Ethernet (50th Birthday) - Computerphile
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- เผยแพร่เมื่อ 30 พ.ค. 2023
- "Ethernet" was named because the inventor believed that the standard could transcend different types of media & 50 yrs on, we still use it! Dr Steve Bagley explains and demos the idea
/ computerphile
/ computer_phile
This video was filmed and edited by Sean Riley.
Computer Science at the University of Nottingham: bit.ly/nottscomputer
Computerphile is a sister project to Brady Haran's Numberphile. More at www.bradyharan.com
Bit sad how he didn't mention that once a collision is detected, all sending machines "scream" for a short amount of time to announce to everyone that a collision just occurred and retransmission would be attempted shortly
That's pretty cool 😮
Haha I was worried he wouldn't mention that that type of connection was called a vampire tap.
iirc, each host has its own random wait before screaming, right? Or maybe I'm thinking of a different collision-handling strategy or something else altogether. In any case, thanks for bringing it up 😂
@@kphaxx nah, as soon as they detect the collision they start screaming a.k.a. broadcasting a jamming signal across the wire which is intended to disrupt all current transmissions and cause crc errors for all who receive them, making them discard the package as invalid.
Ever since pretty much all networks are full-duplex, fully switched, there's been no real need for csma/cd anymore 🥲
@@kphaxx correct. Each machine had a unique, effectively random MAC address, and so they'd each wait a unique period before a retransmit. This wouldn't be enough for some colliders, so they'd be honor-bound to exponentially increase their pause delays before re-trying. 10BASE2 was a trip. Then the 3com and Novell/Anthem ISA Ethernet cards came out cheap. You could plug a fiber MAU adapter dingus (Allied TeleSyn) and go between buildings without electrocuting everything.
’course once chatty stuff like Appletalk started filling the segment with chatter from everyone, it would be hard to get 5Mb throughput. Mercifully Kalpana invented the cheap (🤣) switch and things got way easier to wire up. I still loved having 4 friends bring over PCs for a lan party in the coax days 😹
The bit of expert improv at 5:50 that both Sean and Steve immediately picked up on was *chef's kiss*
Or just done in editing :)
@@Dima-ht4rb the guy on camera halts for half a second when camera guy starts speaking before he realises, so no its not editing
I worked with Sailesh Rao, the inventor of 1000 Base-T (802.3ab-1999) at Intel (and Level One) - every time I plug an Ethernet cable into a router. I remember him scribbling "the architecture of 4D-PAM5 encoding, with 4 lines each transferring 250 Mb/s" on a white board and saying, "give me the BER for this on CAT-5 - maybe use Matlab!"
Fascinating
Steve's struggle with the sticker at 8:47 and Sean's strategic zoom-in was both clever and unintentionally hilarious
Ethernet won out because the standard was free to use, and also did not need you to pay a license fee per card, unlike some of the competitors, like Token Ring, where you had to pay IBM for it, and Arcnet did not scale as well, even though it did use a very much cheaper cable, but in the end Ethernet would run on the same cables, and being low cost the cards got cheap fast, and of course got used a lot, so the peripherals grew fast, and the cost kept dropping. Still have the crimp tooling for Arcnet, which came in really handy doing CCTV work, as the connectors are almost completely compatible in most cases.
There's an irritating meme that 'the worst standards win out'. Actually the most open standards win out. Now the initial version may lack some features compared to the more expensive proprietary alternative but later versions catch up and surpass that alternative pretty quickly. See for example USB vs Firewire and ISA/EISA vs MCA. Though admittedly with EISA was quickly replaced with PCI. Still PCI and USB have always been royalty free whereas Firewire and MCA both needed a license fee to implement. The latest versions of USB and PCI Express are still in use and massively outperform the last versions of Firewire and MCA, both of which have more or less disappeared.
You can see this possibly happening again with RISC-V which is royalty free vs ARM (paid license) and x64(dual source but almost impossible for anyone else to license). If RISC-V lacks anything important it will just get added.
The PC industry basically runs on royalty free standards and because everyone uses them any limitations tend to get worked around.
