Cape Town to Coari: a 5168 km internet detour through Atlanta

The Internet world is not only about high speeds and instant connections, but also about complex routes that data travel on their journey. However, sometimes these routes become so redundant that users may notice delays, especially when using time-sensitive applications. A recent case recorded by GeoCables illustrates how data from Cape Town, South Africa, en route to Coari, Brazil, took an unexpected detour through Atlanta, USA, deviating 5168 km from the straight line! This nearly doubled the distance the signal had to travel and caused a significant increase in round-trip time (RTT), up to 348 milliseconds in the best measurements with an average of 368 ms over 24 checks - instead of theoretically possible 90 ms for a direct path.

Why does the route go through Atlanta?

At first glance, it may seem strange that data sent from South Africa to South America crosses North America. However, in this case, it all comes down to the peculiarities of global internet infrastructure and routing economics. Key providers involved in the data transfer, Xneelo (South Africa), Arelion (Sweden), and Claro S.A. (Brazil), play a crucial role in global transit. For example, Arelion is one of the largest global transit operators, providing backbone internet access. Its node in Atlanta is a major traffic exchange point through which significant volumes of data pass.

The traffic likely went through Atlanta due to the absence of direct submarine cables or peering agreements between South Africa and Brazil. The current cable infrastructure connecting Africa and South America is insufficient for ensuring direct and fast connections between these regions. Instead, data often gets directed through the more developed infrastructure in North America, where major traffic exchange points are concentrated.

How does this affect users?

Such routes may remain unnoticed by ordinary users when browsing web pages or sending text messages. However, for applications sensitive to delays, this can become a serious issue. For example:

• Videocalls: Video conferences such as Zoom or Microsoft Teams start to noticeably suffer from RTT above 150-200 ms. A delay of 349 ms leads to noticeable delays in voice and video, making it difficult to hold a conversation.
• Online games: For gamers, an increased ping above 100-150 ms can mean a significant drop in gaming experience, especially in competitive games. An RTT of 349 ms makes the game almost unplayable.
• Financial trading: In high-frequency trading, where milliseconds can cost millions, such delays are completely unacceptable.
• Cloud services: Working with remote servers, such as editing documents or rendering video, becomes slower due to the high time costs for each request and response.

Why does regional traffic go "the wrong way"?

Routing traffic is determined by a combination of factors: available submarine cable infrastructure, peering agreements between providers, and economic considerations. In this case, one bottleneck is the lack of a direct cable between South Africa and Brazil. Instead, data is forced to use existing paths through North America, which increases both physical distance and latency.

Additionally, despite the presence of cables such as WACS and Seabras-1, connecting Africa and South America via the Atlantic Ocean, transit providers often choose routes through more congested but economically advantageous nodes, such as Atlanta. This highlights the importance of developing direct connections between regions to minimize such issues.

Real Events Along the Route

GeoCables monitoring for 2026 recorded several interesting events in geographical proximity to the route. For example, three months before measurement, on June 5, a green alert level was declared in South Africa due to flooding, which was located 593 km from the route. A few weeks later, on July 14, an earthquake of magnitude 5.6 was registered 11 km north of Pichigua, Peru, approximately 646 km from the route. Also, on May 21, flooding (green alert level) occurred in the United States, 607 km from the traffic point in Atlanta.

However, GeoCables data confirms that the described internet detour through Atlanta was not caused by these events. The reason lies exclusively in routing and infrastructure peculiarities.

The Global Web Needs Updates

The case of the route from Cape Town to Kohari highlights the need for further development of global submarine cable networks and improvement of peering agreements between regions. Users in Africa and South America continue to face unjustifiably high latency, which hinders the use of modern applications. GeoCables will continue to monitor and analyze such cases to shed light on hidden aspects of global internet infrastructure.