Software Networks

1Virtualization

In this chapter, we introduce virtualization, which is at the root of the revolution in the networking world, as it involves constructing software networks to replace hardware networks.

Figure 1.1 illustrates the process of virtualization. We simply need to write a code which performs exactly the same function as the hardware component. With only a few exceptions, which we shall explore later on, all hardware machines can be transformed into software machines. The basic problem associated with virtualization is the significant reduction in performance. On average (though the reality is extremely diverse), virtualization reduces performance by a factor of 1000: that is, the resulting software, executed on the physical machine that has been virtualized, runs 1000 times more slowly. In order to recover from this loss of performance, we simply need to run the program on a machine that is 1000 times more powerful. This power is to be found in the datacenters hosted in Cloud environments that are under development in all corners of the globe.

It is not possible to virtualize a certain number of elements, such as an antenna or a sensor, since there is no piece of software capable of picking up electromagnetic signals or detecting temperature. Thus, we still need to keep hardware elements such as the metal wires and optical links, or the transmission/reception ports of a router and a switch. Nevertheless, all of the signal-processing operations can be virtualized perfectly ...