diff --git a/include/Makefile.am b/include/Makefile.am
new file mode 100644
index 0000000..c94d3ee
--- /dev/null
+++ b/include/Makefile.am
@@ -0,0 +1,3 @@
+noinst_HEADERS=mISDNif.h internal.h lapd.h
+
+SUBDIRS=osmocom
diff --git a/include/internal.h b/include/internal.h
new file mode 100644
index 0000000..131e12b
--- /dev/null
+++ b/include/internal.h
@@ -0,0 +1,102 @@
+#ifndef _INTERNAL_H_
+#define _INTERNAL_H_
+
+/* things I don't know what to do with yet. */
+
+/* extracted from include/openbsc/debug.h. */
+#define BSC_CTX_BTS     2
+
+/* from include/openbsc/signal.h, we need SS_INPUT and S_GLOBAL_SHUTDOWN. */
+enum signal_subsystems {
+	SS_PAGING,
+	SS_SMS,
+	SS_ABISIP,
+	SS_NM,
+	SS_LCHAN,
+	SS_SUBSCR,
+	SS_SCALL,
+	SS_GLOBAL,
+	SS_CHALLOC,
+	SS_NS,
+	SS_IPAC_NWL,
+	SS_RF,
+	SS_MSC,
+	SS_HO,
+	SS_INPUT,
+};
+
+enum signal_global {
+	S_GLOBAL_SHUTDOWN,
+	S_GLOBAL_BTS_CLOSE_OM,
+};
+
+/* from include/openbsc/vty.h, we need E1INP_NODE */
+#include <osmocom/vty/vty.h>
+#include <osmocom/vty/buffer.h>
+#include <osmocom/vty/command.h>
+
+enum bsc_vty_node {
+	GSMNET_NODE = _LAST_OSMOVTY_NODE + 1,
+	BTS_NODE,
+	TRX_NODE,
+	TS_NODE,
+	SUBSCR_NODE,
+	MGCP_NODE,
+	GBPROXY_NODE,
+	SGSN_NODE,
+	NS_NODE,
+	BSSGP_NODE,
+	OML_NODE,
+	E1INP_NODE,
+	NAT_NODE,
+	NAT_BSC_NODE,
+	MSC_NODE,
+	OM2K_NODE,
+	TRUNK_NODE,
+	PGROUP_NODE,
+};
+
+/* from include/openbsc/debug.h */
+enum {
+        DRLL,
+        DCC,
+        DMM,
+        DRR,
+        DRSL,
+        DNM,
+        DMNCC,
+        DSMS,
+        DPAG,
+        DMEAS,
+        DMI,
+        DMIB,
+        DMUX,
+        DINP,
+        DSCCP,
+        DMSC,
+        DMGCP,
+        DHO,
+        DDB,
+        DREF,
+        DGPRS,
+        DNS,
+        DBSSGP,
+        DLLC,
+        DSNDCP,
+        DNAT,
+        Debug_LastEntry,
+};
+
+struct osmo_fd;
+struct msgb *ipaccess_read_msg(struct osmo_fd *bfd, int *error);
+void ipaccess_prepend_header(struct msgb *msg, int proto);
+
+#include <stdint.h>
+
+int make_sock(struct osmo_fd *bfd, int proto,
+              uint32_t ip, uint16_t port, int priv_nr,
+              int (*cb)(struct osmo_fd *fd, unsigned int what), void *data);
+
+uint8_t *trau_idle_frame(void);
+
+#endif
diff --git a/include/lapd.h b/include/lapd.h
new file mode 100644
index 0000000..fb980d1
--- /dev/null
+++ b/include/lapd.h
@@ -0,0 +1,46 @@
+#ifndef OPENBSC_LAPD_H
+#define OPENBSC_LAPD_H
+
+#include <stdint.h>
+
+#include <osmocom/core/linuxlist.h>
+
+typedef enum {
+	LAPD_MPH_NONE	= 0,
+
+	LAPD_MPH_ACTIVATE_IND,
+	LAPD_MPH_DEACTIVATE_IND,
+
+	LAPD_DL_DATA_IND,
+	LAPD_DL_UNITDATA_IND,
+
+} lapd_mph_type;
+
+struct lapd_instance {
+	struct llist_head list;		/* list of LAPD instances */
+	int network_side;
+
+	void (*transmit_cb)(uint8_t *data, int len, void *cbdata);
+	void *cbdata;
+
+	struct llist_head tei_list;	/* list of TEI in this LAPD instance */
+};
+
+extern uint8_t *lapd_receive(struct lapd_instance *li, uint8_t *data, unsigned int len,
+			     int *ilen, lapd_mph_type *prim);
+
+extern void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t sapi,
+			  uint8_t *data, unsigned int len);
+
+struct lapd_instance *lapd_instance_alloc(int network_side,
+					  void (*tx_cb)(uint8_t *data, int len,
+							void *cbdata), void *cbdata);
+
+
+/* Start a (user-side) SAP for the specified TEI/SAPI on the LAPD instance */
+int lapd_sap_start(struct lapd_instance *li, uint8_t tei, uint8_t sapi);
+
+/* Stop a (user-side) SAP for the specified TEI/SAPI on the LAPD instance */
+int lapd_sap_stop(struct lapd_instance *li, uint8_t tei, uint8_t sapi);
+
+#endif /* OPENBSC_LAPD_H */
diff --git a/include/mISDNif.h b/include/mISDNif.h
new file mode 100644
index 0000000..8e065d2
--- /dev/null
+++ b/include/mISDNif.h
@@ -0,0 +1,387 @@
+/*
+ *
+ * Author	Karsten Keil <kkeil@novell.com>
+ *
+ * Copyright 2008  by Karsten Keil <kkeil@novell.com>
+ *
+ * This code is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU LESSER GENERAL PUBLIC LICENSE
+ * version 2.1 as published by the Free Software Foundation.
