I made 50k calls to explore the telephone network | Hacker News Reader

I made 50k calls to explore the telephone network

shufflingbytes.com

333 pointsValtteriL177 comments

> I was very surprised to hear this bizarre message about the end of the world and a zombie apocalypse when listening to the recordings.

So that's the reason someone called, we thought zombie apocalypse had already started...is what I would like to say, but reality is a bit more boring. It's one of our test numbers that we used for integration testing one of our call center integrations for our WebRTC monitoring platform (https://www.callstats.io) and someone decided to have a bit of fun with call flow :)

If you had pressed 1, you would have got a message about choosing to be rescued and that the agents take long tea breaks.

(disclaimer: I work at 8x8 on the callstats product)

This is perfect

really?

This is correct :D I verified this by calling again and pressing 1.

I am the author of WarVOX (a mostly dead project these days). Some useful links:

- WarVOX 2.0 Presentation: https://speakerdeck.com/hdm/derbycon-2011-acoustic-intrusion... - WarVOX Source: https://github.com/rapid7/warvox

The US legal restrictions on wardialing are complicated and changes to the law made it difficult to continue the project.

For fans of ToneLoc, I implemented the data format and visualization with my latest project (Rumble Network Discovery): - https://www.rumble.run/blog/subnet-grid-report/

Thank you for your contributions to WarVOX, and to so many other projects that advanced the security community.

I never would have guessed that in 2021 we'd have headlines about IRC drama and wardialing! Maybe history does repeat itself :)

No kidding and thank you!

Wow ToneLoc… that really takes me back. It’s so fascinating to remember something for the first time in over 20 years.

The author says that lots of measures were taken not to wake people up in the middle of the night, but that despite those efforts 3 people were. Wouldn't the most obvious method have been not to dial numbers at night local time?

Its very unlikely they didn't think of that. Not all humans attached to phone numbers reside in the physical area of the area code.

"WarVOX spent 60 seconds on every call, whether it was answered or not. This resulted in a wardialing speed of 1 call/minute. For 56874 calls, this means roughly 40 days calling day and night."

Seems like he did actually call at night times.

I think given their efforts to avoid calling people at their local night, it's safe to assume "day and night" refers to the caller's local night.

my reading was that OP took efforts not to call people but still rang at all hours. I think your reading and assumption are mistaken.

It's entirely possible.

56784 (calls) / 40 (days) = ~1422, round down to 1400 for 'easy math'

1400 / 24 (hours per day) = ~58 per hour (round up to 60)

60 / 60 (seconds) = 1 per minute so nope, he was hammering at it 24/7 (unless my maths is totally wrong which is always possible).

not all people only sleep at night.

True, but the author admits to waking people in the middle of the night.

In the middle of the receiver's night. It is impossible to know with 100% certainty the local time of the person just by their phone number.

Why not simply call and ask what time it is?

Privilege is being a day person.

Oh hey! I have experience with this! I used to analyze data for a call center. We had a law that prevented us from calling people at night.

This is hard because of the following reasons: Zip codes and time zones don't align well (looking at you, West Florida!)

Area codes and zip codes don't align well

Area codes and time zones don't align well

People move!

There is only one time zone in finland

But that Finnish phone number could belong to someone in England.

Who was vacationing in Thailand.

Area codes mean little in the mobile phone era. Just tells you where a person lived when they were a teenager or otherwise first got their own phone.

Not in Germany. The mobile network has distinct numbers. You can have a land line number mapped to a cellphone, but it's rare these days, don't know anybody who does this. It was popular back when calling cellphones was more expensive than land lines.

"Area" codes in German cellphones were never the area but the cellphone provider. But that became none sense, when you could move your number to any other cellphone provider like I did. I own the same cell phone number since 1998 and was with almost any of the cellphone providers (except QUAM and E-Plus).

Actual area codes in Germany are always area codes. I doesn't matter if they are mapped to the cellphone or to SIP. When you make an address change, then your area code changes. Happened to my area code. But moved it to a friends house in the same area, so that I can keep it (illegally). Because I "own" that number as well since about 1998.

I moved away from Germany and I still have a German landline number via SIP. Are you saying this is illegal?

If you inform your SIP provider about your new address, then they need to give you a new number. If you number has the "area" code specially for SIP, then it is not a problem. But if you have an actual area code, then this is not allowed according to the rules of Bundesnetzagentur.

Good to know. They certainly don't seem to be super eager to enforce this, since I have been using it from a foreign IP address and with a foreign billing address for a long time. Maybe there is a field for physical address that I should have updated...

You can't just port the number to a VoIP provider and keep it regardless of location?

I work for a VoIP provider so when I got rid of my secondary phone I just ported it to my system and now I can do whatever I want with it.

A bunch of my clients have numbers from all over the state or even the country that route in to their one actual office.

It seems really stupid for that to be legally prohibited.

Yes, according to the rules of Bundesnetzagentur, the SIP provider needs to give you a new phone number from the within the new area, when you give them the new address. Also for SIP providers the rule is, the area code is only for the customers in which area they are.

So what do companies do that serve wider areas spanning multiple area codes?

