PHOLD performance of conservative synchronization methods for distributed simulation in ns-3

The scalability and runtime performance of large-scale discrete event network simulations has been improved previously by spreading processing effort across multiple processors, increasing the provided computational power while decreasing the wallclock execution time of each simulation trial. The popular network simulator ns-3 provides two distributed frameworks that differ in their synchronization implementations. This paper provides those thresholds under which certain selection criteria would deem one synchronization option better than the other in terms of runtime performance. It specifically focuses on the performance of each synchronization method by stripping the model of simulated network topologies and overhead and purely utilizing the synchronization implementations and event scheduler of ns-3. Simulations have been performed across a variety of lookahead values, neighbor selections, and remote traffic percentages, and neighbor connectivity thresholds have been determined that suggest where it is more appropriate to use one option over the other.