Optimum caching strategies for a telco CDN

Abstract

In order to cope with the rapidly increasing video traffic (both downloaded and streamed) resulting from Internet TV, a telecommunications company (telco) can deploy a network of caches, which sit closer to the user than the point-of-presence of a traditional content distribution network (CDN), like Akamai or Limelight Networks. This network of highly distributed caches, often referred to as a telco CDN, is a network enabler that saves a huge amount of traffic on the links toward the Internet by handling user requests locally without having to retrieve data from the origin server. Because for Internet TV the set of available content is huge and rapidly evolving, the choice of the caching algorithm and cache collaboration strategy can have a considerable impact on the reduction in traffic. The caching algorithm decides which objects to cache, and the cache collaboration strategy, at times in combination with preloading, determines how cacheable items are propagated throughout the telco CDN. In this paper we determine the best combination of a caching algorithm and a cache collaboration strategy for a telco CDN.