@Jolter
you are turning a discussion into an argument again.
Whether you like it or not the fact is the 7 layers exist, from level 7 the application layer that we interact with, to layer 1 the physical layer the lowest hardware level that is implemented for interconnectivity.
The internet is not the only game in town, there is a variety of different connectivity that is not internet based, we are talking radio based, defence based, high security applications, small bespoke implementations that avoid the internet.
NASA for example does not use the internet to communicate with devices in orbit. The Navy does not use the internet to communicate with ships at sea.
And in these lesser observed areas manufacturers implement the 7 layers for safety, data integrity, and security.
As for updating my knowledge I dont need to, I have worked at all levels in support of pc's, peripherals, servers, server farms, clusters, - Individuals, Companies, Corporations, Defence organisations, Banks, Hospitals, Government, the Armed forces.
The majority of my work was internet based and companies often cut corners there, but the internet was only one small part of the entire mix of connectivities I was responsible for supporting.
I do not wish to turn this into a fight, I was not correcting you I was praising your knowledge and contributing.
You seem very defensive however.
I was not questioning your knowledge why are you questioning mine, particularly when you make assertions that conflict with my hard won experience in industry working at all levels. And I have a significant amount of experience from the very highest level to the lowest.
I was simply pointing out that the OSI layers exist in the same way that laws exist. Not all manufacturers comply with the OSI and not all people comply with the law, but people should comply with the law and companies should comply with OSI.
But where they do comply with OSI and where they do comply with good practice, they apply error checking when transporting data between layers. This cannot be denied. If you were to deny this I would be forced to question your knowledge and experience.
It could be the case that you are very knowledgeable academically but educationalists do not know everything and in the real world academic knowledge sometimes falls short.
Error checking between OSI layers exists, it has not disappeared simply because it is not always applied by manufacturers who chose not to implement it.
Spanning of course exists where devices span layers error checking between layers is then unnecessary.
And simply because many manufacturers chose not to implement it does not mean we should not implement it. We should not abandon laws just because lots of people ignore them.
Now for a real world example of implementation of the OSI 7 layers and implementation of error checking that destroyed a businesses ability to operate.
I was tasked some years ago to resolve a catastrophic failure in a company that prevented any of the companies home workers from connecting and functioning.
The problem turned out to be caused by the error checking in the device at layer 1.
It was finding errors in the data every few seconds and then forcing a disconnect and resend of the data. Nobody could work and the company survival was threatened. This was a tier 1 catastrophic failure and every engineer assigned to it globally had failed to resolve it despite escalations and extensive work on it.
Nobody had the guts to turn off the error checking because it was bad practice to do so as it was mandatory to have error checking at the OSI layer boundary for this equipment.
I had to insist that we break the rules and disable error checking, I got my way because the fault could not be resolved in any other way and the equipment with error checking turned off, performed faultlessly.
I was told YOU CANT TURN ERROR CHECKING OFF everyone was trained to never break this fundamental rule it was a law. This is the difference between academic knowledge and real world knowledge. The world is not black and white sometimes we have to break rules that teachers say must not be broken to get results.
I do believe that you are very knowledgeable but the way you have approached your posts suggests a very detailed academic knowledge that does not always work in the real world.
You are not the only very knowledgeable person in the world. And when I add information to a thread that you have commented on that does not mean that I am questioning or doubting your knowledge or abilities.
As for your assertion that brevity is the key to understanding, I disagree brevity usually means leaving something out.
Technical subjects demand full and complete descriptions and answers or the entire story is not told.
And with the brevity comes lack of knowledge, and this lack of knowledge sometimes causes wrong decision making because we dont have all the facts..
In chat rooms nobody likes walls of text, but in technical descriptions walls of text are required or important information is missing.
The only way forward to escape this issue would be to refuse to speak technically in chat rooms, and that means we just chat pointlessly, I dont want that.
I refuse to miss out pertinent information simply because the reader cannot be bothered to read a full and complete text.
If they cannot be bothered to read a technical description in its entirety the fault lies with the reader and not the author.
Less is not more here, less is less.