Peer-to-Peer Content Delivery

This chapter provides an overview of peer-to-peer content delivery. P2P technologies offer a new approach to content delivery networks that combines improved system scalability with low implementation cost. P2P content delivery is thus, an important technique for commercial systems, such as IPTV. This chapter highlights the design issues of P2P content delivery networks, including topology, delivery path selection, push versus pull, and control strategy for content flow. In addition, various approaches for content caching are discussed and some example systems are used to illustrate the approaches. The chapter concludes with a discussion of hybrid P2P-CDN designs. Classification of P2P content delivery schemes, topology constraints, categories of data topology and delivery path, P2P caching, and so on is reviewed. Caching is a well-known strategy in many networked applications. It provides the capability to reduce origin server load and bandwidth requirement, reduce network bandwidth usage, and reduce client-side latency that leads to improved scalability and performance with lower cost.