diff --git a/openbsc/include/openbsc/sms_queue.h b/openbsc/include/openbsc/sms_queue.h
index d377aca..d048566 100644
--- a/openbsc/include/openbsc/sms_queue.h
+++ b/openbsc/include/openbsc/sms_queue.h
@@ -2,7 +2,9 @@
 #define SMS_QUEUE_H
 
 struct gsm_network;
+struct gsm_sms_queue;
 
 int sms_queue_start(struct gsm_network *, int in_flight);
+int sms_queue_trigger(struct gsm_sms_queue *);
 
 #endif
diff --git a/openbsc/src/sms_queue.c b/openbsc/src/sms_queue.c
index f61cf63..f6d09cf 100644
--- a/openbsc/src/sms_queue.c
+++ b/openbsc/src/sms_queue.c
@@ -35,17 +35,225 @@
 #include <openbsc/debug.h>
 #include <openbsc/gsm_data.h>
 #include <openbsc/gsm_04_11.h>
+#include <openbsc/gsm_subscriber.h>
 #include <openbsc/signal.h>
 
 #include <osmocore/talloc.h>
 
+/*
+ * One pending SMS that we wait for.
+ */
+struct gsm_sms_pending {
+	struct llist_head entry;
+
+	struct gsm_subscriber *subscr;
+	unsigned long long sms_id;
+	int failed_attempts;
+	int resend;
+};
 
 struct gsm_sms_queue {
+	struct timer_list resend_pending;
+	struct timer_list push_queue;
 	struct gsm_network *network;
 	int max_pending;
 	int pending;
+
+	struct llist_head pending_sms;
+	unsigned long long last_subscr_id;
 };
 
