When the isp wars were going strong, before broadband put everyone under the thumb of monopolists and also before gmail, spam filtering was a serious competative advantage.
Why can’t phone companies take an RBL like approach? If your VoIP service garners too many complaints because you are selling to robocallers then you don’t get to have calls delivered to e.g. ATT mobile customers anymore?
Are there legal or technical interconnection requirements that would make such a thing impossible?
The two biggest carriers have a 1-2% monthly churn rate.
https://www.statista.com/statistics/283511/average-monthly-c...
That’ll probably require fixing the broken design of the telephone system.
At a technical level, spam filtering relies heavily on analyzing email text. Doing similar analysis on voice calls is way harder. Also, there's UI issues. You can redirect suspected spam emails to a folder the user can inspect for false positives. What do you do with a call that hits the robocall filter?
More details here: https://www.broadcastingcable.com/news/fcc-clarifies-robocal...
Note that Ajit Pai (then a commissioner, not chairperson like now) voted AGAINST this.
Full disclosure: We (Nomorobo) advocated to the FCC to allow carriers to block robocalls.
All this occurs against the background of the Communications Act's common-carrier obligations, and the FCC's call-completion rules, which generally prohibit blocking calls. What the FCC did in the order you linked is to simply say "nothing in the Communications Act or our rules or orders prohibits carriers or VoIP providers from implementing call-blocking technology that can help consumers who choose to use such technology to stop unwanted robocalls."
Is that a safe harbor? No, as the next sentence clarifies, what can be blocked depends on the nature of the call: "Additionally, in the interests of public safety, we strongly encourage carriers, VoIP providers, and independent call-blocking service providers to avoid blocking autodialed or prerecorded calls from public safety entities, including PSAPs, emergency operations centers, or law enforcement agencies; blocking these calls may compromise the effectiveness of local and state emergency alerting and communications programs."
As explained in other posts here, it's hard for a carrier to tell what is a robocall. What is an "unwanted" robocall is even harder--it's a heavily-litigated issue in the TCPA context. (In fact, the rest of the order was about expanding what counts as an unwanted robocall in violation of the TCPA).
That leaves carriers between a rock and a hard place--it they block over-inclusively, businesses who think they fall into a TCPA exception could sue them for violating their common-carrier obligations. Then they get to litigate whether that business falls within the scope of the "unwanted robocalls" the FCC referred to (but did not define). Carriers have a huge incentive to not wander into that morass by offering call-blocking features.
I don't really want my carrier deciding what calls to block. I just want them to ensure the veracity of caller ID data so that I can perform useful blocking at my end. There shouldn't be anything stopping them from removing fraudulent and unverifiable caller ID info from the calls they route my way. That leaves me free to block calls that lack caller ID info, and I'm assuming all the risks that entails.
This makes third party call blocking products a better/easier solution for carriers to recommend as a solution.
That approach could work here.
It’s not clear to me that carriers would be allowed to do that, especially accounting for situations where VoIP traffic is laundered through a legitimate service (so the entity at the exchange boundary with the end-user carrier is a legitimate one).
Could they get around common carrier restrictions by offering that service as opt in? I’m not so sure about that either.
Send it straight to voicemail, where the user can inspect for false positives?
My operator should be able to have a short list of teleoperators in this zip code, and drop other calls.
I think no-one receiving calls from parked non-local voip numbers would be an acceptable price to pay for the elimination of voip spam. You are free to disagree, tech is all about making compromises.
Incidentally, this quickly follows the path we took with SMTP. I can no longer telnet into a random SMTP server and dump incoming mail, which no doubt ruined the carefully honed scripts of many sysadmins.
Telemarketers have learned that certain area codes convert at much higher rates than others. 202, 203, 212, 213 are prime targets. 242, 246, 406 and 701? Notsomuch.
If your NPA isn't important to you, get a number in those areas. (Some carriers will let you choose your area code as long as you're within the same billing center.)
For reference, I've had the same New Jersey mobile number since 2001.
Google Voice has had spam lists forever, it's likely they are pooling the data from there.
T-Mobile does have the ScamID/block thing that can be controlled by shortcode. Documentation here https://explore.t-mobile.com/callprotection
Stuff it’s more confident about gets blocked outright. I think they’re automating what they’d do if you went into your account and manually blocked a number.
Carriers have no economic incentive to do this. Most people on AT&T aren't going to jump to Verizon because of the number of robocalls they get on AT&T. It's not worth the hassle of changing.
I remember at one of the WWDC keynotes, Tim Cook announced this as a new iPhone feature. But he also noted that it was only available in China. I wonder if whatever the Chinese carriers have done can be imported to the United States.
My wife's iPhone will occasionally get an incoming call with small text below reading "Possible spam." She never uses her phone for voice, so she never answers the phone anyway.
Those features of CallKit are what we (Nomorobo) use to stop the robocalls.
Every phone network will then quickly begin passing on that cost to anyone they "peer" with and it will be a non-issue soon enough.
Is there a compelling reason to allow such spoofs?
A few use cases to spoof the number:
* Appointment reminder systems - if I see the caller ID is from my doctor's office, I'm going to pick it up and hear the reminder. When the calls come from some other number, people think it's spam. People still expect reminder calls even if you/HN crowd would prefer an email/text.
