diff --git a/src/input/lapd.c b/src/input/lapd.c
index 5a475c4..bced94a 100644
--- a/src/input/lapd.c
+++ b/src/input/lapd.c
@@ -36,6 +36,7 @@
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/timer.h>
 #include <osmocom/abis/lapd.h>
+#include <osmocom/abis/lapd_pcap.h>
 
 #define LAPD_ADDR2(sapi, cr) ((((sapi) & 0x3f) << 2) | (((cr) & 0x1) << 1))
 #define LAPD_ADDR3(tei) ((((tei) & 0x7f) << 1) | 0x1)
@@ -311,6 +312,10 @@
 		msg = msgb_alloc_headroom(56, 56, "DL EST");
 		msg->l2h = msgb_push(msg, 8);
 		memcpy(msg->l2h, resp, 8);
+
+		/* write to PCAP file, if enabled. */
+		osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_OUTPUT, msg);
+
 		LOGP(DLLAPD, LOGL_DEBUG, "TX: %s\n",
 			osmo_hexdump(msg->data, msg->len));
 		li->transmit_cb(msg, li->transmit_cbdata);
@@ -336,6 +341,9 @@
 	struct lapd_sap *sap;
 	struct lapd_tei *teip;
 
+	/* write to PCAP file, if enabled. */
+	osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_INPUT, msg);
+
 	LOGP(DLLAPD, LOGL_DEBUG, "RX: %s\n", osmo_hexdump(msg->data, msg->len));
 	if (msg->len < 2) {
 		LOGP(DLLAPD, LOGL_ERROR, "LAPD frame receive len %d < 2, "
@@ -585,6 +593,9 @@
 	else
 		msg->l2h[1] = LAPD_ADDR3(lctx->tei);
 
+	/* write to PCAP file, if enabled. */
+	osmo_pcap_lapd_write(li->pcap_fd, OSMO_LAPD_PCAP_OUTPUT, msg);
+
 	/* forward frame to L1 */
 	LOGP(DLLAPD, LOGL_DEBUG, "TX: %s\n", osmo_hexdump(msg->data, msg->len));
 	li->transmit_cb(msg, li->transmit_cbdata);
@@ -645,6 +656,7 @@
 	li->transmit_cbdata = tx_cbdata;
 	li->receive_cb = rx_cb;
 	li->receive_cbdata = rx_cbdata;
+	li->pcap_fd = -1;
 	memcpy(&li->profile, profile, sizeof(li->profile));
 
 	INIT_LLIST_HEAD(&li->tei_list);
diff --git a/src/input/lapd_pcap.c b/src/input/lapd_pcap.c
new file mode 100644
index 0000000..c83bc60
--- /dev/null
+++ b/src/input/lapd_pcap.c
@@ -0,0 +1,159 @@
+/* (C) 2008-2012 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * Author: Harald Welte <laforge@gnumonks.org>
+ *         Pablo Neira Ayuso <pablo@gnumonks.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <errno.h>
+
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+
+#include <osmocom/abis/lapd_pcap.h>
+
+/*
+ * pcap writing of the mlapd load
+ * pcap format is from http://wiki.wireshark.org/Development/LibpcapFileFormat
+ */
+#define DLT_LINUX_LAPD		177
+
+struct pcap_hdr {
+	uint32_t magic_number;
+	uint16_t version_major;
+	uint16_t version_minor;
+	int32_t  thiszone;
+	uint32_t sigfigs;
+	uint32_t snaplen;
+	uint32_t network;
+} __attribute__((packed));
+
+struct pcap_rechdr {
+	uint32_t ts_sec;
+	uint32_t ts_usec;
+	uint32_t incl_len;
+	uint32_t orig_len;
+} __attribute__((packed));
+
+struct pcap_lapdhdr {
+	uint16_t pkttype;
+	uint16_t hatype;
+	uint16_t halen;
+	uint64_t addr;
+	int16_t protocol;
+} __attribute__((packed));
+
+osmo_static_assert(offsetof(struct pcap_lapdhdr, hatype) == 2, hatype_offset);
+osmo_static_assert(offsetof(struct pcap_lapdhdr, halen) == 4, halen_offset);
+osmo_static_assert(offsetof(struct pcap_lapdhdr, addr) == 6, addr_offset);
+osmo_static_assert(offsetof(struct pcap_lapdhdr, protocol) == 14, proto_offset);
+osmo_static_assert(sizeof(struct pcap_lapdhdr) == 16, lapd_header_size);
+
+int osmo_pcap_lapd_open(char *filename, mode_t mode)
+{
+	int fd;
+	struct pcap_hdr pcap_header = {
+		.magic_number	= 0xa1b2c3d4,
+		.version_major	= 2,
+		.version_minor	= 4,
+		.thiszone	= 0,
+		.sigfigs	= 0,
+		.snaplen	= 65535,
+		.network	= DLT_LINUX_LAPD,
+	};
+
+	LOGP(DLLAPD, LOGL_NOTICE, "opening LAPD pcap file `%s'\n", filename);
+
+	fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, mode);
+	if (fd < 0) {
+		LOGP(DLLAPD, LOGL_ERROR, "failed to open PCAP file: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	if (write(fd, &pcap_header, sizeof(pcap_header))
+					!= sizeof(pcap_header)) {
+		LOGP(DLLAPD, LOGL_ERROR, "cannot write PCAP header: %s\n",
+			strerror(errno));
+		close(fd);
+		return -1;
+	}
+	return fd;
+}
+
+/* This currently only works for the D-Channel */
+int osmo_pcap_lapd_write(int fd, int direction, struct msgb *msg)
+{
+	int numbytes = 0;
+	struct timeval tv;
+	struct pcap_rechdr pcap_rechdr;
+	struct pcap_lapdhdr header;
+	char buf[sizeof(struct pcap_rechdr) +
+		 sizeof(struct pcap_lapdhdr) + msg->len];
+
+	/* PCAP file has not been opened, skip. */
+	if (fd < 0)
+		return 0;
+
+	pcap_rechdr.ts_sec	= 0;
+	pcap_rechdr.ts_usec	= 0;
+	pcap_rechdr.incl_len   = msg->len + sizeof(struct pcap_lapdhdr);
+	pcap_rechdr.orig_len   = msg->len + sizeof(struct pcap_lapdhdr);
+
+	header.pkttype		= 4;
+	header.hatype		= 0;
+	header.halen		= 0;
+	header.addr		= direction == OSMO_LAPD_PCAP_OUTPUT ? 0x0 : 0x1;
+	header.protocol		= ntohs(48);
+
+	gettimeofday(&tv, NULL);
+	pcap_rechdr.ts_sec = tv.tv_sec;
+	pcap_rechdr.ts_usec = tv.tv_usec;
+
+	memcpy(buf + numbytes, &pcap_rechdr, sizeof(pcap_rechdr));
+	numbytes += sizeof(pcap_rechdr);
+
+	memcpy(buf + numbytes, &header, sizeof(header));
+	numbytes += sizeof(header);
+
+	memcpy(buf + numbytes, msg->data, msg->len);
+	numbytes += msg->len;
+
+	if (write(fd, buf, numbytes) != numbytes) {
+		LOGP(DLLAPD, LOGL_ERROR, "cannot write packet to PCAP: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	return numbytes;
+}
+
+int osmo_pcap_lapd_close(int fd)
+{
+	LOGP(DLLAPD, LOGL_NOTICE, "closing LAPD pcap file\n");
+	return close(fd);
+}