Comment 6 for bug 940541

It probably also reduces the delay on the internet too, it is just harder to test.

Testing in a lan can be done by doing a SSH copy of a huge file from/to another pc in the lan in one terminal and in another terminal you do a ping to the same or to another address.

Changing the size of the txqueuelen of the network interface in use affects the delay.
For most fun, try doing it in a wireless network.