Lots of ideas about controlling ID spoofing
It makes for an interesting read, to be sure, but let's get real : what is it you want ? Peace and quiet, only disturbed by a call from someone you know.
In France, we have the Red List. It is a list maintained by a government-controlled entity and imposes that any number on that list may not be called by commercial entities without prior approval from the person.
So cold-callers avoid numbers on that list like the plague because, if they do make the mistake and call me all I have to do is call my operator and lodge a complaint and they will be found and fined - I don't know how and I don't need to care.
About fifteen years ago I got mighty angry at one point about all the marketing calls at dinner or during the evening film, so fed up was I that I signed up to that service. Since I explained to my operator how much of a nuisance the marketers were, my operator signed me up for nothing.
Ever since that day, I have been asking myself why I hadn't signed up earlier. Even if you pay the one-time fee of €50, it is worth it for the peace and quiet you experience for the rest of your life. For the last fifteen years, I got one call. The lady started her speech and I just said, "Excuse me, you are aware that I'm on the Red List ?" (except it was in French, of course). After a half-second of silence she immediately started offering excuses and saying how sorry she was, then hung up in a hurry. I had never felt so good.
Does that not sound like a good solution ? I don't care if the ID was spoofed, it's not my problem. If they call, I just complain, then it will be their problem.