2600.network Dialup Service

288 112 2 years ago

Sweet, I've been looking for one of these to test CSD calls out for the first time in like 20 years before GSM gets shut down on T-Mobile. There was one other service in Vancouver that probably shut down last year but I'm not sure data calls work internationally.

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/

lxgr5• 2 years ago

Could you theoretically use an analog modem (or worst case an acoustic coupler) over IMS (VoLTE etc., which should all have at least some QoS), or are the jitter rates and codecs too bad for that (like they often are for Fax over VoIP on fixed lines)?

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.

joecool10293• 2 years ago

Theoretically, maybe. If you got a good 'HD voice' (higher bitrate EVS codec) call, it's possible you could negotiate and send a slower fax signal. No way on a full-rate or half-rate GSM codec or amr-nb though, just doesn't have the bandwidth, chops too much.

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.)

grishka• 2 years ago

We still have 2G on all carriers in Russia with no plans to shut it down (no plans to introduce 5G either though). But I'm not sure there are any operational dial-up providers left I could test CSD with. But I am now curious to test it.

WarOnPrivacy2• 2 years ago

How well can digital phone lines carry dial-up connections? It was an issue in the early days of digital lines - same as with fax. For fax we got v.34 and other improvements. IDK about dialup tho.

toast0• 2 years ago

If you can run g.711 for your codec, things should work ok, depending on your jitter... g.711 is the digital calling code from 1972 that telcos used for T1/E1. On voip, it's packetized into 20ms bursts rather than multiplexed one sample at a time.

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.

lxgr5• 2 years ago

Early digital lines were purely circuit switched and didn’t add any jitter (unlike modern VoIP based “lines”), so there shouldn’t have been any problems running analog or digital fax over these.

V.34 was mostly a speed improvement, as far as I remember, no?

devkit1• 2 years ago

I think WarOnPrivacy was thinking of the T.38 standard. Once T.38 gained enough adoption in the various providers fax over IP became far more reliable.

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.

FrankPetrilli• 2 years ago

Quite well. I wrote a blog post about this a few years back: https://frank.petril.li/posts/dialup-adventures-1/

shrubble• 2 years ago

If you have an ATA like a Cisco SPA122 , Linksys or Polycom 302, then you should be able to get between 2400 and 14,400 baud speeds; you will have to try different speeds.

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).

kingforaday• 2 years ago

Projects like this warm my heart. There is a level of detail to appreciate on the capture of 2600, the POTS regional numbers ending in 2600, and BBS xfers.

Kudos to the owner, founder, and maintainers. You embody the spirit of 2600!

alberth• 2 years ago

FYI - 2600 Hz is a common handshake tone used in telco.

Hence why “2600” is referenced.

https://en.m.wikipedia.org/wiki/2600_hertz

0xEF3• 2 years ago

Lots of fun history around 2600Hz for those too young to remember or not part of the phreaking crowd, a fairly extinct form of hacker these days.

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.

https://www.thingiverse.com/thing:2630646

plapsley8• 2 years ago

Shameless plug for my book on the history of the subject, for those interested: https://explodingthephone.com/

4624363472• 2 years ago

A phreaker going by Joybubbles was the first to exploit the tone by whistling.

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.

retrac• 2 years ago

for those too young to remember or not part of the phreaking crowd

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.

4624363472• 2 years ago

FYI - 2600 Hz is a common handshake tone used in telco.

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.

riddley• 2 years ago

Is this where the name of the zine came from, I guess?

djbusby• 2 years ago

Yep. See also Captain Crunch

peterleiser3• 2 years ago

Yes. Details under "Publication History": https://en.m.wikipedia.org/wiki/2600:_The_Hacker_Quarterly

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...

userbinator• 2 years ago

I've wondered if the Atari 2600 was named such in reference to that, and online searches seem to confirm that it was.

coin• 2 years ago

2600 Hz is a common handshake tone used in telco

WAS not IS. It was phased out sometime in the 80s.

op00to3• 2 years ago

I remember messing with a self-made blue box at my school's pay phone in the early 90s, mystifying and amazing my nerdy friends. That fun ended when the phone company visited the school, and it was blantantly obvious who was the culprit in the rash of telephone billing crimes committed from a single pay phone, only after 3pm. No charges pressed, but I had to promise some dude in a suit I had learned my lesson. I hadn't.

devjab• 2 years ago

It was also the inspirational name behind a multitude of “hacker” (really more like tinker) communities back around the millennium. I’m not sure where these went, maybe they were killed by social media, but there used to be a lot of 2600 named tinker group for technology “nerds” here in Scandinavia. I guess what happened was the same thing which happened for me, people got older and stopped “hanging-out”, but I wonder where younger technology “nerds” go today. I think that it’s really interesting that the whole, very anarchistic mentality, which later spawned things like Anonymous doesn’t seem to have caught on with the younger generations even though they are even more oppressed and left behind by the current western economies and governments than my “generation” was. Most of it is still run by the people from that period who are now all 40+.

