A Hal Pomeranz from 2010 suggests a great way to teach TCP/IP header structure to students: he builds header diagrams out of legos, then mixes them up and has the students reconstruct them.
The use of color here really highlights certain portions of the packet header. For example, the source and destination addresses and ports really jump out. But there are some other, more subtle color patterns that I worked in here. For example, if you look closely you’ll see that I matched the color of the ACK bit with the blue in the ACK number field. Similarly the colors of the SYN bit and the sequence number match, as do the URG bit and urgent pointer field.
Actually I wish I had a couple of more colors available. Yes, Lego comes in dozens of colors these days, but they only make 2×8 blocks (aka one “Lego Byte”) in six colors: White, Black, Red, Yellow, Blue, and Beige.
So while I tried to use Beige exclusively for size fields, Red for reserved bits, Yellow for checksums, and so on, I ultimately ended up having to use these colors for other fields as well– for example, the yellow sequence number fields in the TCP header. Maybe I should have just bought a bunch of “nibbles” (2×4 blocks) in other colors and not been so choosy about using full “Lego Bytes”.
Since 2010, the lego patent has expired and cheapish wire-extrusion 3D printing has become a reality -- and there's cool procedural models for generating arbitrary-sized bricks and labelling them with arbitrary type. Someone needs to make a printable TCP diagramming set on Thingiverse!
Practical, Visual, Three-Dimensional Pedagogy for Internet Protocol Packet Header Control Fields
(via Hacker News)
Karl Schroeder (previously) is literally the most visionary person I know (and I've known him since 1986!): he was the first person to every mention "fractals" to me, then "the internet" and then "the web" -- there is no one, no one in my circle more ahead of more curves, and it shows in his […]
Veteran reviewer/interviewer Rick Kleffel (previously) has just posted a long podcast interview (MP3) with Neal Stephenson, discussing his latest novel, Fall; or, Dodge in Hell ("a science fiction novel with a fantasy novel stuck inside of it").
A couple of weeks ago, I was thrilled to hear Subgenius founder, the Reverend Ivan Stang, interviewed on the Comedy on Vinyl podcast (previously) and to discover that the Church of the Subgenius was selling a $35 Salvation/Membership/Ordainment kit that was chock full of goodies.
Even if you feel like AirPods are worth the price tag, you’ve got to admit there’s a certain anxiety that comes with using them. What if I lose them? What if they get wet in the rain? Or drenched in sweat? Or fall into the drink you dropped them into? Shiny tech is great, but […]
With the quick-fix appeal of video games and their own cell phones, it can be tough to keep kids focused on supposedly “educational” toys. And while it may seem counter-intuitive to fight tech with more tech, we’re all in when it comes to the Toybox 3D Printer. We’re not sure if anyone had envisioned a […]
Whether you’re an artist, designer or just organizing a photo album, photo editing software is a must. And software designers know it: Platforms like Photoshop and Lightroom have a ton of helpful features, but you’ll pay for them in spades. Luckily, there’s some competition in the photo editing arena. Right now, Skylum’s Luminar software is […]