The Internet's Global Journey: How Does It Travel?

The internet is a complex system that allows us to access information from all over the world in a matter of seconds. But how does this information travel across vast distances? The answer lies in a combination of technology and infrastructure. Data travels through the internet in the form of packets, which contain information such as addresses, requests, and content. These packets move through cables, wireless connections, and satellite technologies, reaching their destination through routing systems that determine the most efficient path.

However, the foundation of this global network is a vast array of undersea cables. Stretching across the ocean floor, these cables form the backbone of the internet, connecting continents and countries. This method of transmitting data is not new; it dates back to the 19th century when the first successful transatlantic cable was laid. Today, thousands of miles of cables crisscross the oceans, carrying data at incredibly high speeds.

So, the next time you send an email or browse a website, remember that it's not just travelling through cyberspace – it's also traversing the depths of the oceans, thanks to the intricate network of undersea cables that power our digital world.

Data travels in 'packets'

Data travels in packets. In networking, data is called "packets" and these packets contain everything needed to browse the web. Each packet has a "wrapper" with a "header" and a "footer". The wrapper contains information that tells computers what type of data is in the packet, how it fits with other data, where the data came from, and where it is going. Each packet can carry a maximum of 1,500 bytes.

When you send an email, the message breaks up into packets that travel across the network. Different packets from the same message don't have to follow the same path. This is part of what makes the internet robust and fast. Packets travel from one machine to another until they reach their destination. As the packets arrive, the receiving computer assembles them like a puzzle, recreating the message.

All data transfers across the internet work on this principle. It helps networks manage traffic. If one pathway becomes clogged, packets can go through a different route. This is different from the traditional phone system, which creates a dedicated circuit through a series of switches. If something happened to that connection, the call would end.

If one connection fails, data can travel across an alternate route. This works for individual networks and the internet as a whole. For instance, if a packet doesn't make it to the destination, the receiving machine can determine which packet is missing by referencing the other packets. It can then send a message to the sending machine to send the missing packet again, creating redundancy. This all happens in the span of just a few milliseconds.

Packets are addressed and routed

The internet travels across the world through a labyrinth of undersea cables, stretching across the floors of the oceans. This method of sending data is preferred over satellites due to its stability and reliability. In fact, 99% of all international data is transferred through these cables.

Data is sent through the internet in the form of packets. These packets are addressed and routed through a process called routing, which is the process of selecting a path for traffic in a network. In the context of the internet, routing refers to IP routing, which assumes that network addresses are structured and that similar addresses imply proximity within the network. Structured addresses allow a single routing table entry to represent the route to a group of devices.

Routing tables are used to direct the forwarding of packets from their source to their destination through intermediate network nodes by specific packet-forwarding mechanisms. These tables maintain a record of the routes to various network destinations and can be specified by an administrator, learned by observing network traffic, or built with the assistance of routing protocols.

When a host system initially sends a packet, it looks up the packet's destination address in its routing table to determine if the destination is on the local network. If the destination is local, the packet goes directly to the host with that IP address. If not, the packet goes to a router on the local network.

Routers are intermediate nodes that can be in the form of network hardware devices such as routers, gateways, firewalls, or switches. General-purpose computers can also forward packets and perform routing, although they may not have specialized hardware for the task.

When a router receives a packet, it checks its routing table to determine if the destination address is for a system on one of its attached networks or if the message needs to be forwarded to another router. It then sends the message to the next system in the path to the destination. This process is repeated on each router that receives the message until it reaches the destination system.

Packets travel via cables or wireless

The internet is a network of computers that communicate with each other using packets of data. These packets contain all the necessary information, such as the destination address and the request. When you send an email, for example, it is broken down into these packets, which then travel across the network and are reassembled by the receiving computer. This is known as IP Convergence, where all systems are routed through IP, creating a single network for maintenance and upgrades.

These packets of data can travel via cables or wireless connections. In the case of cables, they are thin wires, often no thicker than a strand of hair, that stretch across the ocean floor. These cables connect continents and countries, allowing data to travel swiftly from one place to another. The data is propelled through these cables using fibre-optic technology, with lasers transmitting information at nearly the speed of light.

While wireless connections are becoming more common, these connections eventually link up with physical cables that carry the information across vast distances. Wireless signals operate similarly to radio signals, with WiFi signals creating waves that transmit data.

The choice between cables and wireless connections depends on various factors, including distance, infrastructure, and speed requirements. Cables remain the preferred method for long-distance data transmission, especially across oceans, due to their stability and reliability. On the other hand, wireless connections offer more flexibility and convenience, especially for short-range data transfer.

The combination of cables and wireless technologies ensures that data can travel efficiently and effectively around the world, connecting people and devices in a global network.

Fibre-optic cables are super-fast

Fibre-optic cables are made of tiny strands of glass, which transmit data through pulses of light. These strands are about 125 microns in diameter, slightly thicker than a human hair. Many of these strands are bundled together to form a cable. The pulses of light travel at an incredibly fast rate, and because they are made of glass, they are less susceptible to electrical interference.

The technology behind fibre-optic cables has been around since the 1970s, but it was initially very expensive. Now, prices are declining, and consumers are increasingly turning to fibre-optic cables to connect their data networks. Fibre-optic cables are also more reliable than other types of cables, with minimal outages and reduced signal degradation over long distances. They are also less susceptible to severe weather conditions.

The speed of fibre-optic cables is due in part to the fact that they use light instead of electricity to transmit data. This makes them much faster than older copper cables, which can only carry signals up to 328 feet without amplification. In contrast, fibre-optic cables can send signals up to 25 miles, depending on the wavelength and type of cable.

The high speeds of fibre-optic cables have enabled dramatic progress in the telecom field. Some even say that fibre-optic technology is what made the Information Age possible. With further advancements in technology, fibre-optic networks are expanding rapidly, bringing super-fast internet speeds to homes and businesses around the world.

Undersea cables connect continents

Undersea cables have been connecting continents since the 1850s, when the first submarine communications cables were laid to carry telegraphy traffic. In 1858, the first transatlantic telegraph cable was completed, connecting the United States and Britain. This cable allowed for the first instant telecommunications links between continents.

The process of laying these cables is complex and time-intensive. A ship carries thousands of miles of cable, weighing thousands of metric tons, out to sea. Workers then spool the cable into large tanks, laying it out in a circle to avoid snagging or knotting. Even with teams working 24/7, it takes about four weeks to load the ship with enough cable. Once at sea, the ship moves slowly, at about six miles per hour, as the cables are pulled from the tanks and laid on the ocean floor.

Today, nearly 750,000 miles of cable connect the continents, supporting our constant demand for communication and entertainment. These cables are typically owned by large tech companies like Google, Amazon, Facebook, and Microsoft, or by consortia of telecommunications operators.

The reliability of these submarine cables is high, and they offer far greater capacity than satellite connections. While satellite connections account for only about 1% of global data transmissions, undersea cables carry 99% of international data.

However, these cables are vulnerable to damage from fishing trawlers, anchors, earthquakes, and even shark bites. Repairs can be challenging and time-consuming, requiring specialised ships and equipment to locate and fix the breaks. Despite these challenges, undersea cables remain the fastest, most efficient, and cost-effective way to send information across the oceans.

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