I wrote a "ring knocking" tool back in my college days so that I could connect to my Linux box at home from the labs at school since I was on dial-up. I'd go to the payphone, put in a quarter, call my line and let it ring the requisite number of times, hang up, get my quarter back, then go to the lab and check my school email account. The ringconnectd daemon would detect the rings, wait a few seconds, connect to my ISP, and mail me its current IP address.
I tried to do something similar not too long ago. Different application really, but I wanted to do something on the other end depending on how often it rang. Sadly I discovered that apparently in all-digital "modern" phone networks (SIP, VoIP etc.) the ringing tone you hear as a caller is simply ingested by your network operator and the tone you hear as the one getting called is basically just some audio file that plays over and over, triggered by a single "hey, someone is calling now!"-message sent by a modem unit, which to my surprise are still using AT commands to this day. Bummer. Turns out even the duration of how long it rings depends on too many factors, so what you hear on one end (ringing) might be off by multiple seconds on the other end.
At least it explains the "You only heard it ring once? I let it ring like five times before I hung up! Seriously!"-anecdotes I keep picking up. :)
> the ringing tone you hear as a caller is simply ingested by your network operator
In my experience this depends on the network in question: SIP supports "early media" and I've seen it in action a few times. You can tell by the fact that phone UIs usually don't count connection time in that state, yet you can hear a prerecorded announcement, music mixed with the dialing tone etc.
I remember some creative uses of this as well: If you controlled the signalling stack, it was possible to keep a connection open in this state indefinitely without either end getting charged.
The early media can still be generated at any point of the calling chain. It doesn't have to correspond to actual ringing, if ringing does happen on the POTS side.
(For a test, you can call someone in the UK and check if you hear Pink Floyd style beeps)
This is also true with silences. When we switched from analogue phone calls to digital phone calls in the 90's, SIP began to ingest white noise during silences due to discomfort perceived by the users thinking they got hung up or the network has been disconnected.
When I was a teenager in the 90s in the UK, if I wanted my parents to collect me from somewhere then I could let them know by calling the operator from a payphone and asking for a reverse charge to my parents landline. Calls to the operator were free but reverse charged calls cost a lot to those who accepted them.
When asked for my name I would usually use my first name and use my last name as the place to pick me up from. If that gave them enough information then they could reject the call, which would cost them nothing.
When I went to sleep away camp one summer when I was 11, it required me to take an airplane by myself. To let my parents know I had arrived, they told me to call collect, use my regular name, and they would reject the call.
If it was an actual emergency, I was to immediately call back again and then they would accept the call. It was a great way to get free messages.
Ah, memories! Later in the 90s they (who?) introduced a new automated service which I think was called “0800 REVERSE”. The beauty of it being automated was you could quickly give the required message in full, or even the number of the payphone you were calling from.
Yep, one of my friends in high school (1980s) was on my sports team. He would call his mom "collect" from the school's payphone [0] at the end of each practice (end times varied by as much as an hour) and the name was something from a Chevy Chase movie (Fletch?) and his mom would reject the call, and get in the car and head over to pick him up.
[0] Remember this was the 80s, no mobile phones. And a collect call was free from a payphone, since the callee was expected to accept and pay the charges.
Some memories with those time. We used missed calls for varying reasons depending on the people we interact with.
* When going to meet someone, first missed calls says you've started, then the second missed calls says you've reached. This will be informed before hand while scheduling the meet.
* You're supposed to reject when you're expecting a mutually agreed missed call, and if the call comes the 2nd time immediately, then you should pick up.
* During meets, there usually is one organizer who everyone gives missed call to update their status and they'll follow-up with another missed call to those who didn't update. I know it sounds complicated, but it surprisingly isn't.
* Before mobile, landline was pretty common and caller IDs were almost non-existent, missed calls with a pattern are the way to denote that its you that's calling to make sure her parents does not pick up the phone :). One ring, then two rings, and she should be near the phone for the next call to pick (you hope and pray its not her dad, again.) and pretend to talk with a friend.
Yup, there were several tricks like these!
My father used to travel a lot and paying for roaming was expensive. So when he was available to speak, he'd just give a missed call at a fixed time and we used to call him from the landline (much cheaper). If we didn't get a missed call, he was busy.
I also remember while going to college, I had bus connectivity, but had to walk the last 3km or so home. I used to call either of my parents to come pick me up when I was around 15 minutes away from the bus stop.
