Simulate network control

There is a tc command on Ubunut to manipulate traffic control settings, for example to introduce artificial packet dropping.

Add a packet delay of 100ms ± 10ms with the current delay depending 25% on the last delay:

tc qdisc change dev eth0 root netem delay 100ms 10ms 25%

You can even configure more convoluted settings:

sudo tc qdisc change dev lo root netem delay 50ms 200ms loss 10% 25% reorder 25% 50%

• Packet delay of 50ms ± 200msd
• Packet loss of 10% to 25%
• Reorder packages between 25%-50% of the time

This page gives more thorough examples.