what is it about fax technology that i can't just program my phone to send a fax? what are fax machines doing that i can't emulate in software???
Give our API a shot and shoot me a note for some extra credits as a h/t to a fellow HNer. (See profile for email.)
$0.05/page was well worth a cURL call, especially when the docs had great examples that just needed me to swap out the file name for mine.
Side Note: Yes I am just old enough to want, and actively go out to have, a home phone albeit with current technology. I'll take retro-futurism when I can get it.
And all those fax machines have a "private" mode where the images don't get saved. On the machines I used. And most only save the cover sheet for sent faxes.
I would love to see a "Privacy Button" on more than just browsers and fax machines. Perhaps there's some market there, be it free or money or otherwise.
It doesn't surprise me that a "modern day fax machine" [why am I even viably capable of saying such a phrase] would have a similar capability.
Even standard unencrypted email is largely opportunisticly encrypted these days. Security properties of that is "debatable", but a fax isn't encrypted at all...
And about the worst-case scenario and the perception for me of a point-to-point architecture.
If I email something, then if it's "largely" encrypted, that is no consolation if that doesn't hold. I'd feel it was on me for doing it.
On the other hand, if I fax something, and someone who shouldn't sees it, it's likely an insider at the destination location, and in any case, it's not my fault as long as faxing is regarded as reasonably secure.
MITM the connection - even ignoring opportunistic encryption, almost certainly easier to physically witetap some random office than it is to wiretap the internet connection between google's data center and microsoft's data center (picked as two random big email providers)
Insider at destination: your email account has a password and audit logs. Fax machines sit in the middle of a room. Usually anyone can just walk over
Insider at source: most people have their own computer/email account set up. Going to some sketchy shop with a public fax machine that any malicious party could have secretly modified is much worse.
I hadn't looked at Google's email encryption report probably since it came out, was very happily surprised to see it's over 90% now[0]. Still doesn't say anything about the issues with accepting self-signed certificates etc though.
[0] https://transparencyreport.google.com/safer-email/overview
Some gsm phones had the ability to transmit a fax but they actually used a different protocol to talk to a fax gateway. I never saw one of these in the wild.
I haven’t been in that “biz” for a couple of decades but nowadays a different approach will be used anyway (pdf via IP to a fax gateway -> POTS)
This is quite wrong. I believe you are confusing Hz with bitrate, as the most advanced modems communicate at 56kbit/s using PCM. To clear it up, a regular phone line has a 4000Hz bandwidth. With digital lines, you require sampling at at least 8000Hz (Nyquist theorem). It's impossible to send a frequency above 4000Hz using this line. Each sample is considered to have 7 usable bits of data, giving it a capacity of 8000 * 7 = 56 kbit/s.
Most faxes are compatible with the T.30 standard, which doesn't acknowledge the usage of digital lines, and sends data using the older V.34 modem standard. This is either at 28kbit/s or 34kbit/s. This uses a method called Quadrature Amplitude Modulation (QAM), and a maximum baud rate of 3429 symbols per second. Since the centre frequency is set at 1959Hz, you won't have frequencies greater than the centre + bandwidth/2 = 1959 + 3429/2 = 3674Hz. You get 10 bits with each symbol, resulting in 3429 * 10 = 34 kbit/s.
Edit: Here's someone attempting to use the slowest supported T.30 standard, 300 bit/s, over his cell phone, and you can see it's not perfect: https://www.youtube.com/watch?v=uQqWHLZjOjA
The T.38 protocol exists to allow faxes to send over a packetized network. Already if you're sending a fax there's a high chance it's been converted to T.38 at some point, as SPs gradually move toward a fully packetized core.
If it needed a "56kHz channel", it would not have worked in the phone-over-copper-wire days either.
If we assume the parent meant 56kbps, that's still incorrect. The fastest fax machines use V.34bis modems (ignoring ISDN), which give you 33.6kbps, though many (most?) still support the oldest standard, V.27, at 2400bps!
