Internet Architectures

In order to explain how the Internet works, this chapter takes a closer look at the architecture that underlies the Internet, as well as at its architectural principles and mechanisms. After providing a brief overview of the Internet’s history, this chapter examines today’s core infrastructure and explains the role of Internet service providers (ISPs). In addition, the essential mechanisms enabling Internet communication are explained, namely the Internet Protocol (IP) suite, IP addresses, the domain name system (DNS), as well as IP packet routing and forwarding. This chapter also explains how large content providers, like Google, Amazon, and Netflix, provide Internet users all over the world with efficient and reliable services by utilizing specialized content delivery networks. The description of four emerging architectural concepts that extend the established Internet architecture with more efficient and/or effective ways of providing innovative Internet services (i.e., software-defined networking, network function virtualization, overlay networks, and information-centric networking) conclude this chapter.