Same for AppleTalk was using vert cheap câbles (some adaptées run on téléphones câbles)
But it wasn't open AT all (a IBM PC edition exists but was less common) and it didn't scale well (32 machine whithout resorting to hacks)
It would be amazing to make a video describing the CAN network used in modern vehicles and industrial automation. The csma/cd and bus arbitration techniques are simple and elegant, and the protocol is a superb illustration of how multi-drop networks can be implemented in embedded systems for sending and control.
As someone interested in CAN for 3D printing, I really want this, it's like wizardry
@@mizz1414 I used CAN in advanced medical systems, and it was superb!
@@mizz1414 As you say, 3D printers are starting to use CAN. Hobby grade radio controlled aircraft are also using CAN. I have a flight controller which communicates with the GPS and the airspeed sensor using CAN.
I have a general idea how CAN works but I'd also like to see a Computerphile video on the topic.
EtherCAT is interesting .used in industry like for robots, CNC and such. uses the same cables but different protocol. like RTOS but for network
Thank heavens they didn’t stick to the DIX name.
The recent CHM panel video is truly excellent.
Yes, vampire taps weren’t friendly and often resulted in a trip to find bandages. AUI connectors we’re still used quite a bit into the mid, and even late, 90’s, especially on what we now call MDF switches.
Also, promiscuous mode is a modern concept, switches didn’t exist originally, only hubs and bridges. You could see everything, everywhere from anywhere.
And of course, 10-BASE-T, full-duplex with separate TX/RX pairs into switches (instead of hubs) ultimately all but eliminated collisions.
I got a job as a researcher in one of my university's tech labs in 1997, and it was just the time when thick ethernet (10base5) was over and everybody was laying thin ethernet cables (10base2) through every PC, with the T-adapters and terminating resistors :) And then of course after some time we changed to 10baseT and it was at first somewhat puzzling having to have a separate cable for each PC. At first it was to hubs (sort of dummy repeaters) but later switches started to became the norm. Ahh the nostalgia!
Anyone still laying 10base2 in 1997 shouldn't have been employed long enough to change it to twisted pair. 10/100baseT was the common new installation format by then.
Back in the spring of 1997, I was working on a contract job to convert the Ontario government offices from 10base2 to 10baseT.
Around 1990 or 1991, shortly after I started at the phone company, we installed cabling for a new insurance company building. We ran a 25 pair and a thinnet to each desk.
Great video. As a networking nerd I work with Ethernet all the time and it’s simplicity and yet it’s ingenuity always surprises me.
I have a memory of reading a Usenet post where one of the original ethernet designers said if he could change one thing in 10base5 it would be the slide lock connectors on the drop cables. That made me smile, we had lots of hassles with them.
Xerox PARC came up with some of the best tech innovations of all time, Ethernet is high up there.
Really wanna work at a PARC or Bell Labs. There's no meaningfully-sized pool of jobs at a similar monopoly-sponsored R&D facility that I'm aware of in the US today.
How many of those innovations have been ascribed to Apple since? :P
@@Robstafarian None?
@@weksauce I can think of two, the mouse and the desktop-metaphor GUI, which have been ascribed to Apple countless times.
@@Robstafarian Hmmm, I've only ever heard that Jobs went to PARC and incorporated some of the underlying things into Apple, never that Apple invented them. Who is doing this innumerable (and wrong) ascription?
Bus networks really take me back, I remember in my first year at senior school having an IT room full of Acorn Archimedes and if we all logged on at the same time it would seriously slow down and eventually would crash the whole network! I think we were using Acorn proprietary cables though instead of ethernet and it was running on Acorn's EcoNet standard.
The resiliency of modern ethernet is impressive. It'll run even without all wires connected. At a certain point i was running it on some weird 6 wire intercom or phone cable that i have no idea of, how it ended up on my PC.
It did explain why i wasn't getting the usual speed.
Another interesting occurance was when i suffered from a lot of radio interference. Took me until i noticed my ethernet connection was running at 10mbit that i re-inserted the plug, and the interference was gone. Evidently again not all of the contacts of the plug made good contact, making it a non-paired cable, radiating tons of RF hash.
