1. A distributed simulation system comprising a plurality of nodes, wherein each node of the plurality of nodes is configured to simulate a different portion of a system under test using a simulator program configured to perform a simulation as a series of timesteps, and wherein each timestep includes at least a first phase and a second phase, and wherein each node of the plurality of nodes is configured not to cause the simulator program to evaluate a model of the different portion of the system under test during the first phase even if one or more commands are received by that node during the first phase, and wherein each node of the plurality of nodes is configured to cause the simulator program to evaluate the model during the second phase in response to receiving a command including one or more signal values for signals of the model.