The real issue sending a (T.30) fax over a cell phone line would be jitter and packet loss, since most cell networks are IP-based nowadays. T.30 is not very resilient to noise or timing issues. There's the T.38 standard, which was designed for sending faxes over a packet-switched network, but it's still sensitive to timing issues (esp. since often you'd be talking to a real fax machine on the other end, after going through a T.38/T.30 gateway).
Cell phones certainly don't give you the bandwidth that a copper landline does, but it'd certainly be enough to transmit a fax... if you could keep the error rate low enough... which I doubt.
(Source: I built the initial production version of Twilio's fax product.)
Those 2400bps are not using 2400bps from the line, but are modulated to an analog signal that uses the lines full bitrate. From Nyquist–Shannon sampling theorem we know that a 56bps line can transfer something like half of it in analog form, so 33.6 is marginal.
T.38 is sensitive since it needs to end the analog side, practically receiving the fax.
Fax in general is sensitive since the standards have left too much freedom for implementers, especially like you said in the timing parts, causing incompatibilities between machines.
(Source: I have built fax relay over VoIP products in the late 90's)
IIRC from the water cooler talk, one of the remaining customers was a lighthouse, that had to send a daily report, things like that.
Also made http://maleprincess.com/ for fun
Cheapest service I know of if you infrequently need to send a fax and wait a few days for the possible reply.
More seriously though, the organizations still using faxes are not interested in "disruption", or anything else that is newer than the 80s.
hmm so you're basically saying that fax machines only listen to data coming across on a 56KHz carrier wave? i guess that makes sense since the same device (a fax machine) can function both as a telephone and fax (and you'd need to distinguish in hardware which mode you were operating in upon "picking up the phone").
but what i don't understand is the telephony (i'm not a network engineer): when i make a phone call from either a fax or a phone isn't there, at this point in time, a hop through a digital connection? so doesn't some interchange between me and the person i'm calling ultimately decide what frequency carrier the receiver hears?
Notably, the entire telephone network is standardized on G.711 as a codec, which is raw PCM audio at 64 kbps, from 300–3400 Hz sampled at 8,000 samples/sec. (There's some regional differences that determine whether the network uses G.711u or G.711a, but that's not really important here.)
Also relevant: The digital telephone network is exclusively a switched (not packet-based) network, so you're guaranteed near-zero latency. This is particularly important for fax modems, which don't tolerate any jitter.
The end result is a connection that might not sound the best (due to the narrow bandwidth), but has call quality characteristics that are standardized and guaranteed across the network.
(At some point in the future the telephone network will upgrade codecs to G.722 and AMR-WB, which will give higher voice quality. This is the "HD Voice" feature you see on VoLTE phones. But it'll be a while before that's universal.)
Seems like this fact could be exploited more often in internet applications. High bandwidth channel for static assets, low latency channel for e.g. player movement data?
And that was for the sake of education. He’d hold his lab meetings in Skype, not over a multipoint ISDN video calls on circuit switched wireless ATM. Only when the show is on, speaking to us undergrads through the mic, he declined to admit that IP is more adopted.
Circuit switched data looks pretty on paper, that’s true, but at the end of the day no one pays for or bother with it.
Probably it's an interchange between your POTS handset and your local phone service provider's head-end, that determines the "media type" of the call; and then, in the case of fax, that call is forwarded (including media type) to the other land-line's service provider's head-end, where the service provider then negotiates+accepts the media type, rings the fax on the line until off-hook, and then sets the opened line to operate at that frequency.
I'm guessing that the thing picking up the carrier on the sender's head-end is the same thing that parses DTMF tones off the line; and therefore, not a component that exists in the signal chain of cellular service providers.
