How the Internet Connects Across Countries and Continents | The Secret World of Undersea Cables, Satellites, and Global Routing Infrastructure in 2025

Table of Contents

• What Connects the Internet Globally?
• Are Undersea Cables Still the Primary Method of Global Internet Transfer?
• How Do Submarine Cables Work?
• What Happens When You Access a Website Overseas?
• Flowchart: How Data Travels Internationally Over the Internet
• What Role Do Satellites Play in Internet Connectivity?
• What Are Internet Exchange Points (IXPs)?
• Are There Risks to Global Internet Connectivity?
• Why Should You Care About How the Internet Connects Globally?
• Key Elements of Global Internet Connectivity
• Conclusion
• Frequently Asked Questions (FAQs)

The internet may feel wireless, but behind the scenes lies a vast, complex, and mostly physical infrastructure that connects the entire world. One of the most fascinating aspects is how the internet connects between countries and continents—through undersea cables, satellite links, and massive data centers spread across the globe.

In this blog, we’ll explore how this international connectivity works, how data travels across oceans, and why it matters to everyday users. We'll also present a simple flowchart to help visualize this global system.

What Connects the Internet Globally?

The backbone of the internet between countries and continents consists of:

• Submarine (undersea) fiber optic cables

• Landing stations

• Internet Exchange Points (IXPs)

• Satellites (as backup or in remote areas)

• Network routers and peering agreements

  
  

These components ensure that data flows efficiently from your home network in India to a server in California, Japan, or anywhere else on Earth.

Are Undersea Cables Still the Primary Method of Global Internet Transfer?

Yes. Over 99% of international internet traffic flows through undersea fiber optic cables. These cables are laid on the ocean floor and connect continents like invisible digital highways.

As of 2025, there are over 500 active submarine cables, spanning more than 1.4 million kilometers, delivering petabytes of data every second.

How Do Submarine Cables Work?

Submarine cables use light signals transmitted through fiber optics to transfer data at nearly the speed of light. These signals are amplified every 50–100 km using repeaters to maintain signal strength.

Each cable typically contains multiple pairs of fibers, and each pair can carry multiple terabits of data per second.

What Happens When You Access a Website Overseas?

Here’s a simplified path your data follows when visiting a website hosted in another country:

1. Your device (mobile/laptop) sends a request through your local Wi-Fi/router.

2. The signal travels through your ISP’s data center.

3. It passes through national internet infrastructure to reach a cable landing station.

4. The request travels through an undersea cable to another continent.

5. It reaches a landing station in the destination country.

6. The data is routed to the server hosting the website.

7. The server responds, and the process happens in reverse.

Flowchart: How Data Travels Internationally Over the Internet

[Your Device]
      ↓
[Local Router/Wi-Fi]
      ↓
[ISP Network]
      ↓
[National Backbone Router]
      ↓
[Cable Landing Station]
      ↓
[Submarine Fiber Optic Cable]
      ↓
[Landing Station in Destination Country]
      ↓
[Data Center/Server]
      ↓
[Response Sent Back Through Same Route]

This is a simplified version, but it accurately reflects the core steps in international internet connectivity.

What Role Do Satellites Play in Internet Connectivity?

Satellites like those in the Starlink constellation do provide internet access but account for less than 1% of global data traffic. They’re crucial for remote locations, ships, airplanes, and as backup options during submarine cable outages.

What Are Internet Exchange Points (IXPs)?

IXPs are physical locations where multiple ISPs and networks connect and share traffic. Major cities often have several IXPs to reduce latency and improve bandwidth efficiency.

Without IXPs, your internet data would take longer and cost more to route between networks.

Are There Risks to Global Internet Connectivity?

Yes, although the infrastructure is resilient, threats include:

• Submarine cable cuts (from fishing, anchors, earthquakes)

• Cyberattacks on core routers or IXPs

• Political controls over national infrastructure

• Dependence on major tech hubs like the U.S., Europe, and China

Global redundancy (multiple cables and ISPs) helps minimize outages.

Why Should You Care About How the Internet Connects Globally?

Understanding this helps you:

• Grasp why some international websites load slower.

• Know why internet outages happen during natural disasters.

• Understand how data sovereignty and privacy laws affect your traffic.

• Realize the importance of cybersecurity in international routing.