+ *
+ * This code 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 LESSER GENERAL PUBLIC LICENSE for more details.
+ *
+ */
+
+#ifndef mISDNIF_H
+#define mISDNIF_H
+
+#include <stdarg.h>
+#ifdef linux
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/socket.h>
+#else
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/socket.h>
+#endif
+
+/*
+ * ABI Version 32 bit
+ *
+ * <8 bit> Major version
+ *		- changed if any interface become backwards incompatible
+ *
+ * <8 bit> Minor version
+ *              - changed if any interface is extended but backwards compatible
+ *
+ * <16 bit> Release number
+ *              - should be incremented on every checkin
+ */
+#define	MISDN_MAJOR_VERSION	1
+#define	MISDN_MINOR_VERSION	1
+#define MISDN_RELEASE		20
+
+/* primitives for information exchange
+ * generell format
+ * <16  bit  0 >
+ * <8  bit command>
+ *    BIT 8 = 1 LAYER private
+ *    BIT 7 = 1 answer
+ *    BIT 6 = 1 DATA
+ * <8  bit target layer mask>
+ *
+ * Layer = 00 is reserved for general commands
+   Layer = 01  L2 -> HW
+   Layer = 02  HW -> L2
+   Layer = 04  L3 -> L2
+   Layer = 08  L2 -> L3
+ * Layer = FF is reserved for broadcast commands
+ */
+
+#define MISDN_CMDMASK		0xff00
+#define MISDN_LAYERMASK		0x00ff
+
+/* generell commands */
+#define OPEN_CHANNEL		0x0100
+#define CLOSE_CHANNEL		0x0200
+#define CONTROL_CHANNEL		0x0300
+#define CHECK_DATA		0x0400
+
+/* layer 2 -> layer 1 */
+#define PH_ACTIVATE_REQ		0x0101
+#define PH_DEACTIVATE_REQ	0x0201
+#define PH_DATA_REQ		0x2001
+#define MPH_ACTIVATE_REQ	0x0501
+#define MPH_DEACTIVATE_REQ	0x0601
+#define MPH_INFORMATION_REQ	0x0701
+#define PH_CONTROL_REQ		0x0801
+
+/* layer 1 -> layer 2 */
+#define PH_ACTIVATE_IND		0x0102
+#define PH_ACTIVATE_CNF		0x4102
+#define PH_DEACTIVATE_IND	0x0202
+#define PH_DEACTIVATE_CNF	0x4202
+#define PH_DATA_IND		0x2002
+#define PH_DATA_E_IND		0x3002
+#define MPH_ACTIVATE_IND	0x0502
+#define MPH_DEACTIVATE_IND	0x0602
+#define MPH_INFORMATION_IND	0x0702
+#define PH_DATA_CNF		0x6002
+#define PH_CONTROL_IND		0x0802
+#define PH_CONTROL_CNF		0x4802
+
+/* layer 3 -> layer 2 */
+#define DL_ESTABLISH_REQ	0x1004
+#define DL_RELEASE_REQ		0x1104
+#define DL_DATA_REQ		0x3004
+#define DL_UNITDATA_REQ		0x3104
+#define DL_INFORMATION_REQ	0x0004
+
+/* layer 2 -> layer 3 */
+#define DL_ESTABLISH_IND	0x1008
+#define DL_ESTABLISH_CNF	0x5008
+#define DL_RELEASE_IND		0x1108
+#define DL_RELEASE_CNF		0x5108
+#define DL_DATA_IND		0x3008
+#define DL_UNITDATA_IND		0x3108
+#define DL_INFORMATION_IND	0x0008
+
+/* intern layer 2 managment */
+#define MDL_ASSIGN_REQ		0x1804
+#define MDL_ASSIGN_IND		0x1904
+#define MDL_REMOVE_REQ		0x1A04
+#define MDL_REMOVE_IND		0x1B04
+#define MDL_STATUS_UP_IND	0x1C04
+#define MDL_STATUS_DOWN_IND	0x1D04
+#define MDL_STATUS_UI_IND	0x1E04
+#define MDL_ERROR_IND		0x1F04
+#define MDL_ERROR_RSP		0x5F04
+
+/* DL_INFORMATION_IND types */
+#define DL_INFO_L2_CONNECT	0x0001
+#define DL_INFO_L2_REMOVED	0x0002
+
+/* PH_CONTROL types */
+/* TOUCH TONE IS 0x20XX  XX "0"..."9", "A","B","C","D","*","#" */
+#define DTMF_TONE_VAL		0x2000
+#define DTMF_TONE_MASK		0x007F
+#define DTMF_TONE_START		0x2100
+#define DTMF_TONE_STOP		0x2200
+#define DTMF_HFC_COEF		0x4000
+#define DSP_CONF_JOIN		0x2403
+#define DSP_CONF_SPLIT		0x2404
+#define DSP_RECEIVE_OFF		0x2405
+#define DSP_RECEIVE_ON		0x2406