Aside from those freak issues, wired ethernet has been that old, rock solid technology that just works all the time. Only thing that sucks is trying to make your own cables with low budget tools.
Actually only 2 pairs out of 4 are needed for 100 Mbps Ethernet.
That cybersecurity lab environment looks like a lot of fun. A designated "red" and "blue" sides with a retractable padded wall to keep the teams apart during labs.
I just love it at around 03:30 ... they have images of the BBC machine (sans monitor) connected to each other!
Even today, I'm still using scrapped 30+ year old 10BASE2 networking cables (with BNC connectors) to build antennas and use as radio feedlines. I grabbed a lifetime supply when it was being thrown out.
Superb video! Happy 50th, Ethernet.
In the beginning of the video I'm so focused on UTP and switches it tool a while to realize he was talking about the original thick wire and vampire taps. Great overview about early Ethernet.
It became popular precisely because you could freely plug or unplug a machine without bringing down the network
"The one network, to rule them all, even though it's not a ring network."
The fact he said it..... Groan.
The fact they left in the video....... O...M...G!
Nerds! 🙄🙄🙄
Great video! My first network at home was a 10base2 beast in 1994 . Two PCs running Windows for Workgroups 3.11 equipped with ex rental NE2000 clone network cards. I ran the RG58 coax on the floor along skirting boards.
Still use RJ8 coax cable in some situations! Just a couple years ago I installed an internal LTE network in an office building, and all the antennas and their controllers were wired up using RJ8. A couple miles of the stuff, all told, though none of the runs were more than a couple hundred feet. It was quite the job, because that cable ain't light lol. Glad I don't have to do that again, in-wall structured CAT6 is enough of a PITA for me!
Watching this video through a 1000Base-T that goes to a switch where it goes over a 1000Base-SX fiber then to another switch where it goes to a 10GBase-SR to my router where it goes back down to a 1000Base-T and then to my ISP via a 1000Base-EX. Long live Ethernet!
Switching seems like a much more elegant solution for collisions but of course that would be obvious in hindsight. They put a lot of work into solving that problem!
Awesome to see the birth of a technology we all still rely on
But it also takes processing power, whereas this doesn't.
Wasn't practical at the time - couldn't make the performance in software, or make hardware cheap enough. The specialised type of memory needed was the problem.
There was a device that came before switches: The bridge. Basically a two-port switch, which you used to connect two hubs (or runs of 10base2) together.
Switching doesn't work for wireless or other real shared medium . Because there's no switch between computer and medium.
@@johndododoe1411 switches for wireless exist as long as seperate frequencies are used. Wireless mesh networks work based on switching, for example.
@@JoQeZzZ And memory for buffering the packets, especially in dual-speed 10/100 Mbps switches I remember the original SynOptics Lattisnet 16 port 28115 Ethernet switch. About the size of a VCR and ten times heavier with all the 1K memory chips in it.
Just.. brilliant. Thank you
We always called them bee-sting connectors. The thick coax was the 'backbone' and then thinner coax was used to connect to the computers via BNC connectors. If you unplugged the wrong BNC connector all the downstream computers went off line! Happy days :)
Hahaha you guys. Adlibbed the two computers talking at the same time and didn't even crack a smile.
Thanks for the trip down memory lane a lot of my youth was spent working all that stuff. At the time i wasn't totally convinced and then in 1977 i saw Star Wars and the hole picture came into focus 😊
Hey as an American let me just say, go ahead and use metric exclusively. The types of people who would voluntarily click on a video about the 50th anniversary of Ethernet are going to be fine thinking about and understanding meters.
Brilliant video.
I don't miss hubs and their collision light. Thank goodness for switches.
The newer standards above 1Gb have dropped the collision detection overhead and require fully switched subnets(No systems using those speeds would use a shared bus anyway.).
I was wiring offices when there were many standards. Ethernet was the most reliable network, by far.
Ethernet, or the Thin Ethernet developed later was the basis of my career working for a DEC Distributor in the late 80's, configuring & specifying ethernet cards & minicomputers, routers, repeaters, bridges and software. I even designed a colour graphic info "Configurator" to show off and sell all the kit DEC made for Ethernet.
