Submarine cables carry whole Internet Traffic ! More than 95

Submarine cables carry whole Internet Traffic. I am not exaggerating. Today’s 95{ea8372c0850978052e20c0d53be15bc420c794e9b9b32f0ee9dfe0056552e01e} of the Internet Traffic is carried over Submarine cables.



They are so important but as a network engineer how much do you know about Submarine cables ?




I explained the fundamentals of submarine cables in this post. If you are working in the Service Provider industry (In fact in any large scale network) or if you are interested in interconnection between the networks, you need to know the fundamentals of the submarine cable systems. If you are looking for a structured, detailed training on the submarine cables , interconnection and service provider networks , then click here.



In this post I will explain the basics of Submarine cables and provide you some interesting data. This will be the basis of the upcoming more advanced transport networking posts. Sit back and enjoy !


Sub marine cable which is also called as Subsea cables are deployed to connect countries, regions and the continents.



Submarine cables are laid by specialized cable-laying ships must and if a cable is broken , another special ship must be used. This generally means that laying a cable is logistically challenging and very expensive.



And when a cable breaks, it sometimes isn’t possible to fix it immediately if a cable-fixing ship isn’t nearby (and for this reason, most submarine cables use a ring topology in case one stretch is broken and ring based protection protocols are provided by the upper layer protocols such as SONET/SDH, OTN etc.).



It’s also amazing to consider that the first trans-Atlantic cables were laid in the 1860s, and trans-Pacific cables followed in the early 1900s. These cables were incredibly low-bandwidth — repeaters didn’t exist yet, so the only way of getting a signal across the ocean was by increasing the voltage and creating a very noisy link — but by the early 1900s, the British Empire had already connected up most of the continents (see below).




first submarine cable map




Traditionally, private companies and consortiums formed by telecom carriers owned cables, but this model is changing. Content providers such as FAMGA (Facebook, Amazon, Microsoft ,Google and Apple) are new major investors in new submarine cables. Cloud computing , Inter Datacenter traffic are the big demand drivers of this new private cable investments.


As more millions more people around the world adopt cloud computing and private backbone networks , we’ll be certain to see even more cable deployment in the near future.


Subsea cables , on the inside, they have a core made of layers of fibre and wires covered in a protective layer to keep the ocean out.



submarine cable inside






submarine cable shore





The cables are several inches thick when they are near shore. At the deepest levels of the ocean, they are much thinner. That difference in size is because the cables actually face more threats in shallow waters, including everything from fishing ship anchors to sharks (It happened just couple times though, it is real, sharks bite the cables 🙂 )



submarine cable shark bite



It’s also worth noting that the only continent that isn’t wired into the internet is Antarctica; the temperature of the Antarctic Ocean is too low.





One Reply to “Submarine cables carry whole Internet Traffic ! More than 95”

  1. Totally agree that the outage of submarine cable is painful for the telecom companies as it talks months to be fixed. Not to mention the high latency of submarine cable which sometimes reach 155ms so that the service providers prefer the terrestrial cable, which is less stable but has better performance when considering the latency as a factor for the provided quality

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