diff --git a/src/e1_input.c b/src/e1_input.c
index 057633c..d11a3ce 100644
--- a/src/e1_input.c
+++ b/src/e1_input.c
@@ -428,6 +428,9 @@
 	if (link->ts->type == E1INP_TS_TYPE_SIGN)
 		osmo_timer_del(&link->ts->sign.tx_timer);
 
+	if (link->ts->line->driver->close)
+		link->ts->line->driver->close(link->ts);
+
 	talloc_free(link);
 }
 
@@ -454,7 +457,7 @@
 				"no action set for signalling messages.\n");
 			return -ENOENT;
 		}
-		ts->line->ops->sign_link(msg, ts->line, link);
+		ts->line->ops->sign_link(msg, link);
 		break;
 	case E1INP_TS_TYPE_TRAU:
 		ret = subch_demux_in(&ts->trau.demux, msg->l2h, msgb_l2len(msg));
diff --git a/src/input/hsl.c b/src/input/hsl.c
index a9a9a78..dd9f17d 100644
--- a/src/input/hsl.c
+++ b/src/input/hsl.c
@@ -74,6 +74,47 @@
 
 #define TS1_ALLOC_SIZE	900
 
+static void hsl_drop(struct e1inp_line *line, struct osmo_fd *bfd)
+{
+	line->ops->sign_link_down(line);
+}
+
+static int process_hsl_rsl(struct msgb *msg, struct e1inp_line *line)
+{
+	char serno_buf[16];
+	uint8_t serno_len;
+	struct hsl_unit unit_data;
+
+	switch (msg->l2h[1]) {
+	case 0x80:
+		/*, contains Serial Number + SW version */
+		if (msg->l2h[2] != 0xc0)
+			break;
+		serno_len = msg->l2h[3];
+		if (serno_len > sizeof(serno_buf)-1)
+			serno_len = sizeof(serno_buf)-1;
+		memcpy(serno_buf, msg->l2h+4, serno_len);
+		serno_buf[serno_len] = '\0';
+		unit_data.serno = strtoul(serno_buf, NULL, 10);
+
+		if (!line->ops->sign_link_up) {
+			LOGP(DINP, LOGL_ERROR, "Fix your application, "
+				"no action set if the signalling link "
+				"becomes ready\n");
+			return -EINVAL;
+		}
+		line->ops->sign_link_up(&unit_data, line, E1INP_SIGN_NONE);
+		msgb_free(msg);
+		return 1;       /* == we have taken over the msg */
+	case 0x82:
+		/* FIXME: do something with BSSGP, i.e. forward it over
+		 * NSIP to OsmoSGSN */
+		msgb_free(msg);
+		return 1;
+	}
+	return 0;
+}
+
 static int handle_ts1_read(struct osmo_fd *bfd)
 {
 	struct e1inp_line *line = bfd->data;
@@ -85,14 +126,11 @@
 	int ret = 0, error;
 
 	error = ipa_msg_recv(bfd->fd, &msg);
-	if (error <= 0) {
-		if (e1i_ts->line->ops->error)
-			e1i_ts->line->ops->error(NULL, line, ts_nr, error);
-		if (error == 0) {
-			osmo_fd_unregister(bfd);
-			close(bfd->fd);
-			bfd->fd = -1;
-		}
+	if (error < 0)
+		return error;
+	else if (error == 0) {
+		hsl_drop(e1i_ts->line, bfd);
+		LOGP(DINP, LOGL_NOTICE, "Sign link vanished, dead socket\n");
 		return error;
 	}
 	DEBUGP(DMI, "RX %u: %s\n", ts_nr, osmo_hexdump(msgb_l2(msg), msgb_l2len(msg)));
@@ -106,19 +144,10 @@
 
