If you dig into Evan Doorbell's stuff, he explains this nicely. It has to do with where the intercept was caught (the particular CO / switch level / device).
Not quite in the spirit, I suppose, but you can find out more about most of the numbers by googling them. One guy published youtube videos for a couple of them. Kind of fun.
Someone set up a strange number with something like this a while ago, with a bunch of randomized recordings. Some of these appear to be inside jokes or otherwise have hidden meanings about unorthodox behavior from phone systems - +1-248-200-0008.
Decibels are only ever a relative measurement on a logarithmic scale. In this case, we aren't even talking about sound (these are dB of power), but this is true independent of base unit. For sound, to represent silence, you actually need -∞ dB. The fact that this is a relative scale is also why your mixer/home theatre receiver represents full intensity as 0 dB and any volume adjustments as some negative number of dB (some mixers may allow you to go a little bit over 0 dB but of course this risks clipping when a full-strength signal comes in).
Fun fact though: the sound scale is capped on the upper extreme depending on your environment. You know how recordings of launches of rockets sound like the sound is clipping? It's not hardware limitations. The sound is actually clipping as the pressure hits vacuum. See https://en.wikipedia.org/wiki/Sound_pressure#Sound_pressure_... .
A 0dB tone is a tuning tone. Most amplifiers are tuned to a particular frequency at 0dB, and with a good phone connection, you can even do this over the wire. It's problematic if there are too many hops between you and the source. For example, calling a 0dB tone in a small CO in central Montana didn't give me a usable reference when I was calling from Huntsville, AL, in the 1970's. There were about four hops in there.
It was originally 1000Hz, but it turns out this could cause framing errors on D4 trunks because the framing recovery circuit could misidentify the bit pattern as valid framing bits. So they changed it to 1004Hz, enough to sidestep the problem, but still close enough that it would still represent "exactly" a milliwatt of energy, within the required precision of the instruments anyway.
When ESF framing was invented, precise tones no longer posed a problem, but a lot of D4 trunks hung around for decades, so last I checked most milliwatt tones were still 1004Hz.
It has the Hall and Oats recording number, but is missing the one for They Might Be Giants. Does anyone know if it's still active?
TMBG used to release all of their new music on an answering machine before you could buy it. Kind of a pre-internet version of artists releasing singles on YouTube before you can buy the album.
There used to be (maybe still is) an 800 number you could call to get your ANI, basically the billing number for whatever phone you were calling from. Kinda fun.
For the second one, I'm getting "Please, enter your password", then, after typing the passcode – "The toll-free number you have dialed has been disconnected. No further information is available about this number. 074T"
Potentially as a backup distribution service. If you're running a translator transmitter to extend service range, and can't get the signal some other way, maybe you can dial in and pipe the phone out the radio.
In the NYC vicinity, dialing the -9901 suffix on many phone exchanges will give you a recorded message identifying the central office you reached. For example, if you call (212) 736-9901, it tells you that the switch is on West 36th Street[1] and a list of area codes/prefixes it serves. Amusingly, the switch still identifies itself as "Bell Atlantic", which is what the local Regional Bell Operating Company was called before it became "Verizon" in 2000 (it was also briefly "NYNEX").[2]
NYNEX: just clicked that's what Phantom Phreak from Hackers was on about: "the Phantom Phreak, king of NYNEX". And looking at the dates, seems to gel... took me that long to figure out what was said there!
This makes me feel old. I remember seeing Hackers in the theater, when it came out, back in 1995. NYNEX was the local RBOC. Broadband wasn't a thing yet, and everyone was still on dialup.
Briefly? The New York / New England RBOC was called NYNEX for most of the 80's and 90's, a lot longer than it was Bell Atlantic. Bell Atlantic was just a 3 or 4 year thing after it acquired NYNEX.
You're right: NYNEX existed from 1984 (breakup of Bell System) to 1997. But Bell Atlantic was also an RBOC created in 1984. The two companies merged in 1997, with the resulting company being called Bell Atlantic (which was when NY's phone company became Bell Atlantic). Finally, Bell Atlantic acquired GTE in 2000 to form Verizon.[1]
RBOC history is so crazy when you read about it.
All these companies were broken up to eventually reform into huge corporate behemoths again, only decades later ("new" AT&T, Verizon, and Lumen / Century Link) It makes me wonder if we weren't better off just keeping the original AT&T together.
I'm always astonished that after 30 years and the installation of two giant data centers, this little Oregon town hasn't upgraded its telephone exchange. Anyway, here's an automated ghost from the past: 541-447-0054
This makes my heart smile. Rarely these days I’ll connect with a phellow phreak and we chat about bridge parties and other fun stuff. One day the fone number will be a thing of the past and all this an ancient memory.
At one of the HOPEs, someone brought a bunch of 8-bit machines and set them up in the mezzanine. Among them was a TI 99/4A, which for all its failings, had a very nice sound chip accessible from TI BASIC. And, bless whoever brought it, the TI BASIC quick reference card was tucked under the machine, which was all I needed to jog my memory. I implemented a quick tone-dialer with DTMF and redbox tones, adjustable twist, and a few other features.