+static int sms_subscr_cb(unsigned int, unsigned int, void *, void *);
+static int sms_sms_cb(unsigned int, unsigned int, void *, void *);
+
+static struct gsm_sms_pending *sms_find_pending(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->sms_id == sms->id)
+			return pending;
+	}
+
+	return NULL;
+}
+
+static int sms_is_in_pending(struct gsm_sms_queue *smsq, struct gsm_sms *sms)
+{
+	return sms_find_pending(smsq, sms) != NULL;
+}
+
+static int sms_subscriber_is_pending(struct gsm_sms_queue *smsq,
+				     struct gsm_subscriber *subscr)
+{
+	struct gsm_sms_pending *pending;
+
+	llist_for_each_entry(pending, &smsq->pending_sms, entry) {
+		if (pending->subscr == subscr)
+			return 1;
+	}
+
+	return 0;
+}
+
+static struct gsm_sms_pending *sms_pending_from(struct gsm_sms_queue *smsq,
+						struct gsm_sms *sms)
+{
+	struct gsm_sms_pending *pending;
+
+	pending = talloc_zero(smsq, struct gsm_sms_pending);
+	if (!pending)
+		return NULL;
+
+	pending->subscr = subscr_get(sms->receiver);
+	pending->sms_id = sms->id;
+	return pending;
+}
+
+static void sms_pending_free(struct gsm_sms_pending *pending)
+{
+	subscr_put(pending->subscr);
+	llist_del(&pending->entry);
+	talloc_free(pending);
+}
+
+static void sms_pending_resend(struct gsm_sms_pending *pending)
+{
+	struct gsm_sms_queue *smsq;
+	LOGP(DSMS, LOGL_DEBUG,
+	     "Scheduling resend of SMS %llu.\n", pending->sms_id);
+
+	pending->resend = 1;
+
+	smsq = pending->subscr->net->sms_queue;
+	if (bsc_timer_pending(&smsq->resend_pending))
+		return;
+
+	bsc_schedule_timer(&smsq->resend_pending, 1, 0);
+}
+
+static void sms_pending_failed(struct gsm_sms_pending *pending, int paging_error)
+{
+	struct gsm_sms_queue *smsq;
+
+	LOGP(DSMS, LOGL_NOTICE, "Sending SMS %llu failed %d times.\n",
+	     pending->sms_id, pending->failed_attempts);
+
+	smsq = pending->subscr->net->sms_queue;
+	if (++pending->failed_attempts < 3)
+		return sms_pending_resend(pending);
+
+	if (paging_error) {
+		LOGP(DSMS, LOGL_NOTICE,
+		     "Subscriber %llu is not reachable. Setting LAC=0.\n", pending->subscr->id);
+		pending->subscr->lac = GSM_LAC_RESERVED_DETACHED;
+		db_sync_subscriber(pending->subscr);
+	}
+
+	sms_pending_free(pending);
+	smsq->pending -= 1;
+	sms_queue_trigger(smsq);
+}
+
+/*
+ * Resend all SMS that are scheduled for a resend. This is done to
+ * avoid an immediate failure.
+ */
+static void sms_resend_pending(void *_data)
+{
+	struct gsm_sms_pending *pending, *tmp;
+	struct gsm_sms_queue *smsq = _data;
+
+	llist_for_each_entry_safe(pending, tmp, &smsq->pending_sms, entry) {
+		struct gsm_sms *sms;
+		if (!pending->resend)
+			continue;
+
+		sms = db_sms_get(smsq->network, pending->sms_id);
+
+		/* the sms is gone? Move to the next */
+		if (!sms) {
+			sms_pending_free(pending);
+			smsq->pending -= 1;
+			sms_queue_trigger(smsq);
+		} else {
+			pending->resend = 0;
+			gsm411_send_sms_subscr(sms->receiver, sms);
+		}
+	}
+}
+
+/**
+ * I will submit up to max_pending - pending SMS to the
+ * subsystem.
+ */
+static void sms_submit_pending(void *_data)
+{
+	struct gsm_sms_queue *smsq = _data;
+	int attempts = smsq->max_pending - smsq->pending;
+	int i;
+
+	LOGP(DSMS, LOGL_NOTICE, "Attempting to send %d SMS\n", attempts);
+
+	for (i = 0; i < attempts; ++i) {
+		struct gsm_sms_pending *pending;
+		struct gsm_sms *sms;
+
+		sms = db_sms_get_unsent_by_subscr(smsq->network, smsq->last_subscr_id, 10);
+
+		/* handle wrapping around */
+		if (!sms) {
+			smsq->last_subscr_id = 0;
+			sms = db_sms_get_unsent_by_subscr(smsq->network,
+							  smsq->last_subscr_id, 10);
+		}
+
+		if (!sms)
+			break;
+
+		/* no need to send a pending sms */
+		if (sms_is_in_pending(smsq, sms)) {
+			LOGP(DSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sms: %llu\n. Skipping", sms->id);
+			sms_free(sms);
+			continue;
+		}
+
+		/* no need to send a SMS with the same receiver */
+		if (sms_subscriber_is_pending(smsq, sms->receiver)) {
+			LOGP(DSMS, LOGL_DEBUG,
+			     "SMSqueue with pending sub: %llu. Skipping\n", sms->receiver->id);
+			sms_free(sms);
+			continue;
+		}
+
+		pending = sms_pending_from(smsq, sms);
+		if (!pending) {
+			LOGP(DSMS, LOGL_ERROR,
+			     "Failed to create pending SMS entry.\n");
+			sms_free(sms);
+			continue;
+		}
+
+		smsq->last_subscr_id = sms->receiver->id + 1;
+		smsq->pending += 1;
+		llist_add(&pending->entry, &smsq->pending_sms);
+		gsm411_send_sms_subscr(sms->receiver, sms);
+	}
+}
+
+/*
+ * Kick off the queue again.
+ */
+int sms_queue_trigger(struct gsm_sms_queue *smsq)
+{
+	if (bsc_timer_pending(&smsq->push_queue))
+		return 0;
+
+	bsc_schedule_timer(&smsq->push_queue, 1, 0);
+	return 0;
+}
 
 int sms_queue_start(struct gsm_network *network, int max_pending)
 {
@@ -55,9 +263,19 @@
 		return -1;
 	}
 
