Several major Internet service providers today also o↵er content distribution services. The emergence of such "network-CDNs" (NCDNs) is driven both by market forces as well as the cost of carrying ever-increasing volumes of tra c across their backbones. An NCDN has the flexibility to determine both where content is placed and how tra c is routed within the network. However NCDNs today continue to treat tra c engineering independently from content placement and request redirection decisions. In this paper, we investigate the interplay between content distribution strategies and tra c engineering and ask whether or how an NCDN should address these concerns in a joint manner. Our experimental analysis, based on traces from a large content distribution network and real ISP topologies, shows that realistic (i.e., history-based) joint optimization strategies o↵er little benefit (and often significantly underperform) compared to simple and "unplanned" strategies for routing and placement such as InverseCap and LRU. We also find that the simpler strategies su ce to achieve network cost and user-perceived latencies close to those of a joint-optimal strategy with future knowledge.
REF discusses the benefit of performing traffic engineering jointly with the content distribution strategy in a "network-CDN", but considers only history-based strategy.
Distributing content simplifies ISP traffic engineering
SIGMETRICS '13
Computer Science