The company behind the BitTorrent technology has opened the source code of its uTorrent Transport Protocol (uTP). A production-ready implementation of the protocol code in C++ is now available from GitHub under the MIT license.

uTP, which is used today in the popular uTorrent BitTorrent client, is designed to reduce network congestion by allowing other traffic to take precedence. This reduces the overall load that BitTorrent puts on networks, both locally and at the ISP level. The developers contend that the new protocol will remove the need for ISPs to throttle or block BitTorrent traffic and could also potentially boost download performance in some cases.

A popular feature in uTorrent lets users specify certain times of day when the application should reduce its bandwidth consumption so that it won't disrupt other users on the network. The virtue of uTP is that it offers a much better solution than that kind of heavy-handed local constriction. The dynamic throttling principle behind uTP will allow BitTorrent connections to automatically back down and make room for other kinds of traffic as needed, and then ramp back up to full speed when the network is less busy.

BitTorrent connections using uTP will be able to use 100 percent of available bandwidth when nothing else is using the network. In theory, that could help reduce total download time relative to the less flexible client-side throttling approaches that users are forced to rely on today.

Similarly, uTP will theoretically help prevent BitTorrent traffic from clogging the tubes at the ISP level. If uTP were to become ubiquitous, the ISPs might not feel compelled to use aggressive traffic shaping and other undesirable QoS strategies that would be detrimental to BitTorrent download performance. Although the ISPs will apparently benefit from uTP adoption, the developers behind the protocol insist that the protocol was principally designed to boost the experience of regular end users and that the advantage to the ISP is largely secondary.

The uTP congestion control mechanism and the protocol itself are documented at the BitTorrent.org website. The developers are also working to standardize the new protocol through the Internet Engineering Task Force (IETF) Low Extra Delay Background Transport (LEDBAT) working group.

Although the protocol is an open standard and offers some intriguing advantages, the technology is not seeing swift uptake. A report from TorrentFreak says that client application developers are still skeptical and some users have suffered performance degradation due to problems with the protocol.

The availability of the source code under a permissive open source software license will now make it easier for application developers to support the protocol in their own applications. It will also open the door for application developers to help identify and fix problems in the implementation, leading to a stronger collective understanding of best practices for uTP adoption.

BitTorrent throttling is one of several issues at the heart of the ongoing net neutrality debate. If market-driven technical innovations like uTP can lessen the network problems that are creating friction between P2P users and ISPs, it could defer the need for regulatory intervention.