One of the most significant changes in the new uTorrent is uTP, the ‘micro transfer protocol’. UTP is a new and improved implementation of the BitTorrent protocol which is designed to be more network-friendly than its predecessor.
With uTP, uTorrent has become more network aware as it will throttle itself if congestion is detected in the network. The uTorrent teams hopes this improvement will eliminate the need for ISPs to throttle BitTorrent traffic, while its users should see less interference with other local applications.
The effectiveness of uTP is still being debated, but some people in the BitTorrent community have noticed another issue. According to some owners of private BitTorrent trackers, uTorrent is no longer playing fair. Since uTorrent users are the only ones using the new protocol, uTorrent favors its own kind over other clients.
This means that when connecting to other clients, uTorrent users will give preference to other uTorrent users, behavior that some have characterized as unfair. As a result, several private BitTorrent trackers have refused to put the newer uTorrent releases on their whitelists, effectively banning the client and forcing their users to stick with the older versions.
Simon Morris, BitTorrent’s VP of Product Management admits that the tracker owners have a point, but says that it is very hard to innovate without having to face such technical downsides. “This is part of the challenge of innovation… but hopefully a challenge we’ll overcome,” Morris told TorrentFreak.
“We’re well aware of these discussions and have been very receptive to the feedback we have received. uTP is being constantly tuned and like any advanced technology on the internet there are edge cases where there’s room for improvement,” Morris adds.
BitTorrent Inc. has opened up the specifications of the uTP protocol and hosted a conference in their San Fransisco offices a few weeks ago to discuss uTP in detail with developers of some of the most popular Bittorrent clients. According to Morris, other popular client developers have shown interest in implementing uTP into their own applications.
Widespread support for the new protocol would of course be the easiest way to get rid of the unfairness allegations, but uTorrent’s major competitor Vuze has no plans to support uTP in the short term. On the other hand, Vuze doesn’t believe the unfairness will result in a noticeable disadvantage for its users.
“In terms of speed, we do not buy-in to the ‘threat’ cited by some, claiming that uTP can result in slower downloads for non-uTP clients due to uTP clients favoring each other during the torrent cold start phase,” Olivier Chalouhi, CTO told TorrentFreak.
Vuze is keeping a close eye on how uTP evolves and will consider adding it to their own client as the technology matures. For now Vuze will continue to work on their own congestion solutions and speed improvements. They have already added UDP transfer support, but not as the primary protocol.
“Vuze added support for UDP transport a few years ago, as a fallback for when TCP connection attempts fail. To date, Vuze chose not to implement UDP as a first-class protocol, as we consciously wanted to avoid claims of a Vuze-specific protocol bias, which we do not believe serves the BitTorrent community at large,” Chalouhi said.
Whether uTorrent’s choice to push uTP forward results in any significant disadvantages for users of other clients is still open for debate. BitTorrent Inc. is, however, committed to play fair and will make the necessary adjustments where needed.
Thus far, only a few private trackers have decided to ban uTorrent and there are currently no signs that it will spread out to more.