I work at a web company with ~15 other people and a relatively crappy internet connection (DSL & cable). I'm looking for a software-based solution that will automatically cap traffic from users that are using it at, say, 80% of the line's capacity so that when people are uploading/etc the internet won't die for everyone else.
Person A starts uploading a file
Person B's connection drops to nothing
I want to make this so that person B doesn't notice anything unless he's also using a lot of traffic (uploading a file himself)