The next version of μTorrent might put Internet service providers in a pickle. According to an article on The Register, the developers behind the popular BitTorrent client have decided to use UDP instead of TCP as the default protocol for file transfers, allegedly in an effort to evade Bell Canada's traffic shaping techniques.
The article's author—network architect Richard Bennett—writes that ISPs have congestion control mechanisms in place chiefly for TCP traffic, since UDP accounts for "less than two per cent of all internet traffic." UDP is typically used for voice-over-IP, video conferencing, online gaming, and other applications that require low latency at the expense of reliability.
Now, if one of the most popular (if not the most popular) BitTorrent clients out there starts pumping massive amounts of traffic via UDP, Bennett predicts that the links connecting ISPs "will become much less responsive to load management." Translation: slowdowns for most Internet users. At that point, ISPs might start throttling UDP traffic—but doing so would "utterly destroy" VoIP, Bennett says.
While the article admittedly sounds somewhat alarmist, Bennett reportedly worked on the Ethernet-over-twisted-pair and Wi-Fi standards, so he hopefully has a good grasp of the technology involved. We'll have to see what μTorrent's developers and ISPs actually end up doing, though.