Anyway, I assume these as well as the tone are also a strong inspiration for the name.

thelittleone• 2 years ago

Was certainly around before the millenium, approximately '94 on #efnet.

ughitsaaron• 2 years ago

The publication is still around, at least online. Weirdly, I also noticed there’s a 2600 Meetup group nearby where I live.

aequitas• 2 years ago

2600:: is also an easy to remember IPv6 address for a ping connectivity check, it reverses to www.sprint.net, part of cogent now.

sonicanatidae2• 2 years ago

It was used to signal the status of Trunk lines, specifically if they were in use or open/available. By blowing a 2600 tone at the right time, you could seize the trunk and reroute the call.

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.

oldstrangers• 2 years ago

Dial ups, war dialing, and telnet were peak internet as a child.

washadjeffmad2• 2 years ago

Orinoco Gold! I switched to passive Atheros when they ended up in netbooks, but I probably still have my scancat equipment somewhere.

dylan6043• 2 years ago

G3 MacBook Pro clamshell, Orinoco Gold PCMCIA expansion card, an external cable connected to a threaded rod in a Pringles can. Gotta love the old farts strolling down memory lane with back in the day stories.

crtasm• 2 years ago

Wifi was somewhat later but yes, also lots of fun things to explore!

Solvency• 2 years ago

So how do I realistically access this with a modern laptop and zero ancient modems left to my name.

SuperNinKenDo• 2 years ago

You could possibly use tethering to your mobile phone in some way, although I'm unsure, I'm just throwing an idea out there.

tjohns• 2 years ago

Cellular compression will not play nicely with analog modems. (Or any lossy compression, really - this is why you have to use lossless G.711 to have any hope of this working on VoIP.)

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.

palmfacehn• 2 years ago

https://stirfriedpixels.wordpress.com/2014/11/07/on-homemade...

Klonoar• 2 years ago

I mean, the site itself notes:

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?

ac29• 2 years ago

That solves the no phone line problem, not the no modem problem

xyst• 2 years ago

This predates me by at least a decade. How do you use the “BBS”? So once you dial in, it uses IVR to read and write messages?

Sounds painful to me once you have more than a dozen active users

pokot0• 2 years ago

It’s just text interface like running a program on a terminal, just the program runs on the remote computer. Much like a telnet session, with some primitives to transfer files.

porkbeer2• 2 years ago

Typically BBS's were single user systems, although many multiuser systems existed too.

Delk• 2 years ago

All the data is digital (in case of BBS, mostly text, although file transfers are also possible). The analogue phone line is only used for transmitting digital data over the analogue medium. The dial-up modem converts the digital data to an analogue voice signal at the transmitting end and back from analogue to digital at the receiving end. (That's what a modem is: a modulator-demodulator.)

So no, you don't interact with a BBS by speech.

op00to3• 2 years ago

google a "telnet BBS" and see for yourself. the experience is the same, especially if you can set up a 1200 BPS serial connection.

numpad0• 2 years ago

AIUI, I'm myself way below BBS age too, I believe you sign in to a shell program to someone else's *nix box that offers BBS features. The shell that spawns at the remote side is a stripped down ncurses program rather than being /bin/bash.

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.

IgorPartola2• 2 years ago

So a decade and a half ago there used to be the Google Search Appliance (no idea if it still exists). It was essentially a black (actually yellow) box with some Google magic inside that let you have Google search on premises and for local documents you didn’t want leaving your data center back when people still had their own data centers.

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.

jojobas2• 2 years ago

No firewall rules, no unintentional leakage, no accidental logins

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?

solatic• 2 years ago

My understanding of what the parent wrote is the phone line would be disconnected in the normal case - can't break out if it's physically disconnected.

mananaysiempre• 2 years ago

[A] 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.

Cacti2• 2 years ago

Corporate datacenters are still quite common.

b112• 2 years ago

Indeed. People thinking otherwise live in quite the news bubble.

punnerud• 2 years ago

Image of the box: https://www.wired.com/2012/10/google-search-appliance/

CalRobert• 2 years ago

I remember interviewing for Google circa 2010 and they asked me to present on "How does Google make money?". At the time I went with "well aside from ads you have this funky search appliance" and I hoped that they'd find more non-ad ways to make money. They didn't hire me, but it seemed like a neat device.

postexitus• 2 years ago

Erm - so as soon as it dials out, it could give a non-firewalled access to LAN, no? Maybe they also disconnected ethernet while connecting the phone cable, but not sure how effective they can diagnose a problem without the network in place.

