diff --git a/src/gb/gprs_ns2_udp.c b/src/gb/gprs_ns2_udp.c
new file mode 100644
index 0000000..f317219
--- /dev/null
+++ b/src/gb/gprs_ns2_udp.c
@@ -0,0 +1,378 @@
+/*! \file gprs_ns2_udp.c
+ * NS-over-UDP 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) 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 <osmocom/core/select.h>
+#include <osmocom/core/sockaddr_str.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/gprs/gprs_ns2.h>
+
+#include "common_vty.h"
+#include "gprs_ns2_internal.h"
+
+
+static void free_bind(struct gprs_ns2_vc_bind *bind);
+
+
+struct gprs_ns2_vc_driver vc_driver_ip = {
+	.name = "GB UDP IPv4/IPv6",
+	.free_bind = free_bind,
+};
+
+struct priv_bind {
+	struct osmo_fd fd;
+	struct osmo_sockaddr addr;
+	int dscp;
+};
+
+struct priv_vc {
+	struct osmo_sockaddr remote;
+};
+
+/*! 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_fd_close(&priv->fd);
+	talloc_free(priv);
+}
+
+static void free_vc(struct gprs_ns2_vc *nsvc)
+{
+	if (!nsvc->priv)
+		return;
+
+	talloc_free(nsvc->priv);
+	nsvc->priv = NULL;
+}
+
+int gprs_ns2_find_vc_by_sockaddr(struct gprs_ns2_vc_bind *bind, struct osmo_sockaddr *saddr, 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->remote.u.sa.sa_family != saddr->u.sa.sa_family)
+			continue;
+		if (osmo_sockaddr_cmp(&vcpriv->remote, saddr))
+			continue;
+
+		*result = nsvc;
+		return 0;
+	}
+
+	return 1;
+}
+
+static inline int nsip_sendmsg(struct gprs_ns2_vc_bind *bind,
+			       struct msgb *msg,
+			       struct osmo_sockaddr *dest)
+{
+	int rc;
+	struct priv_bind *priv = bind->priv;
+
+	rc = sendto(priv->fd.fd, msg->data, msg->len, 0,
+		    &dest->u.sa, sizeof(*dest));
+
+	msgb_free(msg);
+
+	return rc;
+}
+
+/*!
+ * \brief nsip_vc_sendmsg will send the msg and free msgb afterwards.
+ * \param vc
+ * \param msg
+ * \return < 0 on erros, otherwise the bytes sent.
+ */
+static int nsip_vc_sendmsg(struct gprs_ns2_vc *nsvc, struct msgb *msg)
+{
+	int rc;
+	struct gprs_ns2_vc_bind *bind = nsvc->bind;
+	struct priv_vc *priv = nsvc->priv;
+
+	rc = nsip_sendmsg(bind, msg, &priv->remote);
+
+	return rc;
+}
+
+/* Read a single NS-over-IP message */
+static struct msgb *read_nsip_msg(struct osmo_fd *bfd, int *error,
+				  struct osmo_sockaddr *saddr)
+{
+	struct msgb *msg = gprs_ns2_msgb_alloc();
+	int ret = 0;
+	socklen_t saddr_len = sizeof(*saddr);
+
+	if (!msg) {
+		*error = -ENOMEM;
+		return NULL;
+	}
+
+	ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE - NS_ALLOC_HEADROOM, 0,
+			&saddr->u.sa, &saddr_len);
+	if (ret < 0) {
+		LOGP(DLNS, LOGL_ERROR, "recv error %s during NSIP recvfrom %s\n",
+		     strerror(errno), osmo_sock_get_name2(bfd->fd));
+		msgb_free(msg);
+		*error = ret;
+		return NULL;
+	} else if (ret == 0) {
+		msgb_free(msg);
+		*error = ret;
+		return NULL;
+	}
+
+	msg->l2h = msg->data;
+	msgb_put(msg, ret);
+
+	return msg;
+}
+
+static struct priv_vc *ns2_driver_alloc_vc(struct gprs_ns2_vc_bind *bind, struct gprs_ns2_vc *nsvc, struct osmo_sockaddr *remote)
+{
+	struct priv_vc *priv = talloc_zero(bind, struct priv_vc);
+	if (!priv)
+		return NULL;
+
+	nsvc->priv = priv;
+	priv->remote = *remote;
+
+	return priv;
+}
+
+static int handle_nsip_read(struct osmo_fd *bfd)
+{
+	int rc;
+	int error = 0;
+	struct gprs_ns2_vc_bind *bind = bfd->data;
+	struct osmo_sockaddr saddr;
+	struct gprs_ns2_vc *nsvc;
+	struct msgb *msg = read_nsip_msg(bfd, &error, &saddr);
+	struct msgb *reject;
+
+	if (!msg)
+		return -EINVAL;
+
+	/* check if a vc is available */
+	rc = gprs_ns2_find_vc_by_sockaddr(bind, &saddr, &nsvc);
+	if (rc) {
+		/* VC not found */
+		rc = ns2_create_vc(bind, msg, "newconnection", &reject, &nsvc);
+		switch (rc) {
+		case GPRS_NS2_CS_FOUND:
+			rc = ns2_recv_vc(bind->nsi, nsvc, msg);
+			break;
+		case GPRS_NS2_CS_ERROR:
+		case GPRS_NS2_CS_SKIPPED:
+			rc = 0;
+			break;
+		case GPRS_NS2_CS_REJECTED:
+			/* nsip_sendmsg will free reject */
+			nsip_sendmsg(bind, reject, &saddr);
+			return 0;
+		case GPRS_NS2_CS_CREATED:
+			ns2_driver_alloc_vc(bind, nsvc, &saddr);
+			gprs_ns2_vc_fsm_start(nsvc);
+			rc = ns2_recv_vc(bind->nsi, nsvc, msg);
+			break;
+		}
+	} else {
+		/* VC found */
+		rc = ns2_recv_vc(bind->nsi, nsvc, msg);
+	}
+
+	msgb_free(msg);
+
+	return rc;
+}
+
+static int handle_nsip_write(struct osmo_fd *bfd)
+{
+	/* FIXME: actually send the data here instead of nsip_sendmsg() */
+	return -EIO;
+}
+
+static int nsip_fd_cb(struct osmo_fd *bfd, unsigned int what)
+{
+	int rc = 0;
+
+	if (what & OSMO_FD_READ)
+		rc = handle_nsip_read(bfd);
+	if (what & OSMO_FD_WRITE)
+		rc = handle_nsip_write(bfd);
+
+	return rc;
+}
+
+/*!
