The “OSI Model”: There's no such thing. What they taught you is a lie

> OSI wanted a "connection-oriented network layer", one that worked like the telephone system, where every switch in between the ends knows about the connection. The Internet is based on a "connectionless network layer".

Pretty sure ISO/OSI was pushing for CLNP which is "connectionless network protocol."

Spot on. Being there at they time, the OSI folks made much of the fact that because of their well defined layers, any of the higher levels could run over a connection-oriented or connectionless without change.

In theory. We never really found out for sure.

There are better networking models out there [0] and at least some books use them. Including some popular ones like “Top Down Approach” by Kurose and Ross.

0: https://en.wikipedia.org/wiki/Internet_protocol_suite#Layer_...

The thing that helped my understanding the most was opening wireshark and just observing.

the original leaky abstraction