Bluecobra• 2 years ago

POTS is/was a requirement for remote/out of band access to AT&T network gear as well. I did run into a funny thing when they started to migrate T1/PRI's to fiber. They still insisted that they needed a dedicated POTS line but converted the underlying copper circuits to a single fiber circuit. I was able to work around this with a phone line adapter but if the underlying fiber circuit was down they would be screwed.

threeio• 2 years ago

I had one of those boxes, worked for a company that ran news and magazine publishing sites and we pushed all the data to them as opposed to rewriting our search on the sites.. they were pretty decent and seemed to also help our page rankings on the mothersite ;)

supriyo-biswas• 2 years ago

This isn’t as uncommon as you’d think. AWS’s storage gateway, which is a caching NFS layer over S3, has a diagnostic mode which starts a reverse shell over 22/tcp.

masto• 2 years ago

Sometime around 1999/2000ish, I built a sort of distributed database application. Early web app days, Perl and PostgreSQL on FreeBSD, and almost no JavaScript. It was for fairly sensitive data that the users were a bit squirrely about sharing, so the idea was that you stored all of the bits you owned on your local node, and you could send a remote query to the whole network and each node would execute it, notify the local owner of the data "hey, Sally wants a copy of this record", and they could choose whether or not to send it back.

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.

phone8675309• 2 years ago

This feels like a perfect application for UUCP / NNCP.

ebiester• 2 years ago

Dial up as a part of an appliance was a fairly established pattern. I remember working with IBM in 2007 and they had a tool for a fair number of products that was just about dialing in to a terminal. However, I don't think it dialed back to IBM - people just used the terminal over dialup.

throwawy6153• 2 years ago

This is fantastic!

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.

hereonout2• 2 years ago

An absolutely fantastic publication, nice to see it still going.

If you can find it there's a 1000 page hardback compendium of some of the best articles available too.

elliottcarlson• 2 years ago

You should also check out Phrack Magazine (an online distributed ezine that is still active, albeit with years between issues - they also have a 2024 call for writers though!) at phrack.org

Another older print publication was Blacklisted! 411, very similar format to 2600. I attended some meetups from both of these back in the day.

plapsley8• 2 years ago

If you want something really ancient, check out YIPL/TAP, which was the first phone phreak newsletter (started publishing in May 1971) that was the granddaddy of 2600. You can get it on the Internet Archive: https://archive.org/details/YIPLTAP_1-91

underlines• 2 years ago

For reference, 2600 is a famous phreaking and hacking e-zine from the earlier days. The name 2600 itself is a reference to the 2600hz frequency used in Phone phreaking.

https://en.m.wikipedia.org/wiki/2600:_The_Hacker_Quarterly

Rayston2• 2 years ago

Just to clarify, they are from the early days, but they are also from the now days. They are still publishing. A link to their official site is in the above Wikipedia article.

sonicanatidae2• 2 years ago

They are, but sadly, blowing a 2600 down the line these days just gives someone in the CO a chuckle when they read the logs, a week later.

austin-cheney• 2 years ago

What is the significance of 2600 in networking?

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.

dagw• 2 years ago

2600 Hz was a frequency used as a control tone by the old telephone switches.

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

immibis• 2 years ago

More specifically, local phone lines are full electric circuits from you to whichever piece of equipment you're currently talking to (connected via relays through many other pieces that you've finished talking to). That equipment knows you're still on the phone because current is still flowing through the circuit, regardless of the audio signal.

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.)

jsjohnst• 2 years ago

The old school phone network used in-band signaling for call setup/control. If you made long distance calls pre-90s you might remember tones after the call started connecting as an example. One of the most significant frequencies in that control setup was 2600hz (which disconnected the call in progress and left you with an open tandem trunk, giving full access to call routing functionality), made infamous by Blue Boxes, Captain Crunch, and the magazine of the same name.

op00to3• 2 years ago

Has anyone played with "D-Modem" [1]

"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...

lol_catz• 2 years ago

no V.150.1 support?

Rayston2• 2 years ago

C*Net is a site that might be interest to you as well. They do a lot of interesting things with PBXs and Asterisk and Telephones in general.

https://www.ckts.info/

fnord77• 2 years ago

does POTS still exist? Aren't all land lines VOIP now?

2600.network Dialup Service

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