Learning Objectives

By the end of this chapter, you will be able to:

  • Describe the internet backbone.
  • Explain the role of an Internet Service Provider (ISP).
  • Identify TCP/IP as the core protocol of the internet.

The Internet Infrastructure

The internet is a global network of networks. Its infrastructure can be thought of in several layers.

  • The Backbone: At the highest level is the internet backbone, a network of very high-speed fiber-optic cables that span the globe, both overland and undersea. These backbone networks are owned and operated by a small number of large telecommunication companies.

  • Internet Service Providers (ISPs): ISPs are the companies that provide individuals and businesses with access to the internet. They connect to the backbone and then sell that access to their customers.

  • TCP/IP: The entire system is governed by the TCP/IP protocol suite, which provides the rules for how data is broken into packets, addressed, routed, and delivered reliably across the network.

Summary

The infrastructure of the internet is a hierarchical system. At the top is the high-speed fiber-optic backbone. ISPs connect to this backbone and provide access to end-users. The entire system is held together by the TCP/IP protocol, which ensures that data can be sent and received reliably between any two points on the global network.

Key Takeaways

  • The internet backbone is a global network of high-speed fiber-optic cables.
  • ISPs provide individuals and businesses with access to the internet.
  • TCP/IP is the fundamental protocol suite of the internet.

Discussion Questions

  1. Who owns the internet?
  2. What is the role of an ISP?
  3. Using an analogy, explain the relationship between the internet backbone, ISPs, and your home network.