 	/* HSL proprietary RSL extension */
 	if (hh->proto == 0 && (msg->l2h[0] == 0x81 || msg->l2h[0] == 0x80)) {
-		if (!line->ops->sign_link_up) {
-			LOGP(DINP, LOGL_ERROR, "Fix your application, no "
-				"action set if the signalling link "
-				"becomes ready.\n");
-			return -EINVAL;
-		}
-		ret = line->ops->sign_link_up(msg, line, E1INP_SIGN_RSL);
-		if (ret < 0) {
-			/* FIXME: close connection */
-			if (line->ops->error)
-				line->ops->error(msg, line,
-						E1INP_SIGN_RSL, -EBADMSG);
-			return ret;
+                ret = process_hsl_rsl(msg, line);
+                if (ret < 0) {
+                        hsl_drop(e1i_ts->line, bfd);
+                        return ret;
 		} else if (ret == 1)
 			return 0;
 		/* else: continue... */
@@ -144,7 +173,7 @@
 			"no action set for signalling messages.\n");
 		return -ENOENT;
 	}
-	e1i_ts->line->ops->sign_link(msg, line, link);
+	e1i_ts->line->ops->sign_link(msg, link);
 
 	return ret;
 }
@@ -338,8 +367,10 @@
 
 		LOGP(DINP, LOGL_NOTICE, "enabling hsl BTS mode\n");
 
-		link = ipa_client_link_create(tall_hsl_ctx, line, addr,
-						HSL_TCP_PORT, hsl_bts_process,
+		link = ipa_client_link_create(tall_hsl_ctx,
+						&line->ts[0], "hsl", 0,
+						addr, HSL_TCP_PORT,
+						hsl_bts_process, NULL,
 						NULL);
 		if (link == NULL) {
 			LOGP(DINP, LOGL_ERROR, "cannot create BTS link: %s\n",
diff --git a/src/input/ipa.c b/src/input/ipa.c
index 0cd2540..2d499ee 100644
--- a/src/input/ipa.c
+++ b/src/input/ipa.c
@@ -87,13 +87,13 @@
 
 void ipa_client_link_close(struct ipa_client_link *link)
 {
-	osmo_fd_unregister(&link->ofd);
-	close(link->ofd.fd);
+	osmo_fd_unregister(link->ofd);
+	close(link->ofd->fd);
 }
 
 static void ipa_client_read(struct ipa_client_link *link)
 {
-	struct osmo_fd *ofd = &link->ofd;
+	struct osmo_fd *ofd = link->ofd;
 	struct msgb *msg;
 	int ret;
 
@@ -113,13 +113,19 @@
 		ipa_client_retry(link);
 		return;
 	}
-	if (link->cb)
-		link->cb(link, msg);
+	if (link->read_cb)
+		link->read_cb(link, msg);
 }
 
 static void ipa_client_write(struct ipa_client_link *link)
 {
-	struct osmo_fd *ofd = &link->ofd;
+	if (link->write_cb)
+		link->write_cb(link);
+}
+
+int ipa_client_write_default_cb(struct ipa_client_link *link)
+{
+	struct osmo_fd *ofd = link->ofd;
 	struct msgb *msg;
 	struct llist_head *lh;
 	int ret;
@@ -128,13 +134,13 @@
 
 	if (llist_empty(&link->tx_queue)) {
 		ofd->when &= ~BSC_FD_WRITE;
-		return;
+		return 0;
 	}
 	lh = link->tx_queue.next;
 	llist_del(lh);
 	msg = llist_entry(lh, struct msgb, list);
 