(A similar thing happens in cellular voice signalling—the negotiation of a voice codec—but it happens out-of-band, not in-band, AFAIK—on both ends (like a web browser talking to a web server) unless one end is POTS, in which case the cellular voice provider jumps to the POTS network with a DAC+bank of line couplers. In theory, this means that a cell phone might be able to send a fax to a fax machine, if there was a special voice codec option in GSM/CDMA/VoLTE/etc. for "lossless 56KHz PCM", that would be decoded at the POTS gateway into a raw line signal.)
We would also pull off a clever trick with the reverse. If the modem sensed a digital carrier and your ISP was digitally-connected to your telephone company, the connection could be put into a sort of digital-hybrid mode where the downlink of the connection would be 56kbps (the upstream would still be 28.8kbps maximum). This is where US Robotics "X2" modem names came from.
There's actually a protocol, T.38, which is used on modern VoIP based systems to allow faxes to be transmitted. At each end it actually decodes the fax data and sends it as ordinary data packets. Implementations play some tricks on the fax modem at each end, in order to prevent it dropping out of sync if the data packets are delayed. You could communicate with one of these from phone, but you'd need a T.38 gateway a the other end.
More practical is to cut out the middleman and use twilio's fax gateway at $0.01/page (+ sip trunking cost, which should be similarly trivial): https://www.twilio.com/fax/pricing
Newspapers have used it since the 1800's in one for or another. Wire-Photo https://antique-photos.com/en/helpful-info/476-wire-photos.h... This is a relic of the old Muirhead rotary scanning fax machines abd the same standard persists. This is hard to do via radio. So radios send a pdf to a fax service. I have a fax service for $10 a month, I send it via desktop or mobile, and receive the same way as a pdf. With a mobile printer or office printer you get hard copy. https://www.myfax.com/features
There are radio-fax standards. Marine weather reports are a good example that's still in use: https://en.wikipedia.org/wiki/Radiofax
However, the fax machines we use on our telephones were not designed with this in mind. The protocol is neither tolerant of the reduced bandwidth nor lossy compression from cellular networks... not to mention jitter if the call passes over a packet-switched network.
I did it from various generations of the Nokia Communicator. The phone would initiate a special kind of phone call (from memory, the same AT string used to start an ISDN connection) and then send digital data over the link, not audio tones directly.
This would emerge onto the analogue phone network as fax tones.
I suppose it's possible that the cellular networks simply don't support this anymore, but my first guess would be that it's handsets that lack the software to do it, now.
It was brilliant for getting into systems I managed via a dial-in modem before Internet access was broadly available. In its twilight years, carriers that had a tariff to support it would charge something like $1.35/minute to discourage its use until the tariff could be updated.
There was also an optional assigned special phone number to have it work in reverse (receiving faxes via your connection).
https://github.com/fastily/fax-machine
The whole thing is designed to run on a raspberry pi. The setup costs $1 a month (for the twilio number) and a couple cents per page.
My wife had one of them in the mid-2000's. It was a SonyEricsson, but I don't remember the model number. All I remember was that it was mustard in color and impossibly small.
A quick internet search shows that the SonyEricsson T39 had a GSM modem capable of faxing, but the pictures of it aren't what I remember from my wife's phone.
I thought it was going to end when they dismantled the analog network, and his fax machine with it, but somehow it just got worse. You see, on fax machines you rarely got spam, but on email that's another story. It's hilarious to see the email exchanges he has with some spammers. They've met their worst enemy.
He is more than capable to identify spam, but he doesn't fully understand that, while sent to him, it's nothing personal. He takes it very personal. Very personal. Like, call me late in the evening or during work hours (unheard of for someone in his school) to discuss this outrageous claim that someone made about him. He, like a lot of senior citizen, has a lot of free time. So he naturally replies back. And we're talking full page replies, going into great detail about how they are bad people for doing this to someone like him.
When I entered the workforce I was surprised to see how much fax spam there was, usually a sheet or two every week. It's tapered off to ~ a couple of sheets per fortnight in recent times though. It is kind of amusing to see fax phishing with personalised cover notes attached to some spam about light furnishings etc.
I wish I could do the old "faxing sheets of black paper taped into a loop" trick but I'm sure the scammers are using e-fax now.
