IP over Lasers

[jasonjayr]

They built a program they called (relay) that sends packets between a tun network device & a uart serial device

https://github.com/mikeakohn/small_projects/blob/main/ip_ove...

I .... wonder if they considered just using PPP/SLIP?

[Retr0id]

A while back I was doing some IP-over-UART shenanigans and it took me a surprising amount of research to discover the existence of SLIP. I think it's one of those things that at some point "everyone knew about" and ended up being poorly documented as a result.

[immibis]

I wouldn't be surprised if they were trying to remove them from the kernel since you can use a tun interface instead. They would be very good candidates for moving kernel functionality to userspace.

[tgma]

Aren't regular fiber-optics just mass-deployed IP over lasers? (this message is brought to you by at least one, likely multiple, lasers in prod)

[advisedwang]

Yeah, but kinda cool making it from scratch.

Also this uses air as the medium.

[vpShane]

Yes and no, worth reading in to. Yes in the sense of, technically laser but gets reconverted along the path in many ways, ethernet turning it in to frames after a receiver (modem, whatever equipment) then translates it.

Laser = over air, susceptible to interference like atmospheric things, dust, flies, also; since it's laser and over a distance, the photons will spread out. Beam divergence.

Fiber lines are carefully engineered to contain the light transmission to get it to where it has to go.

Microwave would be better than laser to my knowledge but then your packets are flying around through the air willy nilly. Things like SSL handshakes and unencrypted hello packets are readable.

But, anything lasers is amazing.

[bobmcnamara]

I'd assume most are LEDs or VCSELs. The long range stuff is laser.

[MisterTea]

The AT tiny is not needed at all. You have a digital signal coming right out of the serial cable which can drive the laser using a buffer and a Schmitt trigger on the receiver.

Eliminating crosstalk is the tough part and requires some modulation to ensure the transceiver isn't accidentally listening to itself via reflections or picking up interference.

Look up point to point laser links. They have been around for quite some time.

[toast0]

Back when 10M ethernet was popular, it was pretty easy to wire up something like this with the transceiver (AUI) port... wire the tx to a laser and the rx to a photodiode (or whatever), ???, profit.

There's lots of commercial equipment in this space too.

[eqvinox]

https://ronja.twibright.com/

[riedel]

When I studied our dorm was connected to the campus network via a laser uplink (and the Internet, with each room having a public IP address). I still remember the foggy daya when people, you normally did not see, gathered in the bars, because the network went unbearably slow. It was nice days with every CS student having a server rack in their closet. I had a VT520 hooked up to it be able to read emails and IRC chats bed without having to wait for my PC to boot.

[teeray]

I dreamed of doing something like this growing up so that my neighbor and I could play StarCraft without the latency of dialup. I wish I knew then that it was that straightforward.

[NoiseBert69]

We had a laser link to the university 20 years ago. 10MBit/s for 300 people.

That thing was awful.. lol.

The link was dead during

- Heavy rain

- Fog in the early morning

- While snowing for days

- Pigeons building a nest within the optics

[chasil]

There are many long-range WiFi solutions. I wonder how these would have performed as alternatives.

https://en.wikipedia.org/wiki/Long-range_Wi-Fi

[blacksmith_tb]

Scale it up, and you have Taara[1]

1: https://x.company/projects/taara/

[beAbU]

When I was about 10-12 for a school science fair I built a device called a "photophone" [1] - one of Bell's lesser known inventions.

Basically, a filament flashlight is modified so that a magnetic coil was placed in series. An audio source is then fed through a second coil -- I can't remember the exact details of how this worked. The audio source was one of those fisher price sing-along tape players that I also modified I think. The tape was Abba.

On the other end, a cheapo solar cell was hooked up to a small kit amplifier and then you could hear the audio on a pair of headphones.

This was in 2002 ish, so fibre optics was a thing, but it was basically sci-fi for a scrappy kid in southern Africa. My whole spiel was how this was the precursor to fibre optics, and how one day all communications will be done using light in stead of electrons.

Fun times!

