1. School of Computing and Communications (SCC), Lancaster University, Lancaster, U.K.
2. FORTH, Heraklion, Greece
3. Department of Informatics, Aristotle University of Thessaloniki (AUTH), Thessaloniki, Greece
4. Department of Computer Science, University College London (UCL), London, U.K.
5. Products and Research Department, DE-CIX, Frankfurt, Germany
6. AMS-IX, Amsterdam, XN, The Netherlands