Submarine cable resilience

I forget who said it, but there's a quote about how _of course_ we know more about space than the bottom of the ocean - in space we only have to deal with one atmosphere.

I (briefly) worked as a test engineer on a similar kind of contract. To meet the UX requirements for the system we were building, it had to be reliably operable in sea state 7+. The customer wanted touch screen interfaces. I exited that project when they were looking for volunteers to go spend time offshore in the Gulf of Alaska in bad weather, because that was the test environment they could find that met the requirements. Insanity.

I found that sea, space and automotive are the three most hostile environments, each with very different requirements that made it hard in different ways.

I think the issue is that centralization is more economical due to scale, but that assumes all else (geopolitics or other black swan events) don't impact things.

We saw a similar thing with supply chains and chip suppliers.

I think people conflate decentralization with redundancy or resilience. IMO it just means you have multiple points of failure instead of one.

> reading articles like this does underscore how vulnerable global traffic is.

Then also remember that the internet haven't seen a global outage since forever, worst parts have been when some submarine cables break and traffic has to route around it, but never has the entire thing fully went down. Considering how most of it is built with bandaids, silver-tape and WD40, it's surprising it is as resilient as it is.

Not sure about other blockchains but with Bitcoin, you only need one node to connect via satellite and the chain is good. In fact, there are satellites that broadcast blocks from space (no ISP required). [0]

[0] https://blockstream.com/satellite/

During an internship I worked on optical transport network equipment. Most customers were either submarine or long-haul across land. I was told that many clients would design redundantly, mainly due to people digging up the cables, chopping them in half with a shovel, and being disappointed when there was not much copper to steal.

aren't decentralized systems using the same infrastructure and are also relying on ip to route around missing routes? Just like centralized ones?

I used to have a print copy of that issue. That single article was something like 50-60 pages long with all the (fabulous and informative) pictures.

I think about this often.

Scan from the print issue: https://archive.org/details/wired-magazine-04.12-1996-decemb...

At least for the Baltics, there is the unique aspect of the infamous "shadow fleet". Utterly derelict ships with barely qualified crews.

Yes, I admire the restraint required to not put "unlucky" in quotes.

who have you asked?

Everyone in the industry I can find including people who do recycling of submarine cables. It seems that cross sections are sometimes given away as gifts as part of a project but are really hard to find.

I think it's like slices of tree trucks to build wall clocks (or whatever) kind of wall art out of: If you know a guy who knows a guy who works with trees, then it's easy to get a rough cut-off slice.

It may even be free. If they're already there cutting the thing with an appropriate saw, then slicing off one more bit and saving it for Bill's friend jgrahamc isn't a big deal.

But without that kind of relationship, it's hard.

(I want one, too.)

My history teacher in high school was wrong. He said he was right because the teachers' answer key said X. I replied that X was obviously wrong. He knew he was wrong, because he hid behind what his answer key said.

We didn't get along.

Likely failure was due to not being insulated properly and Wildman Whitehouse:

https://en.wikipedia.org/wiki/Wildman_Whitehouse

The Digital Antiquarian made fantastic "A Web Around the World" series of articles covering start of telegraph all the way to first Web Browser in a style of James Burke Connections.

A Web Around the World, Part 1: Signals Down a Wire January 7, 2022 https://www.filfre.net/2022/01/a-web-around-the-world-part-1...

https://www.filfre.net/2022/01/a-web-around-the-world-part-2...

https://www.filfre.net/2022/02/a-web-around-the-world-part-3...

First working cable was sort of Monty Python Swamp Castle deal.

Someone else with more experience could chime in but I would put it at less practical due to latency (sats are very high up), bandwidth (one laser vs a bundle of 1000s of fiber optic cables), cost (to overcome latency you need a closer orbit which requires more sats), single point of failure, lifespan, intercepted communications, solar flares… and that’s just off the top of my head.

A submarine cable is a bundle of hundreds of strands, so you need quite a few satellites to replace one cable.

Starshield (military arm of SpaceX/Starlink) does this for satellite imaging.

Normally in imaging, you first need to get the satellite over the location you want to image, at the right time - then let it orbit over a downlink location.

There are companies making a lot of money by having downlink capability in useful places (eg: near the poles) - combined with a fat pipe to the Internet.

With Starshield, the satellites talk to each other over laser - so the satellite doesn't have to wait to travel to a downlink location - just relay to of that is already there.

So for certain special cases it can help - but I think you'll find a cable stuffed with multimodal fiber had vastly more bandwidth.

Depends on a lot of things, but most undersea cables have several fibers (typically around 10 fibers), and each fiber runs many wavelengths (typically 40 or 80). Whatever your bandwidth is per wavelength (there are lots of options, at different costs, up to maybe 400gbps) that's a huge amount of bandwidth to replace.

Space lasers probably don't do multiple wavelengths, and aiming a lot of laser transceivers is going to be challenging.

> Alternatively, is there a wavelength of light to which water is completely transparent? Can we shoot lasers of that frequency through open water instead of through cables?

Even if you could, that's only going to work for short hops, long distance fiber includes repeaters every so often (50-100 km) to deal with loss, it would be tricky to build those under the sea ... and you need to power them, which means a cable, might as well include fiber with your power cable.

Modern satellites, in particular Starlink, use optical transceivers that are identical to the ones used for the fiber optic links, with an addition of all the required parts to make them work across free space. So a link between a pair of satellites is very comparable to a single pair of optic fibers.

The cables can go the entire distance between the data centers. The satellites probably connect to their closest neighbors, and any long distance transmission would have to make multiple hops, and share the bandwidth with everything else in the system going through the same nodes.

Since there are hundreds of undersea cables, with a dozen fiber pairs or so each, the cable system has several orders of magnitude greater throughput compared to the current constellation of satellites.