2600.network Dialup Service
2600.network
2600.network
One problem with this premise was that when the appliance was not working how it was supposed to, you couldn’t just log into it to fix it because the Google magic was secret. You needed one of their engineers to access it and figure out what’s wrong, but the wrinkle was that every appliance was installed in a different environment and almost certainly behind a firewall that was not easy to open for this process. So to bypass it Google did a very clever thing and added a dial up modem to the appliance. That way you could just go down to the rack, physically connect it to a phone line, and put it into a diagnostic mode where it would dial out to Google to start the remote session. No firewall rules, no unintentional leakage, no accidental logins from who knows where.
No guarantee that the box won't poke for ways to break out either, or was there a pinky promise? I guess it was somewhat easy to disguise it, the search box is supposed to constantly poke around and index things, right?
Amusingly enough, that was Snowden’s approach, at least they way he tells it.
Some of these installations were located in the middle of nowhere, and in those days we couldn't count on Internet access of any kind. But the company happened to also own a dial-up ISP... so I came up with a system, which I'm kind of proud of even though it was quick a hack. We ended up piggybacking the whole thing on dial-up e-mail using GPG-encrypted attachments. A couple of times a day, each node would call into the ISP and do a standard POP3 and SMTP routine, processing incoming requests and dropping off outgoing ones. Because it wasn't important for it to be real-time, we made the whole thing work asynchronously with the customer only having to supply a phone line.
EDIT: This is that service if you are a Canadian that wants to try it, https://www2.vcn.bc.ca/free-internet-access-via-dial-up/
I wonder if some of the networks that are continuing to offer GSM (usually via some core network emulations, as far as I understand, to make it more compatible with modern core networks) have already broken CSD for similar reasons.
Even back in the early 2000's when I was using free nights and weekends with my T68i to make calls to a free dialup provider in new england (9600baud yea), my call would still drop every hour or so just due to signal hiccups.
(T-Mobile never enabled HS-CSD for 28.8kbps using more timeslots and it's unlikely my current rate plan will allow for CSD calls, but it doesn't mean I won't try, I still have an old sim card able to be used in 2G only phones, including that very same t68i which I tested last summer, still works.)
In theory you can run anything over this that could run over a long distance PSTN link.
In practice most modem technologies do not handle jitter and packet loss well at all, and quirks which a human would not even notice will trip up a data call. It still works, I have clients running credit card machines on VoIP lines all day, but the longer the call and the higher the bandwidth the more likely something is to go wrong. A short 9600bps data exchange from a card machine is a lot easier than a 30 page 33.6k fax which is a lot easier than a 56k modem on a PC.
There's a special method called T.38 that allows VoIP providers with compatible endpoints to convert digital fax calls back to a data stream instead of audio which makes it a lot more tolerant of delay and jitter as well as slightly more tolerant of loss. Something similar could hypothetically be done for data modems but I haven't seen it.
G.722 might sound better to humans, but G.711 is definitely better for modems since it’s effectively just uncompressed PCM (disregarding a bit of dynamic range compression which modems are generally fine with).
It would be possible to mask this with a relatively simple FXS device to hide all of this and pretend it's a modem while packetising the actual data, but I guess the demand is almost zero so why bother.
I've been looking for a solution for many years to retain dialin services without having racks full of modems and trunks that are rapidly going out of fashion and at some point will not be available except via IP (and now we have the same problem at both ends), but they just don't exist.
Regular modems can't make use of that, since the actual phone lines they were designed for (whether analog or digital via G.711) didn't support more than 300-3400 kHz anyway, so anything beyond 8 kHz sampling (corresponding to a Nyquist frequency of 4 kHz) is wasted on them.
Maybe you could go crazy with a custom modem that knows how to exploit the additional high-frequency components of G.722 while dealing with the lossy/psychoacoustic compression across all bands, but I doubt it would yield any improvement over G.711:
> It is compressed, yes, but at higher bitrates it is actually usable for modems/faxes
No, they're both exactly 64 kbps (after compression/"compression"), so you wouldn't be able to fit any more signal in it from an information theoretical point of view.
I had a project using hylafax with about a dozen USB fax modems hooked up to a SIP gateway, connecting through a VPN back to the office where the PBX was and then out to our SIP trunk provider on G.711. It sent a lot of 2-10 page faxes. The system sent over a million faxes over its life, and excluding one receiver that tended to constantly have problems no matter what had an >95% success rate.
