSMO_TDEF_S, 15), 0);
+		break;
+	case FR_ROLE_NETWORK_EQUIPMENT:
+		osmo_timer_schedule(&link->t392, osmo_tdef_get(link->net->T_defs, 392, OSMO_TDEF_S, 15), 0);
+		break;
+	}
+
+	return link;
+}
+
+void osmo_fr_link_free(struct osmo_fr_link *link)
+{
+	struct osmo_fr_dlc *dlc, *tmp;
+
+	if (!link)
+		return;
+
+	osmo_timer_del(&link->t391);
+	osmo_timer_del(&link->t392);
+
+	llist_for_each_entry_safe(dlc, tmp, &link->dlc_list, list) {
+		osmo_fr_dlc_free(dlc);
+	}
+
+	llist_del(&link->list);
+	talloc_free(link);
+}
+
+/* allocate a data link connectoin on a given framerelay link */
+struct osmo_fr_dlc *osmo_fr_dlc_alloc(struct osmo_fr_link *link, uint16_t dlci)
+{
+	struct osmo_fr_dlc *dlc = talloc_zero(link, struct osmo_fr_dlc);
+	if (!dlc)
+		return NULL;
+
+	dlc->link = link;
+	dlc->dlci = dlci;
+	dlc->active = false;
+
+	llist_add_tail(&dlc->list, &link->dlc_list);
+
+	dlc->add = true;
+	tx_lmi_q933_status(link, Q933_IEI_PVC_STATUS);
+
+	return dlc;
+}
+
+void osmo_fr_dlc_free(struct osmo_fr_dlc *dlc)
+{
+	llist_del(&dlc->list);
+	talloc_free(dlc);
+}
+
+/* TODO: rework osmo_fr_dlc_alloc/free with handling it's own memory.
+ * For network role: The dlc have to created by the application (e.g. vty).
+ * The dlc shouldn't free'd directly. It should be communicated to the
+ * other side and wait until it's confirmed OR the link go off and free it afterwards.
+ * For user equpment role: The dlc can be created by the application or the dlc will be created
+ * by the frame relay because the network is configuring the dlc.
+ * The dlc shouldn't be free'd. Only the handler should be set to NULL.
+ */
+
+struct osmo_fr_dlc *osmo_fr_dlc_by_dlci(struct osmo_fr_link *link, uint16_t dlci)
+{
+	struct osmo_fr_dlc *dlc;
+
+	llist_for_each_entry(dlc, &link->dlc_list, list) {
+		if (dlc->dlci == dlci)
+			return dlc;
+	}
+	return NULL;
+}
diff --git a/src/gb/gprs_ns2.c b/src/gb/gprs_ns2.c
index cf04924e..096e80bf 100644
--- a/src/gb/gprs_ns2.c
+++ b/src/gb/gprs_ns2.c
@@ -59,7 +59,6 @@
  * This implementation has the following limitations:
  * - Only one NS-VC for each NSE: No load-sharing function
  * - NSVCI 65535 and 65534 are reserved for internal use
- * - Only UDP is supported as of now, no frame relay support
  * - There are no BLOCK and UNBLOCK timers (yet?)
  *
  * \file gprs_ns2.c */
@@ -258,6 +257,15 @@ char *gprs_ns2_ll_str_buf(char *buf, size_t buf_len, struct gprs_ns2_vc *nsvc)
 	case GPRS_NS_LL_E1:
 		snprintf(buf, buf_len, "e1)");
 		break;
+	case GPRS_NS_LL_FR:
+		if (!gprs_ns2_is_frgre_bind(nsvc->bind)) {
+			buf[0] = '\0';
+			return buf;
+		}
+
+		snprintf(buf, buf_len, "fr)netif: %s dlci: %u", gprs_ns2_fr_bind_netif(nsvc->bind),
+			 gprs_ns2_fr_nsvc_dlci(nsvc));
+		break;
 	default:
 		buf[0] = '\0';
 		break;
diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c
new file mode 100644
index 00000000..ae54a41b
--- /dev/null
+++ b/src/gb/gprs_ns2_fr.c
@@ -0,0 +1,545 @@
+/*! \file gprs_ns2_fr.c
