I would also bet that there are regulations that require phone providers to complete all calls that are presented to them.

My provider, T Mobile, does overwrite the caller ID with “Scam Likely” for what they believe to be telemarketing calls, which is probably the best they can do until we implement a standard that authenticates the origination ID of calls.

In the early days of fighting email spam, that was enough. Every network operator was responsible for receiving spam complaints and responding appropriately. Network providers that couldn’t or wouldn’t prevent spammers from using their networks were blacklisted and other networks would refuse to route mail originating from them.

It wasn’t perfect, but it was far better than nothing.

I'm curious - is this available in a call passed through twilio ?

I would like to log, or pass, the prior network hop using twiml ... or a twilio function, I guess ...

Distrusting one of them and the calls that come from them is something of a non-sequitur since you chose them and intentionally became one of their customers and pay them to receive those calls.

TL;DR This isn't like email or IP traffic where you're interacting with other IPs in a purely untrusted network model. Merely analyzing the previous hop doesn't tell us anything valuable.

This assumes that is that there isn’t some kind of international treaty that forbids doing so. The existence of such has been claimed from time to time in similar discussions but I have yet to see an actual citation.

That's wrong, phone signalling systems always specify the originating number and it cannot be spoofed. The key thing is that only 911 responders and similar lines have the CLIRIGN flag set on their lines which means that the spoofed number transmitted via CLIP is ignored and the real one used instead.

In addition victims of e.g. threat calls can have the MCID flag set on their line which makes the provider systems log all call information for later retrieval by police.

It really annoys me that there isn’t a way of filtering calls based on country. 99% of my junk calls come from Australian numbers, so if I could just block Australia...

Do spam callers really think I'm expecting a call from the same area code, same exchange as my own number? Do most people have friends that have phone numbers with the same first six digits in common with their own?

I feel like this trick can't possibly work on anyone who has already seen it twice, and just based on the number of times I've seen it, I have to assume everyone has seen it at least five times by now, either that or they aren't even paying attention to caller ID at all.

All of the weirdness and strange patterns and methods you see in practice by these actors make perfect sense when you realize their targets are seniors.

In fact, even the ability to keep someone on the phone past the first 2 seconds of recorded intro greeting makes sense if that's the only interaction with a human you get all day/week.

The lives of inactive, retired seniors in the United States - especially in small or rural towns - is tremendously bleak.

And yes, they've spent their entire life with technology wherein everyone they talked to had the same NPA+PREFIX.

> In hindsight it may have helped us work contact lists faster but it did nothing for our survey completion rates. People who were not likely to answer an out-of-state call were apparently also not likely to answer a survey, even once you got them on the phone. To us, that trade-off was still worth it, because we were usually contracted to try each contact on our list either 3-5 times or until we reached a person who (completed or) declined the survey or asked you to stop calling.

> If you didn't want the calls, then we straight did not want you to continue getting them.

Don't chase leads that won't pay off. Do as little extra work as you can, to increase the likelihood of learning when a lead is known bad, so you can stop wasting effort there.

In the US, outside of the dense metro areas, this is a much more common than you think. For non-metro areas, it is quite common for everyone in the area (business and personal) with which you might receive a call has a number in the same exchange as your number.

But it is doubtful the spammers are considering that fact. It is much more likely they simply did A/B testing and saw a measurable increase in answer rate if the transmitted caller ID matched area code and exchange of the number they were dialing. And so they simply started using this trick, because their testing showed it worked.

And I worked for a call center company once, which employed a similar technique. Not down to the exchange, but by area code. We ran the numbers and found that we were much more likely to reach a person if we called through a number that belonged to their own area code, people don't pick up for out-of-state callers.

We were calling for customer satisfaction surveys, on behalf of companies they had done some business with – and almost always with a presence in their local area. So it wasn't technically a deception, unless you think that area codes should reliably represent the caller's location, in which case you'd be fighting a losing battle to be sure...

In hindsight it may have helped us work contact lists faster but it did nothing for our survey completion rates. People who were not likely to answer an out-of-state call were apparently also not likely to answer a survey, even once you got them on the phone. To us, that trade-off was still worth it, because we were usually contracted to try each contact on our list either 3-5 times or until we reached a person who (completed or) declined the survey or asked you to stop calling.