My dad installed many Arcnet networks with twisted pair. We had a nice Indiana Jones Poster, with whip in hand, fighting network cables like snakes. It was Titled, Raiders of the lost Arcnet! Probably contemporary of the film, it would be great to find it.
Aged like fine wine
No mention for David Boggs, recently passed away?
Installing vampire taps was fun, specialized tools and all, we all love tools.
Do you have a link to the original memo? It looks like one of those fun RFCs of h past.
Many thanks. I learned lots. Thanks also to PARK, who by now must be owed a medal of honour from the USA government or president for their contribution on so many levels.
I wonder if it's possible to make a bus network with twisted pair cables, without needing additional electronics. Like just get a bunch of cat 5, and make T junctions through the wires inside. Ethernet the protocol should be able to work with that, right? Might be useful in a pinch.
My first network was with coax cables and properly soldered BNC connectors, T pieces and terminators. I still use it on three old computers.
I love learning about networking.
Collisions are NOT detected by detecting corrupted data. Collisions are detected by the cable having DOUBLE VOLTAGE since two carriers are interfering! Then all stations have the responsibility to shout collision! It's an ANALOG process, not digital. The stations don't need to store and compare date to detect a collision. Remember which decade we're talking about!!
I did a lot of vampire tapping to AUI converters. UTP is so much easier and better.
Like all computer technology, you came up with something that worked, and hoped it became the standard. When it did, no matter the shortcomings, it was the thing you did.
Ethernet relay came into its own when network switching became affordable. Then with full duplex no collisions. A bus network that became a star or hub spoke network.
I didn't know Computerphile was based in Nottingham! I'd love to pick your brains!
i love it, thank you
Hypothetically can you still have a Bus for modern connections then? Like port 1 on a switch has an ethernet cable which gets tapped by two devices for example?
Happy Birthday Ethernet, we love you 😍
Ethernet with Demand Priority Tokens was invented by HP & was called 100VG-ANYLAN. It was conceptually sound but a commercial failure due to its expense.
Those sharp spikes make me think about a title for a documentary or history book, “Blood and Ethernet”
“Even though it’s not a ring network…” I see you, combo-nerd! 😉
Pls explain.
@@eadweard. one network to rule them all = a Lord of the Rings reference. “Even though it’s not a ring network” which is a reference to a much more limited network technology than the Ethernet topic of discussion.
So he is a combination of Tolkein and networking nerds 🙂
@@BobAxiom oh yes I see thank you.
From Ethernet to SkyNet in 50 years. Not bad.
As soon as the diagram started i had flashbacks to today's numberphile video. Coincidence that you're both touching the same topic?
where on earth do they get that line printer paper from? I haven't seen that stuff since the 1990's!!
sounds like he is describing 10Base-5 (thick net) / 10Base-2 (thin Net) or other coax based networks.
I wonder is that the origins of the AUI port?
I'd guess Ethernet ended up winning because of the Ne1000 and NE2000 PC network cards and clones They gave cheap networking for dos and Windows right when people were really starting to need/want networking. They were cheap enough they even managed to enter the consumer market. They were what you needed for Doom giving huge Marketshare to ethernet
Thanks for video. Ehternet
We used to love shouting "don't step on the vampire!" when anyone got near the 10B5 boxes :-P
@7:48; Wait - so Ethernet was supposed to be essentially a similar naming intent as "Cloud computing" has?
That's interesting - and something I hadn't considered until you mention that there.
How far backwards compatible is ethernet? If one took an ethernet cable today and connected multiple computers to it would it work or have all of the work to make that function been left by the road side so everything would break?
Very - I’ve plugged that machine (late 80s ATari MegaST) and others (Acorn Archimedes) connected via 10base2 Ethernet onto our local LAN (via a 10mbit 10baseT hub to convert)
Having said that, modern switches are starting to abandon support for 10Mbit Ethernet. Unsurprising really, I suspect any 10mbit network would be swamped by the amount of traffic on a modern Ethernet.