+ * NS-over-FR-over-GRE implementation.
+ * GPRS Networks Service (NS) messages on the Gb interface.
+ * 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05)
+ * as well as its successor 3GPP TS 48.016 */
+
+/* (C) 2009-2010,2014,2017 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2020 sysmocom - s.f.m.c. GmbH
+ * Author: Alexander Couzens <lynxis@fe80.eu>
+ *
+ * All Rights Reserved
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+
+#include <sys/ioctl.h>
+#include <netpacket/packet.h>
+#include <linux/if_ether.h>
+#include <linux/hdlc.h>
+#include <linux/if.h>
+
+#include <osmocom/gprs/frame_relay.h>
+#include <osmocom/core/byteswap.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/gprs/gprs_ns2.h>
+
+#include "common_vty.h"
+#include "gprs_ns2_internal.h"
+
+#define GRE_PTYPE_FR	0x6559
+#define GRE_PTYPE_IPv4	0x0800
+#define GRE_PTYPE_IPv6	0x86dd
+#define GRE_PTYPE_KAR	0x0000	/* keepalive response */
+
+#ifndef IPPROTO_GRE
+# define IPPROTO_GRE 47
+#endif
+
+struct gre_hdr {
+	uint16_t flags;
+	uint16_t ptype;
+} __attribute__ ((packed));
+
+static void free_bind(struct gprs_ns2_vc_bind *bind);
+static int fr_dlci_rx_cb(void *cb_data, struct msgb *msg);
+
+struct gprs_ns2_vc_driver vc_driver_fr = {
+	.name = "GB frame relay",
+	.free_bind = free_bind,
+};
+
+struct priv_bind {
+	struct osmo_fd fd;
+	char netif[IF_NAMESIZE];
+	struct osmo_fr_link *link;
+};
+
+struct priv_vc {
+	struct osmo_sockaddr remote;
+	uint16_t dlci;
+	struct osmo_fr_dlc *dlc;
+};
+
+static void free_vc(struct gprs_ns2_vc *nsvc)
+{
+	OSMO_ASSERT(nsvc);
+
+	if (!nsvc->priv)
+		return;
+
+	talloc_free(nsvc->priv);
+	nsvc->priv = NULL;
+}
+
+static void dump_vty(const struct gprs_ns2_vc_bind *bind, struct vty *vty, bool _stats)
+{
+	struct priv_bind *priv;
+	struct gprs_ns2_vc *nsvc;
+
+	if (!bind)
+		return;
+
+	priv = bind->priv;
+
+	vty_out(vty, "FR bind: %s%s", priv->netif, VTY_NEWLINE);
+
+	llist_for_each_entry(nsvc, &bind->nsvc, blist) {
+		vty_out(vty, "    %s%s", gprs_ns2_ll_str(nsvc), VTY_NEWLINE);
+	}
+
+	priv = bind->priv;
+}
+
+/*! clean up all private driver state. Should be only called by gprs_ns2_free_bind() */
+static void free_bind(struct gprs_ns2_vc_bind *bind)
+{
+	struct priv_bind *priv;
+
+	if (!bind)
+		return;
+
+	priv = bind->priv;
+
+	OSMO_ASSERT(llist_empty(&bind->nsvc));
+
+	osmo_fr_link_free(priv->link);
+	osmo_fd_close(&priv->fd);
+	talloc_free(priv);
+}
+
+static struct priv_vc *fr_alloc_vc(struct gprs_ns2_vc_bind *bind,
+				   struct gprs_ns2_vc *nsvc,
+				   uint16_t dlci)
+{
+	struct priv_bind *privb = bind->priv;
+	struct priv_vc *priv = talloc_zero(bind, struct priv_vc);
+	if (!priv)
+		return NULL;
+
+	nsvc->priv = priv;
+	priv->dlci = dlci;
+	priv->dlc = osmo_fr_dlc_alloc(privb->link, dlci);
+	if (!priv->dlc) {
+		nsvc->priv = NULL;
+		talloc_free(priv);
+		return NULL;
+	}
+
+	priv->dlc->rx_cb_data = nsvc;
+	priv->dlc->rx_cb = fr_dlci_rx_cb;
+
+	return priv;
+}
+
+int gprs_ns2_find_vc_by_dlci(struct gprs_ns2_vc_bind *bind,