Old gov contract expired 2022: https://www.gsaadvantage.gov/ref_text/GS35F0503M/0VX37Z.3RNG... (search for CSD, it's there)
New gov contract in effect (no CSD): https://www.gsaadvantage.gov/ref_text/47QTCA22D008N/0YTCAI.3...
EDIT: I tried to CSD dialup using my K850i which can handle my new and older SIM cards, no good. Simple Choice plans are way too new for this (the old plan I had in the early-mid 2000's was the Get More one)
Hence why “2600” is referenced.
A phreaker going by Joybubbles was the first to exploit the tone by whistling. Later, a toy whistle in a cereal box was found to be able to produce the tone, leading to further exploit by John Draper, aka, Cap'n Crunch.
You can 3D print the whistle these days for a bit of nostalgia.
Woz spoke at UC Berkeley (might have been 1998 commencement), and I asked him to sign an issue of 2600 magazine. After he signed it he flipped through it and asked if 2600 was still good and worth reading because he was thinking of getting a subscription for his son.
Joybubbles (formerly Joe Engressia) specifically denied being the first. In this interview (no timestamp), he mentions having heard of others phreaking as far back as the 50s: https://www.2600.com/offthehook/mp3files/1991/off_the_hook__...
He also demonstrates whistling 2600hz during that interview, including doing so on one of the only US trunks in service at the time still using it for supervision.
> Later, a toy whistle in a cereal box was found to be able to produce the tone, leading to further exploit by John Draper, aka, Cap'n Crunch.
Not true, even he admitted, belatedly, that Denny Teresi introduced him to it:
> https://www.dailydot.com/debug/john-draper-beyond-the-little...
> Denny called me and told me about this whistle that blew the magic tone that disconnects long distance phone calls, and that he had a spare. He asked me if I could drive him to San Francisco so he could show me how it worked.
"The stark shift happened fast; in 1995, the number of pay phones in the U.S. peaked at 2.6 million, Slate reported in 2022. In less than three decades, that's dwindled to fewer than 100,000."
I was born in the very late 1970's, so I had the pleasure of trying to build my own Blue Box just as payphones were starting to see their death in the early 1990's. It was my first real attempt to be part of a group I felt I belonged with; the hackers. I grew up with the verbal history I mentioned, which as you pointed out is factually incorrect, but I cannot deny the power that mythos had over my thinking for the last few decades.
Always important to remember that the telecom revolution was underway in 1890, let alone 1990. I still think the telephone system trumps the Internet in terms of revolutionary impact on society.
Was a common supervision tone used by the NA toll network prior to the introduction of SS7. Also practically everyone here knows (or ought to) that already, given that Jobs and Woz dabbled in making Blue Boxes for profit, and Blue Boxes produced 2600hz (along with the set of MF tones used to encode numbers). The fact you posted your redundant FYI with a mobile wikipedia link (phoneposting) is even more egregious.
And "Blue Boxes" exploited the 2600Hz signal to make free phone calls, explained here under "Operation": https://en.m.wikipedia.org/wiki/Blue_box
Steve Wozniak built Blue Boxes and Steve Jobs sold them: https://artsandculture.google.com/asset/blue-box-designed-an...
WAS not IS. It was phased out sometime in the 80s.
Anyway, I assume these as well as the tone are also a strong inspiration for the name.
I miss those days. Crawling in dumpsters at the local CO, staying up until 5a, on a school night, because you'd just discovered something really, really cool.
Kudos to the owner, founder, and maintainers. You embody the spirit of 2600!
If you use one of the newer predictive voice codecs, expect a lot less success, but maybe moving to older/slower modem speeds will help.
V.34 was mostly a speed improvement, as far as I remember, no?
https://en.wikipedia.org/wiki/T.38
edit: That is I assume that they meant VoIP when they say digital phone lines. Fax over digital ISDN lines has been reliable since its inception as far as I am aware.
You are right btw. I was working off long disused recollections and then had to leave.
Faxes routinely get 9600 and 14,400 speeds over these ATAs; it helps a great deal if your coded is G711 which is an uncompressed codec (it is u-law PCM in the USA; PCM is just like the bits recorded on a music CD, but at a much lower bitrate).
And agreed, many hours spent dialing and driving around with friends, laptops, serial cables attached to GPS devices, and wifi antennas.
"D-Modem replaces a softmodem’s physical hardware with a SIP stack. Instead of passing audio to and from the software DSP over an analog phone line, audio travels via the RTP (or SRTP) media streams of a SIP VoIP call." [2]
Seems pretty cool.
