Lecture 3: Protocols and Layering (Jan 27)

In this lecture, Dr. Gunes went further in depth on the topic of Protocols and Layering. A protocol was defined and described using the human conversation analogy. We compared and contrasted programs and processes. We talked about the server client relationship and how a server is a process running on a machine. Dr. Gunes spoke a lot about the OSI model and its importance in networked systems. We then went into depth of each of the 7 layers in the OSI model and talked about the Responsibilities and Issues corresponding to each layer. As a class we reached a fundamental understanding of how the headers of a packet are used to navigate each of the 7 layers. Particularly interesting to me was how the MAC address was used for low level routing. This was an extremely informative lecture that delivered a firm grasp of layering and protocol fundamentals.

Lecture 2: Introduction (Jan 25)

Today, Dr. Gunes made an introduction to Network Systems in this lecture. He gave the definition of "network". He explained and compared multi-access and point to point networks. Then, he talked about different types of networks(according to their sizes) which are Local Area Network (LAN), Wide Area Network (WAN) and Metropolitan Area Network (MAN). And, he compared these different types of networks according to their reliability and speed. Then, he went over the Internet. He talked about the components of the Internet. He showed the roughly hierarchical architecture of the Internet. He explained the differences between the Tier-1,2 and 3 ISPs. For example, a university network is Tier-3 type. Then, he talked about Internet service providers and Internet design goals and principles. An interesting thing was that there is no mention of security among the Internet design goals. Finally, he explained why we use layering, the advantages of layering and gave some layered system examples. For example, federal express is a good example of layered systems. In conclusion, I highly benefited from this lecture, since it was a good introduction to Network Systems.