Mininet : improving the reproducibility of networking research

In most research communities, the ability to reproduce research results is a key step in validating and accepting new research results. Ideally, all published papers should contain enough information to enable researchers to reproduce the results discussed in the paper. Reproducibility is relatively easy for theoretical or mathematically oriented papers. If the main contribution of the paper is a proof or a mathematical model, then the paper contains all the information about the results. If the paper is more experimental, then reproducibility of often a concern. There are many (sometimes valid) reasons that can explain why the results obtained by the paper are difficult to reproduce :

  • the paper contains measurement data that are proprietary. This argument is often used by researchers who have tested their new solution in a commercial network, datacenter or used measurement data such as packet traces whose publication could revela private information
  • the source code used for the paper is proprietary and cannot be released to other researchers. This argument is weaker, especially when researchers extend publicly available (and often open-source) software to perform their research. Although they have benefitted from the publicly available software, they do not release their modification to this software

During the Conext2012, Brandon Heller, Nikhil Handigol, Vimalkumar Jeyakumar, Bob Lantz and Nick McKeown have presented a container-based emulation technique called Mininet 2.0 that enables researchers to easily create reproducible experiments. The paper describes in details the extension that they have developed above the Linux kernel to be able to emulate efficiently a set of hosts interconnected by virtual links on a single Linux kernel. The performance that they obtained is impressive. More importantly, they explain how they were able to reproduce recent networking papers on top of Mininet. Instead of performing the experiments themselves, they used Mininet 2.0 for a seminar at Stanford University and 17 groups of students were able to reproduce various measurements by using one virtual machine on EC2.

Beyond proposing a new tool, they also propose a new way to submit papers. In the introduction, they note :

To demonstrate that network systems research can indeed be made repeatable, each result described in this paper can be repeated by running a single script on an Amazon EC2 [5] instance or on a physical server. Following Claerbout’s model, clicking on each figure in the PDF (when viewed electronically) links to instructions to replicate the experiment that generated the figure. We encourage you to put this paper to the test and replicate its results for yourself.

I sincerely hope that will see more directly reproducible experimental papers in the coming months and years in the main networking conferences.

Brandon Heller, Nikhil Handigol, Vimalkumar Jeyakumar, Bob Lantz, Nick McKeown, Reproducible Network Experiments using Container Based Emulation, Proc. Conext 2012, December 2012, Nice, France