A case for virtualization of content delivery networks

Abstract

Content Delivery Networks have gained a popular role among application service providers (ASPs) and infrastructural companies. A CDN is an overlay network that gives more control of asset delivery by strategically placing servers closer to the end-user, reducing response time and network congestion. Many strategies have been proposed to deal with aspects inherent to the CDN distribution model. Though mostly very effective, a traditional CDN approach of statically positioned elements often fails to meet quality of experience (QoE) requirements when network conditions suddenly change. In this paper, we introduce the idea of CDN virtualization. The goal is to allow programmatically modification in CDN infrastructure designed for video distribution, adapting it to new operating conditions. We developed a complete simulator focused on CDN overlay network characteristics where we implemented several approaches for each of the CDN elements. Our results show a decrease of 20% in startup delay and network usage.