I'm based in Northeast Ohio, so a the majority of my clients are in the Cleveland/Akron/Canton metro area. Those who do on-site services, say a septic system maintenance company or a garage door repair company, will commonly have phone numbers that are local to each of the major suburbs they target. Some of this is a legacy from the old days where people cared about "long distance" calling versus local but I still have these kinds of companies ordering new local numbers in various suburbs to this day just for marketing purposes because a local number makes some people feel better about a company.

Is that just not a thing in Germany? So companies can only have a local phone number in areas where they have an actual physical address?

Companies in Germany mostly have a local number from the area where they are physically located. If a company has multiple sites around the country, they mostly use a number within their HQ area or they get a service/freephone number redirecting to their call center.

Bundesnetzagentur (the regulatory agency for telecommunication, electricity, gas, etc.) has very strict rules which are enforced and the fines can be very expensive, so nobody tries to find a loophole in the system.

How strict are they? Oh boy, they can be worse then your worst nightmare. About 10-15 years ago, a few friends noticed stuff going missing from the shed (it was beer, so it was very serious). They ordered and installed a cheap wireless camera from china and started recording. A few days later they got a letter from Bundesnetzagentur stating they use a restricted frequency and have to stop immediately or they will be fined X000€ (don't remember the exact amount, but it was four figures so a lot of money for students. Also, pretty high for a first offense). Yes, it was the camera which was using some weird frequency band. But how did the Bundesnetzagentur found them? They were wardriving around the city and checking for unusual signals. Literally a few guys in a van filled with RF equipment driving through the city and looking for suspicious stuff [0].

They probably were driving their laps and checking security, since we have a few high profile institutions here, but got a few drunken university guys with a cheap webcam from the internet.

[0] https://de.wikipedia.org/wiki/Bundesnetzagentur#/media/Datei...

Country codes still matter, for the most part.

In the EU pretty much every nation has their own country code. Which means 555-555-5555 will map differently depending on the nation you are in.

And maybe for the EU, knowing what nation a person resides in gives you some idea of their time zone. The US spans 6 time zones (technically 9 if you count non-state territories). Russia spans 11.

Oh, and don't forget, phones lines can be forwarded elsewhere as well. (hopefully the law's text said "area code time zone", and had some wording against tomfoolery like making a forwarding service that sent calls wherever)

People move is a big one. Since smartphones became popular, I’ve noticed that people tend to keep the same phone number from where they got their first phone number. So I will receive calls from all over the place, except they really are all local calls from people that now live in my town. So when I see that a call is from Wisconsin, that is meaningless since it could be from someone living down the street.

When I left a previous state, I paid to port the local area code number away from (major cell carrier) over to Google Voice (I've had this number some 20 years now). Many of the folks I work with (tech sector) have cell numbers from different states, having moved into this state only for work and some day plan to leave/return to their original home.

Yeah, I've moved a couple of times and still have the phone number I got in the second state I lived in. The nice thing is that, for the most part, the only people calling me from that state's area code are robocallers who are spoofing what they hope is my local area code. I very rarely answer unknown numbers anyway, but seeing these kinds of area codes on my caller ID almost guarantee it's a spam call.

And now I know that if I get a call from my numbers zipcode and I don't have them added it's a robocall!

How many hours off can you be with area codes or zip codes? I would have thought that might be about an hour not really more than that.

There is no difference between mobile and land line numbers in North America. There's no national "mobile only" prefix (like in many EU countries), and no "your number changes if you move to a new location": phone numbers are owned by carriers, and you get whatever number your local carrier branch was allocated (which will have the local area code). That's it, the idea that "area codes" are actually location indicators is basically an anachronism from the land line days.

If someone has a mobile phone, which is everyone, and that phone has a Toronto number because they bought the phone plan when they lived in Toronto, then they move to Vancouver, they get to keep their number as long as they stay with their carrier. If you then look at that number and go "the area code is Toronto, 8am is an acceptable time to call that number", now you're calling someone at 5am.

Area codes in North America, by and large, only tells you which city the carrier's branch was located when the phone plan got set up. Canada and the US are huge countries made of mostly empty space with pockets of life spaced far, far apart, and people move from pocket to pocket all the time.

>phone numbers are owned by carriers

>they get to keep their number as long as they stay with their carrier.

You can move phone numbers between carriers.

I was about to say, since 2003 in the US wireless number portability is required. You as a consumer have a right to port your number from one carrier to another, they're only supposed to be able to charge fees related to their costs which is usually $0.

https://www.fcc.gov/general/wireless-local-number-portabilit...

There's more than just the US in North America =)

Now with services such as TextNow, when you sign up for the number they simply let you choose whatever area code you'd like.

FWIW, Cell carriers will do this as well. They don't require you to take a local number when signing up for service.

I have a north Texas area code but live on the west coast again, and the number of idiot robo-dialers I get calling me early in the morning is frustrating.

My phone is now on Do Not Disturb most of the time because of these. Even with the do not call list, Hiya, and Nomorobo.

Recently started using RoboKiller and it's reduced these to a near zero level.

While I understand your argument, there is only one timezone in Finnland and in my understanding he was calling land lines. So all the numbers should end in Finnland. Of course it can happen that a number is forwarded but then I see no blame with the author.