+			     uint16_t dlci,
+			     struct gprs_ns2_vc **result)
+{
+	struct gprs_ns2_vc *nsvc;
+	struct priv_vc *vcpriv;
+
+	if (!result)
+		return -EINVAL;
+
+	llist_for_each_entry(nsvc, &bind->nsvc, blist) {
+		vcpriv = nsvc->priv;
+		if (vcpriv->dlci != dlci) {
+			*result = nsvc;
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/* PDU from the network interface towards the fr layer (upwards) */
+static int handle_netif_read(struct osmo_fd *bfd)
+{
+	struct gprs_ns2_vc_bind *bind = bfd->data;
+	struct priv_bind *priv = bind->priv;
+	struct msgb *msg = msgb_alloc(NS_ALLOC_SIZE, "Gb/NS/FR/GRE Rx");
+	int rc = 0;
+
+	if (!msg)
+		return -ENOMEM;
+
+	rc = read(bfd->fd, msg->data, NS_ALLOC_SIZE);
+	if (rc < 0) {
+		LOGP(DLNS, LOGL_ERROR, "recv error %s during NS-FR-GRE recv\n",
+		     strerror(errno));
+		goto out_err;
+	} else if (rc == 0) {
+		goto out_err;
+	}
+
+	msgb_put(msg, rc);
+	msg->dst = priv->link;
+	return osmo_fr_rx(msg);
+
+out_err:
+	msgb_free(msg);
+	return rc;
+}
+
+/* PDU from the frame relay towards the NS-VC (upwards) */
+static int fr_dlci_rx_cb(void *cb_data, struct msgb *msg)
+{
+	int rc;
+	struct gprs_ns2_vc *nsvc = cb_data;
+
+	rc = ns2_recv_vc(nsvc, msg);
+
+	return rc;
+}
+
+static int handle_netif_write(struct osmo_fd *bfd)
+{
+	/* FIXME */
+	return -EIO;
+}
+
+static int fr_fd_cb(struct osmo_fd *bfd, unsigned int what)
+{
+	int rc = 0;
+
+	if (what & OSMO_FD_READ)
+		rc = handle_netif_read(bfd);
+	if (what & OSMO_FD_WRITE)
+		rc = handle_netif_write(bfd);
+
+	return rc;
+}
+
+/*! determine if given bind is for FR-GRE encapsulation. */
+int gprs_ns2_is_fr_bind(struct gprs_ns2_vc_bind *bind)
+{
+	return (bind->driver == &vc_driver_fr);
+}
+
+/* PDU from the NS-VC towards the frame relay layer (downwards) */
+static int fr_vc_sendmsg(struct gprs_ns2_vc *nsvc, struct msgb *msg)
+{
+	struct priv_vc *vcpriv = nsvc->priv;
+
+	msg->dst = vcpriv->dlc;
+	return osmo_fr_tx_dlc(msg);
+}
+
+/* PDU from the frame relay layer towards the network interface (downwards) */
+int fr_tx_cb(void *data, struct msgb *msg)
+{
+	struct gprs_ns2_vc_bind *bind = data;
+	struct priv_bind *priv = bind->priv;
+	int rc;
+
+	/* FIXME half writes */
+	rc = write(priv->fd.fd, msg->data, msg->len);
+	msgb_free(msg);
+
+	return rc;
+}
+
+static int devname2ifindex(const char *ifname)
+{
+	struct ifreq ifr;
+	int sk, rc;
+
+	sk = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
+	if (sk < 0)
+		return sk;
+
+
+	memset(&ifr, 0, sizeof(ifr));
+	strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	ifr.ifr_name[sizeof(ifr.ifr_name)-1] = 0;
+
+	rc = ioctl(sk, SIOCGIFINDEX, &ifr);
+	close(sk);
+	if (rc < 0)
+		return rc;
+
+	return ifr.ifr_ifindex;
+}
+
+static int open_socket(const char *ifname)
+{
+	struct sockaddr_ll addr;
+	int ifindex;
+	int fd, rc, on = 1;
+
+	ifindex = devname2ifindex(ifname);
+	if (ifindex < 0) {
+		LOGP(DLNS, LOGL_ERROR, "Can not get interface index for interface %s\n", ifname);
