ISPs have been throttling BitTorrent traffic for years already. Although the true reasons for this are not always clear, some ISPs have argued that a high number of BitTorrent connections are slowing down other applications and traffic.
In early 2007, when network neutrality was still a non-issue for most people, BitTorrent inventor Bram Cohen told us that ISPs should find a way to cope with BitTorrent.
“ISPs have to invest in making their networks better and faster rather than stifling applications which consumers use and love,” he said, while encouraging users to switch to non throttling ISPs if possible, or complain to their ISP’s customer services.
A lot of things have changed in the years that followed. Comcast started to prevent its users from seeding content on BitTorrent, and many other ISPs took similar actions to throttle BitTorrent traffic. As a direct result, network neutrality was placed on the political agenda in many countries. It also inspired BitTorrent Inc. to look for solutions that would eliminate the need for throttling entirely, solving the problem at its root.
This is where uTP comes in. uTP is a new and improved implementation of the BitTorrent protocol which is designed to be network friendly. The current implementation often causes interference with other applications, which is the main reason why ISPs try to slow it down, or even stop it altogether. uTP aims to solve this problem.
With uTP, uTorrent (and the Mainline client) will become network aware by throttling itself if congestion in the network is detected. This will have a huge impact on ISP networks according to Simon Morris, BitTorrent’s VP of Product Management. “If uTP is successful it should result in a multi-billion dollar windfall in terms of savings for ISPs,” Morris told TorrentFreak
This means that the new uTorrent will eliminate the need for ISPs to throttle BitTorrent traffic in their networks. Of course, uTorrent users will also be affected by the new protocol. When needed, uTorrent will decrease the upload or download speed to avoid congestion.
According to Morris it’s mainly the upload speed that will be affected. “The throttling that matters most is actually not so much the download but rather the upload – as bandwidth is normally much lower UP than DOWN, the up-link will almost always get congested before the down-link does,” he explained.
“uTP measures the time a packet takes to get sent from peer A to peer B, so in theory uTP will detect congestion anywhere on that path, although in practice the congestion most often happens somewhere on the first-mile uplink connection.”
So does this mean that the new uTorrent will result in slower download times? Not necessarily. Since there is less congestion, uTorrent users will experience no slowdowns in web-browsing, and ideally less congestion and a more efficient use of the network may result in faster download speeds. uTP is currently being tested in uTorrent v2.0 beta and thus far none of the testers have reported any significant problems.
“There are already a couple of hundred thousand people using our v2.0 beta client, and things seem to be progressing very nicely. Our v2.0 client will initiate outgoing uTP connections by default whenever it can. Previous versions of our clients will accept incoming uTP connections – they just won’t initiate them,” Morris said.
“We’re excited that this creates a better experience for millions of consumers, and it also potentially has a massive impact on ISPs – greatly reducing (even eliminating) any justification to manage or shape BitTorrent traffic and allowing ISP networks to handle more BitTorrent traffic, without resulting congestion forcing capital network upgrades ahead of schedule or the ‘need’ to invest in DPI or other traffic shaping gear.”
It is hard to tell if uTP really is BitTorrent’s savior (some highly doubt it), but if it lives up to the expectations it will be beneficial to both users and ISPs. The specs for uTP will eventually be open so other clients will have the opportunity to implement it too. However, since uTorrent and the Mainline client together are used by two thirds of all BitTorrent users, the effects should be immediately noticeable to both those users and ISPs.