diff --git a/scripts/container/sync_barrier_donar b/scripts/container/sync_barrier_donar
index c322268..bddd895 100755
--- a/scripts/container/sync_barrier_donar
+++ b/scripts/container/sync_barrier_donar
@@ -2,11 +2,7 @@
 
 sleep 1
 echo "sync_barrier_start"
-nc -u 127.13.3.7 5000 --sh-exec 'while true; do sleep 1; echo a; done' &
-CAPTURE=$!
-nc -ul 127.0.0.1 5000 --exec /bin/true 
+nc -v --udp --source 127.0.0.1 --source-port 5000 127.13.3.7 5000 --sh-exec '(while true; do sleep 1; echo a; done) & B=$!; read r; kill $B'
 echo "sync_barrier_release"
-sleep 1
-kill $CAPTURE
 sleep 10
 echo "sync_barrier_done"