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Ask HN: Why can't I send faxes from my phone?
218 points by throwlaplace 31 days ago | hide | past | web | favorite | 163 comments
on occasion i've had need to send faxes. most of the time i don't have access to a fax machine and so i end up paying some service that'll let me upload a pdf and charge me $10 for 50 pages.

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???

Founder of Phaxio here. Doing fax well is an annoying problem because the protocols are finicy and the carriers don't usually want to spend time troubleshooting issues.

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.)

I used your service a few times when buying a house. One cURL call and it was done. Super easy and much appreciated.

I am amused and impressed that you chose an API and cURL to send a fax than any of the many apps and services built on top of that API.

At the time, all the ones I could find were like $1/page or more like a $30/month subscription.

$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.

I am likewise amused and completely agree with the idea. Every fax app I have used is either clunky, overpriced, or both. I hadn’t heard of Phaxio until now and am look forward to cURLing my next fax. However, there is some dark part of me that wants to make a clunky bash script for it nonetheless in order to keep me from enjoying sending a fax.

Great product. No affiliation, just a satisfied user.

Thanks! Our team works really hard so that every user feels like this :)

Good to see HIPAA compliance. I will sign up and give it a try for our product.

I give up and tell them I can't send a fax where I'm from. When they ask where I'm from, I tell them I'm from the year 2020.

The thing is, when I'm asked to send sensitive documents over unencrypted email or something, then I'd rather use the fax option. And I don't trust any internet gateway, I go to some local store with actual fax machines. I kinda sorta think of it as more secure than the internet, still?

IIRC, automated character recognition / word alerts in FAX transmissions has been built-in in Echelon since the 1970ies. FAX is as insecure as emails are, under certain threat models. Pretty sure this is mentioned in this nice crypto history overview: https://alternativlos.org/30/

I am not concerned if the NSA knows my SSN.

Nothing to hide, I see. :)

I'd normally agree with you, but in the case of dealing with a mortgage broker who asks for stuff to be emailed/faxed and your entire concern is avoiding having your SSN end up where it shouldn't, I do believe this is rational.

It’s more secure in one specific way, a warrant is required to wiretap a phone line, but not the internet.

Then again most phone lines run over the internet these days. No idea how that works out with snooping laws.

My home phone is VOIP [I'm one of those early-adopter Ooma people]. I accept that when power goes out my phone dies with it just as I accept the warrant issue. Perhaps this is an unintended "transparency issue" so I won't be fooled thinking that my phone conversations are legally sacred, but at origin it was simply a "I'm not paying for that" deal.

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.

What I mean is that even if you have an old school POTS landline (if these are still offered) most of your calls are going to be at least partly routed over the internet, just because it is so much cheaper than maintaining the analog infrastructure.

And, to bring this back around to the topic, you can send a fax with Ooma. :)

As far as I know, most modern fax machines keep a record of things received and transmitted on them. At least the ones at my old work did. We could bring up a week's worth of faxes or something and reprint them.

So your threat vector is still like maybe a few dozen people who have access to the fax machine vs. the entire world?

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 suppose, I was just more referring to the parent's usage of public fax machines at local stores as being safe for sensitive information. The attack vector might be smaller, but if he's choosing public locations to make sensitive faxes believing it's totally safe, that's not entirely true. The owner of the fax machine, employees in the store and possibly other customers may have access to this info.

I don't use fax machines very often these days.

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.

During my time working in the [US] DoD industry, I recall exactly one "training" video informing us that multifunction printers have a storage capacity. Think "You scan something, you save something" type of awareness theatre.

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.

What type of threat model is this?

Even standard unencrypted email is largely opportunisticly encrypted these days. Security properties of that is "debatable", but a fax isn't encrypted at all...

I think it's about the difference between being able to expect a certain level of service or not; regardless of what the actual average is.

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.

I still dont think that makes sense. Every attack you can do against email you can do against fax.

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.

> Even standard unencrypted email is largely opportunisticly encrypted these days

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

Just wait till the year 3000 when we all live under water.

The fax requires a 56KHz channel which has not been used for mobile telephony since the 1980s (when AMPS and GSM were developed. Before then it was just a radio link through an operator). That’s why you can’t use a high speed modem either.

