diff --git a/openbsc/src/libabis/e1_input.c b/openbsc/src/libabis/e1_input.c
index 97dcd33..293175e 100644
--- a/openbsc/src/libabis/e1_input.c
+++ b/openbsc/src/libabis/e1_input.c
@@ -570,6 +570,7 @@
 	if (!link)
 		return -EINVAL;
 
+	isd.line = ts->line;
 	isd.link_type = link->type;
 	isd.trx = link->trx;
 	isd.tei = tei;
diff --git a/openbsc/src/libabis/input/dahdi.c b/openbsc/src/libabis/input/dahdi.c
index a7b45a1..eb66fa0 100644
--- a/openbsc/src/libabis/input/dahdi.c
+++ b/openbsc/src/libabis/input/dahdi.c
@@ -100,7 +100,7 @@
 	struct msgb *msg = msgb_alloc(TS1_ALLOC_SIZE, "DAHDI TS1");
 	lapd_mph_type prim;
 	unsigned int sapi, tei;
-	int ilen, ret;
+	int ilen, ret, error = 0;
 	uint8_t *idata;
 
 	if (!msg)
@@ -122,9 +122,21 @@
 
 	DEBUGP(DMI, "<= len = %d, sapi(%d) tei(%d)", ret, sapi, tei);
 
-	idata = lapd_receive(e1i_ts->driver.dahdi.lapd, msg->data, msg->len, &ilen, &prim);
-	if (!idata && prim == 0)
-		return -EIO;
+	idata = lapd_receive(e1i_ts->driver.dahdi.lapd, msg->data, msg->len, &ilen, &prim, &error);
+	if (!idata) {
+		switch(error) {
+		case LAPD_ERR_UNKNOWN_TEI:
+			/* We don't know about this TEI, probably the BSC
+			 * lost local states (it crashed or it was stopped),
+			 * notify the driver to see if it can do anything to
+			 * recover the existing signalling links with the BTS.
+			 */
+			e1inp_event(e1i_ts, S_INP_TEI_UNKNOWN, tei, sapi);
+			return -EIO;
+		}
+		if (prim == 0)
+			return -EIO;
+	}
 
 	msgb_pull(msg, 2);
 
diff --git a/openbsc/src/libabis/input/lapd.c b/openbsc/src/libabis/input/lapd.c
index 66ff05e..2934b58 100644
--- a/openbsc/src/libabis/input/lapd.c
+++ b/openbsc/src/libabis/input/lapd.c
@@ -310,8 +310,9 @@
 };
 
 /* General input function for any data received for this LAPD instance */
-uint8_t *lapd_receive(struct lapd_instance *li, uint8_t * data, unsigned int len,
-		      int *ilen, lapd_mph_type *prim)
+uint8_t *
+lapd_receive(struct lapd_instance *li, uint8_t * data, unsigned int len,
+	     int *ilen, lapd_mph_type *prim, int *error)
 {
 	uint8_t sapi, cr, tei, command;
 	int pf, ns, nr;
@@ -327,12 +328,14 @@
 
 	if (len < 2) {
 		LOGP(DMI, LOGL_ERROR, "LAPD receive len %d < 2, ignoring\n", len);
+		*error = LAPD_ERR_BAD_LEN;
 		return NULL;
 	};
 
 	if ((data[0] & 1) != 0 || (data[1] & 1) != 1) {
 		LOGP(DMI, LOGL_ERROR, "LAPD address field %x/%x not well formed\n",
 			data[0], data[1]);
+		*error = LAPD_ERR_BAD_ADDR;
 		return NULL;
 	};
 
@@ -344,6 +347,7 @@
 
 	if (len < 3) {
 		LOGP(DMI, LOGL_ERROR, "LAPD receive len %d < 3, ignoring\n", len);
+		*error = LAPD_ERR_BAD_LEN;
 		return NULL;
 	};
 
@@ -356,6 +360,7 @@
 		typ = LAPD_TYPE_I;
 		if (len < 4) {
 			LOGP(DMI, LOGL_ERROR, "LAPD I frame, len %d < 4\n", len);
+			*error = LAPD_ERR_BAD_LEN;
 			return NULL;
 		}
 		ns = data[2] >> 1;
@@ -366,6 +371,7 @@
 		typ = LAPD_TYPE_S;
 		if (len < 4) {
 			LOGP(DMI, LOGL_ERROR, "LAPD S frame, len %d < 4\n", len);
+			*error = LAPD_ERR_BAD_LEN;
 			return NULL;
 		}
 		nr = data[3] >> 1;
@@ -382,6 +388,7 @@
 			break;
 		default:
 			LOGP(DMI, LOGL_ERROR, "LAPD unknown S cmd %x\n", data[2]);
+			*error = LAPD_ERR_UNKNOWN_S_CMD;
 			return NULL;
 		};
 	} else if ((data[2] & 3) == 3) {
@@ -414,6 +421,7 @@
 		default:
 			LOGP(DMI, LOGL_ERROR, "LAPD unknown U cmd %x "
 			     "(pf %x data %x)\n", val, pf, data[2]);
+			*error = LAPD_ERR_UNKNOWN_U_CMD;
 			return NULL;
 		};
 	};
@@ -429,6 +437,7 @@
 	teip = teip_from_tei(li, tei);
 	if (!teip) {
 		LOGP(DMI, LOGL_NOTICE, "LAPD Unknown TEI %u\n", tei);
+		*error = LAPD_ERR_UNKNOWN_TEI;
 		return NULL;
 	}
 
@@ -587,6 +596,7 @@
 		return contents;
 	}
 
+	*error = LAPD_ERR_BAD_CMD;
 	return NULL;
 };
 
diff --git a/openbsc/src/libabis/input/lapd.h b/openbsc/src/libabis/input/lapd.h
index fb980d1..dd22028 100644
--- a/openbsc/src/libabis/input/lapd.h
+++ b/openbsc/src/libabis/input/lapd.h
@@ -26,8 +26,20 @@
 	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);
+enum lapd_recv_errors {
+	LAPD_ERR_NONE = 0,
+	LAPD_ERR_BAD_LEN,
+	LAPD_ERR_BAD_ADDR,
+	LAPD_ERR_UNKNOWN_S_CMD,
+	LAPD_ERR_UNKNOWN_U_CMD,
+	LAPD_ERR_UNKNOWN_TEI,
+	LAPD_ERR_BAD_CMD,
+	__LAPD_ERR_MAX
+};
+
+extern uint8_t *lapd_receive(struct lapd_instance *li, uint8_t *data,
+			     unsigned int len, int *ilen, lapd_mph_type *prim,
+			     int *error);
 
 extern void lapd_transmit(struct lapd_instance *li, uint8_t tei, uint8_t sapi,
 			  uint8_t *data, unsigned int len);