How to simulate a slow network

source: http://blogs.kde.org/node/1878

{/usr}/sbin/tc qdisc add dev lo root handle 1:0 netem delay 20msec

ping localhost

tc qdisc

tc qdisc del dev lo root

tc qdisc add dev eth0 root handle 1:0 netem delay 55msec

tc qdisc add dev lo root handle 1:0 netem delay 60msec 12msec 25%

tc qdisc change dev lo root handle 1:0 netem delay 110msec 5msec 50%