The “real” best thing is to always see “who” is calling on the display on your phone before you answer. We’re about to give up our wireline phone because you have to pay AT&T to block calls or you have to buy a piece of equipment to do it. On smart phones you can simply block them yourself. I have more than 100 in my current iPhone. And any call that comes in with no caller ID goes away immediately. But the worst part of it is AT&T gladly gives these telemarketers the lines they use to assault us. Neat trick, give out the lines, then charge your other customers a monthly fee to stop the calls. AT&T is the biggest $hit company in the world!
So use your call forwarding feature to send those calls to AT&T’s local number.