+#define DSP_ECHO_ON		0x2407
+#define DSP_ECHO_OFF		0x2408
+#define DSP_MIX_ON		0x2409
+#define DSP_MIX_OFF		0x240a
+#define DSP_DELAY		0x240b
+#define DSP_JITTER		0x240c
+#define DSP_TXDATA_ON		0x240d
+#define DSP_TXDATA_OFF		0x240e
+#define DSP_TX_DEJITTER		0x240f
+#define DSP_TX_DEJ_OFF		0x2410
+#define DSP_TONE_PATT_ON	0x2411
+#define DSP_TONE_PATT_OFF	0x2412
+#define DSP_VOL_CHANGE_TX	0x2413
+#define DSP_VOL_CHANGE_RX	0x2414
+#define DSP_BF_ENABLE_KEY	0x2415
+#define DSP_BF_DISABLE		0x2416
+#define DSP_BF_ACCEPT		0x2416
+#define DSP_BF_REJECT		0x2417
+#define DSP_PIPELINE_CFG	0x2418
+#define HFC_VOL_CHANGE_TX	0x2601
+#define HFC_VOL_CHANGE_RX	0x2602
+#define HFC_SPL_LOOP_ON		0x2603
+#define HFC_SPL_LOOP_OFF	0x2604
+
+/* DSP_TONE_PATT_ON parameter */
+#define TONE_OFF			0x0000
+#define TONE_GERMAN_DIALTONE		0x0001
+#define TONE_GERMAN_OLDDIALTONE		0x0002
+#define TONE_AMERICAN_DIALTONE		0x0003
+#define TONE_GERMAN_DIALPBX		0x0004
+#define TONE_GERMAN_OLDDIALPBX		0x0005
+#define TONE_AMERICAN_DIALPBX		0x0006
+#define TONE_GERMAN_RINGING		0x0007
+#define TONE_GERMAN_OLDRINGING		0x0008
+#define TONE_AMERICAN_RINGPBX		0x000b
+#define TONE_GERMAN_RINGPBX		0x000c
+#define TONE_GERMAN_OLDRINGPBX		0x000d
+#define TONE_AMERICAN_RINGING		0x000e
+#define TONE_GERMAN_BUSY		0x000f
+#define TONE_GERMAN_OLDBUSY		0x0010
+#define TONE_AMERICAN_BUSY		0x0011
+#define TONE_GERMAN_HANGUP		0x0012
+#define TONE_GERMAN_OLDHANGUP		0x0013
+#define TONE_AMERICAN_HANGUP		0x0014
+#define TONE_SPECIAL_INFO		0x0015
+#define TONE_GERMAN_GASSENBESETZT	0x0016
+#define TONE_GERMAN_AUFSCHALTTON	0x0016
+
+/* MPH_INFORMATION_IND */
+#define L1_SIGNAL_LOS_OFF	0x0010
+#define L1_SIGNAL_LOS_ON	0x0011
+#define L1_SIGNAL_AIS_OFF	0x0012
+#define L1_SIGNAL_AIS_ON	0x0013
+#define L1_SIGNAL_RDI_OFF	0x0014
+#define L1_SIGNAL_RDI_ON	0x0015
+#define L1_SIGNAL_SLIP_RX	0x0020
+#define L1_SIGNAL_SLIP_TX	0x0021
+
+/*
+ * protocol ids
+ * D channel 1-31
+ * B channel 33 - 63
+ */
+
+#define ISDN_P_NONE		0
+#define ISDN_P_BASE		0
+#define ISDN_P_TE_S0		0x01
+#define ISDN_P_NT_S0  		0x02
+#define ISDN_P_TE_E1		0x03
+#define ISDN_P_NT_E1  		0x04
+#define ISDN_P_TE_UP0		0x05
+#define ISDN_P_NT_UP0		0x06
+
+#define IS_ISDN_P_TE(p) ((p == ISDN_P_TE_S0) || (p == ISDN_P_TE_E1) || \
+				(p == ISDN_P_TE_UP0) || (p == ISDN_P_LAPD_TE))
+#define IS_ISDN_P_NT(p) ((p == ISDN_P_NT_S0) || (p == ISDN_P_NT_E1) || \
+				(p == ISDN_P_NT_UP0) || (p == ISDN_P_LAPD_NT))
+#define IS_ISDN_P_S0(p) ((p == ISDN_P_TE_S0) || (p == ISDN_P_NT_S0))
+#define IS_ISDN_P_E1(p) ((p == ISDN_P_TE_E1) || (p == ISDN_P_NT_E1))
+#define IS_ISDN_P_UP0(p) ((p == ISDN_P_TE_UP0) || (p == ISDN_P_NT_UP0))
+
+
+#define ISDN_P_LAPD_TE		0x10
+#define	ISDN_P_LAPD_NT		0x11
+
+#define ISDN_P_B_MASK		0x1f
+#define ISDN_P_B_START		0x20
+
+#define ISDN_P_B_RAW		0x21
+#define ISDN_P_B_HDLC		0x22
+#define ISDN_P_B_X75SLP		0x23
+#define ISDN_P_B_L2DTMF		0x24
+#define ISDN_P_B_L2DSP		0x25
+#define ISDN_P_B_L2DSPHDLC	0x26
+
+#define OPTION_L2_PMX		1
+#define OPTION_L2_PTP		2
+#define OPTION_L2_FIXEDTEI	3
+#define OPTION_L2_CLEANUP	4
+
+/* should be in sync with linux/kobject.h:KOBJ_NAME_LEN */
+#define MISDN_MAX_IDLEN		20
+
+struct mISDNhead {
+	unsigned int	prim;
+	unsigned int	id;
+}  __attribute__((packed));
+
+#define MISDN_HEADER_LEN	sizeof(struct mISDNhead)
+#define MAX_DATA_SIZE		2048
