Description:

Maintain low latency for interfactive traffic at all times
This means that downloading or uploading files should not disturb SSH or
even telnet. These are the most important things, even 200ms latency is
sluggish to work over.
Allow 'surfing' at reasonable speeds while up or downloading
Even though http is 'bulk' traffic, other traffic should not drown it out
too much.
Make sure uploads don't harm downloads, and the other way around. This is a
much observed phenomenon where upstream traffic simply destroys download
speed. It turns out that all this is possible, at the cost of a tiny bit of
bandwidth. The reason that uploads, downloads and ssh hurt eachother is the
presence of large queues in many domestic access devices like cable or DSL
modems.