diff --git a/interop/receivers/receiver_group127 b/interop/receivers/receiver_group127
new file mode 100755
index 0000000000000000000000000000000000000000..082b6231d9d99614790b2892e47a3e15147377d5
Binary files /dev/null and b/interop/receivers/receiver_group127 differ
diff --git a/src/sender_utils.c b/src/sender_utils.c
index b7c3e2504c2433916ec2ee25a9e87ca57da7dbe8..e4cd77759953ac4dc02e6908a1914e3b184f7429 100644
--- a/src/sender_utils.c
+++ b/src/sender_utils.c
@@ -197,12 +197,12 @@ int handle_returning_ack_nack(sender_state_t *state, int socket_fd)
                 gettimeofday(&time, NULL);
                 unsigned long long int delta_time = time_milliseconds(&time) - time_milliseconds(&state->timers_first_send[state->tail]);
 
-                float used_for_calculation = state->stats->avg_rtt * (state->nbr_of_acked_packets);
-                used_for_calculation += delta_time;
+                float temp_for_calculation = state->stats->avg_rtt * (state->nbr_of_acked_packets);
+                temp_for_calculation += delta_time;
                 state->nbr_of_acked_packets++;
-                used_for_calculation /= state->nbr_of_acked_packets;
+                temp_for_calculation /= state->nbr_of_acked_packets;
 
-                state->stats->avg_rtt = used_for_calculation;
+                state->stats->avg_rtt = (unsigned long long int) temp_for_calculation;
                 
