tc_fqcodel

#!/bin/sh
set -ix
## Paths and definitions
tc=/usr/sbin/tc
ext=$1		# Change for your device!
ext_ingress=$4	# Use a unique ifb per rate limiter!
# Set these as per your provider's settings, at 90% to start with
ext_up=$2		# Max theoretical: for this example, up is 1024kbit => 100kbyte
ext_down=$3	# Max theoretical: for this example, down is 8192kbit = 950 kbyte
q=1514                  # HTB Quantum = 1500bytes IP + 14 bytes ethernet.
# Higher bandwidths may require a higher htb quantum. MEASURE.
# Some ADSL devices might require a stab setting.

quantum=300		# fq_codel quantum 300 gives a boost to interactive flows
# At higher bandwidths (50Mbit+) don't bother
MODULES="ifb sch_htb sch_ingress sch_fq_codel cls_flow cls_u32 act_mirred"
for i in $MODULES
do
  lsmod |grep -q $i || insmod $i
done


ethtool -K $ext tso off gso off gro off # Also turn of gro on ALL interfaces 
ifconfig $ext txqueuelen 1000
# e.g ethtool -K eth1 gro off if you have eth1
# some devices you may need to run these 
# commands independently

# Clear old queuing disciplines (qdisc) on the interfaces
$tc qdisc del dev $ext root
$tc qdisc del dev $ext ingress
$tc qdisc del dev $ext_ingress root
$tc qdisc del dev $ext_ingress ingress
#########
# INGRESS
#########

# Create ingress on external interface
$tc qdisc add dev $ext handle ffff: ingress

ifconfig $ext_ingress up # if the interace is not up bad things happen

# Forward all ingress traffic to the IFB device
$tc filter add dev $ext parent ffff: protocol all u32 match u32 0 0 action mirred egress redirect dev $ext_ingress

# Create an EGRESS filter on the IFB device
$tc qdisc add dev $ext_ingress root handle 1: htb default 11

# Add root class HTB with rate limiting

$tc class add dev $ext_ingress parent 1: classid 1:1 htb rate ${ext_down}kbps
$tc class add dev $ext_ingress parent 1:1 classid 1:11 htb rate ${ext_down}kbps prio 0 quantum $q
$tc class add dev $ext_ingress parent 1:1 classid 1:12 htb rate ${ext_down}kbps prio 0 quantum $q


# Add FQ_CODEL qdisc with ECN support (if you want ecn)
$tc qdisc add dev $ext_ingress parent 1:11 fq_codel quantum $quantum ecn
$tc qdisc add dev $ext_ingress parent 1:12 fq_codel quantum $quantum ecn

#########
# EGRESS
#########
# Add FQ_CODEL to EGRESS on external interface
$tc qdisc add dev $ext root handle 1: htb default 11

# Add root class HTB with rate limiting
$tc class add dev $ext parent 1: classid 1:1 htb rate ${ext_up}kbps
$tc class add dev $ext parent 1:1 classid 1:11 htb rate $((${ext_up} * 10 / 3))kbps ceil $((${ext_up} * 10 / 6))kbps prio 0 quantum $q prio 0
$tc class add dev $ext parent 1:1 classid 1:12 htb rate $((ext_up*10/7))kbps ceil ${ext_up}kbps prio 0 quantum $q prio 1

# Note: You can apply a packet limit here and on ingress if you are memory constrained - e.g
# for low bandwidths and machines with < 64MB of ram, limit 1000 is good, otherwise no point

# Add FQ_CODEL qdisc without ECN support - on egress it's generally better to just drop the packet
# but feel free to enable it if you want.

$tc qdisc add dev $ext parent 1:11 fq_codel quantum $quantum noecn
$tc qdisc add dev $ext parent 1:12 fq_codel quantum $quantum noecn

iptables -t mangle -A POSTROUTING  --src 192.168.1.2 -j CLASSIFY --set-class 1:12                  
iptables -t mangle -A POSTROUTING  --src 192.168.1.3 -j CLASSIFY --set-class 1:12                  
              

# filter for low prio traffic
#$tc filter add dev $ext parent 1:12 prio 1 protocol ip u32 match ip src 192.168.1.2 flowid 1:12
#$tc filter add dev $ext parent 1:12 prio 1 protocol ip u32 match ip src 192.168.1.3 flowid 1:12