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Back in college I had networking course that the original professor was replaced with a adjunct fill-in due to a sabbatical.

For some reason we spent what seemed like an unreasonably long time on ALOHA and Slotted ALOHA... and I still don't really understand why we spent so much time on ALOHA considering it was 2008. We even had to write an ALOHA simulator at one point and the exam was 3/5 questions about ALOHA.

Not really sure where this story is going... but that's my experience with ALOHA.

We talked about aloha a lot in our networking class as well. I went to the University of Hawaii though so it was at least sorta relevant.
Aloha and slotted aloha are still fundamental to most wireless communication networks. Most prevalent is today’s cellular networks.

An aloha like algorithm is used by your phone to initially bootstrap and connect to the network, and to access network after long idle periods. This is called the RACH procedure, which stands for random access channel. So our phones very well perform this action multiple times a day.

5G networks might use an improvement on aloha called non-orthogonal multiple access, but currently will still use the existing RACH design. Figuring out how to pack more users into a random access channel has been a long open research problem.

It’s just a fundamental approach to a shared-medium problem. Start with ALOHA. See that it works! But it can be improved. Move on to slotted. Then explore carrier sense. Etc.
We also spent a fairly significant chink of time on ALOHA, alongside RIPv2.

I think they're commonly covered at universities as they're relatively simple protocols, but still demonstrate the concepts that they're taught for quite well.

The alternatives would be for the lecturer to invent their own protocol for demonstration/lecturing on, or to use more modern and comprehensive protocols.

Distributed computing of today is like the dial up of computer networking, or worse. We're doomed to repeat those mistakes if we don't know the history.