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Symbiotic Network Simulation and Emulation

A testbed capable of representing detailed operations of complex applications under diverse network conditions is invaluable for understanding the design and performance of new protocols and applications before their real deployment. We introduce a novel method that combines high-performance large-scale network simulation and high-fidelity network emulation, and thus enables real instances of network applications and protocols to run in real operating environments and be tested under simulated network settings. Using our approach, network simulation and emulation can form a symbiotic relationship, through which they are synchronized for an accurate representation of the network-scale traffic behavior. We introduce a model downscaling method along with an efficient queuing model and a traffic reproduction technique, which can significantly reduce the synchronization overhead and improve accuracy. We validate our approach with extensive experiments via simulation and with a real-system implementation. We also present a case study using our approach to evaluate a multipath data transport protocol.