Insight and Perspectives for Content Delivery Networks Valaki Fig. 1 (1/06) Figure 1 Cdn Content Distributor Cdn Content Delivery Network Overview

Under a CDN, the client-server communication is replaced by two communication flows: one between the client and the surrogate server, and another between the surrogate server and the origin server. This distinction into two communication flows reduces congestion (particularly over popular servers) and increases content distribution and availability. To maintain (worldwide) distributed copies of identical content, the practice for a CDN is to locate its surrogate servers within strategic data centers (relying on multiple network providers), over a globally distributed infrastructure. In this context, the most indicative advantages from using CDNs are: