diff --git a/openbsc/src/libbsc/bts_ericsson_rbs2000.c b/openbsc/src/libbsc/bts_ericsson_rbs2000.c
index 5c75192..d603033 100644
--- a/openbsc/src/libbsc/bts_ericsson_rbs2000.c
+++ b/openbsc/src/libbsc/bts_ericsson_rbs2000.c
@@ -120,21 +120,18 @@
 		}
 		break;
 	case S_L_INP_LINE_INIT:
-		/* Right now Ericsson RBS are only supported on DAHDI */
-		if (strcasecmp(isd->line->driver->name, "DAHDI"))
+	case S_L_INP_LINE_NOALARM:
+		if (strcasecmp(isd->line->driver->name, "DAHDI")
+		 && strcasecmp(isd->line->driver->name, "MISDN_LAPD"))
 			break;
 		start_sabm_in_line(isd->line, 1);
 		break;
 	case S_L_INP_LINE_ALARM:
-		if (strcasecmp(isd->line->driver->name, "DAHDI"))
+		if (strcasecmp(isd->line->driver->name, "DAHDI")
+		 && strcasecmp(isd->line->driver->name, "MISDN_LAPD"))
 			break;
 		start_sabm_in_line(isd->line, 0);
 		break;
-	case S_L_INP_LINE_NOALARM:
-		if (strcasecmp(isd->line->driver->name, "DAHDI"))
-			break;
-		start_sabm_in_line(isd->line, 1);
-		break;
 	}
 
 	return 0;
diff --git a/openbsc/src/libbsc/bts_nokia_site.c b/openbsc/src/libbsc/bts_nokia_site.c
index 4b5c50f..c43eb5f 100644
--- a/openbsc/src/libbsc/bts_nokia_site.c
+++ b/openbsc/src/libbsc/bts_nokia_site.c
@@ -84,7 +84,7 @@
   Attention: this has to be adapted for mISDN
 */
 
-void start_sabm_in_line(struct e1inp_line *line, int start, int sapi)
+static void start_sabm_in_line(struct e1inp_line *line, int start, int sapi)
 {
 	struct e1inp_sign_link *link;
 	int i;
diff --git a/openbsc/src/libbsc/bts_siemens_bs11.c b/openbsc/src/libbsc/bts_siemens_bs11.c
index 2514d99..33f5b76 100644
--- a/openbsc/src/libbsc/bts_siemens_bs11.c
+++ b/openbsc/src/libbsc/bts_siemens_bs11.c
@@ -562,6 +562,28 @@
 	return 0;
 }
 
+/* Tell LAPD to start start the SAP (send SABM requests) for all signalling
+ * timeslots in this line */
+static void start_sabm_in_line(struct e1inp_line *line, int start)
+{
+	struct e1inp_sign_link *link;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(line->ts); i++) {
+		struct e1inp_ts *ts = &line->ts[i];
+
+		if (ts->type != E1INP_TS_TYPE_SIGN)
+			continue;
+
+		llist_for_each_entry(link, &ts->sign.sign_links, list) {
+			if (start)
+				lapd_sap_start(ts->lapd, link->tei, link->sapi);
+			else
+				lapd_sap_stop(ts->lapd, link->tei, link->sapi);
+		}
+	}
+}
+
 /* Callback function to be called every time we receive a signal from INPUT */
 static int inp_sig_cb(unsigned int subsys, unsigned int signal,
 		      void *handler_data, void *signal_data)
@@ -579,6 +601,19 @@
 				bootstrap_om_bs11(isd->trx->bts);
 			break;
 		}
+	case S_L_INP_LINE_INIT:
+	case S_L_INP_LINE_NOALARM:
+		if (strcasecmp(isd->line->driver->name, "DAHDI")
+		 && strcasecmp(isd->line->driver->name, "MISDN_LAPD"))
+			break;
+		start_sabm_in_line(isd->line, 1);
+		break;
+	case S_L_INP_LINE_ALARM:
+		if (strcasecmp(isd->line->driver->name, "DAHDI")
+		 && strcasecmp(isd->line->driver->name, "MISDN_LAPD"))
+			break;
+		start_sabm_in_line(isd->line, 0);
+		break;
 	}
 
 	return 0;