+ * \brief bind to an IPv4/IPv6 address
+ * \param[in] nsi NS Instance in which to create the NSVC
+ * \param[in] address the address to bind to
+ * \param[out] result if set, returns the bind object
+ * \return
+ */
+int gprs_ns2_ip_bind(struct gprs_ns2_inst *nsi,
+		     struct osmo_sockaddr *local,
+		     int dscp,
+		     struct gprs_ns2_vc_bind **result)
+{
+	struct gprs_ns2_vc_bind *bind = talloc_zero(nsi, struct gprs_ns2_vc_bind);
+	struct priv_bind *priv;
+	int rc;
+
+	if (!bind)
+		return -ENOSPC;
+
+	if (local->u.sa.sa_family != AF_INET && local->u.sa.sa_family != AF_INET6) {
+		talloc_free(bind);
+		return -EINVAL;
+	}
+
+	bind->driver = &vc_driver_ip;
+	bind->send_vc = nsip_vc_sendmsg;
+	bind->free_vc = free_vc;
+	bind->nsi = nsi;
+
+	priv = bind->priv = talloc_zero(bind, struct priv_bind);
+	if (!priv) {
+		talloc_free(bind);
+		return -ENOSPC;
+	}
+	priv->fd.cb = nsip_fd_cb;
+	priv->fd.data = bind;
+	priv->addr = *local;
+	INIT_LLIST_HEAD(&bind->nsvc);
+
+	llist_add(&bind->list, &nsi->binding);
+
+	rc = osmo_sock_init_osa_ofd(&priv->fd, SOCK_DGRAM, IPPROTO_UDP,
+				 local, NULL,
+				 OSMO_SOCK_F_BIND);
+	if (rc < 0) {
+		talloc_free(priv);
+		talloc_free(bind);
+		return rc;
+	}
+
+	if (dscp > 0) {
+		priv->dscp = dscp;
+
+		rc = setsockopt(priv->fd.fd, IPPROTO_IP, IP_TOS,
+				&dscp, sizeof(dscp));
+		if (rc < 0)
+			LOGP(DLNS, LOGL_ERROR,
+				"Failed to set the DSCP to %d with ret(%d) errno(%d)\n",
+				dscp, rc, errno);
+	}
+
+	ns2_vty_bind_apply(bind);
+
+	if (result)
+		*result = bind;
+
+	return 0;
+}
+
+struct gprs_ns2_vc *gprs_ns2_ip_bind_connect(struct gprs_ns2_vc_bind *bind,
+					     struct gprs_ns2_nse *nse,
+					     struct osmo_sockaddr *remote)
+{
+	struct gprs_ns2_vc *nsvc;
+	struct priv_vc *priv;
+
+	nsvc = ns2_vc_alloc(bind, nse, true);
+	nsvc->priv = talloc_zero(bind, struct priv_vc);
+	if (!nsvc->priv) {
+		gprs_ns2_free_nsvc(nsvc);
+		return NULL;
+	}
+
+	priv = nsvc->priv;
+	priv->remote = *remote;
+
+	nsvc->ll = GPRS_NS_LL_UDP;
+
+	return nsvc;
+}
+
+struct osmo_sockaddr *gprs_ns2_ip_vc_sockaddr(struct gprs_ns2_vc *nsvc)
+{
+	struct priv_vc *priv;
+
+	if (nsvc->ll != GPRS_NS_LL_UDP)
+		return NULL;
+
+	priv = nsvc->priv;
+	return &priv->remote;
+}
+
+struct osmo_sockaddr *gprs_ns2_ip_bind_sockaddr(struct gprs_ns2_vc_bind *bind)
+{
+	struct priv_bind *priv;
+
+	priv = bind->priv;
+	return &priv->addr;
+}
+
+int gprs_ns2_is_ip_bind(struct gprs_ns2_vc_bind *bind)
+{
+	return (bind->driver == &vc_driver_ip);
+}
+
+int gprs_ns2_ip_bind_set_dscp(struct gprs_ns2_vc_bind *bind, int dscp)
+{
+	struct priv_bind *priv;
+	int rc = 0;
+
+	priv = bind->priv;
+
+	if (dscp != priv->dscp) {
+		priv->dscp = dscp;
+
+		rc = setsockopt(priv->fd.fd, IPPROTO_IP, IP_TOS,
+				&dscp, sizeof(dscp));
+		if (rc < 0)
+			LOGP(DLNS, LOGL_ERROR,
+			     "Failed to set the DSCP to %d with ret(%d) errno(%d)\n",
+			     dscp, rc, errno);
+	}
+
+	return rc;
+}