diff --git a/Makefile b/Makefile
index 8368ed96f7e1f8aa23e8cd14a2e204f383bccc90..f030fde8e51c62072239456985bfe3891dc8f0d8 100644
--- a/Makefile
+++ b/Makefile
@@ -46,6 +46,8 @@ makelinksim:
 tests: debug
 	@./tests/run_tests.sh
 
+# It runs every receivers from interop/receivers with our sender
+# And every senders from interop/senders with our receiver
 interop: debug
 	@./tests/run_interop.sh
 
diff --git a/interop/receivers/receiver_group38 b/interop/receivers/receiver_group38
index bdb8f3136a2e9a947d1cdce458a7651e77ccf21d..f52697916b0b8124446f7e23d1b516226e699bd8 100755
Binary files a/interop/receivers/receiver_group38 and b/interop/receivers/receiver_group38 differ
diff --git a/interop/senders/sender_group38 b/interop/senders/sender_group38
index d46b3e90cb8ad050ee7746af94809e4adc437dc4..1fabb651098d17f1c25c6e7bb758a6614dcb2a0a 100755
Binary files a/interop/senders/sender_group38 and b/interop/senders/sender_group38 differ
diff --git a/tests/perfomance_test.sh b/tests/perfomance_test.sh
index 50cf19f5417d5e807a8d0879cf1ccabe04495354..90bc020df02bc2c0984aa689b6768247ccd48c9c 100755
--- a/tests/perfomance_test.sh
+++ b/tests/perfomance_test.sh
@@ -42,8 +42,8 @@ for ITER in 1 2 3; do
 
     # 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 $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
+    port1=$(comm -23 <(seq 30000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
+    port2=$(comm -23 <(seq 30000 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} \
diff --git a/tests/run_interop.sh b/tests/run_interop.sh
index b89b39a264686f198287b38adac3ff026d6d4954..5ee1a8a8f84638bd440ae6a60eb4ce7cfae9cde1 100755
--- a/tests/run_interop.sh
+++ b/tests/run_interop.sh
@@ -20,11 +20,11 @@ modes=(
     'without_FEC'
 )
 
-ERROR_RATE=1
-CUT_RATE=1
+ERROR_RATE=2
+CUT_RATE=5
 DELAY=100
 JITTER=100
-LOSS_RATE=1 
+LOSS_RATE=5
 
 dir="tests_logs/interop/"
 
@@ -40,6 +40,7 @@ senders=interop/senders/*
 echo -e "\n\nStarting the test of interoperability with other RECEIVERS..."
 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}"
     j=1
@@ -64,6 +65,7 @@ done
 echo -e "Starting the test of interoperability with other SENDERS..."
 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}"
     j=1
diff --git a/tests/run_sender_receiver.sh b/tests/run_sender_receiver.sh
index a90061273ff88a7b5350e8aee99d7755d7a516ac..2c2d1a962dc2af6ac5e6a8bb05c3a489ba99c104 100755
--- a/tests/run_sender_receiver.sh
+++ b/tests/run_sender_receiver.sh
@@ -86,8 +86,8 @@ if [ "$#" -gt 6 ]; then
 
     # 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 $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
+    port1=$(comm -23 <(seq 30000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
+    port2=$(comm -23 <(seq 30000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
 
     linksimulator_logs="${DIR}linksim.log"
     touch $linksimulator_logs
@@ -99,7 +99,7 @@ if [ "$#" -gt 6 ]; then
 else
     # The next line 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 $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
+    port1=$(comm -23 <(seq 30000 65200 | sort) <(ss -Htan | awk '{print $4}' | cut -d':' -f2 | sort -u) | shuf | head -n 1)
     port2=$port1
 fi
 
@@ -153,7 +153,7 @@ wait_for_receiver=5
 sleep $wait_for_receiver  # We wait 5s for the receiver to finish up
 
 if kill -0 $receiver_pid &> /dev/null ; then
-    echo -e "${RED}The receiver didn't stop ${wait_for_receiver} after the end of the transfer!${NC}"
+    echo -e "${RED}The receiver didn't stop ${wait_for_receiver}s after the end of the transfer!${NC}"
     kill -9 $receiver_pid
     err=1
 else  # We check the return value of the receiver
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index a8da3e677a04d9cf45d28c8403956ea82c270cf4..62d593e4ee36182d6bc3aaea788e71a9363aa0b0 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -69,7 +69,7 @@ ERROR_RATE=5
 CUT_RATE=5
 DELAY=100
 JITTER=100
-LOSS_RATE=1 
+LOSS_RATE=10
 
 
 if [ -d linksimulator/ ]; then