Since there was no tape deck and everything was just resident in RAM, I fully expected that someone would reboot the machine and do something else with it moments after I walked away. It was fun in the moment, that's all I wanted. Much to my surprise, I came back several hours later and there were folks playing with the dialer, and to my even greater surprise, someone had extended it with MF and bluebox tones in the interim!
I always enjoy reading about this kind of stuff even though a lot of is only applicable in the US. On UK landlines you can dial 17070 to access BT line test functions.
When you dial a very well spoken voice reads your phone number back to you. It's rarely been useful to me but I did once astonish someone by using it, they were convinced it was meant to be a secret number and that I was probably breaking the law!
I had a lot of fun with lists like these in the 70s/80s. To this day I give all of my creditors a phone number which I know has rung busy since 1983 thanks to lists like these. It would be very interesting to war-dial all of the US exchanges in 2022 to see what answers.
If you like learning about telephone system, phone phreak Evan Doorbell has a very interesting series of podcasts about his time exploring the telephone system in the 1970's. The podcasts include his recordings from that time period.
It was neat to hear some of the old tones and recorded messages I grew up with, as well as ones that were well before my time:
yeah, I love Evan's stuff, especially the recordings about George, the answering machine, and random answering machine outgoing messages from the 80's Atlanta area. fantastic!
Yeah! This stuff is a total gas. Here's this professional-broadcaster-quality voice, narrating a personal story about 50 year-old recordings of noises made by equipment that doesn't exist any more. (With threats by 'Ernestine') So: pure entertainment.
After the series of many narrated tapes, there's another series of raw tapes (unnarrated ... test what you've learned).
The magic of the PSTN was you could work your way into the bowels of the Military and talk to a guy guarding nukes just by dialing the right number and bullshitting. Today you can't really social engineer your way into unauthorized access on Slack, for example (you have to have an account first). I suppose e-mail is the final remnant of the information wild west. Well, that and public ELK stacks...
94 comments
[ 3.4 ms ] story [ 164 ms ] threadhttps://www.thisisarecording.com/Bell-System.html
https://telephoneworld.org/telephone-sounds/modern-north-ame...
Fairly easy to download and use on your own voip system if you want.
http://www.evan-doorbell.com/production/group1.htm
I'm wondering what do these codes at the very end of some AT&T recordings mean? "312 8L" seems to occur on 5 totally different ones.
That’s exactly what I’d expect a hacker to say ;-)
Now, where did I put my Captain Crunch whistle?
Do I recognize some of these voices?
I made 50k calls to explore the telephone network (shufflingbytes.com)
333 points | ValtteriL | 7 months ago | 180 comments
https://news.ycombinator.com/item?id=27602383
Any phone people here?
https://en.wikipedia.org/wiki/Loop_around
I'm not a phone person but I've heard of this before.
Fun fact though: the sound scale is capped on the upper extreme depending on your environment. You know how recordings of launches of rockets sound like the sound is clipping? It's not hardware limitations. The sound is actually clipping as the pressure hits vacuum. See https://en.wikipedia.org/wiki/Sound_pressure#Sound_pressure_... .
When ESF framing was invented, precise tones no longer posed a problem, but a lot of D4 trunks hung around for decades, so last I checked most milliwatt tones were still 1004Hz.
μ-law for the win.
TMBG used to release all of their new music on an answering machine before you could buy it. Kind of a pre-internet version of artists releasing singles on YouTube before you can buy the album.
800-223-1104 (passcode 910777)
RING A BELL (213) 223-6101
<a href="tel:2027621401">(202) 762-1401</a>
so that they maybe would be really click-dialable :-)
Is this meant to announce your own number back at you? I called from outside the US and got a very different number from my own, which is fascinating.
I wonder if the number I got is the notional phone number of a virtual international trunk line or something like that.
In the NYC vicinity, dialing the -9901 suffix on many phone exchanges will give you a recorded message identifying the central office you reached. For example, if you call (212) 736-9901, it tells you that the switch is on West 36th Street[1] and a list of area codes/prefixes it serves. Amusingly, the switch still identifies itself as "Bell Atlantic", which is what the local Regional Bell Operating Company was called before it became "Verizon" in 2000 (it was also briefly "NYNEX").[2]
[1] This building, apparently: https://skyscraperpage.com/cities/?buildingID=69989
[2] https://en.wikipedia.org/wiki/Verizon_Communications#Bell_At...
[1] https://en.wikipedia.org/wiki/NYNEX#History
At one of the HOPEs, someone brought a bunch of 8-bit machines and set them up in the mezzanine. Among them was a TI 99/4A, which for all its failings, had a very nice sound chip accessible from TI BASIC. And, bless whoever brought it, the TI BASIC quick reference card was tucked under the machine, which was all I needed to jog my memory. I implemented a quick tone-dialer with DTMF and redbox tones, adjustable twist, and a few other features.
Since there was no tape deck and everything was just resident in RAM, I fully expected that someone would reboot the machine and do something else with it moments after I walked away. It was fun in the moment, that's all I wanted. Much to my surprise, I came back several hours later and there were folks playing with the dialer, and to my even greater surprise, someone had extended it with MF and bluebox tones in the interim!
It was neat to hear some of the old tones and recorded messages I grew up with, as well as ones that were well before my time:
http://www.evan-doorbell.com/production/group1.htm
After the series of many narrated tapes, there's another series of raw tapes (unnarrated ... test what you've learned).