Long before cell phones and answering machines my Dad was a pharmacist in a small town. He was happy to drive down to the drugstore when a customer called our home needing an after-hours refill, except on Sunday which was his recharge day. On Sundays we were instructed never to answer the phone unless it rang twice, paused, then rang again. Close family members knew the secret code; customers just learned Dad wasn't available on Sundays.
My (now retired) pharmacist said he got a call on Christmas Day because someone got someone a surprise travel holiday that left the next day and they didn’t have enough meds to be away that long.
He doesn’t believe they realized he was half in the bag filling their prescriptions.
Same here. Even if my dad wasn't on call, his job would call every saturday and sunday with some dumb emergency caused by their own cheapness. So we pulled the phone plug at night, and at daytime we counted the rings.
Eastern Europe already checked in, but I thought I'd add yet another anecdote.
In St Petersburg, Russia the only GSM provider had luxurious free 10 seconds, and $0.40/minute after that. Plus fixed monthly fee, of course. $0.40 was very expensive by Russia late 90s standards and at that time mobile phones were used by three (or really just two) distincitve groups: gangsters, emerging business people, and... dudes in IT.
Criminals didn't care about money, but IT crowd was crafty and resourceful.
Some phones allowed to configure a beep after 9 seconds prompting you to hang up and redial. Those were valued, but it didn't stop at that - there was even a cottage industry of firmware and hardware hacks for certain models to drop the call and redial automatically.
...and then providers switched to only 5 and then 3 seconds, and $0.10/min, yet for a few more years there were still annoying die-hards who kept their modded phones and old contracts with free 10 seconds and ridiculous price, which were no longer available for new clients.
I used Google calendar to send free SMS to myself with information about my services running on my raspberry pi. Each service had a future calendar entry with SMS reminder. Under normal operation the service would move the entry forward in time. If it had crashed, I got a SMS.
We also had an understanding of the number of based on the number of rings, too: 1 ring and hang up was when my aunt got home and 2 rings was my cousin got home. They could call us long distance to let us know they got home OK.
Yeah this was big among my age group in Australia too, in the late 80s early 90s. Pay phones only charged if the other end picked up, so it was an easy way to tell dad to pick you up or that you’d be late.
Pay phones (the yellow ones) in Melbourne in the early 90s let you both hear each other for under 1 second. Calling multiple times you could let your parents know to pick you up from wherever you were :)
I used to just say my message really fast when I was using the French equivalent (PCV France). So my dad would get a call saying something like “you are receiving a PCV call from: canyoupleasecomefetchmeatschoolloveyouthanks. Do you accept it?”. He would then hang up.
When I was young I used to use the 1800-REVERSE number, which would require the person answering the phone to pay. I thought it was a great way to contact my parents if I had run out of phone credit.
This was a thing among my parent's friends and relatives when I was a child in the north of England in the seventies. People would say something like "give me two rings to let me know you got home safe". I have no idea what the cost of landline calls was back then.
It also features in Iain Bank's novel Whit from 1995. The main character is a member of a Scottish religious cult, who mitigate their exposure to "ungodly" technology by using a message-passing code based on the number of rings before hanging up. Its a long time since I read the book, but I seem to recall some detail about it having to be error-tolerant because the ring-tones that the caller hears don't necessarily match those heard by the recipient.
I recall in Ukraine in nienties some mobile operators did not charge for the first few seconds of a call (I think it was 2 or 3). There was an art of communication around that...
In case you didn’t know, this media group was started by Sofia Schmidt, Daughter of Eric Schmidt. It focuses on tech stories from other countries besides the USA.
I don't understand the dismissive attitude. It's very much an all or nothing argument that completely ignores the middle ground.
I personally think this is a fantastic gateway. I'd love to have a better global perspective, but I simply don't have the resources (or time) to build a deeply informed opinion. This type of media gives me access to foreign tech within easy reach. Honestly, it gives me exposure to topics that I wouldn't even know exists. If it's a topic that piques my interest, I can certainly find alternative coverage (hopefully with less bias).
I recall reading this article about Bangladesh[1] from the site. Even for someone who know basically nothing about Bangladesh, it wasn't hard to notice major inconsistencies in their narrative; my analysis at the time[2]. It seems they took something fairly ordinary and tried hard to spin it into a "look how different these people are" (different in a bad way, for the most part, from my impressions) story to sell to Americans. Needless to say I take what they write with a big grain of salt.
