Quality of Experience Engineering for Customer Added Value Services: From Evaluation to Monitoring

7

User Driven Server Selection Algorithm for CDN Architecture

Said HOCEINI, Hai Anh TRAN and Abdelhamid MELLOUK.

7.1. Introduction

The end-to-end QoE model is efficient and indispensable in current network systems. It carries the user experience to guarantee the satisfaction of end users instead of focusing only on technical parameters as current Quality of Service (QoS) systems. In fact, as proven previously, satisfying the end user is the new trend of Internet development as well as emerging high quality applications. However, the end-to-end QoE model will be abstract if it is not applied to any real network architecture. In this chapter, we decide to apply this model to a Content Distribution Network (CDN) architecture, which has been introduced to improve the delivered service quality.

CDN [YIN 10] is considered as the user-centered solution in moving the content from the origin servers to the servers close to end users. This approach is used to improve the scalability of a network service due to the fact that it is able to provide services to a large number of clients with a reasonable service quality. Actually, the user requests are transferred to replica servers instead of being sent to the origin server. This helps the system to avoid congestion as well as overload issues at the core network and server side. In addition, this cache-related approach minimizes the delay time. Theoretically, CDN architecture has two main layers: the routing layer and the meta-routing layer. ...