-	ret = send(link->ofd.fd, msg->data, msg->len, 0);
+	ret = send(link->ofd->fd, msg->data, msg->len, 0);
 	if (ret < 0) {
 		if (errno == EPIPE || errno == ENOTCONN) {
 			ipa_client_retry(link);
@@ -142,6 +148,7 @@
 		LOGP(DINP, LOGL_ERROR, "error to send\n");
 	}
 	msgb_free(msg);
+	return 0;
 }
 
 int ipa_client_fd_cb(struct osmo_fd *ofd, unsigned int what)
@@ -162,11 +169,14 @@
 		link->state = IPA_CLIENT_LINK_STATE_CONNECTED;
 		break;
 	case IPA_CLIENT_LINK_STATE_CONNECTED:
-		LOGP(DINP, LOGL_NOTICE, "connected read/write\n");
-		if (what & BSC_FD_READ)
+		if (what & BSC_FD_READ) {
+			LOGP(DINP, LOGL_NOTICE, "connected read\n");
 			ipa_client_read(link);
-		if (what & BSC_FD_WRITE)
+		}
+		if (what & BSC_FD_WRITE) {
+			LOGP(DINP, LOGL_NOTICE, "connected write\n");
 			ipa_client_write(link);
+		}
 		break;
 	default:
 		break;
@@ -177,10 +187,12 @@
 static void ipa_link_timer_cb(void *data);
 
 struct ipa_client_link *
-ipa_client_link_create(void *ctx, struct e1inp_line *line,
-		       const char *addr, uint16_t port,
-		       int (*cb)(struct ipa_client_link *link,
-				 struct msgb *msgb), void *data)
+ipa_client_link_create(void *ctx, struct e1inp_ts *ts, const char *driver_name,
+		       int priv_nr, const char *addr, uint16_t port,
+		       int (*read_cb)(struct ipa_client_link *link,
+				      struct msgb *msgb),
+		       int (*write_cb)(struct ipa_client_link *link),
+		       void *data)
 {
 	struct ipa_client_link *ipa_link;
 
@@ -188,16 +200,36 @@
 	if (!ipa_link)
 		return NULL;
 
-	ipa_link->ofd.when |= BSC_FD_READ | BSC_FD_WRITE;
-	ipa_link->ofd.cb = ipa_client_fd_cb;
-	ipa_link->ofd.data = ipa_link;
+	if (ts) {
+		struct e1inp_driver *driver;
+
+		driver = e1inp_driver_find(driver_name);
+		if (driver == NULL) {
+			talloc_free(ipa_link);
+			return NULL;
+		}
+		ts->line->driver = driver;
+		ipa_link->ofd = &ts->driver.ipaccess.fd;
+	} else {
+		ipa_link->ofd = talloc_zero(ctx, struct osmo_fd);
+		if (ipa_link->ofd == NULL) {
+			talloc_free(ipa_link);
+			return NULL;
+		}
+	}
+
+	ipa_link->ofd->when |= BSC_FD_READ | BSC_FD_WRITE;
+	ipa_link->ofd->priv_nr = priv_nr;
+	ipa_link->ofd->cb = ipa_client_fd_cb;
+	ipa_link->ofd->data = ipa_link;
 	ipa_link->state = IPA_CLIENT_LINK_STATE_CONNECTING;
 	ipa_link->timer.cb = ipa_link_timer_cb;
 	ipa_link->timer.data = ipa_link;
 	ipa_link->addr = talloc_strdup(ipa_link, addr);
 	ipa_link->port = port;
-	ipa_link->cb = cb;
-	ipa_link->line = line;
+	ipa_link->read_cb = read_cb;
+	ipa_link->write_cb = write_cb;
+	ipa_link->line = ts->line;
 	ipa_link->data = data;
 	INIT_LLIST_HEAD(&ipa_link->tx_queue);
 