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)

> The fax requires a 56KHz channel

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

I figured that audio compression on mobile networks prevented the sending of faxes as tones.

You're right - though it's more about the precise timing of the tones than the frequencies themselves.

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.

Wish this wasn't the highest-rated comment, as it's not correct.

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.)

You are confusing bitrates here, the fax emits an analog signal and doesn't interface the digital line directly- it's not a digital packet switch protocol.

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)

CDMA also had a fax technology, under I think IS-95 data, but I didn't work on it myself. I've been out of the industry a couple years myself, but there were still a handful of customers using it that kept delaying the shutdown of the old tech, and there wasn't really an upgrade path.

IIRC from the water cooler talk, one of the remaining customers was a lighthouse, that had to send a daily report, things like that.

There were cellphones capable of sending/receiving a fax, in 2000 IIRC. Apparently it was used by about ~0 people worldwide, so the capability was discontinued.

>The fax requires a 56KHz channel

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?

Yes, once your call gets to the central office it's moved onto a digital connection -- essentially an ISDN line.

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.)

>The digital telephone network is exclusively a switched (not packet-based) network, so you're guaranteed near-zero latency.

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?

One of the professors when I was in a university was from ex-national telco R&D, and he was very vocal about those “real” bandwidth/latency/privacy assured telecom techs, “far superior” than “toys” like TCP/IP.

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.

Low jitter is a luxury for the document web, but if approximately all human social interaction is going to be through digital video for the foreseeable future, we might start to care...

It is already used with QoS [1]

[1] https://en.m.wikipedia.org/wiki/Quality_of_service

Which is traffic prioritization on the same channel. Having an extra link for high-priority traffic would be...exotic...but workable, sure.

It isn't a 56kHz channel. It is a 56k bps channel encoded as complex tones onto a 4kHz voice connection. The telephone system wiring does not have the bandwidth to carry a signal that is 2-3x the range of human hearing.

> so doesn't some interchange between me and the person i'm calling ultimately decide what frequency carrier the receiver hears?

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.)

Copper wire has a lot of bandwidth, but traditional phone lines had low-pass filter at 4KHz, so anything above is cut off. Between switching stations signal is modulated and multiplexed, but on the receiving end it is again restored to the original analog signal. Therefore fax-machines couldn't possibly expect anything on 56KHz for sure, it would never get to them. Also, faxes make that well-known noise when establishing connection, and if it were around 56KHz, we wouldn't be able to hear it - anything above 15KHz is very hard to hear for adults. So the OP probably meant 56kbps as a transmission rate, which again is not true because faxes existed much before 56K was possible and many worked on as low rates as 2400bps.

I seem to recall some occasions in the early 90's where there was exactly this problem and fax was not guaranteed to work with some land line due to the digital nature.

In the early days of running "analog" telephony over digital circuits, the edges of the audible hearing range would get clipped and compression would muddy the sharpness of the tones used. Humans couldn't tell much of a difference but devices cared a great deal. Nowadays you can run a fax over specific codecs designed to not do this (G.729, I think? Maybe G.711, it's been a few years).

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.

Perhaps someone could start a relay service.

We made http://mailprincess.com/ a while ago which is $1 per fax

Also made http://maleprincess.com/ for fun

You should really get an SSL Cert. They are free these days

It exists, but will only deal with USA numbers = I live in Canada, maybe one day ....?

These exist! They're not cheap and probably ripe for disruption.

The Twilio API supports fax, so I used it to make this: https://5dollarfax.com/

Cheapest service I know of if you infrequently need to send a fax and wait a few days for the possible reply.

Disrupting fax over internet? Why not just disrupt fax?


More seriously though, the organizations still using faxes are not interested in "disruption", or anything else that is newer than the 80s.

They exist and cost $10 for a couple of pages, as the OP said.

Faxes rely on modems. modems rely on precise timing and aren't able to cope with any slippage.

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

To send a fax you need access to a handhshaked landline. A direct wire between the stations. Faxes synchronize themselves, send data and test the bit, makeing sure it is properlt placed in the data queue, and send the next and so on =handshake. Suggest you look up old fax synchronization and I tossed my last muirhead rotary in 1982 - used it for weather maps.https://electronics.howstuffworks.com/gadgets/fax/history-of...

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

What exactly makes this "hard via radio"?