Because it will take much longer if you restrict calling time to the day.

He should have done it. He could have reserved just 8 hours for "night" to do the minimum, so he'd only use 50% more time then (still have 16 hours per day to make calls).

> The author says that lots of measures were taken not to wake people up in the middle of the night, but that despite those efforts 3 people were.

It's pretty presumptuous to assume calling in the middle of the night is a problem as opposed to calling when people are asleep. Which could be any hour of the day.

>Wouldn't the most obvious method have been not to dial numbers at night local time?

There's a super obvious method to avoid all the issues. Don't robocall people at all. This person placed about 20k phone calls between 10pm and 6am. Whether someone answered or not, a ringing phone waking a person a significant intrusion. They also called people and recorded them without their consent.

Here's an easy rule of thumb: in the absence of explicit informed consent don't experiment with other people's stuff. It's amazing that there are adults who don't understand this.

Also, a brief search on the internet suggests Finland is a two party consent state for recording phone calls.

>There was a single response that was present in 1074 answered calls (91% of all interesting answers) and that waits for the caller to interact with itself. It says “Tervetuloa palveluun” (Welcome to the service) followed by repeating “Anna tunnusluku” (Please give access code). The machine does not give any hint of what kind of service it is.

I wonder whats that about.

Sounds like a dial-in meetings system maybe?

Back in the day, you'd have to ring up or write (using stamps) to get the user manuals. Or dumpster dive, which the one time we tried it kinda sucked since we expected manuals but got all the pass-codes instead which ended the game.

Google “Tervetuloa palveluun” “Anna tunnusluku” see where it leads. You'll need Google translate as you get into it.

It appears to be a service offered by http://elisa.fi

The excerpt from the manual[1], translated to English.

  Call the number __________________________
   You will hear the bulletin “Welcome to the service”
   You will hear the message “Enter the passcode”

http://esco.elisa.fi/rest/esco/blob/yritysten-asiakastuki/Va...

Quite possibly calling cards or conference lines. Recording voice prompts is "hard" so many just try to make due with the included prompts in asterix/freeswitch.

My first thought (influenced heavily by Hollywood) was that it was some kind of assassin or other criminal service. You call in, give the correct pass phrase and someone tells you where to get your vacuum repaired locally (if you know what I mean).

>As there are no Shodan-like search engines for the telephone network, I needed to do the exploration myself.

in the 2000's there was a massive telephone search engine hosted at bellsmind.net. You could find brief descriptions of hundreds of thousands of phone numbers. You could just run down a list of 800 numbers and call the ones that looked interesting. Some presented you with a new dialtone. Some played weird little jingles. Some lead you to a real person. A few were set up by phone hobbyists and let you play games.

At some point the law caught up with BellsMind and the database was taken down. The whole site is gone now - even the blog.

You can see remnants of that database here (just skip through time to see new stuff - the rest is mostly broken): https://web.archive.org/web/20041015131435/http://bellsmind....

EDIT: This is the page for "The 944 Project", which was a crawl of the entire 800-944-XXXX space. Easily the best list at the time. Some stuff might still be there. https://web.archive.org/web/20050125030027/http://bellsmind....

Dunno what I said the last time a call violated the do-not-call list and woke me. They actually called back later to tell me how shook up they were, and that they'd been discussing my response with their lawyers.

I don't see a difference between kidnapping one person for a week, and taking ten seconds away from 56,874 people. I'd support similar penalties.

I decided to fix this problem.

Phone.com is aimed at small businesses; if you have three extensions in your house they default to ringing separately like cubicles. However, any HN reader will have no trouble customizing their service.

I have one service spanning homes on both coasts. The phone number I give out has a white list, or answers with a recorded message to press 7. Apparently this is enough to evade all robocalls. Successful callers ring the extensions where I'm scheduled to be, and the Phone.com app on my cell phone.

My cell phone is otherwise set to "Do Not Disturb" so it only rings if you're in that address book. The Phone.com app is a bit clumsy (it doesn't track switching to AirPods once the call starts, for example) but for answering calls it works.

Some legitimate businesses robodial numbers before putting on a human. They don't get through. Life goes on. They should know better than to appear to be a robocall.

So a captcha for phones? Like "press 7 to reach me". Great idea acctually.

I have this set up at twilio with a simple Studio workflow and so far it defeats 100% of automated dialers:

A lot of auto-dialers wait to hear a human, so to trigger anything listening for a response, the challenge goes "Can you hear me? This number is protected by Samaritan Call Protection" (shout-out to Person of Interest)

Then about a second later, it follows "Press 5 to be connected."

Things that dial 5 get a ring-through to my cell, things that don't get blackholed.

This is exactly what I do, but I use a randomly-generated-per-call two-digit number to advance the caller from my (Asterisk-based) IVR. It works like a charm.

The "unknown machine" sounds like dtmf tones + pulse tones. It's anyone's guess what the actual meaning of the numbers are, but the tone+pulse encoding suggests a super legacy, perhaps proprietary automated system that you'd call up to get the status of something - maybe factory machinery or a power plant, but really it's anyone's guess. Pulse dialing was still somewhat common until the mid 80s so this system is potentially upwards of 40 years old.

