A Modelled Study of Content Delivery Networks

Delivery Networks (CDNs) appeared at late 90´s as a means of reducing response time experienced by Internet users by distributedly placing multiple servers, called surrogates, in the client network neighbourhood. Many companies have deployed their own propietary CDN hiding implementational aspects, which guides to a lack of a general open model that describes CDN behaviour from an analytical perspective. This article proposes a general expression for a CDN considering certain design parameters, such as caching hit rate, delay and number of clients and surrogates.