Yeah, there's a lot going on in ppp systems.

I was slightly surprised how the old scripts I used for dialup over 20 years (and a different country) ago were still used for LTE modem connections, complete with an even larger set of AT commands to control the device. I still think of AT commands as "Hayes" commands, even though Hayes themselves haven't existed this century. (Dennis Hayes still exists personally, as far as I know, as does his business partner Dale Heatherington - who retired at age 37 in the mid 80s, and seems to have had a great time since then.)

I guess ppp will be with us forever. I was pretty impressed that someone managed to implement a ppp wifi modem on the very cheap ESP8266 microcontroller. If you have a serial port, you can now talk (not very fast) over wifi: https://www.tindie.com/products/theoldnet/rs232-serial-wifi-modem-for-vintage-computers-v4/

(there's a github link to the source in there for folks who might build their own)

 Stewart