Since the development of P2P networking during the late 90’s, P2P applications have multiplied because of its advantages. However, in today’s Internet, we need to mitigate the problem of IPV4 depletion Network Address. In order to solve the problems of P2P applications in NAT(Network Address Translator ) -based network is essential. For instance, the UDP hold punching . P2P applications will establish a lot of connections when it works, like file-sharing. It not only put a tremendous load on the CPU of every client but also burdens the NAT router. Our purpose is to design a software solution to solve it. In our design, we successfully raise the performance of NAT router in Linux environment i.e. form 45(Mbps) to 81(Mbps). And try to solve and analyze the problems of bursting connections on P2P file-sharing applications.