Radio spectrum is precious, so virtually any type of radio telephony is significantly compressed, either in terms of raw audio bandwidth or by applying lossy digital compression — often both. This applies to both 2-way radio and cellular telephones.

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.

The codec used in calls to landlines disallows the bandwidth required.

This used to be possible over GSM, at least in the UK, and so I assume most places that use(d) GSM.

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.

This was called circuit-switched data (CSD). The handset would emulate a serial modem to the attached computer and the mobile network would know how to emit the correct "noises" to the far end of the connection.

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.

Yeah, I had fax on my mobile plan in Finland as well (and if it just requires CSD I'd guess it still works). Never had any use for it, though.

There was also an optional assigned special phone number to have it work in reverse (receiving faxes via your connection).

It doesn't have to be expensive or complicated. I've written a simple web app that wraps Twilio's fax capabilities.


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.

Some older cell phones were capable of sending faxes. I don't know why today's phones don't have that option anymore.

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.

Given the percentage of "faxing" that is eFax to eFax, I wonder if we'll even notice when the last fax machine is turned off...

Genuine question: why there are folks still using fax?

Up until very recently my grandpa would use fax to send complaints to just about anything. It was about as stereotypical grumpy old man as you can imagine. He's a good person, just old-school formal when he writes. Comes of as a bit ... harsh.

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.

Au contraire; fax spam was a reasonably big problem: https://www.sfgate.com/bayarea/article/2-2-trillion-lawsuits...

>You see, on fax machines you rarely got spam

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.

I used to have a fax number one off of a pharmacy .... I got someone's prescription every week or so ....

I can't wait to be old and have this much free time. I'm going to annoy the heck out of some youngsters.

"Waste what life I have left? I'll not only waste yours but also the potential of what you've got ahead of you."

In the US, clinical medicine and law firms use it because it has an unusual legal status: it’s considered secure and positively delivered if some device at the other end acknowledges it.

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.

How is it secure though? It’s unencrypted!

It's considered secure by the law (probably because historically the phone network was considered mostly secure). Doesn't matter if it isn't really until the law changes or some court overthrows it.

It's point-to-point. Unless someone is tapping your phone line, or you dial the wrong number, where's the insecurity?

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)_/¯.

> where's the insecurity?

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.

Again the threat vector is the people within physical vicinity. People who would then be subject to trespassing or theft charges. And likely caught on camera.

Versus the entire world on the internet.

Yeah, I'll take fax security over normal email security, thanks.

But the current standard for normal email security is TLS at every leg from inbox to inbox?

I mean I get the dream of not having the consider the network as an adversarial entity but surely they're about the same?

Somehow institutions are still pretending the emperor is wearing the nicest looking clothes, they're pretending fax is secure from "photoshopping"/data tampering.

Due to the GDPR (most regional regulators do not consider normal fax to be secure, and of course it creates otherwise unnecessary paper copies of data) medical systems in Europe are being slowly weaned off it. I gather a lot of doctors are putting up a fight.

> 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.

I recall reading how noodle shops in Japan take orders [at least To Go and//or Pick Up] via fax.

I'm waiting for faxing to come back like cassettes:

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

You do it and I'll be the first subscriber, as long as i can afford it :)

I'm not really an artist but ok sure. I can certainly fax some doodles. I'll think about how to pitch and present it. I'll register artsyfax.com this week and throw something together. I even have a pnp modem and a pots line.

There's probably Linux fax software nobody has used in 15 years that can import vcards and be scripted with lua or something.

do you have a way of receiving a fax? I don't have a way of testing this thing.

> Genuine question: why there are folks still using fax?

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.)

It seems to be the same as cheques and magstrip-only cards - uniquely American thing that rest of the world hasn't seen in years.

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.

Aha, another Apple developer who remembers that! So I wasn't confabulating.

I remember in an old job we didn’t have a fax machine... Until we started opening a US office, because apparently it’s pretty much mandatory there.

Because legally it's the same as a physical document. Which is not true for printouts, emails, etc.

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.


Considering a fax is a print, I'm not sure what the printout comment is regarding.

The presence and non-exclusion of email/IP gateways show how backwards the law surrounding this is.

The law is not based on reality.

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.

I wouldn’t be quite so hard on the law here.