@@ -220,8 +252,8 @@
 		if (errno != EINPROGRESS)
 			return ret;
 	}
-	link->ofd.fd = ret;
-	if (osmo_fd_register(&link->ofd) < 0) {
+	link->ofd->fd = ret;
+	if (osmo_fd_register(link->ofd) < 0) {
 		close(ret);
 		return -EIO;
 	}
@@ -246,7 +278,7 @@
 void ipa_client_link_send(struct ipa_client_link *link, struct msgb *msg)
 {
 	msgb_enqueue(&link->tx_queue, msg);
-	link->ofd.when |= BSC_FD_WRITE;
+	link->ofd->when |= BSC_FD_WRITE;
 }
 
 int ipa_server_fd_cb(struct osmo_fd *ofd, unsigned int what)
diff --git a/src/input/ipaccess.c b/src/input/ipaccess.c
index 399ad45..74e2071 100644
--- a/src/input/ipaccess.c
+++ b/src/input/ipaccess.c
@@ -75,6 +75,91 @@
 	0x01, IPAC_IDTAG_SERNR,
 };
 
+static const char *idtag_names[] = {
+	[IPAC_IDTAG_SERNR]	= "Serial_Number",
+	[IPAC_IDTAG_UNITNAME]	= "Unit_Name",
+	[IPAC_IDTAG_LOCATION1]	= "Location_1",
+	[IPAC_IDTAG_LOCATION2]	= "Location_2",
+	[IPAC_IDTAG_EQUIPVERS]	= "Equipment_Version",
+	[IPAC_IDTAG_SWVERSION]	= "Software_Version",
+	[IPAC_IDTAG_IPADDR]	= "IP_Address",
+	[IPAC_IDTAG_MACADDR]	= "MAC_Address",
+	[IPAC_IDTAG_UNIT]	= "Unit_ID",
+};
+
+const char *ipaccess_idtag_name(uint8_t tag)
+{
+	if (tag >= ARRAY_SIZE(idtag_names))
+		return "unknown";
+
+	return idtag_names[tag];
+}
+
+int ipaccess_idtag_parse(struct tlv_parsed *dec, unsigned char *buf, int len)
+{
+	uint8_t t_len;
+	uint8_t t_tag;
+	uint8_t *cur = buf;
+
+	memset(dec, 0, sizeof(*dec));
+
+	while (len >= 2) {
+		len -= 2;
+		t_len = *cur++;
+		t_tag = *cur++;
+
+		if (t_len > len + 1) {
+			LOGP(DMI, LOGL_ERROR, "The tag does not fit: %d\n", t_len);
+			return -EINVAL;
+		}
+
+		DEBUGPC(DMI, "%s='%s' ", ipaccess_idtag_name(t_tag), cur);
+
+		dec->lv[t_tag].len = t_len;
+		dec->lv[t_tag].val = cur;
+
+		cur += t_len;
+		len -= t_len;
+	}
+	return 0;
+}
+
+int ipaccess_parse_unitid(const char *str, struct ipaccess_unit *unit_data)
+{
+	unsigned long ul;
+	char *endptr;
+	const char *nptr;
+
+	nptr = str;
+	ul = strtoul(nptr, &endptr, 10);
+	if (endptr <= nptr)
+		return -EINVAL;
+	if (unit_data->site_id)
+		unit_data->site_id = ul & 0xffff;
+
+	if (*endptr++ != '/')
+		return -EINVAL;
+
+	nptr = endptr;
+	ul = strtoul(nptr, &endptr, 10);
+	if (endptr <= nptr)
+		return -EINVAL;
+	if (unit_data->bts_id)
+		unit_data->bts_id = ul & 0xffff;
+
+	if (*endptr++ != '/')
+		return -EINVAL;
+
+	nptr = endptr;
+	ul = strtoul(nptr, &endptr, 10);
+	if (endptr <= nptr)
+		return -EINVAL;
+	if (unit_data->trx_id)
+		unit_data->trx_id = ul & 0xffff;
+
+	return 0;
+}
+
 static int ipaccess_send(int fd, const void *msg, size_t msglen)
 {
 	int ret;
@@ -126,10 +211,48 @@
 	return 0;
 }
 
