Case Studies in Computer Network Measurement

A network lies at the heart of many modern computer systems including most distributed and parallel systems. A good understanding of the behaviour and performance of the network is, therefore, a prerequisite for the understanding the behaviour and performance of many computer systems. Understanding network behaviour and performance is challenging because networks are among mankind´s largest and most complex creations and because most networks, including the Internet, are not designed with network measurement in mind. As a consequence, much network measurement relies on inference from data that does not directly describe the item of interest. Measurement also often requires a widely spread physical infrastructure, for example a network of monitoring machines. This is expensive both in terms of the hardware required and the resources needed to deploy and maintain the systems.