December 14, 2013

Internet History, Technology, and Security

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A non-technical friend of mine expressed an interest in trying out the Internet History, Technology, and Security course on Coursera. I agreed to do the course with them as support. So I ended up studying this basic introduction to the Internet for 9 weeks at the same time as A Global History of Architecture.

Consisting of 4 weeks history, 3 weeks on the layer model of networking and 2 weeks on security, I didn’t learn much during this course. Admittedly, a Computer Science graduate with over twenty years experience (including university) is not the intended audience. It is for people with little or no technical background. The course acts as a relaxed and easy introduction to the Internet. Each week consists of under an hour of video lectures and a mini-test. There is a multiple choice exam at the end and peer assessed assignments for bonus marks.

The presenter could charitably be called an acquired taste. There is quite a bit of talking about himself. The highlights for me were the interviews with various people instrumental in building the Internet. These include a few of the lesser known innovators like Robert Metcalfe, Robert Cailliau and Van Jacobson. The history starts with Bletchley Park and Colossus, but then moves quickly onto early networks and the start of the Internet. The history stops once the network becomes a given after the beginnings of the web and Netscape (later transformed into Mozilla). The lecturer does a good job of describing in simple terms how the Internet stack works, without resorting to code. Instead of the 10 layer OSI model I learnt at university, a more understandable 4 layer stack is presented as: the Link layer (Ethernet); the Internet layer (IP); the Transport layer (TCP); and, the Application layer (web browsers, email, etc). While repetitive, the system is explained very well – packets become analogous to postcards, routers to train stations and port numbers to telephone extensions. The security lectures are more a users guide and reminder that a system can never be completely secure. There is also discussion on Public key cryptography and how it is used on the Internet.

I think the last word should belong to the friend who prompted my attendance on this course. They said “interesting but basic, I learnt enough to make it worthwhile. The lecturer was poor. I probably wouldn’t finish if you were not doing it with me.”


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