If you’re anything like me, your internet connection is a connection to family, to friends, to work, to business partners, to entertainment – and everything in between. When people think of the internet these days, “the cloud” often comes to mind, for storage and apps and streaming games and videos, regardless of your location or your device.
But most people don’t really give much thought about what’s behind the scenes, what’s powering the internet and the cloud. Would it astonish you to know that subsea cables are the invisible force driving today’s internet? That’s right. When you’re binge watching your favorite show, or watching your two hundredth funny cat/dog/goat/horse video, or saving the world in an alternate online universe, infinite amounts of that data are traveling across the bottom of the ocean. While satellites might seem the more likely approach for data delivery, physical cables laid across ocean floors are capable of far more capacity and lower latency.
Subsea cables aren’t a new concept. The first transatlantic cable was completed in 1858, connecting the United States and Britain via telegraph. Queen Victoria sent a congratulatory message to President James Buchanan – the message took around 17 hours to deliver, at a rate of 2 minutes and 5 seconds per letter by Morse code. Not exactly up to internet era standards where everyone wants more, faster.
Today’s subsea market is booming, with around 378 submarine cables in service around the world, spanning over 1.2 million kilometers (according to TeleGeography), delivering petabytes of information around the globe daily. Hyperscale players like Google, Facebook, Amazon and Microsoft own or lease more than half of the undersea bandwidth.
So how does it work? Subsea cables use fiber optic technology. At its basic level, fiber optic communication is a method of transmitting information from one place to another using pulses of light sent through an optical fiber. Lasers on one end fire at extremely rapid rates down thin glass fibers to receivers at the other end of the cable. A subsea cable itself is usually roughly the size of a garden hose, made up in a large part by protective and insulation layers due to the harsh undersea conditions in which the cables must function. The actual filaments that carry the light signals are extremely thin, about the diameter of a human hair. Fiber optic cables carry these laser signals at a rate of terabits per second.
Where does Cisco fit into this subsea cable world? Cisco continues to be a leading optical transport vendor driving this evolution. Our optical networking solutions enable us to tailor the light signals for the best performance for such a long distance, without wasting any precious spectrum. We put multiple channels onto a single fiber by giving each channel its own color of light, or wavelength. And, we put as much capacity as possible onto each wavelength and then combine many wavelengths onto a single fiber.
In the past few months, we’ve had unprecedented momentum in both the subsea and terrestrial markets – made noticeable with several recent announcements, including deployments with Superloop and AARNet, as well as a MAREA subsea cable trial. In this trial, we demonstrated 26.4Tbps over 6,600 kms of subsea cable, from Virginia Beach in the U.S. to Bilbao, Spain. This 26.4Tbps performance surpasses all other deployments to date, setting a global spectral efficiency record. Think of spectral efficiency as a measure of how efficiently we used the fiber’s total available capacity. In layman’s terms, we delivered the maximum amount of data that can be transmitted in the available spectrum.
When the internet emerged in the mid 1990s, we were astounded by its disruptive influence. It was merely the beginning. By 2022, more IP traffic will cross global networks than in all prior “internet years” combined up to the end of 2016 (according to the Cisco VNI). In other words, more traffic will be created in 2022 than in the 30+ years since the internet started. That’s less than three years away! As the world continues to demand videos, apps and gaming – and as we look to the future of self-driving cars, artificial intelligence, and virtual and augmented reality – the internet and its rapid, reliable connectivity will only continue to grow as a powerful force that shapes our world and future.
Learn how the Cisco NCS 1004 is helping our customers keep up with current and future demands with more capacity, longer distance and lower cost per bit.
Very eye opening and cool! Thank you for providing the opportunity to learn something new.
Fantastic article! Thanks for putting this in layman’s terms.
https://submarine-cable-map-2019.telegeography.com/
Stupid questions: Is that a single spliced fiber with one transmitter/receiver pair at each end or are there active devices along the way boosting the signal? What do we do to secure the cables from physical tampering (obviously the ocean does a pretty good job all by itself)? Was the 26.4 encrypted traffic and what’s the overhead or effective payload at that data rate (once encryption is removed)? Very cool stuff but it does raise concerns when all that traffic is vulnerable at the physical layer.
Hi David,
Having worked for a few subsea cable providers, so I love this stuff.
Each sub-sea fiber optic cable could contain 10’s or even 100’s of fiber pairs inside the cable. The fiber optic cable is usually 10-20 mm in diameter which a larger diameter shielded (20 – 40mm) cable that surround it; usually. These are usually reinforced with marine stainless steel to prevent damage to the fiber optic cable inside from seismic activity of the earth, Ship anchor drops and yes some sharks too. Along the cable length, there are ‘repeaters’ which regenerate the with amplifiers so that the signal can get get to it’s destination. These cable are buried in the sea floor in order to minimise these effects. These is massive amounts of power running through these cable, if someone was to ‘tamper’ with them, they’ll get electrocuted.
