ISO is a theoretical model on how things work, suitable for teaching and for reference. In reality, there are only 4 layers and not the finely chiseled concern-separating layers at the bottom.

[–] credo@lemmy.world 5 points 2 days ago* (last edited 2 days ago) (1 children)

ISO is an organization. OSI is a model.

Edit: there are also definitely more than four “layers” (standard handoff points).

Physical involves the media and transmission format (e.g. EMF, waveform, etc)
data link involves multiplexing and addressing on the local segment
Network involves beyond-segment addressing
Transport involves standard endpoint communication methods (tcp/udp)

Are you implying this is where everything ends?

What about application level multiplexing (sockets)?

[–] a_non_monotonic_function@lemmy.world 1 points 1 day ago

I'm not implying anything.