In Japan many businesses are still wedded to a fax. It’s much easier to scribble a take out order on a piece of paper.
Contrast that with email, which goes through any number of emails, sits in queues, gets backed up, etc.
Of course some of the time you're actually faxing a fax-to-email gateway, but ¯\_(ツ)_/¯.
All of the other security issues aside, how about simply walking over to the unprotected fax machine and leaving with a stack of "private" records?
Not sure you want to die on the hill of defending fax security.
Versus the entire world on the internet.
Yeah, I'll take fax security over normal email security, thanks.
I mean I get the dream of not having the consider the network as an adversarial entity but surely they're about the same?
I recall reading how noodle shops in Japan take orders [at least To Go and//or Pick Up] via fax.
Artists draw pictures and robodial a secret fan list (through a POTS modem and some 90s software) of fax machines where insiders can get exclusive limited physical copies of the art and the copies with the earliest timestamps become the most valued.
People will just be sitting around their house and they hear the fax machine starting to unexpectedly print something on a Saturday afternoon. Then, like some tactile version of a phone alert, they slowly watch the paper slide out of the machine with the latest artwork.
The lost joy of anticipation in the 30 or so seconds of waiting as you see the thing slowly form in front of you, recaptured once again.
Alternatively they hear from their friend that a new artwork is out and they anticipate going home and checking the tray of their fax machine to see their own copy.
This should be a thing, it sounds fun
There's probably Linux fax software nobody has used in 15 years that can import vcards and be scripted with lua or something.
In healthcare, because despite the technical reality that it is electronic, it's not considered “electronic media” under HIPAA, so security and transaction & code sets standardization rules that apply to electronic transactions do not apply to transactions conducted by fax.
It's a giant compliance hole in HIPAA that entities in the healthcare space ruthlessly exploit. (Various incentives to move to mechanism that are considered electronic under HIPAA have chipped away at it, but the compliance hole still keeps people using it.)
I do remember not that long ago opening an apple developer account required filling out a form with your card details and faxing it to some US-based number. It was madness back then already.
There is no technical reason for it to be so, but it is what it is.
Fax is actually ancient tech, predating the phone way back into the telegraph days.
The presence and non-exclusion of email/IP gateways show how backwards the law surrounding this is.
If I sent you a fax, and your fax machine (of whatever type) printed it out, that copy is legally as good as the original.
If I scan, then email, and you print it out, it is not legally as good as the original.
It doesn't matter if it makes sense, it is what it is.
The law is based on precedent.
Fax was a new technology. For the first time a signed document could be sent over the wire in minutes, instead of having a courier go via train and take days. This is 100 years before computers were common.
When computers became common fax was already well established so there was no good reason to add a second exception.
Few offices had them, too -- teletypes were more common than fax machines, even though teletypes didnt do graphics like fax. I've read that police departments had fax machines for mug shots or maybe fingerprints, but i have no first-hand knowledge.
Anyway, I'm just trying to relate history to you from someone who was there. Wikipedia articles or retrospectives don't always get the nature of things right, even if they do get the hard facts like dates right.
Another example: you could say television was invented in the first decade of the 1900s. But they weren't household items until the 1950s, maybe late 1940s if you want to count NYC specifically.
This equipment would have typically been installed at a telegraph office, not at the end user site, but the basic technology is far older than most people assume.
I wonder how long it shall take to have electronic communication to be accepted, legally, as normal and standard across the board.
I have gone so far as to have a digital copy of my analogue signature to drag-drop into an electronic document. And this has been accepted as legal. Courtroom legal. IRS legal. "Don't fuck with this" type of legal.
I hope this continues into the future.
This will not work in Europe. You need proper public-key cryptosigning here. That was what I meant when I wrote "legally admissible digital signature". What you wrote is called "digitised signature" here, and would only be useful as a decorative sign.
See https://en.wikipedia.org/wiki/Electronic_signature to start.