+#define MAX_DATA_MEM		(MAX_DATA_SIZE + MISDN_HEADER_LEN)
+#define MAX_DFRAME_LEN		260
+
+#define MISDN_ID_ADDR_MASK	0xFFFF
+#define MISDN_ID_TEI_MASK	0xFF00
+#define MISDN_ID_SAPI_MASK	0x00FF
+#define MISDN_ID_TEI_ANY	0x7F00
+
+#define MISDN_ID_ANY		0xFFFF
+#define MISDN_ID_NONE		0xFFFE
+
+#define GROUP_TEI		127
+#define TEI_SAPI		63
+#define CTRL_SAPI		0
+
+#define MISDN_MAX_CHANNEL	127
+#define MISDN_CHMAP_SIZE	((MISDN_MAX_CHANNEL + 1) >> 3)
+
+#define SOL_MISDN	0
+
+struct sockaddr_mISDN {
+	sa_family_t    family;
+	unsigned char	dev;
+	unsigned char	channel;
+	unsigned char	sapi;
+	unsigned char	tei;
+};
+
+struct mISDNversion {
+	unsigned char	major;
+	unsigned char	minor;
+	unsigned short	release;
+};
+
+#define MAX_DEVICE_ID 63
+
+struct mISDN_devinfo {
+	u_int			id;
+	u_int			Dprotocols;
+	u_int			Bprotocols;
+	u_int			protocol;
+	u_char			channelmap[MISDN_CHMAP_SIZE];
+	u_int			nrbchan;
+	char			name[MISDN_MAX_IDLEN];
+};
+
+struct mISDN_devrename {
+	u_int			id;
+	char			name[MISDN_MAX_IDLEN];
+};
+
+struct ph_info_ch {
+	int32_t 		protocol;
+	int64_t			Flags;
+};
+
+struct ph_info_dch {
+	struct ph_info_ch	ch;
+	int16_t			state;
+	int16_t			num_bch;
+};
+
+struct ph_info {
+	struct ph_info_dch	dch;
+	struct ph_info_ch 	bch[];
+};
+
+/* timer device ioctl */
+#define IMADDTIMER	_IOR('I', 64, int)
+#define IMDELTIMER	_IOR('I', 65, int)
+/* socket ioctls */
+#define	IMGETVERSION	_IOR('I', 66, int)
+#define	IMGETCOUNT	_IOR('I', 67, int)
+#define IMGETDEVINFO	_IOR('I', 68, int)
+#define IMCTRLREQ	_IOR('I', 69, int)
+#define IMCLEAR_L2	_IOR('I', 70, int)
+#define IMSETDEVNAME	_IOR('I', 71, struct mISDN_devrename)
+
+static inline int
+test_channelmap(u_int nr, u_char *map)
+{
+	if (nr <= MISDN_MAX_CHANNEL)
+		return map[nr >> 3] & (1 << (nr & 7));
+	else
+		return 0;
+}
+
+static inline void
+set_channelmap(u_int nr, u_char *map)
+{
+	map[nr >> 3] |= (1 << (nr & 7));
+}
+
+static inline void
+clear_channelmap(u_int nr, u_char *map)
+{
+	map[nr >> 3] &= ~(1 << (nr & 7));
+}
+
+/* CONTROL_CHANNEL parameters */
+#define MISDN_CTRL_GETOP		0x0000
+#define MISDN_CTRL_LOOP			0x0001
+#define MISDN_CTRL_CONNECT		0x0002
+#define MISDN_CTRL_DISCONNECT		0x0004
+#define MISDN_CTRL_PCMCONNECT		0x0010
+#define MISDN_CTRL_PCMDISCONNECT	0x0020
+#define MISDN_CTRL_SETPEER		0x0040
+#define MISDN_CTRL_UNSETPEER		0x0080
+#define MISDN_CTRL_RX_OFF		0x0100
+#define MISDN_CTRL_FILL_EMPTY		0x0200
+#define MISDN_CTRL_GETPEER		0x0400
+#define MISDN_CTRL_HW_FEATURES_OP	0x2000
+#define MISDN_CTRL_HW_FEATURES		0x2001
+#define MISDN_CTRL_HFC_OP		0x4000
+#define MISDN_CTRL_HFC_PCM_CONN		0x4001
+#define MISDN_CTRL_HFC_PCM_DISC		0x4002
+#define MISDN_CTRL_HFC_CONF_JOIN	0x4003
+#define MISDN_CTRL_HFC_CONF_SPLIT	0x4004
+#define MISDN_CTRL_HFC_RECEIVE_OFF	0x4005
+#define MISDN_CTRL_HFC_RECEIVE_ON	0x4006
+#define MISDN_CTRL_HFC_ECHOCAN_ON 	0x4007
+#define MISDN_CTRL_HFC_ECHOCAN_OFF 	0x4008
+
+
+/* socket options */
+#define MISDN_TIME_STAMP		0x0001
+
+struct mISDN_ctrl_req {
+	int		op;
+	int		channel;
+	int		p1;
+	int		p2;
+};
+
+/* muxer options */
+#define MISDN_OPT_ALL		1
+#define MISDN_OPT_TEIMGR	2
+
+#endif /* mISDNIF_H */
diff --git a/include/osmocom/Makefile.am b/include/osmocom/Makefile.am
new file mode 100644
index 0000000..999a3ee
--- /dev/null
+++ b/include/osmocom/Makefile.am
@@ -0,0 +1 @@
+SUBDIRS=gsm