+		return ifindex;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sll_family = AF_PACKET;
+	addr.sll_protocol = htons(ETH_P_ALL);
+	addr.sll_ifindex = ifindex;
+
+	fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+	if (fd < 0) {
+		LOGP(DLNS, LOGL_ERROR, "Can not get socket for interface %s. Are you root or have CAP_RAW_SOCKET?\n", ifname);
+		return fd;
+	}
+
+	if (ioctl(fd, FIONBIO, (unsigned char *)&on) < 0) {
+		LOGP(DLGLOBAL, LOGL_ERROR,
+			"cannot set this socket unblocking: %s\n",
+			strerror(errno));
+		close(fd);
+		fd = -EINVAL;
+	}
+
+	rc = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
+	if (rc < 0) {
+		LOGP(DLNS, LOGL_ERROR, "Can not bind for interface %s\n", ifname);
+		close(fd);
+		return rc;
+	}
+
+	return fd;
+}
+
+/*! Create a new bind for NS over FR.
+ *  \param[in] nsi NS instance in which to create the bind
+ *  \param[in] netif Network interface to bind to
+ *  \param[in] fr_network
+ *  \param[in] fr_role
+ *  \param[out] result pointer to created bind
+ *  \return 0 on success; negative on error */
+int gprs_ns2_fr_bind(struct gprs_ns2_inst *nsi,
+		     const char *netif,
+		     struct osmo_fr_network *fr_network,
+		     enum osmo_fr_role fr_role,
+		     struct gprs_ns2_vc_bind **result)
+{
+	struct gprs_ns2_vc_bind *bind = talloc_zero(nsi, struct gprs_ns2_vc_bind);
+	struct priv_bind *priv;
+	struct osmo_fr_link *fr_link;
+	int rc = 0;
+
+	if (!bind)
+		return -ENOSPC;
+
+	bind->driver = &vc_driver_fr;
+	bind->send_vc = fr_vc_sendmsg;
+	bind->free_vc = free_vc;
+	bind->dump_vty = dump_vty;
+	bind->nsi = nsi;
+	priv = bind->priv = talloc_zero(bind, struct priv_bind);
+	if (!priv) {
+		rc = -ENOSPC;
+		goto err_bind;
+	}
+
+	priv->fd.cb = fr_fd_cb;
+	priv->fd.data = bind;
+	if (strlen(netif) > IF_NAMESIZE) {
+		rc = -EINVAL;
+		goto err_priv;
+	}
+	strncpy(priv->netif, netif, sizeof(priv->netif));
+
+	ns2_vty_bind_apply(bind);
+	if (result)
+		*result = bind;
+
+	/* FIXME: move fd handling into socket.c */
+	fr_link = osmo_fr_link_alloc(fr_network, fr_role, netif);
+	if (!fr_link) {
+		rc = -EINVAL;
+		goto err_priv;
+	}
+
+	fr_link->tx_cb = fr_tx_cb;
+	fr_link->tx_cb_data = bind;
+	priv->link = fr_link;
+	priv->fd.fd = rc = open_socket(netif);
+	if (rc < 0)
+		goto err_fr;
+
+	priv->fd.when = OSMO_FD_READ;
+	rc = osmo_fd_register(&priv->fd);
+	if (rc < 0)
+		goto err_fd;
+
+	INIT_LLIST_HEAD(&bind->nsvc);
+	llist_add(&bind->list, &nsi->binding);
+
+	return rc;
+
+err_fd:
+	close(priv->fd.fd);
+err_fr:
+	osmo_fr_link_free(fr_link);
+err_priv:
+	talloc_free(priv);
+err_bind:
+	talloc_free(bind);
+
+	return rc;
+}
+
+/*! Return the network interface of the bind
+ * \param[in] bind The bind
+ * \return the network interface
+ */
+const char *gprs_ns2_fr_bind_netif(struct gprs_ns2_vc_bind *bind)
+{
+	struct priv_bind *priv;
+
+	if (bind->driver != &vc_driver_fr)
+		return NULL;
+
+	priv = bind->priv;
+	return priv->netif;
+}
+
+/*! Find NS bind for a given network interface
