Hierarchical content routing in large-scale multimedia content delivery network

Content Delivery Network (CDN) is an intermediate layer of infrastructure that helps to efficiently deliver the ever increasing multimedia content from content providers to a large community of geographically distributed clients. Content routing is an essential component of CDN architecture. In this paper we propose a hierarchical content routing architecture for large-scale CDN, in which CDN servers perform intracluster and inter-cluster content routing based on a two-level hierarchical overlay network. We analyze the routing overhead and the corresponding CDN performance of different intracluster content routing schemes. In particular, we propose a semi-hashing based scheme for intra-cluster content routing and a content-query based scheme for inter-cluster content routing. Through qualitative analysis and simulations we show that the semi-hashing based scheme is scalable (small routing overhead), efficient (high content sharing efficiency), and flexible (adjustable parameters).