An architecture for Content Distribution Internetworking

The purpose of this thesis is to discuss issues of design, implementation and evaluation of a protocols architecture that can effectively support the interoperation and cooperation of separately administered Content Delivery Networks (CDNs). In general, a CDN can be thought of as an infrastructure that provides scalable content delivery from content providers to content consumers: specifically, a CDN can increase the capacity of a web site by delivering content from caches which are located closer to the end users than the origin server. In order to enable a CDN to scale beyond its own administrative and physical borders, it can be interconnected to multiple, independently administered CDNs to form a federation of CDNs, termed Content Distribution Internetwork (CDI). A CDI allows every CDN in that CDI both to augment the number of potential content consumers and to get the content access faster, i.e. reducing the user response time. Although the CDI emerging technology has stimulated the interest of international standardization bodies such as the IETF, a standard architecture for CDIs has not been defined, yet. This thesis aims at contributing to the definition of one such standard architecture by (i) analysing solutions to problems of content distribution in CDIs and (ii) proposing and evaluating a specific protocols architecture for information exchange in CDIs.