How the Internet is powered in the depths of the sea
Subsea cables, which are bundles of fragile glass Fibre protected by heavy armour, carry roughly 98% of international internet traffic, linking continents via light pulses and landing stations that connect to national Fibre networks.
Did you ever wonder how the Internet reaches across oceans so that we can communicate – via Email, social media or Internet Voice functionality – between South Africa and the rest of the world? And how is it that, in the blink of an eye, a local gamer can execute a tactical manoeuvre with a team-mate in England to annihilate an ‘enemy’ in Australia? And what enables us to download American-made YouTube videos and watch X rants in real time from Donald Trump?
The Internet is able to reach across oceans like this because a huge chunk of it is actually placed in the oceans. Many people don’t realise that around 98 percent of international Internet traffic is carried around the world by subsea cables.
Let’s take a look.
The Hidden Deep-Sea Internet Highway
The Internet ‘superhighway’ joins continents and countries through both subsea as well as terrestrial cables. The data wires in this interconnected web bring high-speed Internet access to all parts of the globe, through around 1.5 million kilometres of cable criss-crossing the ocean floor.
These cables are laid on the seabed at an average depth of 3,600 metres. Today, there are about 500 subsea cables that are either live or under construction, and if their total lengths were combined, they could stretch – roughly – from the Earth to the moon, about three times over.
The cables are typically funded by the telecom industry, sovereign nations and technology companies such as Facebook and Google. So the reality is that the backbone of the planet’s Fibre cables are deep in the sea, quietly linking people and businesses to each other, all the time (except when something happens, but that’s a different story).
Thin Cables, Extraordinary Power
Fibre Optic cables transfer data across the world in the blink of an eye via light pulses, which travel through fragile wires just thicker than a needle. Fibre Optic cables are tiny tubes made of glass or plastic, which are in turn protected by multiple layers of hard materials like metal and rubber.
A single Fibre Optic can transmit 100 gigabits of data a second, with new cables able to transmit around 400 gigabytes per second. Thousands of Fibre Optics get bundled together and insulated, making one Fibre cable.
Subsea cables typically include a protective jelly around Fibre Optic cables and are also contained within multiple layers of plastic and copper wires. Under the water, ‘repeaters’ are connected at certain points. They amplify the signal and boost signal strength over long distances. The copper wires contained within the cable casing carry around 10 000 volts of electricity to power these repeaters.
The bottom line (pardon the pun) is that both within the sea and on land, the fine tubes that carry data packets at the speed of light need to be protected, which makes the cable overall – once properly wrapped up and protected – look much bigger than the thin part that actually does all the work.
From Sea to Land
When subsea cables under the world’s oceans reach the shore, they are then connected to landing stations, which are an essential part of the Fibre network infrastructure – they distribute the data carried on the networks, joining the submarine cables to terrestrial cables.
For example, there’s a landing station in Mtunzini in KwaZulu-Natal, where the SEACOM cable reaches South African shores. This cable connects the subsea cable directly to a data centre in Midrand, Johannesburg.
Once plugged into the landing stations on shore, the cables take on their overland mutation and are distributed by FNOs (Fibre network operators). The FNOs are responsible for deploying, managing and maintaining Fibre Optic networks – their role is the physical infrastructure, or, in short, running the cables under and next to roads and buildings.
Be Connected with Vox
As an Internet Service Provider (ISP), here at Vox we don’t physically lay the cables ourselves, but instead partner with a number of FNOs around the country to bring South Africans high-speed Fibre to the Home (FTTB) and Fibre to the Home (FTTH) offerings. Some of our local FNO partners include Openserve, Vumatel, Frogfoot, Metrofiber Networx and Octotel (you can find out more here).
An ISP – like Vox – provides Internet access to businesses or residential customers. An ISP’s role is to operate on top of the existing network infrastructure and manage services by offering different plans and packages based on speed and other features.
So next time someone talks about cyber ‘space’, you can point them in the right direction – that it’s mostly all about the ‘cyber oceans’. Except, of course, when it comes to a small section of Internet connectivity that’s powered by Satellite in outer space (just to talk about actual space here for a second).
Satellite really comes into its own in regions where Fibre cables can’t be laid, perhaps because of rough terrain (like mountains) or because the area is just too remote. Vox also offers Satellite services – because as modern life becomes increasingly dependent on the Internet, reliable connectivity is more important than ever before.
Whether it’s for following the news, being connected for work, gaming, staying in touch with friends and family, or streaming shows and movies in your down-time, it’s great to live in today’s connected world. Whatever your needs, Vox will get you connected and keep you in the conversation.
Frequently Asked Questions
Q: What are subsea (submarine) cables and why do they matter?
Subsea cables are bundles of Fibre optic strands laid on the ocean floor that carry roughly 98% of international internet traffic. They form the global backbone that determines international speed, latency and reliability for streaming, gaming and global business traffic.
Q: Does Vox lay subsea cables?
No, Vox does not lay subsea cables. Instead, we partner with Fibre Network Operators (FNOs) and make use of landing‑station capacity so we can deliver international bandwidth into South Africa and on into local networks.
Q: How do subsea cables affect my home or business connection?
Subsea capacity affects international latency and throughput. Good access to landing stations and local distribution networks means smoother streaming, faster international downloads and better performance for cloud apps and gaming.
Q: How can I check if Vox Fibre is available at my address?
Plug in your home address on the Vox availability tool and select ‘Connect me’ to see whether Vox Fibre to the Home is offered at your location.
Q: What if Fibre isn’t available where I live?
Where Fibre is not yet available, for example in very remote or rugged areas, Vox offers Satellite services as an alternative to keep you connected.
Q: What support and contract options does Vox offer for business and residential Fibre?
Vox provides 24 / 7 / 365 support at no extra monthly cost and a range of contract terms to suit different needs. Business Fibre can include dedicated options, static IPs and VLANs; residential plans may offer zero upfront fees on qualifying 36‑month contracts. Contact Vox for package details and tailored service options.