diff --git a/include/osmocom/gsm/Makefile.am b/include/osmocom/gsm/Makefile.am
new file mode 100644
index 0000000..f9d5e7c
--- /dev/null
+++ b/include/osmocom/gsm/Makefile.am
@@ -0,0 +1 @@
+SUBDIRS=abis
diff --git a/include/osmocom/gsm/abis/Makefile.am b/include/osmocom/gsm/abis/Makefile.am
new file mode 100644
index 0000000..8bdcc96
--- /dev/null
+++ b/include/osmocom/gsm/abis/Makefile.am
@@ -0,0 +1,3 @@
+osmoabis_HEADERS = e1_input.h subchan_demux.h ipaccess.h trau_frame.h
+
+osmoabisdir = $(includedir)/osmocom/gsm/abis
diff --git a/include/osmocom/gsm/abis/e1_input.h b/include/osmocom/gsm/abis/e1_input.h
new file mode 100644
index 0000000..1911568
--- /dev/null
+++ b/include/osmocom/gsm/abis/e1_input.h
@@ -0,0 +1,226 @@
+#ifndef _E1_INPUT_H
+#define _E1_INPUT_H
+
+#include <stdlib.h>
+#include <netinet/in.h>
+
+#include <osmocom/core/linuxlist.h>
+//#include <openbsc/gsm_data.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/gsm/abis/subchan_demux.h>
+
+#define NUM_E1_TS   32
+
+enum e1inp_sign_type {
+	E1INP_SIGN_NONE,
+	E1INP_SIGN_OML,
+	E1INP_SIGN_RSL,
+};
+const char *e1inp_signtype_name(enum e1inp_sign_type tp);
+
+struct e1inp_ts;
+
+struct e1inp_sign_link {
+	/* list of signalling links */
+	struct llist_head list;
+
+	/* to which timeslot do we belong? */
+	struct e1inp_ts *ts;
+
+	enum e1inp_sign_type type;
+
+	/* trx for msg->trx of received msgs */	
+	struct gsm_bts_trx *trx;
+
+	/* msgb queue of to-be-transmitted msgs */
+	struct llist_head tx_list;
+
+	/* SAPI and TEI on the E1 TS */
+	uint8_t sapi;
+	uint8_t tei;
+
+	union {
+		struct {
+			uint8_t channel;
+		} misdn;
+	} driver;
+};
+
+enum e1inp_ts_type {
+	E1INP_TS_TYPE_NONE,
+	E1INP_TS_TYPE_SIGN,
+	E1INP_TS_TYPE_TRAU,
+};
+const char *e1inp_tstype_name(enum e1inp_ts_type tp);
+
+/* A timeslot in the E1 interface */
+struct e1inp_ts {
+	enum e1inp_ts_type type;
+	int num;
+
+	/* to which line do we belong ? */
+	struct e1inp_line *line;
+
+	union {
+		struct {
+			/* list of all signalling links on this TS */
+			struct llist_head sign_links;
+			/* delay for the queue */
+			int delay;
+			/* timer when to dequeue next frame */
+			struct osmo_timer_list tx_timer;
+		} sign;
+		struct {
+			/* subchannel demuxer for frames from E1 */
+			struct subch_demux demux;
+			/* subchannel muxer for frames to E1 */
+			struct subch_mux mux;
+		} trau;
+	};
+	union {
+		struct {
+			/* mISDN driver has one fd for each ts */
+			struct osmo_fd fd;
+		} misdn;
+		struct {
+			/* ip.access driver has one fd for each ts */
+			struct osmo_fd fd;
+		} ipaccess;
+		struct {
+			/* DAHDI driver has one fd for each ts */
+			struct osmo_fd fd;
+			struct lapd_instance *lapd;
+		} dahdi;
+	} driver;
+};
+
+struct gsm_e1_subslot {
+	/* Number of E1 link */
+	uint8_t e1_nr;
+	/* Number of E1 TS inside E1 link */
+	uint8_t e1_ts;
+	/* Sub-slot within the E1 TS, 0xff if full TS */
+	uint8_t e1_ts_ss;
+};
+
+enum e1inp_line_role {
+	E1INP_LINE_R_NONE,
+	E1INP_LINE_R_BSC,
+	E1INP_LINE_R_BTS,
+	E1INP_LINE_R_MAX
+};
+
+struct e1inp_driver {
+	struct llist_head list;
+	const char *name;
+	int (*want_write)(struct e1inp_ts *ts);
+	int (*line_update)(struct e1inp_line *line, enum e1inp_line_role role);
+	int default_delay;
+};
+
+struct e1inp_line {
+	struct llist_head list;
+	int refcnt;
+
+	unsigned int num;
+	const char *name;
+