+ * \param[in] nsi NS instance
+ * \param[in] netif the network interface to search for
+ * \return the bind or NULL if not found
+ */
+struct gprs_ns2_vc_bind *gprs_ns2_fr_bind_by_netif(
+		struct gprs_ns2_inst *nsi,
+		const char *netif)
+{
+	struct gprs_ns2_vc_bind *bind;
+	const char *_netif;
+
+	OSMO_ASSERT(nsi);
+	OSMO_ASSERT(netif);
+
+	llist_for_each_entry(bind, &nsi->binding, list) {
+		if (!gprs_ns2_is_fr_bind(bind))
+			continue;
+
+		_netif = gprs_ns2_fr_bind_netif(bind);
+		if (!strncmp(_netif, netif, IF_NAMESIZE))
+			return bind;
+	}
+
+	return NULL;
+}
+
+/*! Create, connect and activate a new FR-based NS-VC
+ *  \param[in] bind bind in which the new NS-VC is to be created
+ *  \param[in] nsei NSEI of the NS Entity in which the NS-VC is to be created
+ *  \param[in] dlci Data Link connection identifier
+ *  \return pointer to newly-allocated, connected and activated NS-VC; NULL on error */
+struct gprs_ns2_vc *gprs_ns2_fr_connect(struct gprs_ns2_vc_bind *bind,
+					uint16_t nsei,
+					uint16_t nsvci,
+					uint16_t dlci)
+{
+	bool created_nse = false;
+	struct gprs_ns2_vc *nsvc = NULL;
+	struct priv_vc *priv = NULL;
+	struct gprs_ns2_nse *nse = gprs_ns2_nse_by_nsei(bind->nsi, nsei);
+	if (!nse) {
+		nse = gprs_ns2_create_nse(bind->nsi, nsei);
+		if (!nse)
+			return NULL;
+		created_nse = true;
+	}
+
+	nsvc = gprs_ns2_fr_nsvc_by_dlci(bind, dlci);
+	if (nsvc) {
+		goto err_nse;
+	}
+
+	nsvc = ns2_vc_alloc(bind, nse, true);
+	if (!nsvc)
+		goto err_nse;
+
+	nsvc->priv = priv = fr_alloc_vc(bind, nsvc, dlci);
+	if (!priv)
+		goto err;
+
+	nsvc->nsvci = nsvci;
+	nsvc->nsvci_is_valid = true;
+	nsvc->ll = GPRS_NS_LL_FR;
+
+	gprs_ns2_vc_fsm_start(nsvc);
+
+	return nsvc;
+
+err:
+	gprs_ns2_free_nsvc(nsvc);
+err_nse:
+	if (created_nse)
+		gprs_ns2_free_nse(nse);
+
+	return NULL;
+}
+
+/*! Return the nsvc by dlci.
+ * \param[in] bind
+ * \param[in] dlci Data Link connection identifier
+ * \return the nsvc or NULL if not found
+ */
+struct gprs_ns2_vc *gprs_ns2_fr_nsvc_by_dlci(struct gprs_ns2_vc_bind *bind,
+					     uint16_t dlci)
+{
+	struct gprs_ns2_vc *nsvc;
+	struct priv_vc *vcpriv;
+
+	llist_for_each_entry(nsvc, &bind->nsvc, blist) {
+		vcpriv = nsvc->priv;
+
+		if (dlci == vcpriv->dlci)
+			return nsvc;
+	}
+
+	return NULL;
+}
+
+/*! Return the dlci of the nsvc
+ * \param[in] nsvc
+ * \return the dlci or 0 on error. 0 is not a valid dlci.
+ */
+uint16_t gprs_ns2_fr_nsvc_dlci(struct gprs_ns2_vc *nsvc)
+{
+	struct priv_vc *vcpriv;
+
+	if (!nsvc->bind)
+		return 0;
+
+	if (nsvc->bind->driver != &vc_driver_fr)
+		return 0;
+
+	vcpriv = nsvc->priv;
+	return vcpriv->dlci;
+}
diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h
index 493b3918..6ea2fcc2 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -60,6 +60,7 @@ enum ns_stat {
 enum gprs_ns_ll {
 	GPRS_NS_LL_UDP,		/*!< NS/UDP/IP */
 	GPRS_NS_LL_E1,		/*!< NS/E1 */
+	GPRS_NS_LL_FR,		/*!< NS/FR */
 	GPRS_NS_LL_FR_GRE,	/*!< NS/FR/GRE/IP */
 };
 
