Lecture 2: Internet overview

In the previous lecture, we discussed the five-layer model of networking. In this lecture, we will discuss four topics. First, we’ll look at the original goals for the Internet when it was first designed. This is useful because it’ll help us understand why the Internet is the way it is. Second, we’ll look at two approaches to building networks: packet and circuit switching. We’ll explain why the Internet picked packet switching given its goals. Third, we’ll look at the five layers in a bit more detail and understand where (host or router) each layer is implemented in the Internet, again given the goals of the Internet. Fourth, we’ll conclude by discussing how we measure the Internet’s performance.