Could it be an auto-answer from a Telex machine?

https://youtu.be/lCZmVXGyVQQ?t=15

I have no idea what they sound like on a telephone line though.

Sounds like broken audio file on the other end.

It reminded me of alarm central station protocols. The earliest (e.g. 3/1 and 4/2) use pulse, and the later ones (Contact ID, SIA) use DTMF [0]. These systems are still installed and relied upon by alarms today. It does seem the industry is finally coming around to LTE, since a copper pair is basically a fiction we present to alarms at this point.

[0] https://www.emergency24.com/cp/formats.aspx has a cursory overview of many protocols

That reminds me of this talk I heard a while back (I think this is it: https://youtu.be/Hk-21p2m8YY)

The guys working on nmap scanned the entire Internet. That set off some serious alarms because on the target side, it looked like they were aware of the existence of the relationship between IPs/assets that were classified. If memory serves some dudes in black suits showed up at their door lol

I don't think the MiB showed up but they got some very aggressive mail from people who got scanned.

https://youtu.be/Hk-21p2m8YY?t=478

I heard a similar story at a university I once worked. They did some kind of one-off portscan in the early internet days (with blessing of the local providers whose range was scanned). Some local companies got really angry because they spent a lot of time investigating the source.

> To avoid listening to all recordings myself, used Google Cloud Speech-to-Text to transcribe the recordings, and then used the transcriptions

... That's a lot of trust to place in google. Do all this work to gather data, then throw it away and analyze what google did to the data instead.

The amount of way google could have data, this is just peanuts.

All your data are belong to us!

To be fair, most of the original recordings (with caveats listed there) were linked at the bottom, so I presume that the author still has them around - that's hardly "throwing" them away.

I don't think the goal of using Google speech-to-text was to solely use the transcriptions for the rest of the project, but you've gotta find some way to sift through those recordings and pull out the interesting bits. I think that was the right choice providing additional context and picking out the good stuff. Imagine having to listen to ~28 hours of recordings (60 sec * 1724 answered calls) when there's a service that can easily turn those recordings into a more easily consumable format, and then you can go back and listen to the neat stuff.

Excellent points. Still, it puts a lot of trust in the service, the analysis is of their results not the original data.

Furthermore, it feels like cheating, dammit. We dialed half of an area code in a full a week back when, and didn't even have the luxury of recording equipment.

Traditional wardialing was almost always looking for modems, but it sounds like the particular number ranges that this researcher selected didn't contain any modems at all?

I'm sure there are still plenty of modems connected to landlines, not just for ISPs still offering dialup service, but also for SCADA systems and stuff.

The landline network in Finland is currently in the process of being taken down. I suspect the amount of modems connected is minimal.

That sounds like a terrible idea. Taking apart a useful infrastructure, with unlimited potential for adoption, for purposes we don't know about yet. They took apart most of the rail network across Canada, especially the smaller rural links. And sold the land. Imagine trying to recreate an efficient communications system in the future, and trying to purchase right of ways to interconnect all the villages and towns across a 5000km wide country.

The guys, who removed the telephone poles and the wires in these parts, mentioned they paid the local power utility around 40€ per year for each single pole shared with power lines.

Mind you, we're talking (mostly) disused old copper wires, with signal quality too poor to deliver more than a few mbps over ADSL, and most of the country is covered by a very well-built 4G network delivering 10+ mbps pretty much everywhere.

I agree it's sad to see working infrastructure being taken down, but everything was privatized in the 90's/00's and the new network owners have no incentive to keep paying for its upkeep.

What good do some relatively poor quality phone lines do when we have much better coaxial and fiber around?

The one advantage is that the old phone lines have been proven to be very reliable through a lot of times where something like a 4G connection hasn't. I used ADSL as a backup for times when 4G was unreliable, like extreme weather situations. On the other hand, once line noise reduces your speed to kbps rather than mbps, they're also of limited use in this day and age.

A fax machine uses a modem of sorts, just with one specific protocol and purpose.

I can't find anything about how WarVOX differentiates modems from fax machines, but I wouldn't write them off right away.

It is based on peak frequency, you can visually see it here: https://speakerdeck.com/hdm/derbycon-2011-acoustic-intrusion...

IIRC (it has been a bit), there was a specific frequency only used by modem negotiation but not fax machines (3150?).

As "rescently" as 2014 I as involved with an old computer, controlling a pre-processing stage for a high volume composite casting factory. It turned out the computer had a modem and was connected with its own phone line. It also had Norton pcAnyware for remote operation.

The computer had been running since at least 1992. No one remembered ever getting remote support, so I left it disconnected just for good measure. If anyone had actually wanted, I think you could have done a decent amount of damage using that. Especially since no one knew how and what the software on the computer did anymore. :)

As a pre-teen in the early 90s, I spent hundreds of hours wardialing most of the free-to-dial exchanges. I was lucky enough to have a US Robotics modem that reported the extended result status codes to detect voice, continuous tone, and fax lines.

The results were typically for every exchange that 1% of the numbers were modems, 1% were fax machines, 70% were non-intercept recordings or humans, 0.3% were continuous tones and test numbers, and the rest were primarily unallocated or just did not complete.

I did the same thing -- wardialed the free-to-dial extensions in the small town that I grew up in.

