But all these layers exist on both sides of a modem. Really the modem is translating between a type of physical/data layer on one side (e.g. twisted pair ethernet) to a different physical/data layer on the other side (e.g. docsis)

IMO shutdown and restart are good ones to add.

I also made one to set volume to 1% which is just about right for listening to something while my wife sleeps beside me.