Despite all the recent advances telecom companies have made to detect and block spam calls and authenticate callers, we are still several years away from a robocall-free future. Without technology that can authenticate who a caller is, a spammer can change their caller ID to any number they want without being caught. Scammers often use something called neighbor spoofing, where they make it look like they're calling from a phone number that has the same first five or six digits as your own. New technology, such as the SHAKEN/STIR protocols , promise to finally add authentication to caller ID, closing the technical loophole that enables spoofing. Once authenticated caller ID is a reality, then anti-robocall apps that use caller ID will be much more effective.

Source: CNN April 10, 2019 18:33 UTC