diff --git a/src/algo_thunder.c b/src/algo_thunder.c
index 1500534..f264b7d 100644
--- a/src/algo_thunder.c
+++ b/src/algo_thunder.c
@@ -6,7 +6,7 @@
 #include "timer.h"
 #include "proxy.h"
 
-uint64_t compute_delta(struct timespec* prev_time, uint64_t max) {
+uint64_t compute_delta(struct timespec* prev_time, uint64_t max, uint8_t update) {
   struct timespec curr;
   int secs, nsecs;
   uint64_t mili_sec;
@@ -18,7 +18,7 @@ uint64_t compute_delta(struct timespec* prev_time, uint64_t max) {
   }
   secs = curr.tv_sec - prev_time->tv_sec;
   nsecs = curr.tv_nsec - prev_time->tv_nsec;
-  *prev_time = curr;
+  if(update) *prev_time = curr;
   mili_sec = secs * 1000 + nsecs / 1000000;
   if (mili_sec > max) mili_sec = max;
 
@@ -120,7 +120,7 @@ int schedule(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct bu
     // 4. We compute the time difference
     uint64_t mili_sec = 0;
     if (protect == thunderc->total_links)
-      mili_sec = compute_delta (&thunderc->prev_link_time, UINT16_MAX);
+      mili_sec = compute_delta (&thunderc->prev_link_time, UINT16_MAX, 1);
 
     //printf("send packet on link %d with delta=%ld\n", thunderc->selected_link, mili_sec);
     // 5. We create the array
@@ -215,7 +215,7 @@ void classify(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct b
   //printf("Received %ld packets on link %d\n", thunderc->received_pkts_on_link[link_id], link_id);
   struct link_info *li = &ap->fmt.content.link_monitoring_thunder.links_status;
 
-  uint64_t mili_sec = compute_delta (&thunderc->prev_rcv_link_time, UINT16_MAX);
+  uint64_t mili_sec = compute_delta (&thunderc->prev_rcv_link_time, UINT16_MAX, 1);
   for (int i = 0; i < thunderc->total_links; i++) {
     if (thunderc->received_pkts_on_link[i] <= 1) continue;
     thunderc->rcv_delta_t_per_link[i] += mili_sec;
@@ -302,7 +302,8 @@ void classify(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct b
   }
   if (ctx->verbose > 1) fprintf(stderr, "    [algo_thunder] Classify done\n");
 
-  printf("Blacklisted links: ");
+  uint64_t ts = compute_delta (&thunderc->start_time, UINT64_MAX, 0);
+  printf("[%ld] Blacklisted links: ", ts);
   for (int i = 0; i < thunderc->total_links; i++) {
     if (is_blacklisted (thunderc, i)) printf("_");
     else printf("U");
@@ -446,6 +447,10 @@ void algo_thunder_init(struct evt_core_ctx* ctx, struct algo_ctx* app_ctx, struc
     thunderc->received_pkts_on_link[i] = 1;
     thunderc->rcv_delta_t_per_link[i] = 0;
   }
+  if (clock_gettime(CLOCK_MONOTONIC, &thunderc->start_time) == -1){
+    perror("clock_gettime error");
+    exit(EXIT_FAILURE);
+  }
 
   union abstract_packet links = {};
   //fprintf(stderr, "Total links %d\n", thunderc->total_links);
diff --git a/src/proxy.h b/src/proxy.h
index de8faa5..69705f2 100644
--- a/src/proxy.h
+++ b/src/proxy.h
@@ -113,6 +113,6 @@ struct thunder_ctx {
   int64_t estimated_sent[MAX_LINKS];
   size_t monit_pkt_size;
   int64_t allowed_jitter_ms;
-  struct timespec prev_link_time, prev_rcv_link_time;
+  struct timespec prev_link_time, prev_rcv_link_time, start_time;
 };
 void get_estimation(struct thunder_ctx* thunderc, int64_t* sorted_estimation, uint64_t* sorted_occurencies);