In this video, we hook an oscilloscope up to an Ethernet link to see what's going on. Support me on Patreon: / beneater This video is part 4 of an intro to networking tutorial: • Networking tutorial
I'm telling you the future of an education is on RU-vid. All the best instructors, all the best explanations. Knowledge being liberated before our very eyes! Thanks Ben!
Yes..but still Internet is like Encyclopedia. Its a Summary of Knowledge , not knowledge itself. You still have to goto College and Universities to get mentorship of good professors. Yes Ben will be one of them.
@@nickharrison3748 Any thing that can be taught can be taught on the internet. The internet is the encoding and distribution of information, and information is knowledge. Sure, you have to learn “how to apply it” but that itself is instruction and discovery, all of which is aided by the encoding of information.
@@nbme-answers As long as you don't have gaps in knowledge up to the point in the topic what you are interested in - your statement is right, but as an example, you will be unable to calculate derivatives of function if you don't know basic math. So you still have to go to College or University, and when you do so - choose the best one and focus on learning, otherwise, you will become almost specialist of almost any topic without proper knowledge of any of them
@@andrisstuks595 There is no such thing as not having any gaps in knowledge. There are always gaps. Learning is the process of teaching yourself that gaps exist. As for learning calculus, start here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AuX7nPBqDts.html
@@nbme-answers I think he meant for "gaps" is at least have an introductory knowledge (prerequisite) about the topic or field you are interested in specially in this type of field or you will get lost
Just randomly searched for this, this was a great way to finally see the "physical layer". Great video, thanks. I need to see the whole series from the beginning now!
excellent man !! million years working on this and first time go to physical layer and see the signals ... incredable we are SO result-driven animales !! this make my day .. very happy to see details at board level (almost)
So fricken nice! I wish I was taught networking that way lol. This is definitely Networking from an EE Perspective going down another layer of abstraction that you never see when studying Computer Networking in CS.
A year ago when I started watching your videos, I skipped these because I thought it was some Networking turorial... like ...Network+. I thought that was odd, and since I already know that kind of networking, I ignored it. Now, I have built the 6502 computer with a PS2 keyboard, a BB with CRC encoding using logic ICs to xfer serial data to two Nanos, a simple adder, and other fun things from your channel. After doing the PS2, USB and CRC tutorials, I decided to watch these. So glad I did. This stuff is great!
That was excellent, I love your videos. Thank you for making them, but this one especially. I feel like people really get used to understand computers and software in an abstract way and forget that they're made up of really complicated electrical signals at the heart of it all.
Wow, thank you so much...spent a month trying to figure how to build a DIY wifi controlled power supply by implementing an old WiFi router and coding a simple browser interface for my phone - well I got stuck at trying to figure out how to program a circuit for variable power outputs I need via the WiFi router connected...or even better trying to figure out how to adapt router as a output settings memory device for the power supply circuit modifiable over the network. So I was trying to build an oscilloscope probe circuit, for the internet signal, to try to understand how to read and implement the internet signal for the live updates back and forth - I wasn't hoping to find a video that actually tells me precisely what to look for - wow...10 years of coding didn't thought me this - suddenly I understood how data is encoded into the electrical signal and thanks to your video I actually now understand how computing works wtf - brilliant!!
This series is truly amazing. I watched it forever ago and couldn't find it again and was afraid it was lost forever (to me). So glad I found it again. So many tutorials deal with crufty abstractions and networking never made sense until you told me what the wires/bits/frames/packets were actually doing. Many thanks!
This is really good. It makes for a good pratice example aswell for decode the signal. Really silly that most texts books i've read never really bring in some real life experiment to the theory, especially when you can do something really basic to make it more relative to a learner.
I have been tempted to get my oscilloscope hooked up to measure Ethernet speeds for some time. I'm glad you did it for me and I can just watch it here. My initial assumption was that when the transmitting end of the wire went high, the entire wire would be high before it changed to low, meaning that data didn't really travel down the wire, but more like the wire as a whole would reflect the current instantaneous state of the signal on it. But your scope shows it changes from high to low in only 50 nS. Assuming electricity (signal) traveling at .8c that would mean the signal would only travel 40 ft in 50 nanoSeconds. That means that a whole nibble (4-bits) can be on a 100 meter length of cable at once. That blows my mind! And that's only 10-baseT or 10mb speed. Imagine gigabit speeds and how many bytes are on the cable at once.
Your ability to read the decimal numbers after seeing their binary version for a split second left me speechless. I, for one, can't even add 22 + 41 (in decimal) without using my fingers like a first-grader.
BEN....you realize you're giving out all this info for free right? ....excellent content man....I work on ethernet controllers(as a profession) and I never knew this much knowledge goes into these and behind their working.
It's worth mentioning that the letter decoding works only because he knows (guessed) which bit is the first one of a byte. If he skip three first bits and start from there he'd get ")h" which could be a valid message.
Some HP, Agilent, Keysight analyzers are real nice because they'll do the conversion for you, so you'll see the signal on the screen and it will also show you the binary 1s and 0s. This is especially cool when demodulating more complex signals like QAM and OFDM.
Hi Ben, great work with your videos. Loved them. Can this Manchester coding be used between two systems to sync the clock between them? Say a master and a slave that are only communicating wirelessly? Thanks.
This is *gorgeous*. I have that awe-for-science feeling. The only thing I don’t understand is, how did you know where to start reading a byte? I’m guessing it’s part of the contrivance of the situation but I’m still curious how the situation was contrived. edit: haha it was the next video!
I have always wondered how this works. Thanks a million! Can you also say how it works for glass fiber? I suppose that's actually just on off of a laser, or something, right?
was searching for this video for long time. so voltage fluctuation is used to denote 0 n 1. i want to know about how 0 n 1 are denoted in all types of cable
Dear Sir, I have watched almost every of your videos. I kindly request you to build a series on internet connection on the custom hardware like the 8 bit computer or the 6502 computer. I am currently building a 32 bit computer with vga output and a usb keyboard, mouse input. I am also planing to build an OS for it. From your kind subscriber. Thank you for your kind support.
It's just the way he hooked up the wires to the oscilloscope. Think about it, if that is the side of the sender, then what does the receiver side get first? For example, let's say you want to send me a message in order, let's say the message is "hello". If you send that to me one letter at a time from your side you will send: h e l l o, but at my side what i get first is: o l l e h. I have to first flip the message, or flip the bits as he said, to get the correct message. The graph you see in the video is basically the "o l l e h" from my example, due to the way he hooked up the wiring. Were he to reverse the wires, he would get the correct message right away, just depends from what way you're looking.
@@shekharnandkoemarsing158 i think you're confused. packets aren't sent all at once. when i send the message "hello," i begin by sending "h," and you *instantly* receive this (for all intents and purposes), *then* i send "e," which you instantly receive. it's not like feeding a sheet of paper with text on it through a slot where the letters are revealed one at a time in reverse order, it's more like just talking to someone where each sound is continuously received by the other party in the correct order sorry if you figured this out already i'm mostly trying to make sure nobody else gets confused reading this also sorry for being so verbose im high rn oops
i can see how you could recover the clock frequency and most of the phase from any point in the signal, but i see two phases, 180 degrees apart, that are equally valid. one of those phases is invalidated when the bit values transition between 1 and 0, and it holds for half a cycle. but what if there was just a continuous stream of the same bit? how could it tell if it was a continuous stream of 1s or 0s?
also curious about byte boundaries! i would assume the line code is just responsible for transmitting a string of *bits*, and there's a higher-level coding scheme that aligns the bytes. but then you decoded the line code directly into bytes you sent down the wire, how's that work?