The next day, someone from the gas company knocked on my parents door because apparently my war-dialer (who worked during the day when I was at school) knocked offline their monitoring system.

Now-a-days, I'm sure I'd be hauled off to jail instead of a polite request to keep the 13 year old away from the phones for a bit.

At one point, I got a knock on the door from some city detective because I dialed someone who, I guess, was the victim of some abuse and used *57, the code for initiating a trace and reporting it to an already assigned investigator.

The optimal solution, I mean other than knocking off completely, would have been to use a reverse directory to blacklist all the residential subscribers.

Interesting historical tidbit... "back in the day" the phone company often located "interesting" numbers (modem numbers, test numbers, etc.) within a given exchange in the npa-xxx-99zz block, or maybe npa-xxx-9zzz. So a friend and I started war-dialing that block in our local hick town, and found some test loops, ANAC numbers, modem numbers for the switch that served our town, etc, etc. Fun stuff. Then one day right after one of our sessions, we got a call - from the phone company, basically telling us to knock it off before we got into big trouble. I don't remember the exact wording, but that was the gist of it. They knew who we were and where I lived, so that "put the fear of god into us"... briefly.

Then we discovered that you could beige-box the line connected to a COCOT[1] sitting at a remote convenience store out in the middle of nowhere at 2:00am and connect a modem to that. One cheapo refurbished "brick" of a "laptop" later, and we'd go out late Sat. night / early Sunday morning and run our scans and login sessions to their switch from this remote payphone. What was nice was this particular phone's demarc box was the kind that had an RJ-11 connector in it, so we didn't even need alligator clips. We just plugged a long telephone extension cord in, parked my car about 50 feet away and sat in there, huddled around the "laptop" and went to work. Good times.

And then sometime in the late 90's we all realized that we were old enough to be tried as adults if we got caught, and that the authorities were starting to take this stuff more seriously and that getting busted could have real consequences like not getting hired for jobs, not getting into college, or even jail time. I mean, Operation Sundevil[2] had happened almost 10 years earlier, but we assumed that our risk was limited living in the hick town we lived in, with Barney Fife cops and low-tech telco employees, etc. But at some point we all walked away from that stuff, deeming the risk of continuing to play in that world to be too high.

[1]: https://en.wikipedia.org/wiki/COCOT

[2]: https://en.wikipedia.org/wiki/Operation_Sundevil

The 99xx numbers were all payphones where I lived. All the exciting test numbers were the 00xx numbers.

On that note... am I the only one who thinks that it's something of a shame that payphones aren't really a thing anymore?

I also ran a war dialer I had downloaded off of a BBS. I woke up a lot of people. After some testing, I ran it only once overnight.

The next day we received at least three calls from people who were upset about being woken up. I placed the calls from our family phone number, so my mom answered them.

She mentioned these callers but I think she assumed they were confused or something. I did not explain my “experiment” and never got in trouble. But I did not war dial again.

It ran all night so I collected a fair amount of data but did absolutely nothing with it. I think I thought I would find some secret line to the White House.

Society got its revenge though. Due to spam and robocalls, all unknown calls go to silent for me now, I leave my voicemail “full” and POTS is rarely useful.

You had to set your line not to send caller-id data or use *82 on every call. That would stop ordinary people calling you back to complain.

I believe I had done this, which surprised me that people still were able to get the number.

The "exception" music example isn't really an exception. It's Passages by Kenny G which is about as hold music as it gets, it's just heavily modulated.

Maple confirmation message for Clevercrossing sounds a lot like "Mobile confirmation message for global crossing..."

https://en.wikipedia.org/wiki/Global_Crossing

> Ensured that any recording of private individuals did not end up outside the EU, being saved by third parties, or used to train machine learning models

is incompatible with

> To avoid listening to all recordings myself, used Google Cloud Speech-to-Text to transcribe the recordings

This is not true. Google Cloud's speech-to-text service allows users to select the region used to process data, and allows users to pay a higher rate in order to opt out of their data being logged.

But Google's speech-to-text is the epitome of machine learning.

But it's unlikely to train on user inputs/outputs, because they wouldn't know if they were correct

Data that customers are sending to an ML speech-to-text API seems like exactly the sort of data that one would want to save for training future models. Maybe I'm too cynical, but I have no confidence that Google throws away any data that they can get their hands on.

I mean you can just read their description:

By default, Speech-to-Text does not log customer audio data or transcripts. To help Speech-to-Text to better suit your needs, you can opt into the data logging program. The data logging program allows Google to improve the quality of Speech-to-Text through using customer data to refine its speech recognition service. As a benefit for opting in, you gain access to discounted pricing.

Why is the only factual answer in this thread downvoted?

People love to hate on Google here apparently, inconvenient facts to the contrary aside.

I wouldn't be so quick to take their own description as fact.

If you can't trust anything or anyone in life, that's a hard way to live.

Yeah, they could by lying - but they'd be opening themselves up to lawsuits for questionable gain. It would be a dumb risk/reward calculation. That's not to say companies (or people) don't do dumb things, but let's give them the benefit of the doubt until we have reason to believe otherwise.

