Emu: rapid prototyping of networking services by Sultana, N, Galea, S, Greaves, D, Wójcik, M, Shipton, J, Clegg, RC, Mai, L, Bressana, P, Soulé, R, Mortier, R, Costa, P, Pietzuch, P, Crowcroft, J, Moore, AW, Zilberman, N