How is this not "blessed by maths" as not in the previous problem?
Someone somewhere has to bless something, be it a valid vote or a valid digital signature. If there is a "Pope" for one, there should be a "Pope" for the other. Medical, government, religious ... someone somewhere must have a magic "I Bless This" magic wand and all henceforth below shall must be valid.
Why is the branch of "digital signature" considered "good" in this respect but "voting" not? "Medical" not"?
I viciously hate to say the term, yet ... this seems so "tri-cameral" ... and in terms of schizophrenia of illogic.
For a while, it was handy to be able to fax forms to Studylink and WINZ (New Zealand social security/student loans orgs), but they have recently set up a website where you just scan or photograph documents and upload them.
I lived in the UK for 32 years and never sent a fax or even saw a fax machine outside of a museum.
Couple of years ago I moved to Australia. Got a credit card for travel with Bankwest. In order to set up a direct debit to pay it off I had to fax them.
In the end I got them to fax themselves my details.
I'm not sure whether Bankwest is just incompetent, or if they deliberately make this difficult so that more people will miss their payments.
Maybe Bankwest in particular are stuck in the past.
https://www.nytimes.com/2020/04/04/nyregion/coronavirus-ny-u...
I think everyone would love fax to just go away and die, but there are still places where it's used (I believe pharmacies are an example?)
Also I personally would prefer a paid service, faces typically are secure private documents I would want some level of guaranteed and privacy.
More than 10 years later, there's still not an app for that.
The point is that there was no reason for Apple to insist I send them a Fax to join their developer program, but they did anyway. I guess somebody at Apple thought it was more "business like" to introduce another hoop to jump through to make it harder to join the developer program, because just paying $50 was not enough.
So if you can write an app that accesses this API, you can send faxes. It would be easiest to do this as a web service that you can access from your phone via a web page.
https://en.wikipedia.org/wiki/The_Phone_Company
The fact that it costs you so much probably just means that the demand just isn't there.
It was grandfathered in when this requirement was added.
The account could even be managed from a phone app.
I'd just attach a PDF to an email message addressed to <phone number>@<myaccountname>.example.com and I'd get the acknowledgement page back via e-mail (as another PDF) a few minutes later.
Fax machines have embedded modems which decode and respond with a complex set of tones to transmit and receive data that makes up the facsimile image (yup, it's all images to the fax and that's why they still use them).
Smartphones are all digital so you need a gateway to convert digital signals to suitable analog tones to satisfy the fax machine's modem. Conceptually you could implement the gateway functionality as an app because we can still transmit and receive tones, i.e. voice calls. Quantisation and delays might still introduce errors, but the fax protocol does have some basic error checking and re-transmit capabilities.
I found out they were trying to fax each other documents because of some archaic requirement and thought it was the most hilarious thing ever. Totally just sending each other emails with extra steps for no reason.
Is "fax by email" dead or otherwise unattractive?
https://en.m.wikipedia.org/wiki/Fax
My Palm Pilot (with a CDPD backpack) and candybar 2G Nokia could both send FAXes.
I suspect there's no demand.
From an engineering perspective, having a billion cellphones faithfully transmitting info on frequencies humans can’t hear is simply wasteful. https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_code...
“AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM[5] and UMTS.”
The AMR codec uses eight source codecs with bit-rates of 12.2, 10.2, 7.95, 7.40, 6.70, 5.90, 5.15 and 4.75 kbit/s.
Fax machines on the other hand go up to 33kbit/s.
PS: People can produce and hear frequencies well above 3400 Hz, but for phone calls people just don’t notice clipping those frequencies. If anything it helps by removing some background sounds.
As I understand it (and I could be wrong), T.38 solves this by emulating an independent fax modem on each side of the analog connection, and only sending the image data over IP as opposed to sending audio.
This is one of those facts that, no matter how many times I hear it or what proof is offered, I find it impossible to believe.
Your network or device may still be using the 90s cellular voice standard, tho.