When I signed up with them I quizzed their sales people about what traffic shaping technology they employed and whether they used bitfield mangling or similar technologies. They said no, it was a truly unlimited service. Despite numerous calls to their support department (who aren’t technical and just ask you to reset your router) I’ve given up the battle of getting them to at least confirm what they’re doing.

Without any workarounds on my end, torrent downloads were limited to about 55kb/s – A real pain if you’re trying to download some of Simon’s VMWare images.

Thankfully it turned out to be quite simple to get around BT’s traffic shaping system. Enabling RC4 encryption on all the torrent connections was sufficient to up my download speed to about 800kb/s. RC4 not only encrypts the headers but the entire data stream. The only downside is that it requires more CPU time to decrypt the traffic.

Assuming you’re using Vuze (formally Azureus), here are the simple steps you need to take:

1. Go to: Vuze > Preferences.
2. Expand Connection > Transport Encryption.
3. Check “Require encrypted transport”.
4. Set the “Minimum encryption level” dropdown to RC4.
5. Tick the “Allow non-encrypted outgoing connections” checkbox (to enable compatibility with peers not supporting encryption).
6. Tick the “Allow non-encrypted incoming connections” checkbox.

After a minute or so your transfer speeds should jump to about 600kb/s. The ball’s back in your court, BT.