diff --git a/host/src/usb2udp.c b/host/src/usb2udp.c
new file mode 100644
index 0000000..9927594
--- /dev/null
+++ b/host/src/usb2udp.c
@@ -0,0 +1,285 @@
+/* simtrace - main program for the host PC
+ *
+ * (C) 2010-2016 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * 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 <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <time.h>
+#define _GNU_SOURCE
+#include <getopt.h>
+#include <poll.h>
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <libusb.h>
+
+#include <osmocom/simtrace2/simtrace_usb.h>
+#include <osmocom/simtrace2/simtrace_prot.h>
+#include "simtrace2-discovery.h"
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/select.h>
+
+struct libusb_device_handle *g_devh;
+static struct sockaddr_in g_sa_remote;
+static struct osmo_fd g_udp_ofd;
+
+static void print_welcome(void)
+{
+	printf("usb2udp - UDP/IP forwarding of SIMtrace card emulation\n"
+	       "(C) 2016 by Harald Welte <laforge@gnumonks.org>\n\n");
+}
+
+static void print_help(void)
+{
+	printf( "\t-h\t--help\n"
+		"\t-i\t--interface <0-255>\n"
+		"\n"
+		);
+}
+
+struct ep_buf {
+	uint8_t ep;
+	uint8_t buf[1024];
+	struct libusb_transfer *xfer;
+};
+static struct ep_buf g_buf_in;
+static struct ep_buf g_buf_out;
+
+static void usb_in_xfer_cb(struct libusb_transfer *xfer)
+{
+	int rc;
+
+	printf("xfer_cb(ep=%02x): status=%d, flags=0x%x, type=%u, len=%u, act_len=%u\n",
+		xfer->endpoint, xfer->status, xfer->flags, xfer->type, xfer->length, xfer->actual_length);
+	switch (xfer->status) {
+	case LIBUSB_TRANSFER_COMPLETED:
+		if (xfer->endpoint == g_buf_in.ep) {
+			/* process the data */
+			printf("read %d bytes from SIMTRACE, forwarding to UDP\n", xfer->actual_length);
+			rc = sendto(g_udp_ofd.fd, xfer->buffer, xfer->actual_length, 0, (struct sockaddr *)&g_sa_remote, sizeof(g_sa_remote));
+			if (rc <= 0) {
+				fprintf(stderr, "error writing to UDP\n");
+			}
+			/* and re-submit the URB */
+			libusb_submit_transfer(xfer);
+		} else if (xfer->endpoint == g_buf_out.ep) {
+			/* re-enable reading from the UDP side */
+			g_udp_ofd.when |= BSC_FD_READ;
+		}
+		break;
+	default:
+		fprintf(stderr, "xfer_cb(ERROR '%s')\n", osmo_hexdump_nospc(xfer->buffer, xfer->actual_length));
+		break;
+	}
+}
+
+static void init_ep_buf(struct ep_buf *epb)
+{
+	if (!epb->xfer)
+		epb->xfer = libusb_alloc_transfer(0);
+
+	epb->xfer->flags = 0;
+
+	libusb_fill_bulk_transfer(epb->xfer, g_devh, epb->ep, epb->buf, sizeof(epb->buf), usb_in_xfer_cb, NULL, 0);
+}
+
+/***********************************************************************
+ * libosmocore main loop integration of libusb async I/O
+ ***********************************************************************/
+
+static int g_libusb_pending = 0;
+
+static int ofd_libusb_cb(struct osmo_fd *ofd, unsigned int what)
+{
+	/* FIXME */
+	g_libusb_pending = 1;
+
+	return 0;
+}
+
+/* call-back when libusb adds a FD */
+static void libusb_fd_added_cb(int fd, short events, void *user_data)
+{
+	struct osmo_fd *ofd = talloc_zero(NULL, struct osmo_fd);
+
+	printf("%s(%u, %x)\n", __func__, fd, events);
+
+	ofd->fd = fd;
+	ofd->cb = &ofd_libusb_cb;
+	if (events & POLLIN)
+		ofd->when |= BSC_FD_READ;
+	if (events & POLLOUT)
+		ofd->when |= BSC_FD_WRITE;
+
+	osmo_fd_register(ofd);
+}
+
+/* call-back when libusb removes a FD */