I didn't say anyone or anything, in this case we're talking about a company that data mines as one of their primary business models that has been caught lying about the extent of data collection multiple times. They've also been sued successfully multiple times and have settled cases out of court (i.e., paid settlements privately).

I'm not sure what happened, but there used to be a time where not trusting a company like Google would be the smart stance to take. How could anyone with that much power possibly be trustworthy?

The tides have shifted, it seems. People now default to trusting big tech, trusting big govt, trusting big pharma. It was a lot of work, years of propaganda, but they did it!

If you don't trust them to abide by their contracts and agreements, don't use their services. That seems like a minimum requirement to do business with any party.

No point complaining that other people are willing to do business with them.

Over the last decade, most speech-to-text services admitted keeping and humans listening to source recordings beyond what was disclosed in terms of service.

In fact, one of the early “AI/ML” transcription services (which at the time blew away competitors including Google) turned out to be almost zero machine processing, almost entirely a human transcription farm in Egypt.

With almost 100% of the services, including those provided by members of FAANG, admitting this, it seems the risk/reward calc didn’t deter, and a “give the benefit of the doubt” algo seems inappropriate.

They could keep the recordings and have someone verify whether the output is correct.

There is this thing called unsupervised learning. It's quite possible to use this data for further fine tuning of models if the confidence outputs of the current models are high enough that the data is properly labeled, even if that labeling was done automatically. This is a quick way to bootstrap a small set of labelled data into a larger one. Whenever errors are detected later on you can correct for those and then retrain.

Yes, but if you are paying them extra to specifically opt out of users' data being used for that purpose, it's extraordinarily unlikely that they are doing so anyway.

Regarding: "Maple confirmation message for Clevercrossing."

It sounds like they are saying "Global Crossing" which was a telecom company

https://en.wikipedia.org/wiki/Global_Crossing

I'm also fairly sure it says 'mobile' not 'maple'

I am pretty sure I recognize the hold music. I believe it is from uberconference.com. You likely found one of their teleconference lines. Each paid UC user gets their own local number. When a conference is active, dialing it will connect you immediately to the conference. (Of course, the host can chose to require a PIN, but I never had any unknown drop ins.) It is SO much better than Zoom’s system.

That’s a huge amount of people who didn’t answer. Phones are basically worthless to get ahold of people — I called about 40 students last spring for interviews and got only one answer, myself.

Note that he intentionally picked numbers that were unlikely to be personal phone numbers.

That seems to be part of the problem with political polling lately: practically no one answers the phone (and of course not many of those who do are willing to participate).

Did you first leave a voicemail, text, or email as well? Most of my time I am busy. Either sleeping, working, relaxing (TV, games, friends), and only a small small fraction of my time am I doing nothing to such a degree that if pick up an unknown number call. Especially in 2020s due to spam callers.

I've noticed some people saying "kids don't pick up phones anymore" and really, no, we don't. There's more efficient and reliable communication modes available. If I could pay for a sperate set of phone numbers that were text-only, I would have that instead.

I've noticed some people saying "kids don't pick up phones anymore" and really, no, we don't.

Kids? Hell, I'm 47 and that's my policy as well. I basically don't answer unsolicited phone calls unless it's my dad or one of a very small number of close friends or family members. And honestly, even that's not guarantee that I will pick up at times.

Same (44) phone calls are for recruiters and marketing spam, so if I'm not currently looking for a job, the phone doesn't get answered

How would your dad, and the others mentioned, be considered 'unsolicited '. Possible you mean 'untimely '?

> How would your dad, and the others mentioned, be considered 'unsolicited '

Haven't been asked/invited to call?

If I didn't text/email/etc. and ask you to call me, or we didn't somehow otherwise arrange it in advance, that's "unsolicited" to me. Just being a friend/family member doesn't change that underlying premise. The difference is, if you fall into those categories I might pick up anyway, depending on what I'm doing / how I feel.

Calling people is just rude. "Drop everything you are doing and pay attention to me". No thanks, text me instead and I'll look at it when I want.

I feel the same way. I feel like I'm expected to be a business during opening hours. Also sucks that many people don't leave a text message after they call unanswered. Did someone die, did something good happen, was it a pocket dial? Call back and find out!

Spam calls have made the telephone part of my mobile computing platform pretty much worthless, and it makes me dread interviewing and needing to pick up every incoming call. I wish we could all get on the same page and just switch completely to text or email and arrange calls in that fashion.

I use my iPhone’s voicemail transcription to screen most of my calls

Spam calls have ruined phone service. I don't answer calls that I don't recognize, sorry you'll have to leave a message.

I would like to know more about the zombie apocalypse number

Sounds like some PR stunt for a video game or something.

I remember 2600 doing this a few years ago. They claimed that they found a number that was "weird" which encouraged listeners to try it out. Turns out the rabbit hole was run by them :)

Or maybe just part of a game. We recently played an at-home escape room game and one of the clues was a phone number. We dialed it and it was a recording giving information about the next part of the game.

This was set up in 2019, the team having some fun! Thanks for finding us.

See also, /r/weirdnumbers and, if you're into that sort of thing (that is, exploring the phone network), /r/phreaking

Old-skool phreaking[0] (eg, using blue boxes and red boxes) is mostly dead (at least in the US and most "first world" countries. Maybe there is some vestige of in-band signaling left somewhere else) but there is still some fun to be had exploring phones and phone networks.

