Loosely-coordinated, distributed, packet-level simulation of large-scale networks

The complexity and dynamics of the Internet is driving the demand for scalable and efficient network simulation. In this paper, we describe a novel approach that partitions the networks into domains and simulation time into intervals. Each domain is simulated independently of and concurrently with the others with only local domain information over the same simulated time interval. At the end of each interval, global routing information, packet delays and drop rates for each inter-domain flow are exchanged between domain simulators. When the exchanged information converges to the value within a prescribed precision all simulators progress to the next simulated time interval. This approach allows the parallelization with infrequent synchronization, and achieves significant simulation speedups. Such a solution supports simulations of large-scale networks on distributed machines with modest memory size.