Jim Huggins (jkhuggins) wrote,
Jim Huggins
jkhuggins

  • Mood:

What's the bandwidth of a carrier pigeon?

Some of you are familiar with Andrew Tanenbaum's famous quote: "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. " It's a favorite exercise to assign to students in a networking class.

The idea is as follows. Assume you've got a huge amount of data you want to send across town ... say, enough to fill a hundred magnetic tapes. (Ok, it's a really old idea ... stay with me here.) If you calculate the amount of time it takes to write all the data to tape, haul all the tapes outside to a pickup truck, drive across town, haul the tapes inside, and read all the data off the tapes, you have a measure of bandwidth: bits transferred per unit time. Now, compare that number with network speeds commonly available on wide area networks. Often, the results are surprising ... namely, that the pickup truck can beat most networks (at least, the networks available at the time). It's an interesting gedankenexperiment.

Well ... someone's updated it, for real this time. An office in South Africa was having severe problems with their ADSL line, so they decided to see if they could do any better. They got a carrier pigeon, stuck a 4GB data stick to its leg, then sent it to the office across town. By the time the carrier pigeon had finished its work, the ADSL network had only copied 4% of the same amount of data.

Guess it's time to clean up some of those notes ...

SA pigeon 'faster than broadband'(from BBC News)
Subscribe

  • An open letter to my colleagues in academia

    Dear colleagues, This week, I had three different students visit my office hours (or "student hours", as the trendy schools are calling them these…

  • Perseverance

    In sixth grade, I was a student in Mrs. Fitzpatrick's class at Harrison Elementary School in Inkster, MI. One day, substantially into the year, we…

  • I miss harmony.

    (Warning, long, self-indulgent, emo post. Read on at your own risk.) Several years ago, as my patient family will attest, I fell into a YouTube…

  • Post a new comment

    Error

    default userpic

    Your reply will be screened

    Your IP address will be recorded 

    When you submit the form an invisible reCAPTCHA check will be performed.
    You must follow the Privacy Policy and Google Terms of use.
  • 1 comment