Modern day phreaking is more about GSM sniffing[1], messing with the SS7 network[2][3][4], using SCTP[5]/SIGTRAN stuff[6], etc. etc. But, at least for the land-line / PSTN network, even some of the old "colored boxes"[7] still do useful things. You can always beige-box a landline phone, violet-boxes should still work, I think a gold-box would still work, etc.

If you want to dig deeper into how the PSTN works, a good, fun book is Understanding Telephone Electronics[8] by Carr, Winder, and Bigelow. Another interesting one is Digital Telephony[9] by Bellamy. Another "oldie but goodie" is Voice and Data Communications Handbook[10] by Bates and Gregory.

Also, don't ask me how or why I know any of this stuff... :-)

[0]: https://en.wikipedia.org/wiki/Phreaking

[1]: https://www.youtube.com/watch?v=wzyuioto4y8

[2]: https://www.youtube.com/watch?v=0JCusqL-Gdk

[3]: https://www.youtube.com/watch?v=-wu_pO5Z7Pk

[4]: https://en.wikipedia.org/wiki/Signalling_System_No._7

[5]: https://en.wikipedia.org/wiki/Stream_Control_Transmission_Pr...

[6]: https://en.wikipedia.org/wiki/SIGTRAN

[7]: https://en.wikipedia.org/wiki/Phreaking_box

[8]: https://www.amazon.com/Understanding-Telephone-Electronics-J...

[9]: https://www.amazon.com/Digital-Telephony-Telecommunications-...

[10]: https://www.amazon.com/Voice-Communications-Handbook-McGraw-...

  > don't ask me how or why I know any of this stuff...

I think I know. You were a Ghost in the Wire !

Funny you would bring that up. So, all joking aside... my introduction to the world of phreaking / hacking was primarily reading Cyberpunk by John Markoff and Katie Haffner about 1995 or so. I was immediately in awe of Kevin Mitnick and his cadre of phreaker friends, and those were the guys/gals me and my little circle of phreaker friends most wanted to emulate. KM was one of my heroes back in those days (and truth be told, I guess he still is to a degree).

What is interesting is that it was only later that I came to know that that book was very controversial, is of doubtful veracity in parts, and may portray KM in a somewhat inaccurate light. Nonetheless, it launched me on my path to a (short and inauspicious) "career" as a phone phreak. But I've remained fascinated with Kevin's story all the way to the current day, and actually just finished reading The Cyberthief and the Samurai and a couple of other books about his story, which I had not read before.

I'm surprised they found no modems. I don't see any listed. I'm sure there are still modems on the telco system for things like maintenance lines. I've seen them before in data centers to get into the networking hardware if everything else is down, for SCADA systems, to support really old credit card terminals, etc.

I think some of those "off brand" ATM machines you find in like convenience stores and stuff, use dial-up comms as well. So somewhere, out there, there are modems waiting to receive those calls...

Yep. The ATM in my office's lobby (which used to be a bank headquarters, ironically) has a little speaker and you can hear it do the PPP handshake when it connects.

The author also posted an interesting bit on setting up a VOIP/SIP honeypot: https://shufflingbytes.com/posts/sip-honeypot/

Turns out is a ton of automated activity looking to make money via poorly secured phone systems.

Did a similiar thing with ToneLoc in 1993 or 1994 (not 100% sure of exact year, but 1994 at the latest as i still had my 286) using an USR 14400 Sportster in Finland also, but my scan was limited to the 9800/0800 1xxxx set which seemed to cover most of the freephone numbers. (I believe 9800 and 0800 were mapped to the same endpoints back then, memory slightly hazy.)

I do recall getting far more modem pickups than your run, perhaps it was more popular back then. One that made me wonder back then was a modem answering stating it was a 'Cray Communications CMX', sadly now decades later i know that it has nothing to do with the supercomputer manufacturer.

In one of my previous job, I created a fax spamming machine with the same principle: a SIP trunk and an Asterisk machine that bruteforce numeration blocks. After few months we collected an interesting database of fax numbers

What were you trying to do?

Many years ago I did something similar with a piece of software called ToneLoc. I called every number in my my city. The results back then were much more interesting as there were so many more modems and dial in networks.

According to his data, no modems were present. It could be that he classified modems as facsimile, but he doesn't say.

> 11 Calls were answered with only music. The music could indicate something, such as being in queue for some service. All music variants except for one sounded like generic elevator music that could be the default hold music in PBXs.

Someone told me that there used to be actual phone lines playing music 24/7 that elevators would dial and output to a speaker. Speaking of elevators, their emergency lines are also usually just phones and, as someone already pointed out in this thread, with enough knowledge you can call the elevator and listen (and talk) to people in it.

Circa 1998 I dialed a random sample of toll-free numbers in the US and found that 20% of them were numeric pagers. So you could write a script that does something like

   ATDT 1800*******PPP[victim]

where * are random digits. If you did it 100 times, the victim would get about 20 calls from very confused big shots who had no idea who was calling them. You could make 5000 of those calls a day so it would be quite a hassle.

