Diary for herman
Older diary entries for herman (starting at number 28):
4 Dec 2002 (updated 4 Dec 2002) »Links for MAC Lecture
Since I'm describing CSMA/CD today, here are some relevant links.
- The ideas of Aloha aren't just historically interesting. There is even a company trying to put these ideas into practice using satellites.
- Ethernet continues to evolve, and support higher bitrates. This is perhaps the best page about Ethernet.
- Wireless Ethernet? Sorry, there isn't a wireless Ethernet (being as it is CSMA/CD and wireless LANs typically don't have CD). But the 802.11 suite of protocols adapt Ethernet ideas to the wireless domain. These 802.11 networks are proliferating rapidly (consider, for instance, the franchise business of boingo or cafe), becoming interconnected, and even threaten to take over much traditional ISP business. This is an area where keeping up with the buzzwords is a full-time job.
1 Dec 2002 »Second Exam Graded
Now students can concentrate on their projects and not worry about another exam. There will be another homework, but the main thing now is to finish up projects.
20 Nov 2002 »Related Links
Related to today's lecture.
- dynamic DNS services
- Network Address Translation (under Linux)
14 Nov 2002 »Other Sources
From time to time, I surf the Web looking for other material that might connect to the textbook. Now that we're looking at the network layer, I looked in How Stuff Works for information on routers, network address translation, and other stuff. It's a mixed bag. On one hand, there's a good deal of very specific information with examples and pointers to references; on the other hand, some topics are only superficially mentioned. The Ads are annoying.
13 Nov 2002 »Inspiration
Here are three links for inspirational material about networks.
- Clay Shirky's Internet Writings describe, at a high level, what network does to our society and also the converse influences of societal trends on the business of networking.
- Frankston, Reed, Bricklin and others is less well written, but more topical and political.
- George Gilder's Telecosm is an almost poetic description of the dream of the Internet written in the height of the Internet bubble. Reading this explains much of the folly of exaggerated expectations.
13 Nov 2002 »Joel's Take on Abstractions
For its references to TCP, IP, ASP.NET, and so on, I recommend reading The Law of Leaky Abstractions.
12 Nov 2002 »Networking Problems
My workstation (and the course web site) had some networking problems today. The problem with the course web site was easy to fix: the power was off while the computer guys were recabling. But my own machine failed in mysterious ways, showing extremely slow networking. Eventually I tracked it down (after many hours of trying different theories) to damaged software modules. Of course I had a backup, and restoring a library appears to have fixed the problem. I really did use the standard set of tools that I describe in class (ping, netstat, etc) to help me solve the problem.
4 Nov 2002 »Blog Defined
William Safire--columnist for the Sunday New York Times Magazine--explains blogging and defines the word ``blog":``Blog is a shortening of Web log. It is a Web site belonging to some average but opinionated Joe or Josie who keeps what used to be called a ''commonplace book'' -- a collection of clippings, musings and other things like journal entries that strike one's fancy or titillate one's curiosity. What makes this online daybook different from the commonplace book is that this form of personal noodling or diary-writing is on the Internet, with links that take the reader around the world in pursuit of more about a topic.''
4 Nov 2002 »Chat and Instant Messaging
I see that IETF has a proposal for instant messaging. Lookup XMPP and Jabber via search engines (I had to use a cached copy from Google, as important pages must have recently moved).
31 Oct 2002 »Maintenance
I'm devoting a little time to getting the lab machines in B1C ready for projects - if any have advanced to the point to doing testing in the lab. Actually, quite a bit of useful things are available now, if one knows how to use them. For instance, you can use tcpdump and sniff packets, which is useful for low-level debugging. Intrusion detection sometimes works at this low level. Also, I have installed NS, the network simulator, on several machines.
But the harder part is to install hardware needed by projects. Some students will need to test multimedia, meaning that at least soundboards are required. None of the machines have soundboards now, but it's not a big deal to get sound cards. Typically they can be had for $15 or less for a basic model. The only difficulty is to find one that will work well with Linux (some of them don't). So I'm researching sound cards today.
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