Over the last years, the Internet has evolved towards becoming the dominant platform for deployment of new services and applications such as real time and multimedia services, application-level multicast communication and large-scale data sharing. A consequence of this evolution is that features like robust routing, efficient search, scalability, decentralization, fault tolerance, trust and authentication have become of paramount importance. We consider in our paper the specific case of structured peer-to-peer (P2P) overlay networks with a particular focus on Content-Addressable Networks (CANs). An investigation of the existing approaches for structured P2P overlay networks is provided, where we point out their advantages and drawbacks. The essentials of CAN architecture are presented and based on that, we report on the implementation of a CAN simulator. Our initial goal is to use the simulator for investigating the performance of the CAN with focus on the routing algorithm. Preliminary results obtained in our experiments are reported as well.