>> (but written from a distinctly US point of view)
Yes and no.
The US audience is important but its not the only audience. If you look at the authors of those articles you will see that most of the writers are based outside of the US and (as much as in possible) in the areas/countries being reported on.
The goal is to increase that metric as much as possible.
* Fighting brain drain and creeping authoritarianism in Russia’s techno-utopian village
- By Leonid Ragozin who is based in Latvia (as far as I know)
* A defamation lawsuit in Singapore sets a dangerous precedent
- By Kirsten Han, a journalist based in Singapore.
* Peru’s surprise presidential front runner has fewer than 8,000 Twitter followers
- By Jimena Ledgard, based in Lima, Peru
* The mysterious user editing a global open-source map in China’s favor
- By Vittoria Elliott, based in USA, and Nilesh Christopher in Bangalore, India.
Full-disclosure: I work there. Writing from personal knowledge.
To people reading from India, The story is not about picking up unknown numbers (premium services scam) about which we receive advisory every other day; It's about missed calls to avoid call charges and the economy behind that before the WhatsApp days.
When I was travelling a decade ago I needed a way for friends and family to be able to contact me. Roaming rates were ridiculous at the time (something like £3/min to receive calls). As such I got a local prepay SIM card in each country I visited, however sometimes I only had a number for a week or two before I went somewhere else, so giving that out to people wasn't a good idea.
I got a VOIP number in my home country, and set up my mobile number (at home) to redirect to that - this is a feature of GSM, so should be supported nearly everywhere. *21*<destination number># to activate it. My home number was just calling another local number, so it was included in my plan. I setup the VOIP number to forward to the SIM in the country, and every time I went somewhere new I just changed the destination number. So I was reachable, and only had to pay a few pence per minute for it.
That mostly worked, but when someone called me it showed my VOIP number, not the number of the person who originally called. In Asterisk I could see I was receiving the caller's phone number, but my SIP trunk provider was filtering it out. One little email to support and I was able to set the originating number so it showed who actually called me - in reality this meant I could call anyone worldwide with any originator number shown.
The other problem which goes with this article is how to make outgoing calls. At first I used a SIP client on my computer, but then I went to a few places with pretty poor internet so that wasn't possible. I setup a script on Asterisk so if it received a phone call from my number (of the local SIM I had at the time) it would reject the call, then after a few seconds call me back. It would present a dial tone, and allow me to enter a phone number to call, after which it would dial it and connect me. Technically someone could have spoofed that, and made phone calls at my expense, but I figured the risk was pretty low. Boom, ultra low cost international calls while travelling :-)
In Austria the former provider "one" had a prepaid plan, where you where not billed for listening to your mailbox and talking to the mailbox of others using the same provider. You can imagine that they did not earn much among teenagers.
In Eastern Europe when cellphones became widely popular I remember a plan in which the first 3 seconds were not added to the bill and we as teenagers were making the best use of those seconds. Text messages weren't really a thing back then.
I work on a system like this. We provide agricultural advice to farmers (mainly in India and Kenya but also in some other countries). They can leave a missed call on our system, and will receive a call back where they can navigate a menu with information on a variety of topics, or they can record a question which will then be answered by an agronomist (the answer will be pushed to them as a separate call, once it's researched and recorded).
It depends a little bit on the contract with the provider, but the idea is that we are an NGO/charity and we don't want the farmers to have to incur costs for this. If we answer the phone they pay, if we hang up and call back we pay. In some cases we are able to set up toll-free numbers and then we can just answer.
I'm in Canada and all of the services I have looked at bill you once you pick up the call. If you are in your local area (for mobile) it is always a local call but you are still charged for the minutes.
You often don't know who is calling you until you pick up the phone, so you can't make a judgement about whether it's worth paying for the call until you've already started paying.
That, combined with the fact that it appears to be unique to just the US & Canada (maybe NANP in general), makes it bizarre to me.
We did that in Bulgaria back in the days as well. We also had a special verb for the act of ringing and hanging up immediately - "to clip" (from Calling line identification presentation = CLIP).
There was also the case where one of your friends would have many free minutes in one of the network. Then you would just "clip" them and the expectation was that they call you, because it was for free.
„Puścić strzałkę” (to send/drop an arrow) in Polish. Also sometimes called „puścić sygnał (to send/drop a signal), „puścić dzwonek” (to send/drop a ring), and other variants.