* Outbound call centers on behalf of others companies (same reason as above)
* People who work from home but want to make business calls from a personal phone
If no one could spoof, it probably result in a huge uptick of people claiming spam calls since they would be getting tons of calls from numbers they didn't know.
There really needs to be an SPF, DKIM, DMARC for VOIP. I don't think a no spoofing policy would go over well for businesses or consumers.
If you want to place a call with spoofed caller ID info, your provider should require you to prove that the spoofed information is legitimate, not fraudulent. Otherwise, the telco should be obligated to strip the suspect caller ID information from the call so that the recipient can properly identify the call as fishy.
There's no need for any complicated cryptographic solution. Telcos should just be required to know their customer, much like banks, before allowing them to do certain things.
So forcing the fine on the last step in the chain forces everyone to carefully consider who they trust, which is as it should be. Nothing wrong with trust between trusted parties, but clearly the current system has untrustworthy parties given too much power.
That's the thing though, a lot of times they don't control the spoofed number, but there's a legitimate use case for spoofing it. Authorization to spoof is not the same as having control of a number.
The issue is that the PSTN is essentially a huge, worldwide message queue to which pretty much any telco can connect around the world, including shady ones - even if US law actually does fight spoofing, how do you prevent telcos from other countries from continuing the abuse?
Cryptography is needed - when a carrier leases you a number, they give you a certificate with which you can sign other carrier’s certificates if you want to let them use that number as caller ID. Every carrier on the call chain should verify call’s signatures against that and discard any calls with missing or invalid signatures. That will stop malicious spoofing while allowing its legitimate use, just like email where you can use SPF and DKIM to nominate any email provider to be able to send on your domain’s behalf.
If I complain about a call, that should be trackable to the origination carrier and account, and if either one gets too many complaints, it gets thrown off the network (and other penalties).
I'm not suggesting no spoofing, I'm suggesting a fine on the carrier for unauthorized spoofing, which will force them to actually verify that there is authorization.
You didn't make this clarification in your first post. In the first two examples, they don't control the claimed number, which is what I was responding to.
>I'm suggesting a fine on the carrier for unauthorized spoofing, which will force them to actually verify that there is authorization.
This makes sense. Legitimate companies will get authorization agreements signed etc.
It makes telcos money. That's reason enough, since there are no economic downsides to the network operators that enable these crimes. If companies like AT&T and Verizon were also being subject to this $120M fine, we might see them decide to make caller ID trustworthy so that it could be used to block robocalls.
How?
In most areas it was illegal to set that bit unless you were a telco. It was also illegal to sell equipment that set that bit unless you were selling it to a telco. But... it's not that hard to hack.
Someone who's more current can probably give you better information. As to why nobody does anything about it... well.. why should they? They literally don't care. The equipment manufacturers aren't going to change the specs (because it's pretty darn hard to change specs and they are all trying to screw each other over in the specs anyway). The telcos aren't going to demand that the specs are changed because people are making telephone calls -- exactly what they want. It's only if the governments demand the change -- and it will take laws to do that (even then, I imagine that it's cheaper to lobby against the law than to change the equipment -- you have absolutely no idea how crappy those systems are).
Mobile roaming is one for example - when you roam on another carrier and place a call, that carrier directly originates the call and “spoofs” your caller ID to make it look like the call originated from you.
Some companies may use different carriers for either load balancing or least-cost routing and so both of these carriers are required to “spoof” the company’s caller ID.
This can definitely be fixed with a CA system and “delegation” where the main carrier who owns the number can issue certificates for any other carrier you’d like to use to temporarily allow them to use a particular caller ID, and each call request should be signed with that certificate and the signature should be verified by call intermediate carriers down the chain, and the call dropped if the signature is missing or invalid.
The telcos will find a technical solution real fast.
Or if they don't own it then it's on who's inserting the call into the system.
Telco systems are fun. And by fun I mean it's a complete mess. ISDN is hard and full of caveats (look at SIP for a taste of what it involves).
> This is a technical problem.
IMHO, it's both. Economic sanctions need to be put in place to motivate the telcos to create and adopt robust technical solutions.
A user can request a "trace" (usually by dialing a feature code), but not only does this hit the user with a ~$20 fee each time, but the information gathered can only be released to law enforcement, and since local law enforcement would need to make the request, it rarely happens.
I switched to ATT Call Protect which works much better. Now i get 1-2 calls/week. I would go back to nomorobo if it worked better.
We used to show "unblockable" because there was a problem with false positives. Lots of families had sequential numbers that were accidentally getting blocked.
Now, if you give us access to your contacts (local processing only, never transmitted to our servers) we can completely block them.
The 'neighborhood scam' is one which I am frequently subject to, and there is virtually nothing I can do about it (except block all the numbers with the same prefix as my own, but even this only covers the cases where they restrict their spoofed numbers to that small range).
Domestic callers like the one described in this article seem like a very small part of the problem, since they can be tracked and prosecuted. Foreign callers never pay the penalty with our current system, and I suspect they are more numerous based on the accents of most robocall operators I've gotten on the line.