20 January, 2014.

“This Application Level Protocol is Used by Every Other Internet Application. If You Think I am Refering to the Web or HTTP, You Would Be Wrong.”

In this lecture, I will cover three topics on the application layer. First, I will explain networked applications and their interface to the transport layer. Second, I will describe an example protocol that lives in the application layer, HTTP. Third, I will talk about DNS, a directory service used by networked applications.

Reading: Chapter 2 of KR.

• 2.1 Principles of Network Applications
• 2.2 The Web and HTTP
• 2.5 DNS — The Internet’s Directory Service

Slides: PDF

January 13, 2014.

“The Complexity Involved in Engineering the Internet Will Make Your Head Explode, but This One Incredibly Simple Trick Keeps the Complexity Manageable.”

In this first lecture, I will give a brief introduction to the module and introduce many basic concepts, including: host, protocol, packet, packet switching, circuit switching, store-and-forward, delay, throughput, bottleneck link, packet loss, traceroute, and the five layers of the Internet.

Please read the following for a high-level introduction to computer networks and the Internet. We will revisit many of the concepts again in future lectures. Reading:
Chapter 1 of KR.

• 1.1 What is the Internet?
• 1.2 The Network Edge
• 1.3 The Network Core
• 1.4 Delay, Loss, and Throughput (except 1.4.2)
• 1.5 Protocol Layers and Their Service Models

Slides:PDF