The P2P (peer-to-peer) has been widely used in file sharing,online chatting,peer computing,etc.Network traffic generated by P2P applications makes up of a large portion of the overall Internet traffic,which brings significant operational costs to ISP(Internet Service Provider).Further,suboptimal peer selection or the bandwidth limitation of ISPs degrades the performance of P2P applications.P4P (Provider Portal for Applications) is a model aiming to incorporate P2P with ISP and improve the performance of both the ISP and the P2P applications.There are multiple interfaces for ISPs to communicate with P2P applications in P4P,the core of which is the P-distance interface.In this study,we analyze the relationship between the P-distance and the link traffic,and illustrate the disadvantage of P4P in dealing with network topology with bottleneck links.Further,with link utility function as the optimization objective,we propose an Improved-P4P model,making the traffic produced by P2P applications more homogeneous,which can reduce the peak link utilization and protect bottleneck links,and then improve both the network efficiency and the P2P performance.We have built a simulation platform based on BitTorrent and conducted extensive simulations.These simulations demonstrate that the Improved-P4P model achieves a lower cost for ISPs and a better performance for P2P applications than native P2P.Moreover,compared with P4P,the Improved-P4P model reduces traffic on bottleneck links and interdomain links without compromising on the performance of the P2P applications.We believe that relieving of pressure on bottleneck links hold great significance especially in extreme settings.Improved-P4P performs steadily in different topologies and swarm sizes,proving that it is scalable and easy to deploy.