This project is developing new simulation frameworks for the ns-3 discrete-event network simulator, a free and open-source research tool designed for use by computer communications network researchers. Simulation remains in heavy use for network research and education, because of its ease of use, reproducibility, availability, scalability, and ease of software development. However, the workflow of a typical simulation study requires the user's careful attention to a number of best practices in methodology to ensure that the results are credible and reproducible by third parties and that errors are not introduced. This project is building an automation framework for the ns-3 simulator that provides an environment that is more conducive to the creation of rigorous studies. The automation framework guides the user to produce valid network simulation models by composition and consistency checking, and definition of experimental settings. The framework exercises control over large-scale simulation studies, and applies statistical methods for output data analysis and execution control. The framework also collect details required to reproduce the experiment and report results. The framework also allows users to specify wide ranges of simulation network topologies, application traffic, and other parameters, allowing experiments to be conducted on a wide range of scenarios with minimal effort. Finally, maintaining the ns-3 software, documentation, and dissemination activities continue. The additions to ns-3, disseminated as open source software, are improving the methodology and credibility for future simulation-based network research.