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.

I realize the fax predates POTS. But to say "When computers became common fax was already well established" is not really accurate. If you mean the 1970s (personal/home computer revolution), then no one had a fax machine at home back then. They just were not around.

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.

Faxes date from just after the civil war area. They were in common usage for transmitting contracts by the 1880s. Photographic material by the 1920s

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 know how old the technology is. You completely missed my point. They were NOT in coomon use even in the 1970s, even if am article on the internet claims it. I was there. Were you?

All hail to fax, but only now in the time of COVID-19 has the Supreme Court Of The United States accepted that telephones exist -- let alone as a means of communication, but also as a matter of legal deliberation.

I wonder how long it shall take to have electronic communication to be accepted, legally, as normal and standard across the board.

The point I was trying to make is that you sending the fax could be pdf > email > fax service > pots > fax service > email > pdf. The end result is a lower quality replication compared to email > email. There's no way the law says either the fact that it looks worse than the email or that someone can point to a contract that says it took place over pots makes the transmission more valuable.

Legally admissible digital signatures do exist, and you can infinitely photocopy a digitally signed document, though. Not so with fax, where a photocopy would count as a different document.

I have done this and am thankful for it.

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.

> digital copy of my analogue signature to drag-drop into an electronic document

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.

What type of middleman blesses a "legally admissible digital signature"? This sounds like the same, if not a similar, rabbit hole folks in the US conjure up against voting machines.

You bless maths, not the middlemen in digital signatures. Electronic signature infrastructures are usually based on strong public key infrastructures, which I call them legally admissible digital signatures. The primary problem with electronic voting is no possible enforcement of no coercive force rule, not tallying security.

See https://en.wikipedia.org/wiki/Electronic_signature to start.

> The primary problem with electronic voting is no possible enforcement of no coercive force rule, not tallying security.

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.

Coercive forces that cause vote buying cannot be stopped by mathematical axioms. Only way out is to adopt a permanent consensus-free self-stabilising social system, but that algorithm becomes the keystone of whole society then.

A lot of deaf people still use fax machines to do things like place orders (often older deaf folks that can't or won't use email... or when trying to deal with orgs that don't check their email). It's a very accessible technology (except for the blind I suppose). This was the case when I was working with some deaf people around 8 years ago, maybe things have changed since then as fax machines have become less common. But fax is still very popular in Japan IIRC.

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 think this may be something that varies to region.

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.

Weird. My experience with Australian banks has been the opposite. Sign up and ID verification online/in-app, and within a few minutes I have a new bank account I can transfer money in and out of.

Guess it varies per bank. My main accounts are with NAB, and they seem pretty up to date.

Maybe Bankwest in particular are stuck in the past.

Unfortunately, sometimes you have no choice.


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?)

Legacy procedures, some legally mandated I think. I'm thinking about the CA DMV, who had ancient and byzantine computer systems that were quite difficult to replace, both from a technical and from a bureaucratic stand point.

A very good question. It’s like using email to send a telegram.

many legacy businesses have institutional technical debt and higher priorities that makes it easier to not deal with faxes.

Faxburner is free.

And of course this comment has no replies and is 1500 pixels below the dozens of others marketing their paid service.

Have you used faxburner? Most of the comments above are people talking about other services they have founded or used.

Also I personally would prefer a paid service, faces typically are secure private documents I would want some level of guaranteed and privacy.

Faxburner has a premium account service.

I've had good luck with Hellofax (YC company) for sending a fax from time to time. Not literally using your phone, however.

I wonder if you could hold up your smart phone to a landline handset like an acoustic coupler to send a fax?

When I first applied for the Apple Developer Program from the Netherlands in the early days of the iPhone when they first published the SDK, Apple insisted that I fax my registration in to them in the UK, so I had to print it out, and take it by a shop that had a fax machine, and pay several euros to send an international fax to Apple.

More than 10 years later, there's still not an app for that.

There are several apps on the App Store that allow you to do just that?

For a fee (which Apple gets 30% of).

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.

It used to be that faxes had some kind of legal power emails did not, perhaps that was the reason.

I'd bet that any "privileges" faxes might had stem from the fact that they were automatically printed. This makes life a lot easier in a paper-backed office, so they made it a requirement to fax any "formal" communications.

