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The Dunant subsea cable

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Re: The Dunant subsea cable

#101

Post by edoceo »

ThePadawan wrote: post #9
cmpb wrote: post #6

Ah the old "entire digitized Library of Congress" per second metric

I always find comparisons using text data incredibly worthless. I'm sure a Shakespeare play or The Great Gatsby are barely a few megabytes. But if you asked Joe Shmoe on the street "In Great Gatsbys, how big was the last picture your iPhone took", they would rightly have zero idea. It's so useless.

I think all of Shakespeare was like 450,000 LOC.

I used to use that metric when folks ask why it took so long to debug. Like, our project is 600,000 LOC and more complicated than any of his works. He didn't have it all memorized and neither do I. It's a metric PMs can understand.

Re: The Dunant subsea cable

#102

Post by MarkusWandel »

syoc wrote: post #14
aynyc wrote: post #3

I know nothing of this type of engineering. How do you even start a project like this? Map the bottom of the ocean, figure out all the danger zones? What is the cost of doing something like this?

I have no idea about how this stuff, but this wired article from 1996 written by Neal Stephenson about undersea cables is a fantastic read. https://www.wired.com/1996/12/ffglass/

The article is now almost a quarter century old and the cables have gotten better. In fact, even that cable probably got a lot faster after optical coherent detection was introduced, i.e. much more capable modems. But the way the cables are actually laid and especially the details of the shore landings and the issues of terrestrial runs, are as current as ever.

Re: The Dunant subsea cable

#103

Post by eitland »

tzs wrote: post #92
sparsely wrote: post #16

Earlier quoted context omitted.

That is at least 1 order of magnitude cheaper than I would have guessed. Mind boggling that it's cheaper to do that then buy like the 4th best meal delivery app in Canada or whatever.

It's probably cheaper than people would expect because the long run across the deep ocean is a lot more straightforward than most people would expect. 1. For the deep ocean parts of the route, cables and associated equipment (such as repeaters) are simply spooled out from the back of the cable laying ship, to settle on the ocean floor. 2. For shallow waters, the cable is buried. This is done by dragging a plow along…

> Assuming the underwater cable itself is 10 times as expensive as regular cable, its about $150 million for 9000 km.

Still sounds really inexpensive when I consider it contains a large number of repeaters and is meant to stay at the bottom of the ocean.

Edit: Forgot to write, I haven't run the numbers myself but I enjoyed your reasoning here, you put a smile on my face :

> At 5 knots, it would take about 1000 hours to lay the deep sea part of the cable. If the ship costs $50k/hour to operate, that would be about $40 million. (I have no idea what it costs to operate these ships, but Google tells me that big cruise ships cost about that much to operate, and I'd guess that a cable laying ship is cheaper).

Re: The Dunant subsea cable

#104

Post by crispyambulance »

DoomHotel wrote: post #98
crispyambulance wrote: post #81

The article says this cable uses SDM (space division multiplexing). Which, for fiberoptics, means that you have multiple fibers. Of course they HAVE TO put many wavelengths on each fiber, each wavelength carrying a signal. The "state-of-the-art" AFAIK is to use many wavelengths per fiber, each one carrying ~192 wavelengths each wavelength transporting at up to 100Gbps (this is known as DWDM). So so with SDM, you just…

You can send spatially-separated signals down a single multi-mode fiber. https://www.nature.com/articles/s41598-019-53530-6

That's interesting! But multimode fiber isn't feasible for thousands of kilometers? This is transatlantic. Wouldn't that have to be singlemode just for the distances involved?

Re: The Dunant subsea cable

#105

Post by vngzs »

xbmcuser wrote: post #75
_Understated_ wrote: post #19

Earlier quoted context omitted.

Let's say they do tap the cables (I reckon they do too but in case they don't) what can they actually see if the traffic is encrypted?

Forget encryption every second so much data passes through at a time can they even isolate particular data let alone encrypted data. Can they process all that data in real time if not how are they storing it to process later. This is just 1 cable from 1 company there are now dozens of cables of different companies.

