Networking and the Internet

Derek Bridge

Department of Computer Science,
University College Cork

Networking and the Internet


Internets and the Internet

Types of Computer Network

We can classify by distances between devices:

Local Area Networks (LANs)
LANs connect together computers that are relatively close to each other, typically within the same room or building
Wide Area Networks (WANs)
WANs connect together devices or other networks over a greater distance than is practical for local area networking

LANs: Hosts and Switches

[Image of a LAN in which various hosts and a network printer are attached to a LAN switch.] Clip art from Microsoft Office Online

LANs: Ethernet

Wide Area Networks (WANs)

Before the (public) Internet, an organisation wanting to connect distant computers or LANs had three main options:

Networks of networks: internets

An internet is a network of networks, formed by connecting two or more distinct computer networks together

[Image of an internet.] Image of the Fujitsu GeoStream R980 router from HowStuffWorks

The Internet

More Internet terminology

The Internet

[Diagram of the Internet, showing backbones and various POPs.]

Who owns the Internet?

Who runs the Internet?

No one runs the Internet! But various organisations are involved in defining standards

[Organisational chart showing bodies that control Internet standards.] Organisational chart from The TCP/IP Guide

Who pays for the Internet?