diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index 22ca7b2..c1be0ab 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -201,6 +201,7 @@
 	if (reason)
 		LOGPFSMLSRC(fi, LOGL_ERROR, file, line, "NSE %d: SNS failed: %s\n", gss->nse->nsei, reason);
 
+	gss->alive = false;
 	if (gss->role == GPRS_SNS_ROLE_SGSN) {
 		if (!gss->nse->persistent)
 			gprs_ns2_free_nse(gss->nse);
@@ -2599,19 +2600,33 @@
 	if (gss->block_no_nsvc_events)
 		return;
 
-	if (alive == gss->alive)
+	if (gss->alive && nse->sum_sig_weight == 0) {
+		sns_failed(nse->bss_sns_fi, "No signalling NSVC available");
 		return;
+	}
 
 	/* check if this is the current SNS NS-VC */
-	if (nsvc == gss->sns_nsvc) {
+	if (nsvc == gss->sns_nsvc && !alive) {
 		/* only replace the SNS NS-VC if there are other alive NS-VC.
 		 * There aren't any other alive NS-VC when the SNS fsm just reached CONFIGURED
 		 * and couldn't confirm yet if the NS-VC comes up */
-		if (gss->alive && !alive)
-			ns2_sns_replace_nsvc(nsvc);
+		llist_for_each_entry(tmp, &nse->nsvc, list) {
+			if (nsvc == tmp)
+				continue;
+			if (ns2_vc_is_unblocked(nsvc)) {
+				ns2_sns_replace_nsvc(nsvc);
+				break;
+			}
+		}
 	}
 
+	if (alive == gss->alive)
+		return;
+
 	if (alive) {
+		/* we need at least a signalling NSVC before become alive */
+		if (nse->sum_sig_weight == 0)
+			return;
 		gss->alive = true;
 		osmo_fsm_inst_dispatch(nse->bss_sns_fi, NS2_SNS_EV_REQ_NSVC_ALIVE, NULL);
 	} else {