> so much data passes through at a time can they even isolate particular data let alone encrypted data.

They can't. That's why they call it "bulk collection."

https://en.wikipedia.org/wiki/MUSCULAR_(surveillance_program...

Re: The Dunant subsea cable

#106

Post by jeffbee »

easton wrote: post #42
ed25519FUUU wrote: post #40

Earlier quoted context omitted.

Google uses gcp.

For everything? I was under the impression they still ran all the big stuff on their internal cloud with Borg and all the other infrastructure tooling they built.

Yeah, you should think of it more like GCP runs on Borg, not the other way around, although the description is not perfect. Also Google's cloud services like Cloud Spanner and Cloud Bigtable run directly on Borg.

What's terrifying is that Google described each of their B4 sites as having 60tbps uplinks in 2017, growing at 100x per 5 years. So a 250tbps undersea cable is nice but when you think about it probably not enough to make intercontinental transfer too cheap to meter.

Re: The Dunant subsea cable

#107

Post by lifeisstillgood »

Old timer story - years ago, Demon Internet (my old employer) was beginning to enter super-growth and wanted to really set itself up for trans-atlantic connections. So they decided to buy a T1 - 45Mbps link across the atlantic. Now it turns out that BT had only ever resold fractions of T1s - they had never actually had anyone want a whole one. And as such their sales commissions did not cap out.

So, we rang up, a sales guy picked up the phone and got a million pound pay day, and resigned that evening.

But our customers were happy so thats what counts :-)

Re: The Dunant subsea cable

#108

Post by ASinclair »

lifeisstillgood wrote: post #107

Old timer story - years ago, Demon Internet (my old employer) was beginning to enter super-growth and wanted to really set itself up for trans-atlantic connections. So they decided to buy a T1 - 45Mbps link across the atlantic. Now it turns out that BT had only ever resold fractions of T1s - they had never actually had anyone want a whole one. And as such their sales commissions did not cap out. So, we rang up, a sal…

Great story!

Re: The Dunant subsea cable

#109

Post by dna_polymerase »

Cthulhu_ wrote: post #84
dna_polymerase wrote: post #79

Earlier quoted context omitted.

Ever heard of React, Vue or Angular? If you meant mandatory in terms of the actual medium requiring it, I can only hint to interactive applications, aside from that I don't think it would actually be mandatory.

All of those can be rendered server-side if needs be, and in my experience, can actually lead to a superior browsing experience compared to plain server-side served HTML. But it has to be done right. Gatsby + Netlify with a CMS-as-a-service like Contentful or Prismic will lead you to a good result. We made e.g. https://fox-it.com/ using that, its back-end is Wordpress but it's drained empty to rebuild the website. No…

Absolutely the can, yes. I wasn't saying they couldn't. I just answered the question. And those frameworks really introduced the idea of loading JS in order to load content to the broader masses. Things have evolved, sure and it can be done right, but nonetheless, those frameworks are a reason to force JavaScript on the user.

Re: The Dunant subsea cable

#110

Post by jisco »

DoomHotel wrote: post #98
crispyambulance wrote: post #81

The article says this cable uses SDM (space division multiplexing). Which, for fiberoptics, means that you have multiple fibers. Of course they HAVE TO put many wavelengths on each fiber, each wavelength carrying a signal. The "state-of-the-art" AFAIK is to use many wavelengths per fiber, each one carrying ~192 wavelengths each wavelength transporting at up to 100Gbps (this is known as DWDM). So so with SDM, you just…

You can send spatially-separated signals down a single multi-mode fiber. https://www.nature.com/articles/s41598-019-53530-6

It's not the case here. On their website, google states: ... Dunant is the first long-haul subsea cable to feature a 12 fiber pair space-division multiplexing (SDM) design ...

Multi-mode fibers are not feasible for long distance transmission. For long distance communications, using suggested approach, may be better to use multi-core fibers.

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