Efficient content delivery schemes using in-network caching and request redirection

Abstract

Recently video content access and delivery become dominantly used over the Internet. Therefore innovative CDN architectures and technologies are quite essential to efficiently cache and distribute the surging amount of video content. In content delivery networks (CDNs), a CDN server is traditionally used to reduce traffic on the Internet backbone by offloading traffic requests from the origin server. However, sitting outside networks provided by Internet service providers (ISPs), the server cannot reduce traffic on the transit or peering links that connect the ISP network with the Internet backbone and other ISP networks. In order to minimize delivery latency and inter-ISP traffic, a lot of recent researches have addressed localized delivery of large content volumes from network edge by introducing storage module into network entities (e.g., content router). In other words, the content router can be allowed to provide the in-network caching and the localized delivery while keeping on supporting its basic features such as the packet forwarding and the routing. Therefore, from the viewpoint of the design of content routers, the optimal caching length should be carefully determined for minimizing the performance degradation of a router as a result of introducing the storage module to it. But the content router seems very unlikely to cache an entire content because of the limitations of content caching and content delivery capabilities. It however would be better to cache and deliver the prefix that is the beginning portion of content, if its length is short enough. In addition, the prefix caching has a number of advantages such as reduction of both delivery latency to clients and traffic volume over networks, particularly compared to threshold-based multicast scheme running on the centralized server. Therefore, both the bandwidth capacity and the cache size of content router should be carefully designed to evolve from overlay CDN system to novel CDN system, given...