One of the most compelling features of P2P architectures is their self-scalability. For example, in a P2P file-sharing application, although each peer generates workload by requesting files, each peer also adds service capacity to the system by distributing files to other peers. P2P architectures are also cost effective, since they normally don’t require significant server infrastructure and server bandwidth (in contrast with clients-server designs with datacenters). However, future P2P applications face three major challenges: