Post

If you ever see something like "100 Mbps internet" and thought to yourself "100 megabytes per second" congratulations you have been hoodwinked It's actually 12.5 megabytes per second

One might ask, wait, isn't that confusing because both bits and bytes start with a b? Yes. YES IT IS. To distinguish, the world generally does MB/s to indicate MegaBytes per second, and Mbps to indicate MegaBits per second. Isn't that fun.

Yes hi hello, greetings from the world of networking! I realize your character stream is nice and all, but in the context of an actual conduit, they are utterly nonsensical. Signals travel in discrete segments, and here, symbol rate and bit rate and character rate are all different things.

When you’re the dude figuring out how to shove shit over the wire, or over the air, shit like 16-QAM signaling (3 bits per symbol), 8-into-14 encoding (a form of forward error correction), TPC, and a shit load of other line-level encoding techniques make the bit the only sensible increment,

because fractional bytes are not a reasonable increment of data. Sure, it does make some things *seem* annoying once you have the ~luxury~ of TCP to rely on. There’s a reason bit rates are only coin of the realm down at the interface level and below. But, uhhh…

Do yourself the great favor of taking a deep breath and appreciating all the layers of magic you get to abstract away and not think about, and spare a thought for the wizards operating down the stack to make a byte appear for you in the correct order.

Back when I started in the business, the computer industry didn't universally agree that 8 bits was a byte, much less that a word was a multiple of the character size. (And on the first computer I used, the bit rate was "how fast can you carry punch cards to the printer with the 48-letter charset.")

I never got to work with any of them, but what I’ve heard about pre-ASCII character sets was pretty wild! The intermediate hell post-ASCII but pre-Unicode wasn’t great, either. And we frequently just ignore the fact that ASCII characters are still seven bits, padded to eight!

Byte doesn’t mean 8 bits. Having used systems with non 8 bit bytes. Octet does mean 8 bits. A bigger issue is that not all protocols result in an octet per second. Some are even fractional bits per second. It’s more accurate to say bits per second. For one thing it avoids 1000 v 1024.