|
The technology has become the standard LAN worldwide Token Ring will come around again!
|
|
|
|
|
Kent Sharkey wrote: Token Ring will come around again!
And save your Confederate money!
(For USians...)
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
|
|
|
|
|
The name is 50 years old!
Ethernet of today has very little to do with Ethernet 50 years ago. The name, but what else? Cables? Plugs? Topology? Bit rate? Multiplexing?
|
|
|
|
|
The underlying communications protocol hasn't changed.
|
|
|
|
|
The software standard may not have changed much, but the hardware standard certainly has. Going from < 10Mbps to > 1Gbps with little change in the software layers certainly demonstrates the utility of the OSI layered model.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
|
|
|
|
|
"Communication protocols" come at various layers, each covering a varying set of functionalities. The original Ethernet was a pure physical layer. Splitting off some parts of it to a link layer came later. Even today, Ethernet does not at all affect anything above the link layer.
I must admit that I never studied the medium access control in star topography, RJ45-style Ethernet, so for all I know, what used to be CSMA/CD for medium access, it could be that nowadays, CSMA/CD is used for access not to the medium, but to the router. I sort of doubt it, though. Each device has a dedicated cable to the router, no "Multiple Access". A router could of course broadcast some sort of carrier to all other devices rather than the one currently active, to keep them from trying to start transmission. I doubt it. Wikipedia says not. Every connection to the router has its own electronics, with its own flow control.
When I learned about Ethernet as a young student, CSMA/CD was an essential part of the protocol discussion, distinguishing it from e.g. Token Ring or DQDB.
When you run Ethernet over WiFi, is the original coax-oriented CSMA/CD used for access to the air waves?
The original Ethernet protocol was half duplex (obviously, since there was a single physical medium). All documentation I can find of RJ45 based Ethernet claims that it is full duplex.
48 bit Ethernet physical addresses were used for direct physical identification of sender and receiver, handled at the physical layer, by the physical interface. All devices were on the same cable, so there was no 'routing' beyond this; an interface forwarded to its device frames with matching 48 bit address (or a broadcast address) and ignored all other packets. Is that still how this 48 bit address is used?
The original Ethernet could work with 16 bit physical addresses. Is that still supported?
The original transmission mode was plain unconfirmed datagram (connectionless) transmission. Is that still the case?
The payload size was limited to 1500 bytes. Is that still the case?
Is the 'EtherType' field of the frame unchanged from the original definition?
(Actually, the 1976 Metcalfe et. al. paper shows a frame with no EtherType at all.)
Is the frame check sequence (CRC) calculation unchanged from the original definition?
Is the 'end of frame' indication unchanged from the original definition?
Which parts of the 1973 Ethernet protocol have not changed?
|
|
|
|
|
The original Ethernet used a communications protocol sometimes referred to as "send while listening." This means that if you have something to say you just say (send) it. You also listen for garbled messages that are the result of collisions and then back off for a random time before sending again. Regardless of the hardware and technical protocol improvements, 100 GB ethernet works exactly like the original ethernet over coax. The fact that coax was used was because the tools to add additional devices were common, simple, and worked well.
|
|
|
|
|
obermd wrote: This means that if you have something to say you just say (send) it. You also listen for garbled messages that are the result of collisions and then back off for a random time before sending again. Regardless of the hardware and technical protocol improvements, 100 GB ethernet works exactly like the original ethernet over coax.
Is that really so?
For one thing: "if you have something to say you just say (send) it" is not correct. You always wait until there is no signal (carrier) on the cable. That is what "CS" in CSMA/CD refers to: Carrier Sense. If you sense a carrier, you do not send anything.
To quote Wikipedia on "Carrier-sense multiple access with collision detection":
Modern Ethernet networks, built with switches and full-duplex connections, no longer need to use CSMA/CD, because each Ethernet segment, or collision domain, is now isolated.
Maybe I misunderstand Wikipedia, but I take this to mean that you do not "listen for garbled messages that are the result of collisions and then back off for a random time before sending again".
In any case: This medium access control is one single aspect of a physical layer protocol. (At least in the original Ethernet it was physical layer - nowadays some people insist that it belongs in the link layer, even though we are talking about the physical medium/signals.) You may say that this is The Protocol. I dare to think that it is one tiny little speck of "The Ehternet Protocol".
And I still believe that even this physical protocol aspect has changed since 1973.
|
|
|
|
|
Amazon next year will allow auto dealers to sell cars through its site, starting with Hyundai. People that bought this car also bought this car?
Or
Two day delivery with Super Saver Shipping, and it comes in a really big box
|
|
|
|
|
The returning politic is for sure going to be funny
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
Mine came in a bag that said it was saving material and weight in shipping.
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
I’m begging you for the benefit of everyone, don’t be STUPID.
|
|
|
|
|
60,000 people lost full phone service, half of AT&T's network was down, and 500 airline flights were delayed But was it the *right* line of code?
Yeah, Substack. Sorry for all the popups they throw at you, but I was able to read the full article without signing up/paying.
|
|
|
|
|
rm -rf?
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
The Deep Space Optical Communications tool on the Psyche probe achieved successful data transmission to and from Earth from an unprecedented distance. What were the roaming charges like?
|
|
|
|
|
Pfff still nothing compared with SG1 or Star Treck communications
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
We’ve been working on a refresh for the Visual Studio UI to improve productivity, create a more inclusive environment, and keep up with evolving global accessibility requirements. "They're the same picture"
|
|
|
|
|
Kent Sharkey wrote: "They're the same picture"
But with other borders and rounded corners
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
Microsoft ensures Windows 11 is compliant with the Digital Markets Act in the European Economic Area. What are you going to use to download Chrome now?
And look at that - another shortcoming of Brexit 
|
|
|
|
|
Kent Sharkey wrote: And look at that - another shortcoming of Brexit 
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
Only in the EU, so the UK Brexitted themselves out of this ruling.
TTFN - Kent
|
|
|
|
|
I got that, I thought there was going to be a hidden meaning or joke behind it. All good then 
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
Reports on Saturday claim that the board has gone back to Altman and asked him to return to the CEO role, under pressure from investors. Press Ctrl-Altman-Del to restart company
Yes, I basically stole that from The Register. But it was brilliant (on their part).
|
|
|
|
|
Now they are pressing CTRL+Z
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
|
|
|
|
|
A programmer has created an AI version of David Attenborough to narrate his life. Not what they meant when they said document your code
Although I guess that's a documentary of your code
|
|
|
|
|
Major upgrade of functional-first programming language brings lambda shorthands, faster compilation, new diagnostics, and ‘quality of life’ improvements. It's not F#'ing dead, yet
Unlike one other language that shall not be named
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
