diff --git a/README.md b/README.md
index 963cbe1..ba30535 100644
--- a/README.md
+++ b/README.md
@@ -14,8 +14,8 @@ Simple open source self-hosted file sharing solution.
 * Resumable up- and downloads ([TUS](https://tus.io))
 * Set an expire-time for your upload bucket
 * One-time downloads
-* Password protected downloads ([AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard))
-* Requires Node >=7.4
+* Requires Node >=7.4 or use `--harmony-async-await` flag
+* Password protected download list ([AES](https://en.wikipedia.org/wiki/Advanced_Encryption_Standard))  
 
 ![Screenshot](https://raw.githubusercontent.com/psi-4ward/psitransfer/master/docs/psitransfer.gif)
 
@@ -84,6 +84,12 @@ Psitransfer uses [debug](https://github.com/visionmedia/debug):
 DEBUG=psitransfer:* npm start
 ```
 
+## Side notes
+
+* There is no (end-to-end) payload encryption (yet).
+
+:star2: Contribution is highly welcome :metal:
+
 ## License
 
 [BSD](LICENSE)
diff --git a/scripts/traffic-limit.sh b/scripts/traffic-limit.sh
new file mode 100755
index 0000000..630750c
--- /dev/null
+++ b/scripts/traffic-limit.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+set -e
+
+# Helper script to limit traffic for iface:port
+# http://www.codeoriented.com/how-to-limit-network-bandwidth-for-a-specific-tcp-port-on-ubuntu-linux/
+# https://wiki.archlinux.org/index.php/Advanced_traffic_control
+
+if ! which tc &>/dev/null ; then
+  2>&1 echo Error: tc executable not found
+  2>&1 echo Please install iproute2 package
+  exit 1
+fi
+
+IFACE=$1
+RATE=$3
+PORT=$2
+
+if [ -z "$3" ] ; then
+  echo "Traffic limitter"
+  echo "Usage: $0 IFACE PORT RATE"
+  echo
+  echo "Available interfaces: $(ls -m /sys/class/net)"
+  echo
+  echo "Rate units: "
+  echo "  kbps: Kilobytes per Second"
+  echo "  mbps: Megabytes per Second"
+  echo "  gbps: Gigabytes per Second"
+  echo "  off: No rate limit"
+  echo
+  echo "Examples:"
+  echo "  $0 wlan0 8080 10kbps"
+  echo "  $0 wlan0 8080 off"
+  exit 1
+fi
+
+sudo tc qdisc del root dev $IFACE &>/dev/null || true
+
+[ "$RATE" = "off" ] && exit
+
+sudo tc qdisc add dev $IFACE root handle 1:0 htb default 10
+sudo tc class add dev $IFACE parent 1:0 classid 1:10 htb rate $RATE  prio 0
+sudo tc filter add dev $IFACE parent 1:0 prio 0 protocol ip u32 match ip protocol 4 0xff match ip dport $PORT 0xffff flowid 1:10
+sudo tc qdisc show dev $IFACE
diff --git a/tmp/scripts/traffic-limit.sh b/tmp/scripts/traffic-limit.sh
deleted file mode 100755
index bad00b9..0000000
--- a/tmp/scripts/traffic-limit.sh
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/bash
-
-# http://www.codeoriented.com/how-to-limit-network-bandwidth-for-a-specific-tcp-port-on-ubuntu-linux/
-
-IF=$2
-BAND=$1
-PORT=$3
-
-if [ -z "$3" ] ; then
-  echo $0 10kbps wlan0 8080
-  exit 1
-fi
-
-tc qdisc del root dev $IF
-tc qdisc add dev $IF root handle 1:0 htb default 10
-tc class add dev $IF parent 1:0 classid 1:10 htb rate $BAND  prio 0
-tc filter add dev $IF parent 1:0 prio 0 protocol ip u32 match ip protocol 4 0xff match ip dport $PORT 0xffff flowid 1:10
-tc qdisc show dev $IF