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index 63331b95..4eb9d37a 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -31,6 +31,7 @@
 #include <stdint.h>
 
 #include <arpa/inet.h>
+#include <net/if.h>
 
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/byteswap.h>
@@ -42,6 +43,7 @@
 #include <osmocom/core/sockaddr_str.h>
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/socket.h>
+#include <osmocom/gprs/frame_relay.h>
 #include <osmocom/gprs/gprs_ns2.h>
 #include <osmocom/gsm/tlv.h>
 #include <osmocom/vty/vty.h>
@@ -78,12 +80,19 @@ struct ns2_vty_vc {
 	uint16_t nsvci;
 	uint16_t frdlci;
 
+	struct {
+		enum osmo_fr_role role;
+	} fr;
+
+	char netif[IF_NAMESIZE];
+
 	bool remote_end_is_sgsn;
 	bool configured;
 };
 
 static struct gprs_ns2_inst *vty_nsi = NULL;
 static struct ns2_vty_priv priv;
+static struct osmo_fr_network *vty_fr_network = NULL;
 
 /* FIXME: this should go to some common file as it is copied
  * in vty_interface.c of the BSC */
@@ -223,6 +232,11 @@ static int config_write_ns(struct vty *vty)
 				vtyvc->nsei, vtyvc->frdlci,
 				VTY_NEWLINE);
 			break;
+		case GPRS_NS_LL_FR:
+			vty_out(vty, " nse %u fr %s dlci %u%s",
+				vtyvc->nsei, vtyvc->netif, vtyvc->frdlci,
+				VTY_NEWLINE);
+			break;
 		default:
 			break;
 		}
@@ -387,6 +401,44 @@ DEFUN_HIDDEN(nsvc_force_unconf, nsvc_force_unconf_cmd,
 
 #define NSE_CMD_STR "Persistent NS Entity\n" "NS Entity ID (NSEI)\n"
 
