GoalBit: P2P Streaming Goes Open Source

goalbitBandwidth-conscious broadcasters have a new way to distribute their live video streams. A group of Uruguay-based P2P researchers recently released the first English-language version of their open-source P2P streaming application, GoalBit. The application, which is based on a BitTorrent-like architecture, aims to compete with P2P streaming services like PPLive and PPStream by giving anyone looking to distribute their own live video programming a way to do so.

GoalBit, which is available for Windows and Linux, currently features just a handful of Uruguay’s TV networks streaming at fairly low bitrates. But the service looks promising nonetheless, and its extensive documentation could be intriguing to anyone interested in P2P streaming.

GoalBit uses a hybrid approach that combines the best of the BitTorrent world, with features from the likes of P2P networks such as Gnutella and KaZaA’s FastTrack network. Its network features a tracker similar to the one used by BitTorrent clients, but it also makes use of so-called super-peers. These are computers with fat pipes that help to distribute the initial signal until it trickles down to users with ordinary DSL connections and limited upload speeds. Super-peers can be run either by the broadcasters themselves, or self-selected based on the connectivity of the individual end user. The idea of this multilayer approach is to prevent too many direct connections to the broadcaster while at the same time making the system scalable.

Another interesting aspect of GoalBit is that channel lists are distributed in the form of small files similar to .torrent files in the world of BitTorrent. Broadcasters simply have to create such a file with the help of the GoalBit client, announce their stream with a GoalBit tracker and upload the file to a web server — and they’re ready to stream to the world. Well, that’s the theory anyway. The developers of GoalBit state that this so-called “Broadcast Yourself” functionality is still experimental, and I haven’t actually tested it myself.

GoalBit is competing with a wide array of P2P streaming applications, most of which are proprietary. Particularly successful examples are PPLive, which claims up to 30 million active users per month, and PPStream, which boasted 1 billion video viewing hours per month a good year ago. Another player in the open-source P2P streaming field is P2P Next, a European project funded with 14 million euros ($20.4 million) by the European Union. P2P Next demonstrated a streaming client dubbed SwarmPlayer in the summer of 2008 and has since been busy developing and testing a set-top-box implementation.

Companies like PPLIve and PPStream cater primarily to users in China as well as Chinese-speaking audiences worldwide, but P2P streaming apps have also always been popular with sports fans looking for their latest soccer or Olympics fix — a fact that was clearly not lost on the GoalBit makers, as is evidenced by the choice of name.