Submarine Cable Map 2014 • Hacker News Board

Re: Submarine Cable Map 2014

#51

Post by analyticsjam » Fri, Aug 29, 2014, 4:38 PM UTC

I spent a few years supporting these from the financial end. Modern cables are built in a loop so that they automatically fail-over. For instance, most Trans-Atlantic cables have pops in New York, Florida, England, and mainland Europe. If there is a cut in one segment, traffic automatically switches to the other.

Most customers these days are also on products that mux across these cables. So, if your Trans-Atlantic cable has two simultaneous outages, your traffic would automatically route itself across the Pacific. Your latency would go up, but your service would continue.

When I was there, construction was beginning on SMW-4, which had the dubious honor of being the first billion dollar cable. They are typically incorporated via international treaties between states and companies that are roughly about 100 pages long. Each partner has to cover maintenance on the part between the main cable and their drop, while everyone chips in on the main part.

It really is fascinating; outages are typically caused by boat anchors close to shore or large earthquakes. Once a guy in Hawai'i cut the Southern Cross wire with a pair of clippers while doing yardwork.

Re: Submarine Cable Map 2014

#52

Post by gkanai » Fri, Aug 29, 2014, 4:39 PM UTC

nilsimsa wrote: post #46

How do they handle it when cables cross over each other and they need to do repair on the one on the bottom?

The cable repair ships send down custom ROVs that can bring up the broken cable ends. The cable cut is repaired on ship and then placed back on the sea bed. Amazing.

Re: Submarine Cable Map 2014

#53

Post by cbr » Fri, Aug 29, 2014, 4:40 PM UTC

lorenzfx wrote: post #21

corv wrote: post #11

Also good: http://cablemap.info

Since the position of many cables differ strongly in both maps (their position is obviously sketched rather roughly) I wonder what the real position of those cables is? (or if this information is secret)

It's not secret: cables appear on navigational charts so you know where not to put down your anchor.

Re: Submarine Cable Map 2014

#54

Post by runeks » Fri, Aug 29, 2014, 4:41 PM UTC

dalek2point3 wrote: post #47

anyone have any idea what happens to user experience when one of these guys breaks? is it a big deal? what about islands who are surviving off of one cable connection?

You will notice that almost all the cables are laid out in a ring shape. For example, check out the TAT-14 cable: https://en.wikipedia.org/wiki/TAT-14#mediaviewer/File:Map_TA...

If only a single cable break occurs, every point is still reachable from every other point -- the worst thing that happens is that ping times might increase because the packets will have to travel a longer route.

This layout is called a self-healing ring: https://en.wikipedia.org/wiki/Self-healing_ring

Re: Submarine Cable Map 2014

#55

Post by yuribit » Fri, Aug 29, 2014, 5:10 PM UTC

Some days ago we were discussing about sharks eating these calbes and how Google stops them http://www.forbes.com/sites/amitchowdhry/2014/08/15/how-goog...

Re: Submarine Cable Map 2014

#56

Post by dfox » Fri, Aug 29, 2014, 5:15 PM UTC

runeks wrote: post #54

dalek2point3 wrote: post #47

anyone have any idea what happens to user experience when one of these guys breaks? is it a big deal? what about islands who are surviving off of one cable connection?

You will notice that almost all the cables are laid out in a ring shape. For example, check out the TAT-14 cable: https://en.wikipedia.org/wiki/TAT-14#mediaviewer/File:Map_TA... If only a single cable break occurs, every point is still reachable from every other point -- the worst thing that happens is that ping times might increase because the packets will have to travel a longer route. This layout is called a self-…

As typical L2 technology for such cables is SDH/SONET, the difference in latency after single ring failure tends to not be noticeable for normal IP traffic.

Re: Submarine Cable Map 2014

#57

Post by dfox » Fri, Aug 29, 2014, 5:21 PM UTC

RankingMember wrote: post #2

It still amazes me that we laid giant bundles of cabling at the bottom of the ocean and they're as reliable as they are.

The cables themselves fail surprisingly often (anchors, fauna, earthquakes, material faults...) but most connections have redundant paths (almost every undersea network is bidirectional ring) and can be readily repaired (which is the thing that still surprises me)

Re: Submarine Cable Map 2014

#58

Post by ksec » Fri, Aug 29, 2014, 5:23 PM UTC

Does anyone knows the total capacity of all these submarine cables?

Re: Submarine Cable Map 2014

#59

Post by mentat » Fri, Aug 29, 2014, 5:25 PM UTC

The lack of interconnect between Africa and South America is interesting. Wouldn't that be a better route with other transatlantic failures than moving to Pacific transit?

Surveillance issue?

Re: Submarine Cable Map 2014

#60

Post by iSloth » Fri, Aug 29, 2014, 5:33 PM UTC

mentat wrote: post #59

The lack of interconnect between Africa and South America is interesting. Wouldn't that be a better route with other transatlantic failures than moving to Pacific transit? Surveillance issue?

A failure of a transatlantic cable is just going to cause providers (in most cases) to switch their traffic to another transatlantic cable.