In response to the complexity of communication networks, simulation was and remains the only way to evaluate network performance. Unfortunately, traditional simulation methods are not adapted to all networks such as networks with quality of service and networks with dynamic aspect. To overcome this limitation, a new method to simulate dynamic networks based on multi-agents simulation had been proposed. In this paper, we introduce a timely-constrained Agent-based Simulator for Real-Time Schedulers (ASRTS). Our Simulator not only provides the underlying software to build autonomous agents, but also it has the capability to express and enforce timing constraints on actions if the real-time schedulers decide to benefit from the flexible and responsive nature of agents in a multi-agent system.