+/* base handling of the ip.access protocol */
+int ipaccess_rcvmsg_bts_base(struct msgb *msg,
+			     struct osmo_fd *bfd)
+{
+	uint8_t msg_type = *(msg->l2h);
+	int ret = 0;
+
+	switch (msg_type) {
+	case IPAC_MSGT_PING:
+		ret = ipaccess_send_pong(bfd->fd);
+		break;
+	case IPAC_MSGT_PONG:
+		DEBUGP(DMI, "PONG!\n");
+		break;
+	case IPAC_MSGT_ID_ACK:
+		DEBUGP(DMI, "ID_ACK\n");
+		break;
+	}
+	return 0;
+}
+
+static void ipaccess_drop(struct osmo_fd *bfd)
+{
+	struct e1inp_line *line = bfd->data;
+
+	/* e1inp_sign_link_destroy releases the socket descriptors for us. */
+	line->ops->sign_link_down(line);
+
+	/* RSL connection without ID_RESP, release temporary socket. */
+	if (line->ts[E1INP_SIGN_OML-1].type == E1INP_SIGN_NONE)
+		talloc_free(bfd);
+}
+
 static int ipaccess_rcvmsg(struct e1inp_line *line, struct msgb *msg,
 			   struct osmo_fd *bfd)
 {
+	struct tlv_parsed tlvp;
 	uint8_t msg_type = *(msg->l2h);
+	struct ipaccess_unit unit_data = {};
+	struct e1inp_sign_link *sign_link;
+	char *unitid;
+	int len, ret;
 
 	/* handle base messages */
 	ipaccess_rcvmsg_base(msg, bfd);
@@ -137,13 +260,71 @@
 	switch (msg_type) {
 	case IPAC_MSGT_ID_RESP:
 		DEBUGP(DMI, "ID_RESP\n");
+		/* parse tags, search for Unit ID */
+		ret = ipaccess_idtag_parse(&tlvp, (uint8_t *)msg->l2h + 2,
+						msgb_l2len(msg)-2);
+		DEBUGP(DMI, "\n");
+		if (ret < 0) {
+			LOGP(DINP, LOGL_ERROR, "ignoring IPA response message "
+				"with malformed TLVs\n");
+			return ret;
+		}
+		if (!TLVP_PRESENT(&tlvp, IPAC_IDTAG_UNIT))
+			break;
+
+		len = TLVP_LEN(&tlvp, IPAC_IDTAG_UNIT);
+		if (len < 1)
+			break;
+
+		unitid = (char *) TLVP_VAL(&tlvp, IPAC_IDTAG_UNIT);
+		unitid[len - 1] = '\0';
+		ipaccess_parse_unitid(unitid, &unit_data);
+
 		if (!line->ops->sign_link_up) {
 			LOGP(DINP, LOGL_ERROR, "Fix your application, "
 				"no action set if the signalling link "
 				"becomes ready\n");
 			return -EINVAL;
 		}
-		line->ops->sign_link_up(msg, line, bfd->priv_nr);
+		/* the BSC creates the new sign links at this stage. */
+		if (bfd->priv_nr == E1INP_SIGN_OML) {
+			sign_link =
+				line->ops->sign_link_up(&unit_data, line,
+							E1INP_SIGN_OML);
+			if (sign_link == NULL) {
+				LOGP(DINP, LOGL_ERROR,
+				     "No OML signal link set by BSC\n");
+			}
+		} else if (bfd->priv_nr == E1INP_SIGN_RSL) {
+			struct e1inp_ts *e1i_ts;
+                        struct osmo_fd *newbfd;
+
+			sign_link =
+				line->ops->sign_link_up(&unit_data, line,
+							E1INP_SIGN_RSL);
+			if (sign_link == NULL) {
+				LOGP(DINP, LOGL_ERROR, "Don't know where "
+					"to attach this RSL link.\n");
+				osmo_fd_unregister(bfd);
+				close(bfd->fd);
+				bfd->fd = -1;
+				talloc_free(bfd);
+				return 0;
+			}
+			/* Finally, we know which OML link is associated with
+			 * this RSL link, attach it to this socket. */
+			bfd->data = line = sign_link->ts->line;
+			e1i_ts = &line->ts[E1INP_SIGN_RSL+unit_data.trx_id-1];
+			newbfd = &e1i_ts->driver.ipaccess.fd;
+
+			/* get rid of our old temporary bfd */
+			memcpy(newbfd, bfd, sizeof(*newbfd));
+			newbfd->priv_nr = E1INP_SIGN_RSL + unit_data.trx_id;
+			osmo_fd_unregister(bfd);
+			bfd->fd = -1;
+			talloc_free(bfd);
+			osmo_fd_register(newbfd);
+		}
 		break;
 	}
 	return 0;
@@ -160,16 +341,11 @@
 	int ret = 0, error;
 
