International audienceAs the size of today's grid computing platforms increases, the need for self-organization and dynamic reconfiguration becomes more and more important. In this context, the convergence of grid computing and peer-to-peer (P2P) computing seems natural. However, grid infrastructures are generally available as a hierarchical federation of SAN-based clusters interconnected by high-bandwidth WANs. In contrast, P2P systems usually run on the Internet, on top of random, generally flat network topologies. This difference may lead to the legitimate question of how adequate are the P2P communication mechanisms on hierarchical grid infrastructures. Answering this question is important, since it is essential to efficiently exploit t...