[1] https://github.com/AonCyberLabs/D-Modem?tab=readme-ov-file [2] https://www.aon.com/cyber-solutions/aon_cyber_labs/introduci...
There is a really hold hacker magazine at 2600.com, 2600 series routers from Cisco, AT&Ts IPv6 starts with 2600, according to the comments a standard tone used in dialing, and so on.
Basically the old telephone switches would communicate with each other by sending different frequency tones or tone pairs to execute different commands, and 2600 Hz was the tone send to indicate that a call had ended. 2600 Hz was the first of these control frequencies discovered by phone phreaks back in the day and kicked off the whole phreaking scene, and so 2600 became a shorthand for phone phreaking
But for long-distance, to get the most calls out of the fewest wires, they used frequency multiplexing, with no steady current flow. Instead, unused frequency carriers carried a steady 2600Hz tone, which meant the circuit wasn't connected. One end detected the lack of current flow in its local circuit and added 2600Hz; the other end detected 2600Hz and interrupted its circuit. (These frequency-division systems interfaced as local phone lines at both ends). I'm not sure how this worked bi-directionally.
So by sending a 2600Hz tone, your frequency multiplexer would still remain connected, but the other end's frequency demultiplexer would think it had disconnected. When you stop sending 2600Hz, it thinks a new connection is getting set up through the same channel (i.e. HTTP request smuggling), and interprets whatever it receives as the setup instructions for the next connection. So you send 2600 Hz, then you send the super-secret MF-tone encoding of the phone number you want it to connect you to, or you send some super-duper-secret encoding that you normally couldn't dial on your phone. Input sanitization and translation is done in the exchange your phone directly connects to, not in the core of the system, so now that you are talking to the core, you can pass it unsanitized input (i.e. server-side request forgery) - there are no buffer overflows or CSRF, but you can call things that your exchange doesn't give you a way to access, such as internal departments of the phone company that are meant to be called by operators for assistance on complex requests, various test signals, and numbers that are only meant to be dialable locally, such as the operator in that exchange.
I highly recommend checking out https://evan-doorbell.com/group-1-playlist/ which hosts podcasts of an actual past phone phreaker explaining all of this with actual recordings of the phone system from back then highlighting all the dial tones, conversations with operators, internal machinery working noises and so on.
(Networks still work this way, by the way, just with better filtering. If you could somehow get packets into the middle of your ISP's network, you could send them to all sorts of places you can't send them to from your end of the connection.)
I recently stumbled upon a now ancient publication called 2600: The Hacker Quarterly. I enjoy print and it is right up my alley. It contains many neat topics and I figure this is a good post to plug it (not affiliated, just love their minimalist design and ethos). Definitely worth a read, it covers so many neat topics from phreaking to neat BASH scripts.
If you can find it there's a 1000 page hardback compendium of some of the best articles available too.
Another older print publication was Blacklisted! 411, very similar format to 2600. I attended some meetups from both of these back in the day.
Sounds painful to me once you have more than a dozen active users
So no, you don't interact with a BBS by speech.
The program allows narrow range of actions such as `ls /var/bbs/threads/`, `cat /var/bbs/threads/$1`, or `cat | sed -e s/^/\n$(whoami),$(date)\twrote:/ >> /var/bbs/threads/$1.txt`. The grumpy neckbeards with accounts on the remote system would have extensive secret sauce for `/usr/bin/expect` that can aggregate changes for each file so they can catch up to the latest flamewars happening there, while it wouldn't be a requirement to be explained how far away you are on spectrum, or something along that.
idk. More than happy to be corrected.
Back in the days of 2G cellular, GSM had an option to have your cell phone digitally connect to an analog modem in the cell tower, and have the tower place an analog modem call on your behalf. (Very similar to how T.38 works for faxes in the VoIP world.) You'd then connect your cell phone to your laptop over RS-232, IrDA, or Bluetooth. It was called CSD ("circuit-switched data), and used 1x voice channel for 9600 bps, or 4x voice channels for 56 kbps. Needless to say your cell carrier charged quite a bit for using this capability.
I don't know if there's any cell carriers left that still offer CSD calls.
> Don't want to pay for a landline? No worries! You don't have to! Using an Analog Telephone Adapter, you can dial in to 2600.network. The ATA will give you analog service from a SIP VoIP provider.
So presumably, acquire an adapter and hook it up to some VoIP setup?