The original PARC 3MBit/s stuff wouldn’t interoperate since the packets are different (8bit addresses instead of 48-bit for instances)… Ken Shirriff has some good blog posts about hooking an Alto’s Ethernet connection up to modern gear using a Beaglebone Black.😊
Remember: ethernet is the connector. TCP is just one protocol that uses ethernet.
Granted, my Power Mac 7600/133 can only do 10base-T half-duplex, but it has no problem connecting with the rest of the network (including internet).
So what are example of the first setup he drew with a cable for every machine?
Something like a Super Computer / Cluster or multi processor machine I suspect -Sean
*raises glass* Happy Birthday, Ethernet!
Funny how the problem of connecting computers together is very similar to the problem discussed in the Brick Factory video that was just uploaded on the other channel!
A friend of mine referred 10-base-5 as "frozen yellow garden hose". 🙂
I've always heard it called 'yellow snake'.
@@chuckygobyebye My friend was from a part of the country where winter is a thing. If you've ever left your garden hose outside when the temperature drops it takes on properties not far from that 10-base-5 cable.
Never have seen 10BASE5 before. Noice. It was part of a class I took way back in 2009, but never actually saw any of the equipment.
I'm old enough to remember the cable piercing method.
happy birthday ethernet
I remember token ring from when I worked at American Express in Brighton. It solved the issue of collisions as your computer could only talk if it had the token.
But Token Ring had it's own host of problems. And lots of small steps to speed it up. Going from 4 Mbps to 16 Mbps, add in Early Token Release and some schemes to allow as many as four tokens alive on the ring simultaneously if I recall. Thank goodness Ethernet took over before they tried Token Ring faster than 16 Mbps. Hmm... FDDI was sort of that though, wasn't it? A 100 Mbps ring topology.
I have worked with a variety of networks in the past, but none compare to Ethernet.
what is the exact network card model in the Atari Mega ST, pretty please?
Shared wires are still in use. Canbus in vehicles, modbus on power lines
"weird inches and feet" PSA Brits, Canadians, and Australians aren't allowed to be snarky about units if you measure weight in stone and use other imperial units in everyday life.
This is remarkably similar to CAN bus. I wonder if it’s a descendant of this?
Not at all. CAN's approach to collision handling is much more interesting, but only suitable when the bitrate is low and cables short.
Long live Ethernet
I can remember installing these and getting serial printers to work using netcat. RS422 was a nightmare
Basically all modern systems and the way we engage to them (including GUI and the mouse), are from Xerox.
I was really confused at the 6:00 mark! Media access is quite the important component
I believe it was a simple lampoon.
@@AcornElectron "Simple lampoon"?
And, whenever Ethernet failed, we resorted to "Sneakernet", which meant walking a floppy with the files over to the other machine, and manually loading/copying it... ;-)
Wow, I haven't seen dot matrix printer paper in forever! I didn't know they still made that stuff 😂
I'm not sure they do, but I'm sure that big universities still have tons of that stuff in storerooms sitting obsolete, so it is a nice doodle medium for whatever nerdy needs :)
I think it's still made, you can buy it, often called continuous feed paper.
It's often used in low maintenance applications, it somewhat simplifies the infeed and outfeed with lower chance of feed errors, you can print partial pages without wasting the rest of the paper or risking a power cut while waiting for a whole page of data and if used with an impact printer the ribbon runs out slowly.
The kind of application that is checked once per day, like printing out transaction logs at the back of a warehouse.
I remember having Ethernet with external AUI boxes at our high school in 1985 .
This brings back memories. I ran my first Ethernet cables to connect some VAX machines back in the 80s. The big debate back then was Ethernet versus token ring. Ethernet won.
I started my IT career with 10Base2 aka RG58 aka cheapernet. Ah, the good old days. 😉
Yeah its pretty good👍
03:56. My company actually recently released a new software revision - It has been Rev A, Rev B, Rev C, and now Rev 4. No joke.
Steve you're looking healthy, mate! Lost a lot of weight. Best wishes!
Happy International Amiga Day. I remember the IBM storage ring architecture, rings were a cool idea but switches solved the problem for ethernet and that was that.
