diff --git a/owlps-listener/owlps-listener.h b/owlps-listener/owlps-listener.h
index 0efed76..b0b1e60 100644
--- a/owlps-listener/owlps-listener.h
+++ b/owlps-listener/owlps-listener.h
@@ -188,6 +188,8 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
                  const u_char *packet) ;
 void extract_calibration_data(const u_char *packet,
                               owl_captured_request *request) ;
+void extract_packet_numbers(const u_char *packet,
+                            owl_captured_request *request) ;
 void extract_radiotap_data(const u_char *packet,
                            owl_captured_request *request,
                            owl_bool rtap_fields[15]) ;
diff --git a/owlps-listener/owlps-listenerd.c b/owlps-listener/owlps-listenerd.c
index c39a315..f75fd53 100644
--- a/owlps-listener/owlps-listenerd.c
+++ b/owlps-listener/owlps-listenerd.c
@@ -987,6 +987,12 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
         case OWL_REQUEST_NORMAL :
           if (VERBOSE_INFO)
             printf("\nExplicit packet received.\n") ;
+          extract_packet_numbers(&packet[rtap_bytes +
+                                         ieee80211_header_size +
+                                         LLC_HEADER_SIZE +
+                                         sizeof(struct iphdr) +
+                                         sizeof(struct udphdr) + 9],
+                                 &request) ;
           break ;
 
         case OWL_REQUEST_CALIBRATION :
@@ -994,10 +1000,17 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
             printf("\nExplicit calibration packet received.\n") ;
           extract_calibration_data(&packet[rtap_bytes +
                                            ieee80211_header_size +
-                                           LLC_HEADER_SIZE
-                                           + sizeof(struct iphdr) +
+                                           LLC_HEADER_SIZE +
+                                           sizeof(struct iphdr) +
                                            sizeof(struct udphdr) + 9],
                                    &request) ;
+          extract_packet_numbers(&packet[rtap_bytes +
+                                         ieee80211_header_size +
+                                         LLC_HEADER_SIZE +
+                                         sizeof(struct iphdr) +
+                                         sizeof(struct udphdr) + 10 +
+                                         3 * sizeof(float)],
+                                 &request) ;
           break ;
 
         case OWL_REQUEST_AUTOCALIBRATION :
@@ -1010,10 +1023,17 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
             }
           extract_calibration_data(&packet[rtap_bytes +
                                            ieee80211_header_size +
-                                           LLC_HEADER_SIZE
-                                           + sizeof(struct iphdr) +
+                                           LLC_HEADER_SIZE +
+                                           sizeof(struct iphdr) +
                                            sizeof(struct udphdr) + 9],
                                    &request) ;
+          extract_packet_numbers(&packet[rtap_bytes +
+                                         ieee80211_header_size +
+                                         LLC_HEADER_SIZE +
+                                         sizeof(struct iphdr) +
+                                         sizeof(struct udphdr) + 10 +
+                                         3 * sizeof(float)],
+                                 &request) ;
           break ;
 
         default :
@@ -1088,13 +1108,14 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
              "\tMAC AP: %s\n"
              "\tMobile MAC: %s\n"
              "\tMobile IP: %s\n"
-             "\tSequence number (request time): %s\n"
+             "\tRequest timestamp: %s\n"
              "\tRequest arrival time on the AP: %s\n"
              "\tSignal: %d dBm\n"
              "\tPosition X: %f\n"
              "\tPosition Y: %f\n"
              "\tPosition Z: %f\n"
              "\tDirection: %hhd\n"
+             "\tPacket number: %"PRIu16"/%"PRIu16"\n"
              ,
              request.type,
              ap_mac_addr_str,
@@ -1107,7 +1128,9 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
              owl_ntohf(request.x_position),
              owl_ntohf(request.y_position),
              owl_ntohf(request.z_position),
-             request.direction
+             request.direction,
+             ntohs(request.packet_id),
+             ntohs(request.nb_packets)
              ) ;
     }
 
@@ -1142,6 +1165,26 @@ void extract_calibration_data(const u_char *packet,
 
 
 
+/*
+ * Fills 'request' with the number of packets and packet ID extracted
+ * from 'packet'.
+ * Note: 'packet' is read from its first byte, therefore you must not
+ * pass the whole received packet to this function.
+ */
+void extract_packet_numbers(const u_char *packet,
+                            owl_captured_request *request)
+{
+  // Number of packets:
+  memcpy(&request->nb_packets, packet, sizeof(uint16_t)) ;
+  request->nb_packets = request->nb_packets ;
+  // Current packet's ID:
+  memcpy(&request->packet_id, &packet[sizeof(uint16_t)],
+         sizeof(uint16_t)) ;
+  request->packet_id = request->packet_id ;
+}
+
+
+
 /*
  * Fills 'request' with the required data extracted from the Radiotap
  * header of 'packet'. The elements of 'rtap_fields' are set to owl_true
@@ -1430,6 +1473,7 @@ uint_fast16_t make_packet(uint8_t **packet)
     my_position_x = owl_htonf(GET_MY_POSITION_X()),
     my_position_y = owl_htonf(GET_MY_POSITION_Y()),
     my_position_z = owl_htonf(GET_MY_POSITION_Z()) ;
+  uint16_t npkt ;
 
   owl_timestamp_now(&request_time) ;
 
@@ -1444,25 +1488,32 @@ uint_fast16_t make_packet(uint8_t **packet)
 
   offset = 0 ;
   size =
-    sizeof(uint8_t) * 2 + sizeof(owl_timestamp) + sizeof(float) * 3 ;
+    sizeof(uint8_t) * 2 + sizeof(owl_timestamp) + sizeof(float) * 3 +
+    sizeof(uint16_t) * 2 ;
   pkt = malloc(size) ;
 
   // Request type:
-  memset(&pkt[offset], OWL_REQUEST_AUTOCALIBRATION, 1) ;
-  ++offset ;
+  memset(&pkt[offset++], OWL_REQUEST_AUTOCALIBRATION, 1) ;
   // Timestamp:
   memcpy(&pkt[offset], &request_time, sizeof(request_time)) ;
   offset += sizeof(request_time) ;
   // Coordinates:
-  pkt[offset] = GET_MY_DIRECTION() ;
-  ++offset ;
+  pkt[offset++] = GET_MY_DIRECTION() ;
   memcpy(&pkt[offset], &my_position_x, sizeof(float)) ;
   offset += sizeof(float) ;
   memcpy(&pkt[offset], &my_position_y, sizeof(float)) ;
   offset += sizeof(float) ;
   memcpy(&pkt[offset], &my_position_z, sizeof(float)) ;
-#ifndef NDEBUG
   offset += sizeof(float) ;
+  // Number of packets:
+  npkt = htons(GET_AUTOCALIBRATION_NBPKT()) ;
+  memcpy(&pkt[offset], &npkt, sizeof(uint16_t)) ;
+  offset += sizeof(uint16_t) ;
+  // Number of the current packet (1 for the first):
+  npkt = htons(1u) ;
+  memcpy(&pkt[offset], &npkt, sizeof(uint16_t)) ;
+#ifndef NDEBUG
+  offset += sizeof(uint16_t) ;
   assert(offset == size) ;
 #endif // NDEBUG