+	/* array of timestlots */
+	struct e1inp_ts ts[NUM_E1_TS];
+
+	int (*rx)(struct msgb *msg, struct e1inp_ts *ts);
+	int (*rx_err)(int error);
+
+	struct e1inp_driver *driver;
+	void *driver_data;
+};
+
+/* SS_INPUT signals */
+enum signal_input {
+	S_INP_NONE,
+	S_INP_TEI_UP,
+	S_INP_TEI_DN,
+	S_INP_LINE_INIT,
+	S_INP_LINE_ALARM,
+	S_INP_LINE_NOALARM,
+};
+
+/* register a driver with the E1 core */
+int e1inp_driver_register(struct e1inp_driver *drv);
+
+/* fine a previously registered driver */
+struct e1inp_driver *e1inp_driver_find(const char *name);
+
+/* register a line with the E1 core */
+int e1inp_line_register(struct e1inp_line *line);
+
+/* get a line by its ID */
+struct e1inp_line *e1inp_line_get(uint8_t e1_nr);
+
+/* create a line in the E1 input core */
+struct e1inp_line *e1inp_line_create(uint8_t e1_nr, const char *driver_name, int (*rx)(struct msgb *msg, struct e1inp_ts *ts), int (*rx_err)(int error));
+
+/* find a sign_link for given TEI and SAPI in a TS */
+struct e1inp_sign_link *
+e1inp_lookup_sign_link(struct e1inp_ts *ts, uint8_t tei,
+			uint8_t sapi);
+
+/* create a new signalling link in a E1 timeslot */
+struct e1inp_sign_link *
+e1inp_sign_link_create(struct e1inp_ts *ts, enum e1inp_sign_type type,
+			struct gsm_bts_trx *trx, uint8_t tei,
+			uint8_t sapi);
+
+/* configure and initialize one e1inp_ts */
+int e1inp_ts_config_sign(struct e1inp_ts *ts, struct e1inp_line *line);
+int e1inp_ts_config_trau(struct e1inp_ts *ts, struct e1inp_line *line,
+                         int (*subch_cb)(struct subch_demux *dmx, int ch,
+                                         uint8_t *data, int len, void *_priv));
+
+/* Call from the Stack: configuration of this TS has changed */
+int e1inp_update_ts(struct e1inp_ts *ts);
+
+/* Receive a packet from the E1 driver */
+int e1inp_rx_ts(struct e1inp_ts *ts, struct msgb *msg,
+		uint8_t tei, uint8_t sapi);
+
+/* called by driver if it wants to transmit on a given TS */
+struct msgb *e1inp_tx_ts(struct e1inp_ts *e1i_ts,
+			 struct e1inp_sign_link **sign_link);
+
+/* called by driver in case some kind of link state event */
+int e1inp_event(struct e1inp_ts *ts, int evt, uint8_t tei, uint8_t sapi);
+
+/* Write LAPD frames to the fd. */
+void e1_set_pcap_fd(int fd);
+
+/* called by TRAU muxer to obtain the destination mux entity */
+struct subch_mux *e1inp_get_mux(uint8_t e1_nr, uint8_t ts_nr);
+
+void e1inp_sign_link_destroy(struct e1inp_sign_link *link);
+int e1inp_line_update(struct e1inp_line *line, enum e1inp_line_role role);
+
+struct gsm_network;
+int ipaccess_setup(struct gsm_network *gsmnet);
+int hsl_setup(struct gsm_network *gsmnet);
+
+extern struct llist_head e1inp_driver_list;
+extern struct llist_head e1inp_line_list;
+
+int e1inp_vty_init(void);
+void e1inp_init(void);
+
+int _abis_nm_sendmsg(struct msgb *msg, int to_trx_oml);
+
+/* XXX */
+struct input_signal_data {
+	int link_type;
+	uint8_t tei;
+	uint8_t sapi;
+	struct gsm_bts_trx *trx;
+	struct e1inp_line *line;
+};
+
+#endif /* _E1_INPUT_H */
diff --git a/include/osmocom/gsm/abis/ipaccess.h b/include/osmocom/gsm/abis/ipaccess.h
new file mode 100644
index 0000000..2792572
--- /dev/null
+++ b/include/osmocom/gsm/abis/ipaccess.h
@@ -0,0 +1,93 @@
+#ifndef _OSMO_PROTO_IPACCESS_H
+#define _OSMO_PROTO_IPACCESS_H
+
+#include <stdint.h>
+
+#define IPA_TCP_PORT_OML	3002
