Advanced Content Delivery, Streaming, and Cloud Services

Chapter 13Dynamic Reconfiguration for Adaptive Streaming

Norihiko Yoshida

Information Technology Center, Saitama University, Saitama, Japan

13.1 Introduction

When a website catches the attention of a large number of people, it gets an unexpected and overwhelming surge in traffic, usually causing network saturation and server malfunction, and consequently making the site temporarily unreachable. This is the flash crowd phenomenon on the Internet.

For a content delivery network (CDN) to be scalable in such dynamic situations, the CDN should be dynamically reconfigurable. The network would adaptively change its topology and volume according to the observed traffic load and pattern. For delivery and distribution of static contents such as texts and images, there have been a fair amount of studies and systems, some of which are already employed in industry. However, for delivery and distribution of streaming contents such as voices, music, and videos, further studies are still required and anticipated. The difficulty of a streaming CDN comes mostly from the continuity of the contents and the QoS (quality of service) requirement. A stream is delivered spending a certain period of time, meanwhile a load to the CDN would change. The CDN must adapt dynamically during the period by changing its network in the same way as static content delivery and distribution, and also by adjusting the QoS of the stream dynamically. One of the most promising solution to the issues is to divide a stream ...