In June—exactly a week before the June 30th implementation deadline for STIR/SHAKEN in the United States—I had the opportunity to participate in a webinar hosted by Jim Hodges of Heavy Reading.  Below are some highlights from that discussion. 

Since the industry has been talking about STIR/SHAKEN for a while, I’m sure most readers are familiar with it.  But if not, simply put STIR/SHAKEN is the FCC’s answer to ending fraudulent robocalls.  The essence of STIR/SHAKEN is that originating carriers attest to their degree of faith in the presented calling line ID and then attach that attestation to the signaling for the call.  The carriers then pass that attestation across to the terminating network, which extracts it and uses the attestation to drive the end user’s display with some sort of a verification mark.  A green check mark is very commonly used for this purpose.

The attestations that an originating provider can make are listed as A, B and C. “A” attestation indicates the carrier completely trusts the caller ID—they know the customer, they know the number. The terminating provider will use that attestation to drive a green check mark on the end user’s display.

Partial or “B” attestation indicates that the carrier knows the customer, but they’re not sure about the right of that customer to use the number.  Finally, a gateway or “C” attestation really indicates that all bets are off—the carrier doesn’t know they customer or the number.

Now, the actual mechanism for making this attestation happen is a little more complicated, and I have written several blogs about how the technology works. 

In December 2019, the USA Traced Act was passed that established the June 30th deadline to have all IP portions of your network covered by STIR/SHAKEN.  Almost a year later, October 2020, the FCC issued its Second Report and Order that established criteria for and the requirement to file certifications with the FCC indicating the carrier had met the Traced Act requirements. The Second Report and Order carried on to require service providers to reject calls from other carriers who have not filed certifications with the FCC.  And that includes foreign carriers, by the way. Earlier this year, the FCC set the deadline for filing certifications to be June 30th.

So on June 30th, the FCC has mandated that all the IP portions of the carrier network must be covered by a STIR/SHAKEN solution and that all non-IP, or fundamentally TDM, portions of the must be covered by some form of robocall mitigation program to ensure that fraudulent robocalls aren’t being generated on those portions of the network.  The FCC has also said that by that same date, June 30th, carriers must have filed certifications with them saying how they have met these requirements. They also set August 28th as the date after which carriers must reject traffic from any source that have not themselves also done so. Essentially, any incoming call to a carrier’s network that is using North American resources will only be accepted if the carrier presenting that call is in the FCC robocall mitigation database.  In addition, a foreign carrier that is terminating traffic to North America may have that traffic rejected if that carrier too has not registered in the robocall mitigation database.

So, June 30th is a big date that most carriers will not have wanted to miss. By that date, they have to be fully STIR/SHAKEN compliant AND they have to have filed with the FCC telling them how compliant they are, and what steps they took to achieve that compliancy.  For carriers that have not been able to make the June 30th deadline, hopefully with an FCC exemption, getting into compliance quickly should be a priority. Failure to do so could result in customer churn, lost revenue and increased costs. 

If you are a carrier that has not yet selected a STIR/SHAKEN solution, think carefully about it before acting. Do it once and do it right. To lower costs, ease deployment complexity and ensure adherence to the FCC requirements, choose a single STIR/SHAKEN solution that supports both the IP and non-IP portions of their network. This means a single solution that supports both STIR/SHAKEN (IP) and TDM-SHAKEN (non-IP). NetNumber’s STIR/SHAKEN solution, Guaranteed Caller, is one that does just this (among many other things).

As you read this blog, June 30th has now come and gone. So what’s after the June 30th deadline? 


A STIR/SHAKEN like solution for TDM, which we call TDM-SHAKEN, is presently out for letter ballet with ATIS. All signs are that it will be ratified, and it can be expected the FCC will mandate it shortly after that, with a fresh set of compliancy dates. NetNumber’s STIR/SHAKEN solution, Guaranteed Caller, fully supports the ATIS draft TDM standard already and so we can get you ahead of the FCC on this one.

Enterprise STIR/SHAKEN 

While consumer and small business calls will be protected by STIR/SHAKEN, enterprise calls will not, and thus will not be presented with a green check mark.  Enterprises trying to reach their customers won’t be nearly as successful after June 30th.  NetNumber is providing an Enterprise STIR/SHAKEN solution, Guaranteed Caller Enterprise, to close this gap.  And this becomes an opportunity for carriers to sell such a solution to the 30M enterprises in the US.  We believe this large opportunity space presents carriers with an equally large revenue opportunity.


The implementation of STIR/SHAKEN in the US presents a real problem for global carriers trying to deliver traffic to there. As it stands, that traffic will not be delivered with an “A” attestation and so will suffer declining answer rates now that STIR/SHAKEN is the law of the land in the US. To overcome this, NetNumber offers a global STIR/SHAKEN solution, Guaranteed Caller Global, that delivers “A” attestation to global incoming calls. Like the enterprise market space, this represents a real monetization opportunity for carriers.

Other Call Types

The FCC has yet to mandate STIR/SHAKEN treatment for 911 calls, RPH calls, DIV calls and Toll Free calls (just to name a few!). These will all need to be addressed in the near future. 


Text SPAM is on the rise, perhaps a consequence of the bad actors being chased off the voice network by STIR/SHAKEN. There is no reason that STIR/SHAKEN technology could not also be applied to texting. Look for this to develop in the near future.

To close, the June 30th date was a major milestone for the telecom industry. It is in the rearview mirror now, but the road ahead of us stretches to the horizon. There is much more to come in the world of STIR/SHAKEN. Watch this blog for more insights on these emerging developments.

This blog was written by Michael Campbell, Guaranteed Caller Product Manager, NetNumber


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