The Economics of CDNs and Their Impact on Service Fairness

Content delivery networks (CDNs) have become key telecommunication actors. They contribute to improve significantly the quality of services delivering content to end users. However, their impact on the ecosystem raises concerns about their "fairness," and therefore the question of their inclusion in the neutrality debates, becomes relevant. This paper aims at analyzing the impact of a revenue-maximizing CDN on some other major actors, namely, the end-users, the network operators, and the content providers, at comparing the outcome with that of a fair behavior, and at providing tools to investigate whether some regulation should be introduced. We present a mathematical model and show that there exists a unique optimal revenue-maximizing policy for a CDN actor, in terms of dimensioning and allocation of its storage capacity, and depending on parameters such as prices for service/transport/storage. Numerical experiments are then performed with both synthetic data and real traces obtained from a major video-on-demand provider. In addition, using the real traces, we compare the revenue-based policy with policies based on several fairness criteria.