Key Elements of Global Internet Connectivity

Conclusion: The Invisible Web Beneath the Waves

While the internet may feel instantaneous, it depends on an intricate global system of cables, routers, landing stations, and satellites. Each time you stream a video, send a message, or check your email across borders, you’re using this incredible infrastructure.

As global demand increases, more cables and technologies are being deployed to ensure a faster, more resilient internet for the world.

FAQs

What connects the internet between countries?

The internet between countries is mainly connected by undersea fiber optic cables and international Internet Exchange Points (IXPs), which route data efficiently across the globe.

What are submarine cables and how do they work?

Submarine cables are fiber optic cables laid under the ocean. They transmit data using light pulses and are responsible for over 99% of global internet traffic.

How does internet travel between continents?

Data travels through a series of local networks, passes through cable landing stations, undersea cables, and then reaches data centers in other countries.

Are satellites used for international internet?

Yes, but satellites handle less than 1% of internet traffic. They are mainly used for backup or in remote locations.

What is a cable landing station?

A cable landing station is a facility where a submarine cable terminates and connects to the local land-based network infrastructure.

How do IXPs support international internet?

Internet Exchange Points help route data between networks efficiently, reducing the distance data has to travel and improving speed.

What happens if a submarine cable is damaged?

Data is rerouted through alternate paths or cables. However, this can cause slower internet speeds or temporary outages.

How fast is data transmitted across undersea cables?

Data can travel at speeds of terabits per second across multiple fiber pairs in a single undersea cable.

How does my device connect to a server in another country?

Your device sends a request through local ISP routers, which is then routed via submarine cables to reach the server overseas.

Which company owns the most submarine cables?

Major players include Google, Meta, Microsoft, and telecom giants like Tata Communications and Orange.

What is the SEA-ME-WE cable?

SEA-ME-WE (South East Asia–Middle East–Western Europe) is a major submarine cable system that connects Asia, the Middle East, and Europe.

Why is undersea internet better than satellites?

Undersea cables offer higher speeds, lower latency, and greater data capacity than satellites.

How are submarine cables installed?

Special ships lay the cables on the seafloor, carefully avoiding tectonic faults and other obstacles.

Can a shark bite a submarine cable?

Yes, but it’s rare. Modern cables are protected with armored layers to prevent damage.

What is latency in global internet?

Latency refers to the delay in data transmission. Longer distances and more routing points can increase latency.

How secure are submarine cables?

While physical security is high, data security depends on encryption and cybersecurity at both ends of the transmission.

Are there internet backups if cables go down?

Yes, alternate submarine cables, satellite networks, and redundant routing provide backup paths.

How do continents stay constantly connected?

Global ISPs and telecoms maintain multiple redundant cable systems to ensure 24/7 connectivity.

What role do governments play in global internet?

Governments regulate cable landings, cybersecurity, and in some cases, build or fund infrastructure projects.

Which continents are best connected?

North America, Europe, and Asia have the highest cable density and internet exchange hubs.

How much does it cost to build a submarine cable?

A new submarine cable system can cost between $100 million and $500 million.

How long does a submarine cable last?

Most cables are designed to last around 25 years before needing replacement or upgrades.

Who monitors global internet traffic?

Organizations like RIPE, ICANN, and major ISPs track traffic for stability, performance, and security.

Can internet be censored at the cable level?

Yes, governments can regulate cable traffic at landing stations or ISPs to control or censor access.

What is peering in internet infrastructure?

Peering is when ISPs exchange traffic directly, improving speed and reducing reliance on third-party carriers.

What happens during cable maintenance?

Cable-laying ships retrieve the damaged section, repair it onboard, and lay it back down.

Is 5G involved in global internet connectivity?

5G impacts local access speeds but still relies on the same global backbone infrastructure for long-distance data.

How do cloud providers use submarine cables?

Companies like AWS, Google Cloud, and Azure use dedicated fiber pairs in undersea cables to optimize global data center communication.

How can I check if there's a global internet outage?

Websites like Downdetector or SubmarineCableMap provide real-time info on cable disruptions or slowdowns.

Why does international internet sometimes slow down?

Possible causes include high traffic, routing congestion, cable issues, or cyberattacks.

Are there new technologies replacing submarine cables?

Currently, no. Fiber optics remain the most efficient. Quantum networking and next-gen satellites are in early stages.