My experience is much the same as B.A.'s experience. For several years I have been keeping track of calls I get. I get calls from all over the United States, from Canada, from The Dominican Republic, from Puerto Rico, from India, and from Pakistan. There seems to be no end to it.
My caller ID said unknown caller, and they didn't leave a message. Sure its a junk call so don't worry about it. The scammers and telemarketers don't care since most are robot calls.
This is what the message said. "This is Mike from Medical Alert you are eligible for a free medical call button. They are trying to sell medical devices. Another telemarketer got through despite the fact my number is on the laughable, what a joke, federal DO NOT CALL REGISTRY!