The advantage of peer-to-peer (P2P) paradigm relies on two main concepts: cooperation among users and resource sharing. There are many applications based on peer-to-peer paradigm, but the most popular one is the file sharing. We can classify the file sharing application into centralized systems, (having a central server), and decentralized systems. Another classification would be structured and unstructured systems, based on the way of managing the indexing information. In this paper, we have implemented a centralized peer-to-peer application for file sharing. Then we evaluated the performance of the system by means of simulation.