                 if (state->stats->min_rtt == 0 || state->stats->min_rtt > delta_time)
                 {
diff --git a/tests/advanced_test.sh b/tests/advanced_test.sh
deleted file mode 100755
index 0559a0a972ad85f35c564e156b2bb823f55fa62a..0000000000000000000000000000000000000000
--- a/tests/advanced_test.sh
+++ /dev/null
@@ -1,134 +0,0 @@
-#!/bin/bash
-
-GREEN='\033[0;32m'
-RED='\033[0;31m'
-NC='\033[0m'
-
-if [ -z "$1" ]; then 
-  echo "Not given the file to send"
-  exit 1
-fi 
-
-# If the directory does not exist, we create it
-if [ ! -d "tests_logs/advanced_tests/" ]; then
-  mkdir 'tests_logs/advanced_tests/' 2>/dev/null
-fi
-
-FILENAME=$1
-BASENAME=$(basename $FILENAME)
-BSN_PRE="${BASENAME%.*}"
-BSN_EXT="${BASENAME##*.}"
-
-TEST_OUTPUT_FILES="tests_logs/advanced_tests/${BSN_PRE}"
-mkdir "${TEST_OUTPUT_FILES}/" 2>/dev/null
-
-MODES=(
-  'with_FEC'
-  'without_FEC'
-)
-
-ERROR_RATE=10
-CUT_RATE=1
-DELAY=290
-JITTER=30
-LOSS_RATE=1 
-
-echo -e "The linksimulator paramateres are:
-        \t\t-ERROR RATE: ${ERROR_RATE}%    \t-DELAY:  ${DELAY}ms
-        \t\t-CUT RATE:   ${CUT_RATE}%      \t-JITTER: ${JITTER}ms 
-        \t\t-LOSS RATE:  ${LOSS_RATE}%\n"
-
-for MODE in "${MODES[@]}"; do
-  
-  mkdir "${TEST_OUTPUT_FILES}/${MODE}/" 2>/dev/null
-  DIR="${TEST_OUTPUT_FILES}/${MODE}"
-
-  touch "${DIR}/adv_${BSN_PRE}_received_file.${BSN_EXT}" \
-        "${DIR}/adv_valgrind_${BSN_PRE}_receiver.log"    \
-        "${DIR}/adv_valgrind_${BSN_PRE}_sender.log"      \
-        "${DIR}/${BSN_PRE}_receiver_stats.csv"          \
-        "${DIR}/${BSN_PRE}_sender_stats.csv"
-
-
-
-  # The next 2 lines come from: https://unix.stackexchange.com/questions/55913/whats-the-easiest-way-to-find-an-unused-local-port
-  # We use this to be sure we're using unused port
-  port1=$(comm -23 <(seq 65000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
-  port2=$(comm -23 <(seq 65000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
-
-
-  #####   Launching the link simulator   #####
-  ./linksimulator/link_sim -p $port2 -P $port1 -l $LOSS_RATE -d $DELAY -e $ERROR_RATE -c $CUT_RATE -j $JITTER \
-    &>${DIR}/adv_${BSN_PRE}_link.log & link_pid=$!
-
-  #####   Launching the receiver and capturinig its output   #####
-  valgrind --leak-check=full --log-file=${DIR}/adv_valgrind_${BSN_PRE}_receiver.log \
-                ./receiver ::1 $port1 -s ${DIR}/${BSN_PRE}_receiver_stats.csv 1> ${DIR}/adv_${BSN_PRE}_received_file.${BSN_EXT} \
-                2> ${DIR}/adv_${BSN_PRE}_receiver.log & receiver_pid=$!
-
-  cleanup()
-  {
-      kill -9 $receiver_pid
-      kill -9 $link_pid
-      exit 0
-  }
-  trap cleanup SIGINT  # Kill the background procces in case of ^-C
-
-  # Checking the mode (with out without FEC)
-  if [ $MODE = "with_FEC" ]; then
-    # We start the transfer
-    if ! valgrind --leak-check=full --log-file=${DIR}/adv_valgrind_${BSN_PRE}_sender.log \
-        ./sender -f ${FILENAME} ::1 $port2 -c -s ${DIR}/${BSN_PRE}_sender_stats.csv 2> ${DIR}/adv_${BSN_PRE}_sender.log ; then
-      echo "The sender crashed!"
-      cat ${DIR}/adv_${BSN_PRE}_sender.log
-      err=1  # We record the error
-    fi
-  else
-    # We start the transfer
-    if ! valgrind --leak-check=full --log-file=${DIR}/adv_valgrind_${BSN_PRE}_sender.log \
-        ./sender -f ${FILENAME} ::1 $port2 -s ${DIR}/${BSN_PRE}_sender_stats.csv 2> ${DIR}/adv_${BSN_PRE}_sender.log ; then
-      echo "The sender crashed!"
-      cat ${DIR}/adv_${BSN_PRE}_sender.log
-      err=1  # We record the error
-    fi
-  fi
-
-  sleep 5 # We wait 5s for the receiver to finish up
-
-  if kill -0 $receiver_pid &> /dev/null ; then
-    echo "The receiver didn't stop at the end of the transfer!"
-    kill -9 $receiver_pid
-    err=1
-  else  # We check the return value of the receiver
-    if ! wait $receiver_pid ; then
-      echo "Crash of the receiver!"
-      cat ${DIR}/adv_${BSN_PRE}_receiver.log
-      err=1
-    fi
-  fi
-
-  # Stop the link simulator
-  kill -9 $link_pid
-  wait $link_pid 2>/dev/null
-
-  # We verify that the transfer ran through properly
-  if [[ "$(md5sum ${FILENAME} | awk '{print $1}')" != "$(md5sum ${DIR}/adv_${BSN_PRE}_received_file.${BSN_EXT} | awk '{print $1}')" ]]; then
-    echo "The transfer corrupted the file!"
-    echo "Binary difference between the 2 files: (expected vs actual)"
-    diff -C 9 <(od -Ax -t x1z ${FILENAME}) <(od -Ax -t x1z ${DIR}/adv_${BSN_PRE}_received_file.${BSN_EXT})
-    if [ $MODE = "with_FEC" ]; then
-      echo -e "${RED}The transfer (with FEC) has failed!${NC}"
-    else
-      echo -e "${RED}The transfer (without FEC) has failed!${NC}"
-    fi
-    exit 1
-  else
-    if [ $MODE = "with_FEC" ]; then
-      echo -e "${GREEN}The transfer (with FEC) has succeeded!${NC}"
-    else
-      echo -e "${GREEN}The transfer (without FEC) has succeeded!${NC}"
-    fi
-  fi
-done
-
-exit ${err:-0}  # In case of error, we return the error code
\ No newline at end of file
diff --git a/tests/run_interop.sh b/tests/run_interop.sh
index 5ee1a8a8f84638bd440ae6a60eb4ce7cfae9cde1..39ccb4ced542136e89de2099161bde04ea56cb55 100755
--- a/tests/run_interop.sh
+++ b/tests/run_interop.sh
@@ -13,18 +13,19 @@ NC='\033[0m'
 input_files=(
     'tests_files/greeting.txt'
     'tests_files/smile.png'
+    'tests_files/noice.gif'
 )
 