[1] - https://en.wikipedia.org/wiki/Photophone [2] - https://www.youtube.com/watch?v=SxlWrqioifg

[proxysna]

Really like seeing networks over whatever laser things. Very cool stuff. This thing always comes to mind. http://images.twibright.com/tns/1208.html

[kej]

I don't know why, but I would have expected higher speeds. Maybe my mind just assumes "lasers = fast". It would be interesting to know which factors make this setup unreliable at higher speeds.

[Sesse__]

Most likely one of:

  1. Noise in the detection (the room is bright etc.)
  2. The laser being a form that's not susceptible to direct modulation (if it takes a millisecond to start/stop lasing, obviously you cannot turn it on/off very fast)

High-speed laser-based systems (gigabit and beyond) don't try to turn the laser on/off at all, they just have something in front that tries to cancel out the signal (e.g., through self-interference) when you want to send a zero.

[treve]

Individual bits always go fast, the difficulty is always telling many apart. Speed is kind of the wrong word. It's about throughput

[zokier]

I would bet that the laser pointers used here are the bottleneck.

[Lerc]

I have always wanted to give this a try. I have this daft idea of implenting a system logically as an n-dimensional cube and physically on two facing surfaces (even and odd parity processor addresses) with laser connections between the processors. Perhaps it'll be one of my crazy project ideas that I can do in my retirement

[voidUpdate]

I remember trying to my own data transmission over lasers ages ago, back when I didn't really know about how to properly transfer data (PLLs, clock recovery, error correction, etc). It lost timing pretty quickly, but it could just about do a hello world

[lambdaone]

None of this is remotely new or interesting. I was doing IP-over-laser-light at Ethernet speeds over kilometer distances using free-space optics thirty years ago, and even then it wasn't a new technology.

[mschuster91]

It's interesting for a hobby tinkering project. Basically like rudimentary transmitters for ham radio. Understand the fundamentals, then you can move on to better quality DIYs

[rnhmjoj]

Was that RONJA [1]?

[1]: http://ronja.twibright.com/about.php

[beAbU]

Thank you for your valuable contribution to this conversation.

[alberth]

Isn't fiber broadband exactly this?

It's shooting a laser through a fiber optic cable.

[nullbyte808]

Why is the ping worse than connecting to a remote shack in Mongolia?

[psnehanshu]

I was vibe researching TUN/TAP devices a few days ago. Cool to see such cool projects using them. I was mostly thinking about making a VPN prototype through.

[esseph]

There's a billion different types of VPN.

What problem are you trying to solve?

[vin92997]

I want to see the actual laser beams while transmitting those packets.

[CableNinja]

Do not look at the laser, you wont be able to look at it again

[a3w]

A typical computer is connected to the local network using either an Ethernet cable or WiFi. This project connects two computers together through lasers.

No mention of carrier pigeon? IPoAC has three RFCs!

[munchlax]

I'd not expect that to be "typical", unless you're in the middle of some pretty huge nature reserve and still need to file taxes online.

[lifestyleguru]

Now try IP over electricity.

[proxysna]

Powerline is sort of like that. Devices act like an L2 transparent proxies over electrical wiring.

[cestith]

I have UTP and DAC cables here at home. I even have a bit of 10base2 around here, although none of it’s running at the moment.

[a3w]

Photons vs electrons? Just rotate 90 degrees, seem to be swappable more easily than using neutrons or other particles, like tau/muon/electron neutrinos.

Oh wait, didn't fermilab even use neutrinos in 2012? That seems even harder, practically made for an April fools RFC.

[cortesoft]

IP over Lasers: Fiber optics

IP over electricity: Ethernet

[ggm]

We know neolithic internet used free air lasers because we haven't found either optical fibre connectors or copper Ethernet in the trenches we dig at neolithic settlements.

[sigmoid10]

Is this a jab at the people who believe Egyptians must have used electric lights because we can't figure out how they lit and ventilated their tombs at the same time during construction?

[cuttothechase]

Isn't this just fiber optics! Exciting turn of the century tech hitting HN boards in 2025

[rafale]

Every year new engineers and enthusiasts need to be exposed to cutting edge technologies through hands-on introductions like these.