Tag Archives: networking

Linksys BEFW11S4 Wireless-B Broadband Router Problems – Low Reliability and Poor Fault Tolerance

Background

Linksys BEFW11S4 Wireless-B Broadband Router

A few months ago I had to setup a home office and decided I would take the opportunity to upgrade my home network. My Linksys BEFSR41 Etherfast Cable / DSL Router had never given me any problems and so I decided to upgrade to the Linksys BEFW11S4 Wireless-B broadband Router. I now have everything working reliably but getting to this happy state and resolving the problems took a lot of luck and in the end the solution was far from obvious. Judging by the bad reviews on Amazon and elsewhere it appears that many people have been unable to fix similar problems with this device. Below is my description of the problem and a solution that worked for me. Hopefully this will help others, but as always, your mileage may vary!

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Economics and the Internet’s Large-Scale Topology

Distribution of the Internet around the world. (Top) Worldwide router density map obtained using NetGeo tool to identify the geographical location of 228,265 routers mapped out by the extensive router level mapping effort of Govindan and Tangmunarunkit. (Bottom) Population density map based on the CIESIN’s population data. Both maps are shown using a box resolution of 1 degree by 1 degree. The bar next to each map gives the range of values encoded by the color code, indicating that the highest population density within this resolution is of the order 10**7 people/box, while the highest router density is of the order of 10**4 routers/box. Note that while in economically developed nations there are visibly strong correlations between population and router density, in the rest of the world Internet access is sparse, limited to urban areas characterized by population density peaks.

This graph and the explanation above are taken from Modeling the Internet’s Large-Scale Topology by Soon-Hyung Yook, Hawoong Jeong, Albert-Laszlo Barabasi. Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA.

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Posted in Complexity, Globalization, Technology | Tagged , , , , | 1 Comment

The Eight Fallacies of Distributed Computing

L. Peter Deutsch first published the “8 Fallacies of Networking” internally while working at Sun Labs in 1991-92. This is a great list of the kind of wishful thinking that clouds so much system design.

Essentially everyone, when they first build a distributed application, makes the following eight assumptions. All prove to be false in the long run and all cause big trouble and painful learning experiences.

  1. The network is reliable
  2. Latency is zero
  3. Bandwidth is infinite
  4. The network is secure
  5. Topology doesn’t change
  6. There is one administrator
  7. Transport cost is zero
  8. The network is homogeneous
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Internet Cartography – Maps of the World Wide Web and other Cyber Geography

In the Beginning there was one….

This is the first map of The Internet. It shows the first node on the ARPANET at the University California Los Angeles (UCLA) on the 2nd September 1969. The diagram is taken from
Casting the Net: From ARPANET to INTERNET and beyond by Peter H. Salus and was drawn by Alex McKinzie who worked for BBN. Any Travelog needs maps. For a good catalog of Internet cartography checkout The Atlas of Cyberspaces

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