I wish the collision detection mechanism was discussed in greater depth. Because, if a device is transmitting at the same time it is receiving, wouldn't it just hear its own transmission? Perhaps this topic requires an electrical engineer to explain.
Each transmission raises the cable voltage by 1V when sending a high bit . If two machines try, there will be moments at 2V, and they both know they messed up . Then they wait a random time each so on next try, one will be first .
Yes, the collision detection is not digital, it's analog. It's done by detecting abnormally high signal voltages when two carriers are interfering. That's why you see collision lights blinking constantly when you remove terminators at the end of the cable - reflections from the end of the cable have a similar effect. In the video it is said that a collision is detected by comparing sent data with self-received data , but that would be needlessly complex for 1970's technology.
The discussion of collision handling with Ethernet here has got me thinking of CAN, and I don't know if anybody has more insights to add here but it seems to me that CAN has better collision handling than Ethernet. There are error counters, arbitration by the electrical "open collector" style of the transceivers, and messages can be prioritized accordingly.
Aside from that, the main difference practically speaking between the two network protocols that I can think of off the top of my head is the supported distance by CAN transceivers + protocol standards (I think it's 40m or less) and the speed limitation (I think the most I've seen is 2Mbit/s) compared to Ethernet.
CAN collision detection is better because the higher priority sender can continue to transmit and its data isn't corrupted. With Ethernet, _all_ transmissions are corrupted and must cease when a collision occurs, wasting bandwidth.
@@thisnthat3530 Ah okay. Yeah wow that is quite wasteful!
My favorite networking choice was Token Ring....
If I have a lab of 20 computers, and they all need to be re-flashed with an new OS from a Novell server, it was at least 15 times faster on Token Ring (1 hour), than it was on Ethernet (12-14hours)..
I wonder why Token Ring never became a viable competitor to Ethernet ?? Anyone know why ?
1:24 Would quite like to be in that lab.
A big part of Ethernet winning was that the token ring networks which were competing with them had highly restrictive licensing fees.
But in case of a collision between B and C, how do the other machines know that the transmitted data is garbage ?
Probably a checksum kindda thing in each packet
From distant memory when theres a collision the header gets scrambled and so everyone knows, if you expect 1010101 and you see anything else you know that generally something is causing problems and thus you back off for a bit of time.
Wire voltage is out of too loud, so there must be a collision . There's a checksum too, but it's not for collision detection .
As soon as the stations detect a collision, they transmit the “jam” signal so everyone on the wire knows a collision occurred. This triggers the back off algorithm before the machines try to transmit again.
There's probably few hundred pages of incomprehensible legalese on that topic in the standard, which boils down to testing voltage level or something like that.
10:46 "You wouldn't have this sort of running behind the computer" Ha ha ha, ha ha ha ha ha, HA HA HA HA....no, we NEVER did that 🤣
Adding another computer and connecting it to all the previous ones makes the number of cabels grow quadratically if I'm not mistaken.
"even though it's not a ring network" *GROAN*
When I was first trying to setup a home network with 2 PCs, I asked a friend to being a network card and he has bought a Token ring card instead of a Ethernet card. I still have that card somewhere.
I with ther could be a standard PoDL for any Base T and not only the new base T1S/L... PoE is nice but way overkilled for IoT or anything requiring little power on the other end 🎄🖖
Just as a note. If you tried to connect via the T connections you showed the network would not function. Each tap would act like a tuning stub. Instead there was a T BNC connector on the network card - the cable came in one side and went out the other. The network was terminated with 50 ohm connectors to stop end reflections due to impedance mismatch.
Yeah! When 10Base-2 was popular I was a network guy for a mainframe company. In a large data center we'd just started using Ethernet-connected PCs for the mainframe console terminal. During installation one of the mainframe techs figured he's make the installation real neat and keep the Ethernet bus cable under the raised floor and have short stubs connecting from the BNC T-connector under the floor to the BNC connector on the PC NIC. Obviously it didn't work. I had to burst his bubble and made him run the cable up from under the floor to BNC T connectors right at the NIC. Not nearly as pretty, but it worked.
Perhaps in the next 50 years, we'll get plastic clips that don't break off in 3...2...