sfq

gistfile1.sh

# SSH class: for outgoing connections to 
# avoid lag when somebody else is downloading
# however, an SSH connection cannot fill up 
# the connection to more than 70%

echo "#---ssh - id 300 - rate 160 kbit ceil 1120 kbit"
/sbin/tc class add dev eth0 parent 1:1 classid 1:300 htb \
    rate 160kbit ceil 1120kbit burst 15k prio 3

# SFQ will mix the packets if there are several 
# SSH connections in parallel
# and ensure that none has the priority

echo "#--- ~ sub ssh: sfq"
/sbin/tc qdisc add dev eth0 parent 1:300 handle 1300: \
    sfq perturb 10 limit 32

echo "#--- ~ ssh filter"
/sbin/tc filter add dev eth0 parent 1:0 protocol ip \
    prio 3 handle 300 fw flowid 1:300

echo "#--- ~ netfilter rule - SSH at 300"
/sbin/iptables -t mangle -A POSTROUTING -o eth0 -p tcp 
    --tcp-flags SYN SYN -dport 22 -j CONNMARK \
    --set-mark 300