1
Virtualization
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
Software Networks: Virtualization, SDN, 5G and Security, First Edition. Guy Pujolle.
© ISTE Ltd 2015. Published by ISTE Ltd and John Wiley & Sons, Inc.
www.it-ebooks.info
Virtualization
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
Software Networks: Virtualization, SDN, 5G and Security, First Edition. Guy Pujolle.
© ISTE Ltd 2015. Published by ISTE Ltd and John Wiley & Sons, Inc.
www.it-ebooks.info