In Poland in mid 90's we had operator that had first 5 seconds of a call completely charge-free. So communication looked hilarious. Person who called, tried to yell as much as one could in 2-3 seconds, because after that charge-free seconds, you had to pay for the whole minute instantly.
We had something similar as recently as in 2005 in Poland. I don't know the specifics, because I got my first mobile phone in late 2007, but I think that either there was a flat fee incurred when someone picked up or the first minute was charged in advance - in any case the practice died off with the advent of cheap text messages in pre paid plans.
Oh, and it served as an equivalent of Facebook's "poke" among teenagers.
Ah, memories. Visiting India, my company driver used to get upset if I actually answered his calls, since that would cost him money. I soon learned to decline the call and call him back instead.
Heck, even today it’s the polite way to communicate with drivers and maids. Don’t answer the call, but immediately call back and ask them if everything is ok. They won’t call you if it’s not urgent and important.
It's interesting to read this article in these times of side-channel security exploits --- and remind yourself that covert channels are very difficult to completely eliminate, not just inside computers.
My grandma did this back in the 80s here in the US. Back then if you wanted to call someone more than about 10 miles away, it cost money. She lived in downtown LA and we were in a suburb, so it was a toll call.
If she wanted to talk to us, she would call and hang up after one ring. That was our signal to call her. There was no call-ID at the time, so we had to guess if it was her. It still cost us money to call, but she was fine with that!
Missed calls still signal a lot in this day and age.
One example: you send a couple serious texts to a close friend or partner after an argument. They stay unread and you get no response. You then call and see if they pick up after a few rings. If not you hang up and wait or maybe write it off. If the other person is there (and often you know they are there monitoring their phone) maybe now they respond (via txt or call) because they see it as important. If they don’t that says something about where things stand.
Another: you call someone first and get no answer. You then send some texts explaining why you want to chat and the urgency or context. From there you can gauge if the other person cares enough to respond quickly or ignore.
Obviously this all assumes an always online context for both parties, which can cause its own issues when that may not be the case.
Missed calls still hold a lot of important signal in an age of “I only txt” always connected people.
UK Pirate radio had this too. If you liked a song you could upvote by calling a number, they could count how popular a song was by the number of missed calls.
YI wonder if that's where Drake (or one of his ghostwriter s) took the phrase 'hotline bling' from. Before his song I only ever heard that on late 90s pirate radio in London (to describe the Nokia screen lighting up with missed calls)
In Eastern Europe this method was called "mayak" (beacon) and disappeared when calls became practically free even when SMS services was free much earlier because calling has a higher possibility to be noticed by callee.
I remember one mobile operator in late 2000s charged for a call only after first second. So we used to call each other, saying something really fast and hang up to not get charged.
When I was a teenager, one of the local mobile providers had some plans where they would only charge you for a call after being connected for more than five seconds. One friend abused the hell out of this and started using it as "free push-to-talk" essentially. I had a plan with free calling time, so he would also sometimes call me, tell me to call him back, and hang up within about three seconds.
Growing up in the 90s, my siblings had evolved similar signals based on missed calls on our single landline. IIRC a single ring missed call followed by a continuous call was intended for my sister, while my brother had a single ring missed call pattern. My brother was also dating multiple women, and had evolved a system (unfamiliar to me) to keep them all in the dark.
It’s also used by receiving parties that don’t want to accept calls but need a signal and/or those with toll free numbers that may receive numerous calls — voting on some competition shows uses this mechanism. Some campaigns have also used this to collect the number of people “signing a petition”.
Reminds me of childhood. We'd do this when we didn't have enough balance. Expecting the reciever to call back. This would work only within the state. Out of state we used to have something called roaming charges. Charged even when receiving a call. We don't have that anymore these days.
I had a friend who's father didn't want to take work related calls at home. To get someone to pick up the phone, I had to call and let the phone ring once, hang up, and call again. It was simple but it worked.
Before smartphones, apps and easy access to Internet in India, SMS and calls did cost a lot of money. To lower the barriers for response to billboard ads customer would call a hotline, the phone would ring twice and automatically disconnect, and the system would reply within seconds with dynamic content, through a call or texts.
It was my second open source project: https://www.ibiblio.org/pub/Linux/system/network/daemons/rin...
I was still getting support requests for it in the late 2000s from people who were using it in South Africa :)