+	register_signal_handler(SS_SUBSCR, sms_subscr_cb, network);
+	register_signal_handler(SS_SMS, sms_sms_cb, network);
+
 	network->sms_queue = sms;
+	INIT_LLIST_HEAD(&sms->pending_sms);
 	sms->network = network;
 	sms->max_pending = max_pending;
+	sms->push_queue.data = sms;
+	sms->push_queue.cb = sms_submit_pending;
+	sms->resend_pending.data = sms;
+	sms->resend_pending.cb = sms_resend_pending;
+
+	sms_submit_pending(sms);
 
 	return 0;
 }
@@ -91,7 +309,85 @@
 	return sub_ready_for_sm(subscr);
 }
 
-static __attribute__((constructor)) void on_dso_load_sms(void)
+static int sms_sms_cb(unsigned int subsys, unsigned int signal,
+		      void *handler_data, void *signal_data)
 {
-	register_signal_handler(SS_SUBSCR, sms_subscr_cb, NULL);
+	struct gsm_network *network = handler_data;
+	struct sms_signal_data *sig_sms = signal_data;
+	struct gsm_sms_pending *pending;
+
+	/* We got a new SMS and maybe should launch the queue again. */
+	if (signal == S_SMS_SUBMITTED || signal == S_SMS_SMMA) {
+		sms_queue_trigger(network->sms_queue);
+		return 0;
+	}
+
+	if (!sig_sms->sms)
+		return -1;
+
+
+	/*
+	 * Find the entry of our queue. The SMS subsystem will submit
+	 * sms that are not in our control as we just have a channel
+	 * open anyway.
+	 */
+	pending = sms_find_pending(network->sms_queue, sig_sms->sms);
+	if (!pending)
+		return 0;
+
+	switch (signal) {
+	case S_SMS_DELIVERED:
+		/*
+		 * Create place for a new SMS but keep the pending data
+		 * so we will not attempt to send the SMS for this subscriber
+		 * as we still have an open channel and will attempt to submit
+		 * SMS to it anyway.
+		 */
+		network->sms_queue->pending -= 1;
+		sms_submit_pending(network->sms_queue);
+		sms_pending_free(pending);
+		break;
+	case S_SMS_MEM_EXCEEDED:
+		network->sms_queue->pending -= 1;
+		sms_pending_free(pending);
+		sms_queue_trigger(network->sms_queue);
+		break;
+	case S_SMS_UNKNOWN_ERROR:
+		/*
+		 * There can be many reasons for this failure. E.g. the paging
+		 * timed out, the subscriber was not paged at all, or there was
+		 * a protocol error. The current strategy is to try sending the
+		 * next SMS for busy/oom and to retransmit when we have paged.
+		 *
+		 * When the paging expires three times we will disable the
+		 * subscriber. If we have some kind of other transmit error we
+		 * should flag the SMS as bad.
+		 */
+		switch (sig_sms->paging_result) {
+		case 0:
+			/* BAD SMS? */
+			db_sms_inc_deliver_attempts(sig_sms->sms);
+			sms_pending_failed(pending, 0);
+			break;
+		case GSM_PAGING_EXPIRED:
+			sms_pending_failed(pending, 1);
+			break;
+
+		case GSM_PAGING_OOM:
+		case GSM_PAGING_BUSY:
+			network->sms_queue->pending -= 1;
+			sms_pending_free(pending);
+			sms_queue_trigger(network->sms_queue);
+			break;
+		default:
+			LOGP(DSMS, LOGL_ERROR, "Unhandled result: %d\n",
+			     sig_sms->paging_result);
+		}
+		break;
+	default:
+		LOGP(DSMS, LOGL_ERROR, "Unhandled result: %d\n",
+		     sig_sms->paging_result);
+	}
+
+	return 0;
 }