See the links below for more info.
https://www.youtube.com/watch?v=EfxZmYpmpBc
https://www.youtube.com/watch?v=Be39rqFTacg
There is a transmit and receive on each end of the cable with repeaters along the way, similar to long haul transmission, but different types of repeaters for subsea. Physical tampering is challenging given the subsea deployment in general, but cables can be damaged (e.g. by a fishing vessel), in which case signal loss would result. But, one can use the encryption mode on our transponder that will secure transmission easily. Our encryption runs at line rate so there is little effect on payload. Today many of our customers are deploying up to 24T on single cables, but they apply redundancy by splitting the end node sites.
The toughest physical issues subsea cables have are typhoons, earthquakes and ship anchors dredging up the cables. Thus, diversity in the inter-Asia area is growing dynamically as it is in South America and Africa. Sometimes reaching an island is not about bandwidth, it’s about a diverse route. More drops, more hops. More colocation sites as well.
Great article, thanks!!!
Very interesting read, thanks for sharing!
Fantastic development and success in this really specialised field. Another testament to the way Cisco innovates in optical. Congrats on the capacity record, Bill and wishing you and the whole “optical tribe” continued success.
I have learnt something new today. Interesting and well written article. Thank you for posting!
Happened upon a plaque commemorating the British ‘landing point’ of that first transatlantic cable during our family holiday this year.
Located on a small island called ‘Kerrera’ off the west coast of Scotland, near Oban.
There’s a good tea shop nearby and an imposing castle. The distillery in Oban is excellent, the whiskey very ‘moreish’.
Great article.
very insightful and interesting.
Great to hear,
Yes, Cisco’s WHOI Account Team in 1998 started with testing Cisco long haul fiber on “Project NEPTUNE” at Woods Hole Oceanographic Institution (WHOI) and bringing the power of the Internet to the seafloor and beyond.
https://www.whoi.edu/oceanus/feature/neptune-a-fiber-optic-telescope-to-inner-space/
I worked for WHOI in 1996-1997 and sailed with Dr. Chave and Dr. Delaney on the Atlantis. NEPTUNE was never fully built was it?
Thanks Bill. Great market to enter especially with our recent Acacia announcement. Congrats on breaking the spectrum efficient record !
Way to go !!! Cisco is The Future, undoubtedly
Thanks Bill,
Very uplifting!
Fabulous Story! Thank you.
Nice Article. Thanks for Sharing.
Great Article and insight – 26.4TB at that distance is incredible — thank you for keeping Cisco in the front and our Brand strong!
Very nice article. Explaining things in simple English to most extent. I’m surprised there’s no mention of Acacia’s offering in this space. I’d have loved to see some mention of how Acacia is going to make Cisco’s offerings even bigger and better..
I worked on the very first fibre-optic transatlantic cable, TAT-8, which had the enormous capacity of 280Mbp/s on two fibre pairs. Later I worked on PTAT-1 and TAT-9, which had double the capacity with four fibre pairs. At that time the primary use was carrying voice circuits. I also worked on NPC, a trans-pacific cable, probably the first cable to have a business case on data traffic use – mainly fax!
The first transatlantic optical fibre cable, TAT-8, was completed in December 1988 and had a capacity of 280Mb/s over two pairs of fibres.
A dedicated 1.544Mb/s link between US and CERN, Geneva enabled Tim Berners-Lee to demonstrate the World Wide Web he had invented to interested parties in US.
31 years on and you have 26.4Tb/s over one fibre pair, which is 188 times faster than each fibre pair of TAT-8, or a 13.2% compounded annual growth rate in speed.
For clarification, does Cisco’s latest VNI forecast for 2022 take into account the near-broadcast or multicast nature of a significant portion of internet video traffic and adjust the total traffic count downwards accordingly?
Hello Paul – According to the Cisco VNI analysis, there is a projected increase in live Internet video (15-fold growth from 2017 – 2022). This shift reflects the multicast/broadcast nature of Internet traffic (as you have noted). Comparatively, the majority of Internet video traffic will continue to be unicast in nature by 2022 (but it is clearly shifting). We have factored this into our traffic forecast assumptions. You can learn more about our VNI Forecast methodology through our public Q&A document: https://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/qa_c67-482177.html
Great Article !
Very insightful read. Thank you.
As the volume of internet traffic is exponentially increasing every year, how scalable is this ?
Glad that we are now into the submarine cable system business!
I have worked on a subsea carrier company and only a few vendors are out there catering to this specialization.
Very exciting times ahead!
Very good article ! Thank you.
Nice, very good article.