This reminds me of listing a free TV on Craigslist and using a “victims” phone number.

There's people who do this sort of thing in the US network regularly: https://www.twitter.com/shadytel

Some of what can be expected to be found in telco test ranges: https://pastebin.com/7KAuZmQq

Why does audio sound so bad over the phone? Why can we have 1Mbps broadband over these lines but not pristine audio?

Are you talking about a landline phone or a cell phone? There are pretty big differences between the two, traditionally. More concretely, cell phones generally have shitty sounding audio largely due to the compression and other manipulation of the signal that happens in during the overall process.

Landline phones have largely been compressed data since the 70s, and we're still using the same compression algorithms on most phone networks to this day. ~~Most cell phones will use the exact same audio codecs as most landlines and this has been true for decades.~~ EDIT: Actually this isn't exactly true. Most "landlines" will use G.711 while most GSM cell phones will use AMR. Either way, both are pretty highly compressed audio sources but AMR lets you drag the quality even lower.

https://en.wikipedia.org/wiki/G.711

https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_code...

Its been a long time since most landline phones were actually complete circuits from point A to B. Those old mechanical switches were crazy expensive to operate.

Either way, both are pretty highly compressed audio sources but AMR lets you drag the quality even lower.

That may be what I'm thinking of. And IIRC, regarding land-line phones, the issue of compression varied depending on whether you were placing a local call or a long-distance call, and varied depending on the long-distance carrier. But, to be fair, I haven't thought about most of this stuff, or studied these issues, in about 20 years, since I last worked for a company that did telephony work. So quite possibly my memory is wrong, or my knowledge is just outdated now.

It could be those long-distance carriers were transcoding the call at either end and using a more lossy codec internally. G.711 isn't exactly the most efficient compression algorithm but it was relatively cheap to work with when it came out which is why it was so popular. In the 2000's doing the transcoding on both ends of the distance carrier would probably be cheaper than adding more capacity on whatever long-haul lines were there, cheaper to buy some new hardware at each end instead of laying yet another cable or swap out all the RF equipment in between.

i was told once some of the emergency lines on elevators in Germany could be called into once you uncovered their number and expected to read about something similar here but no. Still quite interesting of course.

i wonder if these machine-machine range numbers might only accept calls from other machines in that range...

The elevator call boxes are surprisingly easy to "hack" considering they have virtually no security whatsoever and the industry doesn't appear to have practices that combat social engineering.

https://hackaday.com/2019/08/10/those-elevator-emergency-cal...

Coincidentally, the author works at an elevator company as a Product Security Engineer according to their LinkedIn profile.

Unrelated to the post, but the thumbnail that loads at the top of this page is very large (and slow to load). https://shufflingbytes.com/images/avatar.png

> Maple confirmation message for Clevercrossing

I think this one actually says “Mobile confirmation message for Global Crossing”. It’s a slightly nasal Brit accent so I can see why it might have been a bit harder to decipher.

When 55150 are unanswered, the title begins to feel clickbaity.

Having read the whole thing, I wholeheartedly disagree. I went in expecting something vaguely phreaky, and I was not disappointed.

How would one go about getting a phone number in the Finnish machine to machine space? Sounds like a great number to have to avoid robo call spammers.

Maple confirmation message for Clever crossing

Mobile confirmation message for GlobalCrossing

Yes this, it's Global Crossing which is a telecoms infrastructure company operating big sea cables and the like.

Yeah, that's an interesting find. Some clandestine operation, maybe?

I might have written a wardialer and called all my local numbers right after watching the theatrical release of WarGames.

Does anyone else have a problem with this? I often get multiple calls like this a day!

I firmly believe that the right to privacy includes a right not to be disturbed at random times on my phone.

FIRST: The phone networks need to quickly detect spam like this and block these kind of calls.

SECOND: This kind of behavior needs to be considered white-collar crime with appropriate fines, jail time, and other penalties. (Like not being able to have a phone and internet connection.)

>How I tried to avoid scaring people with ghost calls in the middle of the night. (...) You get a call, which you pick up, but the caller remains silent. After a while, the caller hangs up. This alone can feel threatening to some people.

And the author's solution is... to delete call recordings. What about just playing prerecorded message explaining it? I can't help but question intelligence of the author.

is "illegal termination" when you funnel calls via VoIP to some local mobile network operators using sim cards usually provided to customers? like lets say to avoid billing it like a call into another network?

That’s one example, yes.

In some places that may be illegal, in other places, just a breach of contract. Lots of interesting contraptions on AliExpress with 64 SIMs in it.

Other times, international traffic is supposed to pay more than domestic traffic (governments use it as a source of revenue), but it works on the honour system at some telecoms.

Or someone is letting your traffic appear as coming from a telecom’s no-cost peer, even though you’re not their peer and are supposed to be buying termination.

In these cases, you’re unlikely to get working callerID because that would make it too easy to trace the true origination.

This is wonderful, any thoughts on about doing this in another country?

Avatar describes Moomin characters. These characters were first introduced by Swedish-speaking Finnish illustrator Tove Jansson. I find them very Nordic. But the characters were also adopted by a Dutch-Japanese animation production and they spoke Japanese. I found it also kind of fitting and natural.

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