“We’re at least five years short of where we should be ,” said Henning Schulzrinne, who was chief technology officer of the F.C.C. during the Obama administration. He is also one of the architects of several key technologies, including those that underlie the Voice Over Internet Protocol, or VoIP, which was made popular with Skype, Google Hangouts and FaceTime , and a key tool for robocallers. H e attributes the lag to inaction at every level — from industry, to regulators and even technologists like himself. “We didn’t call up The New York Times and say there will be a catastrophe coming,” Mr. Schulzrinne said. “We didn’t raise as much hell as we should have.”

The same technology that lets grandparents video chat with their distant grandchildren makes robocalling cheap and lucrative. Robocallers — often located overseas — make thousands and sometimes millions of phone calls using VoIP. One of the reasons these calls are so difficult to police is that robocallers usually spoof their origin: They appear to be calling from a phone number they don’t actually own. It’s why you get so many unwanted calls from your own area code, sometimes only a few digits off from your own number.

Spoofing also helps robocallers evade any block lists and spam filters that the carriers use, or that you might have signed on to. To pierce the fog of spoofing, STIR/Shaken adds a layer of authentication to calls. It makes spam call filters more effective, it makes uncovering the source of a robocall easier and it helps ordinary people who might get confused by someone pretending to call from, say, their bank’s official 1-800 number.

Things never had to get this bad. The standards body that proposed the first iteration of STIR/Shaken back in 2006 went on to identify robocalling even more urgently as a problem in 2008. By 2012, robocalling had become such a menace that the Federal Trade Commission called a meeting to develop solutions. And in 2016, the F.C.C. , under Tom Wheeler , who was then the chairman, asked carriers to voluntarily adopt fixes. They are finally acting now.

While the government was convening meetings and was finger-wagging at companies, an ideological battle over deregulation was in full swing . Legal experts disagree as to whether the F.C.C. currently has the authority to police robocalls. It’s enough of a question mark that legislation introduced by Senator Ed Markey, Democrat of Massachusetts, and John Thune, Republican of South Dakota, would specifically require providers of voice services to use authentication services like STIR/Shaken.