My IP phone provider, Voyant, offers a fax api: https://www.voyant.com/product/fax/

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.

There used to be a free service for faxes, at tpc.int.


The fact that it costs you so much probably just means that the demand just isn't there.

TPC.int was kind of crazy. They had a stunt DNS server that made it more convenient to use, so you could mail an address like remote-printer@441234567890.tpc.int (referring to a nonexistent number in Bedford in the usual bigendian E.164 order) and it would be automatically converted to official little-endian RFC 1528 format remote-printer@, after which the usual DNS delegation mechanisms could model the E.164 delegations to route the fax to the nearest server.

For those wondering, the domain tpc.int was registered before `.int` domain registrations required an established international treaty.

It was grandfathered in when this requirement was added.

How about a service that can grab a document out of your Dropbox or other cloud account, then fax it for you? $10 for 50 pages could result in hella margins, if it's done right. (Everything done digitally, of course.)

The account could even be managed from a phone app.

I don't recall which one but years ago I used one of the many email-to-FAX services.

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.

The technology problem is at the fax machine end.

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.

You could when your tablet was a Newton.

Certainly saved the secret nuclear reactor under Washington dc from being blown up.

I remember a long time ago when I worked for a voip phone company, two of our customers asked for fax-to-email and email-to-fax.

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.

as aurizon stated you have to have an intermediary. There are several reputable email to fax services like fax.plus that will allow you to send up to 10 pages for free each page after that is .20 cents. apologies, it's frustrating when you can't other forms of e comms.

Not the most elegant solution, but the price is right. Anveo.com has plans for about $2/month for their VoIP service. And a web based outbound fax that has worked well for me. No extra charge for the outbound fax.

Would even Android allow that kind of access to your phone from a program?

It's not about the access, it's about that you can transmit over the phone network. If you can't transmit it it doesn't matter what client device you have.

I am partially confused.

Is "fax by email" dead or otherwise unattractive?

hellofax.com works for this. I just used it a couple weeks ago took a minute to send a fax live to the receptionist.

Faxzero is a great mostly free solution.

This question feels and reads from the past...

The lossy compression on phone calls might prevent fax from working. Also, I don't know if you can route call audio from anywhere other than the microphone.

HQ audio quality (over 4G) is markedly better than land lines, and the fax protocol has had error correction since digital formats were adopted in the 60s and 70s.


My Palm Pilot (with a CDPD backpack) and candybar 2G Nokia could both send FAXes.

I suspect there's no demand.

The parent’s post is correct. While the perceived quality is much higher, modern cellphones use a lossy format optimized for voice communication.

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.”

Fax uses frequencies that humans can hear though (up to 4KHz)

Sampling frequency 8 kHz/13-bit (160 samples for 20 ms frames), filtered to 200–3400 Hz.

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.

Right, so it must be the bit depth which is the problem, not the frequencies that can be reproduced

Fax has an ip protocol called t.38 however it is inconsistently implemented. Most services still rely on g.711 - essentially uncompressed voice - for transmission of fax tones. However there is no guarantee the end to end call will be g.711 even if specified during call setup. There is an app called eFax - unfortunately the service is not free but I as a subscriber routinely fax over the phone when it’s the only way to communicate (like with a doc office).

While G.711 is uncompressed (it’s the same codec used within the PTSN backhauls), it’s still not great for fax because the fax protocol doesn’t tolerate the jitter introduced by VoIP. (Reliable latency is the one big benefit to switched networks like the PTSN.)

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.

You’re right g.711 is not ideal either. Jitter is a killer. T.38 is a solution when it’s supported on both sides and it is often not. The best solution is email but apparently every title office and pediatrician in the land cannot be bothered! ;) Although thankfully many have moved on.

As a reference point, if you have a cellphone plan with minutes but no data plan, it's not really feasible to dial a 56k-modem endpoint, as it makes use of frequencies that are chopped by the voice codec.

> HQ audio quality (over 4G) is markedly better than land lines

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.

... Wait, why? Standard landlines are 300hz to 3.4khz; pretty low-fi. They should not be particularly hard to beat. VoLTE certainly sounds better than them.

Your network or device may still be using the 90s cellular voice standard, tho.

What's the latency story for VoLTE? Hard to beat analog circuit switching.

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