FreeLab: A Free Experimentation Platform

As researchers, we are aware of how hard it is to obtain access to vantage points in the Internet. Experimentation platforms are useful tools, but they are also: 1) paid, either via a membership fee or by resource sharing, 2) unreliable, nodes come and go, 3) outdated, often still run on their original hardware and OS. While one could build yet-another platform with up-to-date and reliable hardware and software, it is hard to imagine one which is free. This is the goal of this paper: we set out to build FreeLab, a free experimentation platform which also aims to be reliable and up-to-date. The key idea behind FreeLab is that experiments run directly at its user machines, while traffic is relayed by free vantage points in the Internet (web and SOCKS proxies, and DNS resolvers). FreeLab is thus free of access by design and up-to-date as far as its users maintain their experimenting machines. Reliability is a key challenge due to the volatile nature of free resources, and the introduction of errors (path inflation, header manipulation, bandwidth shrinkage) caused by traffic relays.