+#define IPA_TCP_PORT_RSL	3003
+
+struct ipaccess_head {
+	uint16_t len;	/* network byte order */
+	uint8_t proto;
+	uint8_t data[0];
+} __attribute__ ((packed));
+
+struct ipaccess_head_ext {
+	uint8_t proto;
+	uint8_t data[0];
+} __attribute__ ((packed));
+
+enum ipaccess_proto {
+	IPAC_PROTO_RSL		= 0x00,
+	IPAC_PROTO_IPACCESS	= 0xfe,
+	IPAC_PROTO_SCCP		= 0xfd,
+	IPAC_PROTO_OML		= 0xff,
+
+
+	/* OpenBSC extensions */
+	IPAC_PROTO_OSMO		= 0xee,
+	IPAC_PROTO_MGCP_OLD	= 0xfc,
+};
+
+enum ipaccess_proto_ext {
+	IPAC_PROTO_EXT_CTRL	= 0x00,
+	IPAC_PROTO_EXT_MGCP	= 0x01,
+	IPAC_PROTO_EXT_LAC	= 0x02,
+};
+
+enum ipaccess_msgtype {
+	IPAC_MSGT_PING		= 0x00,
+	IPAC_MSGT_PONG		= 0x01,
+	IPAC_MSGT_ID_GET	= 0x04,
+	IPAC_MSGT_ID_RESP	= 0x05,
+	IPAC_MSGT_ID_ACK	= 0x06,
+
+	/* OpenBSC extension */
+	IPAC_MSGT_SCCP_OLD	= 0xff,
+};
+
+enum ipaccess_id_tags {
+	IPAC_IDTAG_SERNR		= 0x00,
+	IPAC_IDTAG_UNITNAME		= 0x01,
+	IPAC_IDTAG_LOCATION1		= 0x02,
+	IPAC_IDTAG_LOCATION2		= 0x03,
+	IPAC_IDTAG_EQUIPVERS		= 0x04,
+	IPAC_IDTAG_SWVERSION		= 0x05,
+	IPAC_IDTAG_IPADDR		= 0x06,
+	IPAC_IDTAG_MACADDR		= 0x07,
+	IPAC_IDTAG_UNIT			= 0x08,
+};
+
+/*
+ * Firmware specific header
+ */
+struct sdp_firmware {
+	char magic[4];
+	char more_magic[2];
+	uint16_t more_more_magic;
+	uint32_t header_length;
+	uint32_t file_length;
+	char sw_part[20];
+	char text1[64];
+	char time[12];
+	char date[14];
+	char text2[10];
+	char version[20];
+	uint16_t table_offset;
+	/* stuff i don't know */
+} __attribute__((packed));
+
+struct sdp_header_entry {
+	uint16_t something1;
+	char text1[64];
+	char time[12];
+	char date[14];
+	char text2[10];
+	char version[20];
+	uint32_t length;
+	uint32_t addr1;
+	uint32_t addr2;
+	uint32_t start;
+} __attribute__((packed));
+
+#endif /* _OSMO_PROTO_IPACCESS_H */
diff --git a/include/osmocom/gsm/abis/subchan_demux.h b/include/osmocom/gsm/abis/subchan_demux.h
new file mode 100644
index 0000000..b71c856
--- /dev/null
+++ b/include/osmocom/gsm/abis/subchan_demux.h
@@ -0,0 +1,101 @@
+#ifndef _SUBCH_DEMUX_H
+#define _SUBCH_DEMUX_H
+/* A E1 sub-channel (de)multiplexer with TRAU frame sync */
+
+/* (C) 2009 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 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 <stdint.h>
+#include <osmocom/core/linuxlist.h>
+
+#define NR_SUBCH	4
+#define TRAU_FRAME_SIZE	40
+#define TRAU_FRAME_BITS	(TRAU_FRAME_SIZE*8)
+
+/***********************************************************************/
+/* DEMULTIPLEXER */
+/***********************************************************************/
+
+struct demux_subch {
+	uint8_t out_bitbuf[TRAU_FRAME_BITS];
+	uint16_t out_idx; /* next bit to be written in out_bitbuf */
+	/* number of consecutive zeros that we have received (for sync) */
+	unsigned int consecutive_zeros;
+	/* are we in TRAU frame sync or not? */
+	unsigned int in_sync;
+};
+
+struct subch_demux {
+	/* bitmask of currently active subchannels */
+	uint8_t chan_activ;
+	/* one demux_subch struct for every subchannel */
+	struct demux_subch subch[NR_SUBCH];
+	/* callback to be called once we have received a complete
+	 * frame on a given subchannel */
+	int (*out_cb)(struct subch_demux *dmx, int ch, uint8_t *data, int len,
+		      void *);
+	/* user-provided data, transparently passed to out_cb() */
+	void *data;
+};
+
+/* initialize one demultiplexer instance */