+DEFUN(cfg_nse_fr, cfg_nse_fr_cmd,
+	"nse <0-65535> nsvci <0-65535> (fr|frnet) NETIF dlci <0-1023>",
+	NSE_CMD_STR
+	"NS Virtual Connection\n"
+	"NS Virtual Connection ID (NSVCI)\n"
+	"frame relay\n"
+	IFNAME_STR
+	"Data Link connection identifier\n"
+	"Data Link connection identifier\n"
+	)
+{
+	struct ns2_vty_vc *vtyvc;
+
+	uint16_t nsei = atoi(argv[0]);
+	uint16_t nsvci = atoi(argv[1]);
+	const char *role = argv[2];
+	const char *name = argv[3];
+	uint16_t dlci = atoi(argv[4]);
+
+	vtyvc = vtyvc_by_nsei(nsei, true);
+	if (!vtyvc) {
+		vty_out(vty, "Can not allocate space %s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	if (!strcmp(role, "fr"))
+		vtyvc->fr.role = FR_ROLE_USER_EQUIPMENT;
+	else if (!strcmp(role, "frnet"))
+		vtyvc->fr.role = FR_ROLE_NETWORK_EQUIPMENT;
+
+	osmo_strlcpy(vtyvc->netif, name, sizeof(vtyvc->netif));
+	vtyvc->frdlci = dlci;
+	vtyvc->nsvci = nsvci;
+	vtyvc->ll = GPRS_NS_LL_FR;
+
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_nse_nsvc, cfg_nse_nsvci_cmd,
 	"nse <0-65535> nsvci <0-65535>",
 	NSE_CMD_STR
@@ -453,13 +505,14 @@ DEFUN(cfg_nse_remoteport, cfg_nse_remoteport_cmd,
 }
 
 DEFUN(cfg_nse_fr_dlci, cfg_nse_fr_dlci_cmd,
-	"nse <0-65535> fr-dlci <16-1007>",
+	"nse <0-65535> nsvci <0-65535> fr-dlci <16-1007>",
 	NSE_CMD_STR
 	"Frame Relay DLCI\n"
 	"Frame Relay DLCI Number\n")
 {
 	uint16_t nsei = atoi(argv[0]);
-	uint16_t dlci = atoi(argv[1]);
+	uint16_t nsvci = atoi(argv[1]);
+	uint16_t dlci = atoi(argv[2]);
 	struct ns2_vty_vc *vtyvc;
 
 	vtyvc = vtyvc_by_nsei(nsei, true);
@@ -474,6 +527,7 @@ DEFUN(cfg_nse_fr_dlci, cfg_nse_fr_dlci_cmd,
 	}
 
 	vtyvc->frdlci = dlci;
+	vtyvc->nsvci = nsvci;
 
 	return CMD_SUCCESS;
 }
@@ -736,6 +790,7 @@ int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi,
 
 	install_lib_element(CONFIG_NODE, &cfg_ns_cmd);
 	install_node(&ns_node, config_write_ns);
+	install_lib_element(L_NS_NODE, &cfg_nse_fr_cmd);
 	install_lib_element(L_NS_NODE, &cfg_nse_nsvci_cmd);
 	install_lib_element(L_NS_NODE, &cfg_nse_remoteip_cmd);
 	install_lib_element(L_NS_NODE, &cfg_nse_remoteport_cmd);
@@ -763,10 +818,11 @@ int gprs_ns2_vty_init(struct gprs_ns2_inst *nsi,
  */
 int gprs_ns2_vty_create() {
 	struct ns2_vty_vc *vtyvc;
-	struct gprs_ns2_vc_bind *bind;
+	struct gprs_ns2_vc_bind *bind, *fr;
 	struct gprs_ns2_nse *nse;
 	struct gprs_ns2_vc *nsvc;
 	struct osmo_sockaddr sockaddr;
+	int rc = 0;
 
 	if (!vty_nsi)
 		return -1;
@@ -787,18 +843,28 @@ int gprs_ns2_vty_create() {
 
 	/* create vcs */
 	llist_for_each_entry(vtyvc, &priv.vtyvc, list) {
-		if (strlen(vtyvc->remote.ip) == 0) {
-			/* Invalid IP for VC */
-			continue;
-		}
+		/* validate settings */
+		switch (vtyvc->ll) {
+		case GPRS_NS_LL_UDP:
+			if (strlen(vtyvc->remote.ip) == 0) {
+				/* Invalid IP for VC */
+				continue;
+			}
 
-		if (!vtyvc->remote.port) {
-			/* Invalid port for VC */
-			continue;
-		}
+			if (!vtyvc->remote.port) {
+				/* Invalid port for VC */
+				continue;
+			}
 