 modes=(
-    'with_FEC'
     'without_FEC'
+    'with_FEC'
 )
 
-ERROR_RATE=2
+ERROR_RATE=10
 CUT_RATE=5
 DELAY=100
 JITTER=100
-LOSS_RATE=5
+LOSS_RATE=20
 
 dir="tests_logs/interop/"
 
@@ -42,7 +43,7 @@ i=1
 for receiver in $receivers; do
     chmod +x $receiver
     receiver_name="${receiver##*/}"
-    echo -e "\n${BROWN}($i/${#receivers[@]}) Testing with ${receiver_name}:\n${NC}"
+    echo -e "\n${BROWN}Testing with ${receiver_name}:\n${NC}"
     j=1
     for file in "${input_files[@]}"; do
         filesize=$(stat -c%s "$file")
@@ -67,7 +68,7 @@ i=1
 for sender in $senders; do
     chmod +x $sender
     sender_name="${sender##*/}"
-    echo -e "\n${BROWN}($i/${#senders[@]}) Testing with ${sender_name}\n${NC}"
+    echo -e "\n${BROWN} Testing with ${sender_name}\n${NC}"
     j=1
     for file in "${input_files[@]}"; do
         filesize=$(stat -c%s "$file")
diff --git a/tests/run_sender_receiver.sh b/tests/run_sender_receiver.sh
index 2c2d1a962dc2af6ac5e6a8bb05c3a489ba99c104..ade846ce8174850c1a8fdccc8fb367a956dafe51 100755
--- a/tests/run_sender_receiver.sh
+++ b/tests/run_sender_receiver.sh
@@ -175,7 +175,7 @@ fi
 if [ $err -ne 1 ]; then
     # We verify that the transfer ran through properly
     if [[ "$(md5sum ${input_file} | awk '{print $1}')" != "$(md5sum ${output_file} | awk '{print $1}')" ]]; then
-        echo "The transfer corrupted the file!"
+        echo "${RED}The transfer corrupted the file!${NC}"
         echo "Binary difference between the 2 files: (expected vs actual)"
         diff -C 9 <(od -Ax -t x1z ${input_file}) <(od -Ax -t x1z ${output_file})
         if [ $mode = "with_FEC" ]; then
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index 5b08d219f58926cc0a0190c6b7ea50bca770de86..bf3157add536a20f3d85cc5262926a2d3db47267 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -60,17 +60,16 @@ modes=(
 
 advanced_test_files=(
   'tests_files/greeting.txt'
-  'tests_files/long_message.txt'
-  'tests_files/thumbs-up-nod.gif'
+  'tests_files/smile.png'
   'tests_files/noice.gif'
 )
 
 
-ERROR_RATE=5
-CUT_RATE=5
-DELAY=100
+ERROR_RATE=10
+CUT_RATE=10
+DELAY=200
 JITTER=100
-LOSS_RATE=10
+LOSS_RATE=20
 
 
 if [ -d linksimulator/ ]; then