+static void libusb_fd_removed_cb(int fd, void *user_data)
+{
+
+	printf("%s(%u)\n", __func__, fd);
+#if 0
+	struct osmo_fd *ofd;
+	/* FIXME: This needs new export in libosmocore! */
+	ofd = osmo_fd_get_by_fd(fd);
+
+	if (ofd) {
+		osmo_fd_unregister(ofd);
+		talloc_free(ofd);
+	}
+#endif
+}
+
+/* call-back when the UDP socket is readable */
+static int ofd_udp_cb(struct osmo_fd *ofd, unsigned int what)
+{
+	int rc;
+	socklen_t addrlen = sizeof(g_sa_remote);
+
+	rc = recvfrom(ofd->fd, g_buf_out.buf, sizeof(g_buf_out.buf), 0,
+			(struct sockaddr *)&g_sa_remote, &addrlen);
+	if (rc <= 0) {
+		fprintf(stderr, "error reading from UDP\n");
+		return 0;
+	}
+	printf("read %d bytes from UDP, forwarding to SIMTRACE\n", rc);
+	g_buf_out.xfer->length = rc;
+
+	/* disable further READ interest for the UDP socket */
+	ofd->when &= ~BSC_FD_READ;
+
+	/* submit the URB on the OUT end point */
+	libusb_submit_transfer(g_buf_out.xfer);
+
+	return 0;
+}
+
+static void run_mainloop(void)
+{
+	int rc;
+
+	printf("Entering main loop\n");
+
+	while (1) {
+		osmo_select_main(0);
+		if (g_libusb_pending) {
+			struct timeval tv;
+			memset(&tv, 0, sizeof(tv));
+			rc = libusb_handle_events_timeout_completed(NULL, &tv, NULL);
+			if (rc != 0) {
+				fprintf(stderr, "handle_events_timeout_completed == %d\n", rc);
+				break;
+			}
+		}
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int rc;
+	int c, ret = 1;
+	int local_udp_port = 52342;
+	unsigned int if_num = 0;
+
+	print_welcome();
+
+	while (1) {
+		int option_index = 0;
+		static const struct option opts[] = {
+			{ "udp-port", 1, 0, 'u' },
+			{ "interface", 1, 0, 'I' },
+			{ "help", 0, 0, 'h' },
+			{ NULL, 0, 0, 0 }
+		};
+
+		c = getopt_long(argc, argv, "u:I:h", opts, &option_index);
+		if (c == -1)
+			break;
+		switch (c) {
+		case 'u':
+			local_udp_port = atoi(optarg);
+			break;
+		case 'I':
+			if_num = atoi(optarg);
+			break;
+		case 'h':
+			print_help();
+			exit(0);
+			break;
+		}
+	}
+
+	rc = libusb_init(NULL);
+	if (rc < 0) {
+		fprintf(stderr, "libusb initialization failed\n");
+		goto close_exit;
+	}
+
+	libusb_set_pollfd_notifiers(NULL, &libusb_fd_added_cb, &libusb_fd_removed_cb, NULL);
+
+	g_devh = libusb_open_device_with_vid_pid(NULL, USB_VENDOR_OPENMOKO, USB_PRODUCT_OWHW_SAM3);
+	if (!g_devh) {
+		fprintf(stderr, "can't open USB device\n");
+		goto close_exit;
+	}
+
+	rc = libusb_claim_interface(g_devh, if_num);
+	if (rc < 0) {
+		fprintf(stderr, "can't claim interface %u; rc=%d\n", if_num, rc);
+		goto close_exit;
+	}
+
+	/* open UDP socket, register with select handling and mark it
+	 * readable */
+	g_udp_ofd.cb = ofd_udp_cb;
+	osmo_sock_init_ofd(&g_udp_ofd, AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, local_udp_port + if_num, OSMO_SOCK_F_BIND);
+
+	rc = get_usb_ep_addrs(g_devh, if_num, &g_buf_out.ep, &g_buf_in.ep, NULL);
+	if (rc < 0) {
+		fprintf(stderr, "couldn't find enpdoint addresses; rc=%d\n", rc);
+		goto close_exit;
+	}
+	/* initialize USB buffers / transfers */
+	init_ep_buf(&g_buf_out);
+	init_ep_buf(&g_buf_in);
+
+	/* submit the first transfer for the IN endpoint */
+	libusb_submit_transfer(g_buf_in.xfer);
+
+	run_mainloop();
+
+	ret = 0;
+
+	libusb_release_interface(g_devh, 0);
+close_exit:
+	if (g_devh)
+		libusb_close(g_devh);
+
+	libusb_exit(NULL);
+	return ret;
+}