 	error = ipa_msg_recv(bfd->fd, &msg);
-	if (error <= 0) {
-		/* skip if RSL line is not set yet. */
-		if (e1i_ts && e1i_ts->line->ops->error)
-			e1i_ts->line->ops->error(NULL, line, ts_nr, error);
-		if (error == 0) {
-		        osmo_fd_unregister(bfd);
-		        close(bfd->fd);
-		        bfd->fd = -1;
-			talloc_free(bfd);
-		}
+	if (error < 0)
+		return error;
+	else if (error == 0) {
+		ipaccess_drop(bfd);
+		LOGP(DINP, LOGL_NOTICE, "Sign link vanished, dead socket\n");
 		return error;
 	}
 	DEBUGP(DMI, "RX %u: %s\n", ts_nr, osmo_hexdump(msgb_l2(msg), msgb_l2len(msg)));
@@ -202,7 +378,7 @@
 			"no action set for signalling messages.\n");
 		return -ENOENT;
 	}
-	e1i_ts->line->ops->sign_link(msg, line, link);
+	e1i_ts->line->ops->sign_link(msg, link);
 
 	return ret;
 }
@@ -233,6 +409,14 @@
 	return 0;
 }
 
+static void ipaccess_close(struct e1inp_ts *e1i_ts)
+{
+	struct osmo_fd *bfd = &e1i_ts->driver.ipaccess.fd;
+	osmo_fd_unregister(bfd);
+	close(bfd->fd);
+	bfd->fd = -1;
+}
+
 static void timeout_ts1_write(void *data)
 {
 	struct e1inp_ts *e1i_ts = (struct e1inp_ts *)data;
@@ -241,9 +425,8 @@
 	ts_want_write(e1i_ts);
 }
 
-static int handle_ts1_write(struct osmo_fd *bfd)
+static int __handle_ts1_write(struct osmo_fd *bfd, struct e1inp_line *line)
 {
-	struct e1inp_line *line = bfd->data;
 	unsigned int ts_nr = bfd->priv_nr;
 	struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1];
 	struct e1inp_sign_link *sign_link;
@@ -274,7 +457,9 @@
 	}
 
 	msg->l2h = msg->data;
-	ipaccess_prepend_header(msg, sign_link->tei);
+	/* This is an IPA CCM, it already contains the header, skip. */
+	if (msgb_tailroom(msg) < sizeof(struct ipaccess_head))
+		ipaccess_prepend_header(msg, sign_link->tei);
 
 	DEBUGP(DMI, "TX %u: %s\n", ts_nr, osmo_hexdump(msg->l2h, msgb_l2len(msg)));
 
@@ -291,27 +476,29 @@
 	return ret;
 }
 
+int handle_ts1_write(struct osmo_fd *bfd)
+{
+	struct e1inp_line *line = bfd->data;
+
+	return __handle_ts1_write(bfd, line);
+}
+
+int ipaccess_bts_write_cb(struct ipa_client_link *link)
+{
+	struct e1inp_line *line = link->line;
+
+	return __handle_ts1_write(link->ofd, line);
+}
+
 /* callback from select.c in case one of the fd's can be read/written */
 static int ipaccess_fd_cb(struct osmo_fd *bfd, unsigned int what)
 {
-	struct e1inp_line *line = bfd->data;
-	unsigned int ts_nr = bfd->priv_nr;
-	unsigned int idx = ts_nr-1;
-	struct e1inp_ts *e1i_ts;
 	int rc = 0;
 
