Internetworking of CDNs

The current deployment approach of the commercial Content Delivery Network (CDN) providers involves placing their Web server clusters in numerous geographical locations worldwide. However, the requirements for providing high quality service through global coverage might be an obstacle for new CDN providers, as well as affecting the commercial viability of existing ones. It is evident from the major consolidation of the CDN market, down to a handful of key players, which has occurred in recent years. Unfortunately, due to the proprietary nature, existing commercial CDN providers do not cooperate in delivering content to the end users in a scalable manner. In addition, content providers typically subscribe to one CDN provider and thus can not use multiple CDNs at the same time. Such a closed, noncooperative model results in disparate CDNs. Enabling coordinated and cooperative content delivery via internetworking among distinct CDNs could allow providers to rapidly “scale-out” to meet both flash crowds [2] and anticipated increases in demand, and remove the need for a given CDN to provision resources. CDN services are often priced out of reach for all but large enterprise customers. Further, commercial CDNs make specific commitments with their customers by signing Service Level Agreements (SLAs), which outline specific penalties if they fail to meet those commitments. Hence, if a particular CDN is unable to provide Quality of Service (QoS) to the end user requests, it may result in SLA violation and end up costing the CDN provider. Economies of scale, in terms of cost effectiveness and performance for both providers and end users, could be achieved by