I did. I told you pretty much how this works. Again, not for end users or line subscribers.
You are now falling down the same rabbit hole that many “power users” have fallen into over the last 8 months. They thought that because certain bulk/wholesale carriers were passing the final results they could really do something with it. Turns out, not as much as they thought. Let me help you with your research.
STIR/SHAKEN was a result of the work around the TRACED Act (active in Dec 2019). These are all part to combat SPAM/robo calls that have climbed through roof. Now STIR/SHAKEN involves security tokens, TLS signatures and all that good stuff so it must be done over IP. The originating carrier must sign the call with a validate certificate and token that has been provided to them. I spent almost 8 months going back and forth with the FCC, compliance consultants and even the STI-GA/PA’s to verify what I needed to do to be in compliance.
As it stands right now, carriers that have TDM networks can’t do digital signatures and add headers. There are numerous rural and small carriers that are still 100% TDM. There are major carriers like ATT and Verizon that still have big portions of their network on TDM (though they are moving fast to kill that). Finally, any carrier that is IP but less than 150K lines are not required to do STIR/SHAKEN at this time.
A little context, I would say that right now roughly 20-25% of the calls still hitting the PSTN are from TDM networks. Right there, up to a quarter of the calls already don’t need to be signed. Then you get down to the under 150K, which there are quite a few of around the country, so now that 25% is up to 30-35% (roughly). Then, of course, you have calls from outside the US that probably through another 10% or so into the mix. Now you’re at roughly 35-45% of the calls going over the PSTN that either can’t sign calls or have no requirement to sign calls.
Now your silver lining there is that the 150K limit is going away by June 30, 2022. So small operating carriers will have no choice but to start signing their calls. This means more signed calls will appear. As well August 2nd 2022 is the deadline for many carriers like ATT and Verizon to turn down their TDM portions of their network. This will have a wide reaching impact as all the CLECs that use incumbent networks are forced to do the same.
Soon the only TDM based networks will be non-competitive incumbents that haven’t made a single innovated move in decades. Even then, the FCC has them in their sights in the near future. TDM is not something anyone wants anymore.
So again, STIR/SHAKEN is a method of CallerID validation to help combat CallerID Spoofing which is highly related to robo/spam calls. It is something that the carriers, the FCC and FTC can use as part of the traceback process for finding bad actors based on reports that have been filed.
Earlier this year the FCC, since it’s a public body, released the reports of three providers that violated all this. In one instance the calls traversed three different carriers from the originating caller to the callee. Because, as I’m sure you know, not every calls is a single straight A-to-Z connection. Sometimes calls have to go through a middle carrier or two because carriers A and Z don’t have a direct relationship.
You are going to find that a lot of calls aren’t signed yet and that signed calls don’t mean anything outside of “we vouch on the callerid”. Getting a full “A” level call can still end up being a car warranty scam, while “B” or “C” can be legit calls.