BitTyrant questions assumptions about BitTorrent

The theory around BitTorrent is that all peers upload as well as download, in roughly equal amounts. The more upload capacity you contribute, the more download capacity you enjoy, in effect leveling the playing field for folks on high-speed and slow-speed connections.

The UW researchers studied real-world BitTorrent swarms, and found the field anything but level. Peers on high-speed connections contribute considerably more than they receive. And we are not talking about generosity of spirit or continuing to seed a torrent after the download has completed; the study shows that -- using typical client settings -- faster peers do not download data as fast as they upload it.

By modifying the popular GPLed client Azureus, the authors of the study created a BitTorrent client named BitTyrant. BitTyrant tries to choose peers intelligently instead of randomly, favoring those that are already operating at an upload/download equilibrium and attempting to maintain connections with active peers.

Nevertheless, it has been described as a "selfish" client, leading some bloggers to denounce it in terms usually reserved for malicious hacks and hostile attacks. By not treating all members of the swarm equally, BitTyrant does offer personal gain at the expense of others.

But wait, says the UW team, the study data shows that without BitTyrant, high-speed users are the ones getting the unfair treatment. So you can't just say "we should ban BitTyrant because it behaves unfairly."