-		if (osmo_sockaddr_str_to_sockaddr(&vtyvc->remote, &sockaddr.u.sas)) {
-			/* Invalid sockaddr for VC */
+			if (osmo_sockaddr_str_to_sockaddr(&vtyvc->remote, &sockaddr.u.sas)) {
+				/* Invalid sockaddr for VC */
+				continue;
+			}
+			break;
+		case GPRS_NS_LL_FR:
+			break;
+		case GPRS_NS_LL_FR_GRE:
+		case GPRS_NS_LL_E1:
 			continue;
 		}
 
@@ -812,15 +878,46 @@ int gprs_ns2_vty_create() {
 		}
 		nse->persistent = true;
 
-		nsvc = gprs_ns2_ip_connect(bind,
-					   &sockaddr,
-					   nse,
-					   vtyvc->nsvci);
-		if (!nsvc) {
-			/* Could not create NSVC, connect failed */
+		switch (vtyvc->ll) {
+		case GPRS_NS_LL_UDP:
+			nsvc = gprs_ns2_ip_connect(bind,
+						   &sockaddr,
+						   nse,
+						   vtyvc->nsvci);
+			if (!nsvc) {
+				/* Could not create NSVC, connect failed */
+				continue;
+			}
+			nsvc->persistent = true;
+			break;
+		case GPRS_NS_LL_FR: {
+			if (vty_fr_network == NULL) {
+				/* TODO: add a switch for BSS/SGSN/gbproxy */
+				vty_fr_network = osmo_fr_network_alloc(vty_nsi);
+			}
+			fr = gprs_ns2_fr_bind_by_netif(
+						vty_nsi,
+						vtyvc->netif);
+			if (!fr) {
+				rc = gprs_ns2_fr_bind(vty_nsi, vtyvc->netif, vty_fr_network, vtyvc->fr.role, &fr);
+				if (rc < 0) {
+					LOGP(DLNS, LOGL_ERROR, "Can not create fr bind on device %s err: %d\n", vtyvc->netif, rc);
+					return rc;
+				}
+			}
+
+			nsvc = gprs_ns2_fr_connect(fr, vtyvc->nsei, vtyvc->nsvci, vtyvc->frdlci);
+			if (!nsvc) {
+				/* Could not create NSVC, connect failed */
+				continue;
+			}
+			nsvc->persistent = true;
+			break;
+		}
+		case GPRS_NS_LL_FR_GRE:
+		case GPRS_NS_LL_E1:
 			continue;
 		}
-		nsvc->persistent = true;
 	}
 
 
diff --git a/src/gb/libosmogb.map b/src/gb/libosmogb.map
index 72437abb..ddfd0710 100644
--- a/src/gb/libosmogb.map
+++ b/src/gb/libosmogb.map
@@ -45,6 +45,14 @@ bssgp_tx_paging;
 bssgp_vty_init;
 bssgp_nsi;
 
+osmo_fr_network_alloc;
+osmo_fr_link_alloc;
+osmo_fr_link_free;
+osmo_fr_dlc_alloc;
+osmo_fr_rx;
+osmo_fr_tx_dlc;
+osmo_fr_role_names;
+
 gprs_ns_signal_ns_names;
 gprs_ns_pdu_strings;
 gprs_ns_cause_str;
@@ -86,6 +94,14 @@ gprs_ns2_free_nse;
 gprs_ns2_free_nses;
 gprs_ns2_free_nsvc;
 gprs_ns2_frgre_bind;
+gprs_ns2_fr_bind;
+gprs_ns2_fr_bind_netif;
+gprs_ns2_fr_bind_by_netif;
+gprs_ns2_fr_connect;
+gprs_ns2_fr_nsvc_by_dlci;
+gprs_ns2_fr_nsvc_dlci;
+gprs_ns2_is_fr_bind;
+gprs_ns2_find_vc_by_dlci;
 gprs_ns2_instantiate;
 gprs_ns2_ip_bind;
 gprs_ns2_ip_bind_by_sockaddr;