ABSTRACT
One defining feature of any P2P system is that the composition of the system is highly dynamic and time-varying in nature. In essence, peers join and leave the system at will. Such population dynamics is also sometimes highly unpredictable. A major consequence is that the network topology can change dramatically over time: some high bandwidth links might come and go, or turn into low bandwidth links without notice. Thus, the performance of the participating peers, in terms of downloading/uploading rates, might be adversely affected by the topology changes. To combat these performance degradations that are unavoidable in a practical P2P system, a topology control component is necessary.
