The FCC is doing this by forbidding legitimate telecom companies from taking calls originating from voice service providers whose certification doesn’t appear in the FCC’s Robocall Mitigation Database. This means “voice service providers will be prohibited from directly accepting that provider’s traffic.”
Technically that works because telecoms must now block traffic from “voice service providers that have neither certified to implementation of STIR/SHAKEN caller ID authentication standards nor filed a detailed robocall mitigation plan with the FCC.” Secure Telephone Identity Revisited (STIR)/ Signature-based Handling of Asserted Information Using toKENs (SHAKEN) is Caller-ID on steroids – it’s a protocol for authenticating phone calls with the help of cryptographic certificates. It’s meant to make certain that when someone calls you, the name showing up on Caller ID really is the person calling. It also lets your phone company know, in theory, who’s responsible for a specific call. STIR/SHAKEN works with both landline and cellular networks. 
Acting FCC Chairperson Jessica Rosenworcel said, “The FCC is using every tool we can to combat malicious robocalls and spoofing – from substantial fines on bad actors to policy changes to technical innovations like STIR/SHAKEN. Today’s deadline establishes a very powerful tool for blocking unlawful robocalls. We will continue to do everything in our power to protect consumers against scammers who flood our homes and businesses with spoofed robocalls.”
Much as I’d like to think that this would drop my spam call count to zero, I know better. For example, while digital telecoms must now be using STIR/SHAKEN, old-school.    Older time-division multiplexing (TDM)/public switched telephone network (PTSN) based networks are still grandfathered in. The FCC requires that “providers using older forms of network technology [must] either upgrade their networks to IP or actively work to develop a caller ID authentication solution.” Still, no date has been set for this changeover.
In addition, as Brad Reaves, North Carolina State University professor of computer science, warned in a Marketplace interview, “There are just too many loopholes and ways to bypass this system.” These include smaller voice providers that still aren’t required to implement STIR/SHAKEN. Besides that, some providers provide US phone service to people living outside the country. They’re not required to participate in STIR/SHAKEN either.
Still, this new FCC move is a step forward. Will it end up substantially reducing spam calls? We’ll soon know if our phones finally stop ringing non-stop with junk calls. We live in hope.
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