383ONLINE NETWORK SIMULATION REALISTIC LARGE-SCALE ONLINE NETWORK SIMULATION

Large-scale network simulation is an important technique for studying the dynamic behavior of networks, network protocols, and emerging classes of distributed applications (e.g. Grid, peer-to-peer, etc.) Large scale and realism are two critical requirements for network simulations of Grid appli-cation studies. Our work here extends previous efforts in three key ways. First, we study networks 100 times larger than in our previous studies (20000 routers). Second, at this scale, we study realistic network structures (100 ASs, BGP4 and OSPF routing) versus flat OSPF routing. Finally, we describe and evaluate a new profile-based load-balancing approach called hierarchical profile-based load balance. Our extensive large-scale experiments with profile-based load balance (PROF) on flat-routed (OSPF) networks sho