Complex Interactions in the Content Distribution Ecosystem and Quality-of-Experience: A White Paper for Internet QoE Workshop

Since their advent in the early 90s, web applications and services have evolved from the simple clientserver model, where content (e.g., a file) is delivered point-to-point from a single web server to a single client, to a vast and complex system consisting of numerous servers (some located close to users and others in large back-end data centers), network elements, and software components owned and controlled by a variety of entities such as content providers (CPs), content distribution networks (CDNs), and Internet Service Providers (ISPs). These three entities along with the users that they serve form the content distribution ecosystem. The content distribution ecosystem is a dominant force driving the evolution of the Internet as CDNs carry most of the world’s web pages, videos, social networks, software downloads, e-commerce sites, software-as-a-service (SaaS) portals, and other web applications. Each entity in the ecosystem has its own business interest, and attempts to optimize the performance of its components more often individually, but sometimes in cooperation with others. Online video streaming services in particular heighten the importance of understanding the complex interactions present in content distribution, where content providers often employ multiple CDNs to stream videos to a large number of geographically dispersed users. The enormous burden that video traffic places on the Internet infrastructure [8] creates tensions, but also opportunities. Interactions, whether competitive or cooperative, among content providers, CDNs and ISPs are inevitable, and will likely evolve rapidly and become far more complex. For example, they have fostered several important trends, e.g., increasing cooperation among ISPs and CDNs that are variously called Network CDNs, Telco-CDNs, Carrier CDNs, or Managed CDNs, while at the same time content providers compete to attract more users via (specialized) streaming apps or devices (e.g., chromecast) on the end systems. The complex interactions among various entities in today’s large-scale content distribution ecosystem makes it a challenging task to ensure high quality-of-experience (QoE) for end users. This is in spite that providing a high quality of QoE for their users is also a key goal for any content or application service provider including online video streaming service providers such as NetFlix, web search services such as Google and Microsoft Bing, social network service providers such as Facebook, and so forth. This is because these service providers rely on either online ads, user subscriptions, or pay-perview/pay-per-click for their revenues. All three monetization models depend on engaging the user by enticing them to watch more videos, conducting more searches or staying on social networking sites longer, and to come back to their website more often.