diff --git a/tests/timer/timer_test.c b/tests/timer/timer_test.c
index 240bc48..bcaafdb 100644
--- a/tests/timer/timer_test.c
+++ b/tests/timer/timer_test.c
@@ -1,7 +1,11 @@
 /*
  * (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
  * All Rights Reserved
  *
+ * Authors: Holger Hans Peter Freyther <zecke@selfish.org>
+ *	    Pablo Neira Ayuso <pablo@gnumonks.org>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -19,59 +23,130 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 
+#include <osmocom/core/talloc.h>
 #include <osmocom/core/timer.h>
 #include <osmocom/core/select.h>
+#include <osmocom/core/linuxlist.h>
 
 #include "../../config.h"
 
-static void timer_fired(void *data);
+static void main_timer_fired(void *data);
+static void secondary_timer_fired(void *data);
 
-static struct osmo_timer_list timer_one = {
-    .cb = timer_fired,
-    .data = (void*)1,
+static unsigned int main_timer_step = 0;
+static struct osmo_timer_list main_timer = {
+	.cb = main_timer_fired,
+	.data = &main_timer_step,
 };
 
-static struct osmo_timer_list timer_two = {
-    .cb = timer_fired,
-    .data = (void*)2,
+static LLIST_HEAD(timer_test_list);
+
+struct test_timer {
+	struct llist_head head;
+	struct osmo_timer_list timer;
+	struct timeval start;
+	struct timeval stop;
 };
 
-static struct osmo_timer_list timer_three = {
-    .cb = timer_fired,
-    .data = (void*)3,
-};
+/* number of test steps. We add fact(steps) timers in the whole test. */
+#define MAIN_TIMER_NSTEPS	16
 
-static void timer_fired(void *_data)
+/* time between two steps, in secs. */
+#define TIME_BETWEEN_STEPS	1
+
+/* timer imprecision that we accept for this test: 10 milliseconds. */
+#define TIMER_PRES_SECS		0
+#define TIMER_PRES_USECS	10000
+
+static unsigned int expired_timers = 0;
+static unsigned int total_timers = 0;
+static unsigned int too_late = 0;
+
+static void main_timer_fired(void *data)
 {
-    unsigned long data = (unsigned long) _data;
-    printf("Fired timer: %lu\n", data);
+	unsigned int *step = data;
+	unsigned int add_in_this_step;
+	int i;
 
-    if (data == 1) {
-        osmo_timer_schedule(&timer_one, 3, 0);
-        osmo_timer_del(&timer_two);
-    } else if (data == 2) {
-        printf("Should not be fired... bug in del_timer\n");
-    } else if (data == 3) {
-        printf("Timer fired not registering again\n");
-    } else  {
-        printf("wtf... wrong data\n");
-    }
+	if (*step == MAIN_TIMER_NSTEPS) {
+		printf("Main timer has finished, please, wait a bit for the "
+		       "final report.\n");
+		return;
+	}
+	/* add 2^step pair of timers per step. */
+	add_in_this_step = (1 << *step);
+
+	for (i=0; i<add_in_this_step; i++) {
+		struct test_timer *v;
+
+		v = talloc_zero(NULL, struct test_timer);
+		if (v == NULL) {
+			fprintf(stderr, "timer_test: OOM!\n");
+			return;
+		}
+		gettimeofday(&v->start, NULL);
+		v->timer.cb = secondary_timer_fired;
+		v->timer.data = v;
+		unsigned int seconds = (random() % 10) + 1;
+		v->stop.tv_sec = v->start.tv_sec + seconds;
+		osmo_timer_schedule(&v->timer, seconds, 0);
+		llist_add(&v->head, &timer_test_list);
+	}
+	printf("added %d timers in step %u (expired=%u)\n",
+		add_in_this_step, *step, expired_timers);
+	total_timers += add_in_this_step;
+	osmo_timer_schedule(&main_timer, TIME_BETWEEN_STEPS, 0);
+	(*step)++;
+}
+
+static void secondary_timer_fired(void *data)
+{
+	struct test_timer *v = data, *this, *tmp;
+	struct timeval current, res, precision = { 1, 0 };
+
+	gettimeofday(&current, NULL);
+
+	timersub(&current, &v->stop, &res);
+	if (timercmp(&res, &precision, >)) {
+		printf("ERROR: timer %p has expired too late!\n", v->timer);
+		too_late++;
+	}
+
+	llist_del(&v->head);
+	talloc_free(data);
+	expired_timers++;
+	if (expired_timers == total_timers) {
+		printf("test over: added=%u expired=%u too_late=%u \n",
+			total_timers, expired_timers, too_late);
+		exit(EXIT_SUCCESS);
+	}
+
+	/* randomly (10%) deletion of timers. */
+	llist_for_each_entry_safe(this, tmp, &timer_test_list, head) {
+		if ((random() % 100) < 10) {
+			osmo_timer_del(&this->timer);
+			llist_del(&this->head);
+			talloc_free(this);
+			expired_timers++;
+		}
+	}
 }
 
 int main(int argc, char** argv)
 {
-    printf("Starting... timer\n");
+	printf("Running timer test for %u steps, accepting imprecision "
+	       "of %u.%.6u seconds\n",
+		MAIN_TIMER_NSTEPS, TIMER_PRES_SECS, TIMER_PRES_USECS);
 
-    osmo_timer_schedule(&timer_one, 3, 0);
-    osmo_timer_schedule(&timer_two, 5, 0);
-    osmo_timer_schedule(&timer_three, 4, 0);
+	osmo_timer_schedule(&main_timer, 1, 0);
 
 #ifdef HAVE_SYS_SELECT_H
-    while (1) {
-        osmo_select_main(0);
-    }
+	while (1) {
+		osmo_select_main(0);
+	}
 #else
-    printf("Select not supported on this platform!\n");
+	printf("Select not supported on this platform!\n");
 #endif
 }