-	/* In case of early RSL we might not yet have a line */
-
-	if (line)
- 		e1i_ts = &line->ts[idx];
-
-	if (!line || e1i_ts->type == E1INP_TS_TYPE_SIGN) {
-		if (what & BSC_FD_READ)
-			rc = handle_ts1_read(bfd);
-		if (what & BSC_FD_WRITE)
-			rc = handle_ts1_write(bfd);
-	} else
-		LOGP(DINP, LOGL_ERROR, "unknown E1 TS type %u\n", e1i_ts->type);
+	if (what & BSC_FD_READ)
+		rc = handle_ts1_read(bfd);
+	if (what & BSC_FD_WRITE)
+		rc = handle_ts1_write(bfd);
 
 	return rc;
 }
@@ -323,6 +510,7 @@
 	.name = "ipa",
 	.want_write = ts_want_write,
 	.line_update = ipaccess_line_update,
+	.close = ipaccess_close,
 	.default_delay = 0,
 };
 
@@ -332,10 +520,18 @@
 	int ret;
 	int idx = 0;
 	int i;
-	struct e1inp_line *line = link->line;
+	struct e1inp_line *line;
 	struct e1inp_ts *e1i_ts;
 	struct osmo_fd *bfd;
 
+	/* clone virtual E1 line for this new OML link. */
+	line = talloc_zero(tall_ipa_ctx, struct e1inp_line);
+	if (line == NULL) {
+		LOGP(DINP, LOGL_ERROR, "could not clone E1 line\n");
+		return -1;
+	}
+	memcpy(line, link->line, sizeof(struct e1inp_line));
+
 	/* create virrtual E1 timeslots for signalling */
 	e1inp_ts_config_sign(&line->ts[E1INP_SIGN_OML-1], line);
 
@@ -367,18 +563,17 @@
 static int ipaccess_bsc_rsl_cb(struct ipa_server_link *link, int fd)
 {
 	struct osmo_fd *bfd;
-	struct e1inp_line *line = link->line;
 	int ret;
 
-	/* create virtual E1 timeslots for signalling */
-	e1inp_ts_config_sign(&line->ts[E1INP_SIGN_RSL-1], line);
-
+        /* We don't know yet which OML link to associate it with. Thus, we
+         * allocate a temporary bfd until we have received ID. */
 	bfd = talloc_zero(tall_ipa_ctx, struct osmo_fd);
 	if (!bfd)
 		return -ENOMEM;
 
 	bfd->fd = fd;
-	bfd->data = line;
+	/* This dummy line is replaced once we can attach it to the OML link */
+	bfd->data = link->line;
 	bfd->priv_nr = E1INP_SIGN_RSL;
 	bfd->cb = ipaccess_fd_cb;
 	bfd->when = BSC_FD_READ;
@@ -406,7 +601,7 @@
 		uint8_t msg_type = *(msg->l2h);
 
 		/* ping, pong and acknowledgment cases. */
-		ipaccess_rcvmsg_base(msg, &link->ofd);
+		ipaccess_rcvmsg_bts_base(msg, link->ofd);
 