+int subch_demux_init(struct subch_demux *dmx);
+
+/* feed 'len' number of muxed bytes into the demultiplexer */
+int subch_demux_in(struct subch_demux *dmx, uint8_t *data, int len);
+
+/* activate decoding/processing for one subchannel */
+int subch_demux_activate(struct subch_demux *dmx, int subch);
+
+/* deactivate decoding/processing for one subchannel */
+int subch_demux_deactivate(struct subch_demux *dmx, int subch);
+
+/***********************************************************************/
+/* MULTIPLEXER */
+/***********************************************************************/
+
+/* one element in the tx_queue of a muxer sub-channel */
+struct subch_txq_entry {
+	struct llist_head list;
+
+	unsigned int bit_len;	/* total number of bits in 'bits' */
+	unsigned int next_bit;	/* next bit to be transmitted */
+
+	uint8_t bits[0];	/* one bit per byte */
+};
+
+struct mux_subch {
+	struct llist_head tx_queue;
+};
+
+/* structure representing one instance of the subchannel muxer */
+struct subch_mux {
+	struct mux_subch subch[NR_SUBCH];
+};
+
+/* initialize a subchannel muxer instance */
+int subchan_mux_init(struct subch_mux *mx);
+
+/* request the output of 'len' multiplexed bytes */
+int subchan_mux_out(struct subch_mux *mx, uint8_t *data, int len);
+
+/* enqueue some data into one sub-channel of the muxer */
+int subchan_mux_enqueue(struct subch_mux *mx, int s_nr, const uint8_t *data,
+			int len);
+
+#endif /* _SUBCH_DEMUX_H */
diff --git a/include/osmocom/gsm/abis/trau_frame.h b/include/osmocom/gsm/abis/trau_frame.h
new file mode 100644
index 0000000..a76da33
--- /dev/null
+++ b/include/osmocom/gsm/abis/trau_frame.h
@@ -0,0 +1,63 @@
+#ifndef _TRAU_FRAME_H
+#define _TRAU_FRAME_H
+/* TRAU frame handling according to GSM TS 08.60 */
+
+/* (C) 2009 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 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 <stdint.h>
+
+/* 21 for FR/EFR, 25 for AMR, 15 for OM, 15 for data, 13 for E-data, 21 idle */
+#define MAX_C_BITS	25
+/* 260 for FR/EFR, 256 for AMR, 264 for OM, 288 for E-data */
+#define MAX_D_BITS	288
+/* for all speech frames */
+#define MAX_T_BITS	4
+/* for OM */
+#define MAX_S_BITS	6
+/* for E-data */
+#define MAX_M_BITS	2
+
+struct decoded_trau_frame {
+	uint8_t c_bits[MAX_C_BITS];
+	uint8_t d_bits[MAX_D_BITS];
+	uint8_t t_bits[MAX_T_BITS];
+	uint8_t s_bits[MAX_S_BITS];
+	uint8_t m_bits[MAX_M_BITS];
+};
+
+#define TRAU_FT_FR_UP		0x02	/* 0 0 0 1 0 - 3.5.1.1.1 */
+#define TRAU_FT_FR_DOWN		0x1c	/* 1 1 1 0 0 - 3.5.1.1.1 */
+#define TRAU_FT_EFR		0x1a	/* 1 1 0 1 0 - 3.5.1.1.1 */
+#define TRAU_FT_AMR		0x06	/* 0 0 1 1 0 - 3.5.1.2 */
+#define TRAU_FT_OM_UP		0x07	/* 0 0 1 0 1 - 3.5.2 */
+#define TRAU_FT_OM_DOWN		0x1b	/* 1 1 0 1 1 - 3.5.2 */
+#define TRAU_FT_DATA_UP		0x08	/* 0 1 0 0 0 - 3.5.3 */
+#define TRAU_FT_DATA_DOWN	0x16	/* 1 0 1 1 0 - 3.5.3 */
+#define TRAU_FT_D145_SYNC	0x14	/* 1 0 1 0 0 - 3.5.3 */
+#define TRAU_FT_EDATA		0x1f	/* 1 1 1 1 1 - 3.5.4 */
+#define TRAU_FT_IDLE_UP		0x10	/* 1 0 0 0 0 - 3.5.5 */
+#define TRAU_FT_IDLE_DOWN	0x0e	/* 0 1 1 1 0 - 3.5.5 */
+
+
+int decode_trau_frame(struct decoded_trau_frame *fr, const uint8_t *trau_bits);
+int encode_trau_frame(uint8_t *trau_bits, const struct decoded_trau_frame *fr);
+int trau_frame_up2down(struct decoded_trau_frame *fr);
+
+
+#endif /* _TRAU_FRAME_H */