If you didn't want the calls, then we straight did not want you to continue getting them. Another rule we had was, it should not be possible for the person's phone to ring, and when they pick up it's just dead air. That means no predictive autodialers. (And of course that was the first rule to change when the company was sold, barf.)

We also ran the numbers on each area code and did a little cost-benefit deciding whether to buy those numbers or not, based on how many times we'd use them. If we didn't own a local number, we didn't use one. And we made sure that if anyone called back, the first thing they reached was a robot with a single digit to push to be added to Do Not Call list.

Turns out if you make it easy for people to get the calls to stop, you get a lot less angry people calling the reception and less angry voicemail messages, which makes for better call center employee experiences and better outcomes all-around. (I guess another strategy is to just spoof Caller ID with a number you don't own, so they can never call you back, and run the predictive rates so high that you never actually talk to an employee either. Totally unethical and it has to stop!)

The number of calls I receive which immediately hang up seconds after I pick up is absolutely ridiculous. I just imagine this call center full of people with auto-dialers going on full-speed across the room, nobody is wearing a headset and nobody is at their desk, but everyone is just sitting around a cash bonfire telling stories and laughing...

And at work, all company phones are on the same first digits.

Of all of them, I think T-mobile is the most willing to actually improve the industry for everyone's benefit.

When we receive a SIP invite (incoming call) from one of our upstream carriers, the amount of metadata information they're able to provide us is often very limited (largely due to interop issues in my opinion). If you think about IP spoofing, BGP, and the state of egress filtering on the internet, it's a very similar situation.

Since this is related to my work, obviously all of the above is just my personal opinion.

I already use white lists -- I simply don't answer the phone if the person isn't in my contacts list and I'm not expecting a call from an unknown number. I assume this is pretty common practice.

> If every cell phone has LTE and internet connection, why the fuck do we need traditional cell phone number?

I almost never have LTE or even mobile data of any kind when I'm outside of cities (for a liberal definition of city).

> Also, why can't cell phone providers use same spam filtering techniques used in email filters?

Because spam filters rely on contents in addition to meta-data. You can't pick up the phone and listen to the contents for a few minutes.

I'm curious what countries /places these are. My operator doesn't even activate 3G on modern phones, I literally have nothing aside from LTE/VoLTE. Since LTE got deployed on the low frequencies reclaimed from analog TV, the reception is generally BETTER than 3G etc.

Also when there are natural disasters, the voice infrastructure is the first to collapse, but data in chat apps still makes it through

The United States. Not even the western or mountain states! One of the places I regularly go that doesn't have data coverage but does have voice coverage is in a national (or maybe state there?) forest in New York state.

> Also when there are natural disasters, the voice infrastructure is the first to collapse, but data in chat apps still makes it through

I don't have any experience with this, so I'll take your word for it.

https://truecaller.com uses a crowd-sourced model to help you identify PSTN callers and spammers not in your contacts.

Besides, I think WhatsApp had the right idea around personal communication at least when Jan and Brian called the shots.

> If every cell phone has LTE and internet connection, why the fuck do we need traditional cell phone number?

I think with SecureElement now common in Android-based devices, eSIMs would be ubiquitous and may be SpaceX's Starlink would mean the end of traditional PSTN: https://news.ycombinator.com/item?id=19680412

I like having my PSTN voicemails emailed to me. And calls logs in csv.

If someone says they called me 3 years earlier, I can find that out without scrolling.

As for your other question - there are still lots and lots and lots of regular phones in the world that call me and that I need to call. As you mentioned in your example - every business, school, government, etc.

They do not intend to fix anything.

This captured FCC would rather everyone use the internet to communicate, since they deregulated that, than telephones which they cannot deregulate. The game is, make money as fast as possible in deregulated industries until people complain of lousy service and the government steps in.

Bonus points if the captured FCC can convince you that they care about these robocalls.

EDIT: Please explain downvotes. You feel the current FCC are saints and would never do such a thing?

IIRC, it was also free, but limited to 200 MB a month.

You basically got a SIM card you could stuff into your embedded sensor app and away you go.

That might be a large enough data cap for plain-text messaging, but not much else.

My hotspot gets spam text messages but I'm only aware of them the once or twice a year I log into its control panel.

You don't. Get a hotspot and use Skype instead. Problem solved.