 		/* this is a request for identification from the BSC. */
 		if (msg_type == IPAC_MSGT_ID_GET) {
@@ -417,9 +612,14 @@
 					"becomes ready\n");
 				return -EINVAL;
 			}
-			link->line->ops->sign_link_up(msg, link->line,
-				     link->port == IPA_TCP_PORT_OML ?
-					E1INP_SIGN_OML : E1INP_SIGN_RSL);
+			/*
+			 * FIXME: parse request here and pass data to callback.
+			 */
+			struct e1inp_sign_link *sign_link;
+
+			sign_link = link->line->ops->sign_link_up(msg,
+					link->line,
+					link->ofd->priv_nr);
 		}
 		return 0;
 	} else if (link->port == IPA_TCP_PORT_OML)
@@ -444,7 +644,7 @@
 			"no action set for signalling messages.\n");
 		return -ENOENT;
 	}
-	link->line->ops->sign_link(msg, link->line, sign_link);
+	link->line->ops->sign_link(msg, sign_link);
 	return 0;
 }
 
@@ -497,9 +697,13 @@
 
 		LOGP(DINP, LOGL_NOTICE, "enabling ipaccess BTS mode\n");
 
-		link = ipa_client_link_create(tall_ipa_ctx, line,
+		link = ipa_client_link_create(tall_ipa_ctx,
+					      &line->ts[E1INP_SIGN_OML-1],
+					      "ipa", E1INP_SIGN_OML,
 					      addr, IPA_TCP_PORT_OML,
-					      ipaccess_bts_cb, NULL);
+					      ipaccess_bts_cb,
+					      ipaccess_bts_write_cb,
+					      NULL);
 		if (link == NULL) {
 			LOGP(DINP, LOGL_ERROR, "cannot create OML "
 				"BTS link: %s\n", strerror(errno));
@@ -512,9 +716,13 @@
 			ipa_client_link_destroy(link);
 			return -EIO;
 		}
-		rsl_link = ipa_client_link_create(tall_ipa_ctx, line,
+		rsl_link = ipa_client_link_create(tall_ipa_ctx,
+						  &line->ts[E1INP_SIGN_RSL-1],
+						  "ipa", E1INP_SIGN_RSL,
 						  addr, IPA_TCP_PORT_RSL,
-						  ipaccess_bts_cb, NULL);
+						  ipaccess_bts_cb,
+						  ipaccess_bts_write_cb,
+						  NULL);
 		if (rsl_link == NULL) {
 			LOGP(DINP, LOGL_ERROR, "cannot create RSL "
 				"BTS link: %s\n", strerror(errno));
diff --git a/src/input/misdn.c b/src/input/misdn.c
index cf8b5d9..9bf3aea 100644
--- a/src/input/misdn.c
+++ b/src/input/misdn.c
@@ -109,8 +109,7 @@
 	}
 
 	if (alen != sizeof(l2addr)) {
-		if (line->ops->error)
-			line->ops->error(NULL, line, ts_nr, -EBADMSG);
+		fprintf(stderr, "%s error len\n", __func__);
 		return -EINVAL;
 	}
 
@@ -173,8 +172,6 @@
 		l2addr.channel, l2addr.sapi, l2addr.tei);
 		break;
 	default:
-		if (line->ops->error)
-			line->ops->error(NULL, line, ts_nr, -EBADMSG);
 		break;
 	}
 	return ret;
diff --git a/src/ipa_proxy.c b/src/ipa_proxy.c
index 980e3c7..4d08e17 100644
--- a/src/ipa_proxy.c
+++ b/src/ipa_proxy.c
@@ -186,10 +186,12 @@
 
 	LOGP(DINP, LOGL_NOTICE, "now trying to connect to destination\n");
 
-	conn->dst = ipa_client_link_create(NULL, NULL,
+	conn->dst = ipa_client_link_create(NULL, NULL, NULL, 0,
 					   route->shared->dst.inst->net.addr,
 					   route->shared->dst.inst->net.port,
-					   ipa_sock_dst_cb, conn);
+					   ipa_sock_dst_cb,
+					   ipa_client_write_default_cb,
+					   conn);
 	if (conn->dst == NULL) {
 		LOGP(DINP, LOGL_ERROR, "could not create client: %s\n",
 			strerror(errno));