Why Internet Data Takes Detours: The Brazil-South Africa Connection

When you send a message or participate in a video call over the internet, you probably don’t think about the path your data takes. However, it might seem odd if, instead of taking the direct 7,602 km route between São Paulo, Brazil, and Amanzimtoti, South Africa, your data makes a detour, first reaching Luanda in Angola and then returning to South Africa. This unusual route was identified by GeoCables on September 1, 2026. What happened, and why does it matter?

How do network providers work?

To understand why the route was so inefficient, it’s important to understand who the key network providers are. In this case, three autonomous systems (AS) were involved in the route: AS22548 (Núcleo de Inf. e Coord. do Ponto BR - NIC.BR), AS37468 (Angola Cables), and AS32437 (Webdev CC T/A Cybertek). NIC.BR is a major local operator in Brazil responsible for coordinating internet resources. Angola Cables is a transit operator specializing in connecting Africa with other continents via submarine fiber-optic cables. Webdev CC is a local South African operator that ensures data delivery within the country.

The route through Luanda is explained by the lack of direct peering (interconnections) between Brazil and South Africa. Instead, traffic is routed through the nearest available submarine cable intersection point. In this case, it’s Luanda, where Angola Cables operates a key hub. This decision may be influenced by both technical and economic factors, such as the cost of transmitting data over specific routes.

Why does this matter to users?

At first glance, a 2,982 km detour might seem insignificant, but in practice, it triples the latency (RTT, round-trip time) compared to the theoretically possible minimum. Ideally, the data could travel the distance in about 76 milliseconds, but in reality, the journey took 262 milliseconds. This has serious implications:

• Video calls: With RTT above 200 ms, users start noticing delays in audio and video, making communication difficult.
• Online gaming: For gamers, every millisecond counts. RTT above 100 ms can make games nearly unplayable, especially in shooters or real-time strategy games.
• Financial trading: High latency is critical for traders, particularly in high-frequency trading, where milliseconds can cost millions.
• Cloud services: Services like Google Workspace or Microsoft 365 become less responsive, reducing user productivity.

Infrastructure context: why is the route suboptimal?

South America and Africa are two continents where internet infrastructure is still developing. Submarine cables connecting these regions are limited. For example, one of the key cables, the South Atlantic Cable System (SACS), connects Brazil and Angola, but there is no direct connection to South Africa. This forces traffic to pass through Luanda, despite the apparent geographical inefficiency.

Additionally, economic reasons may play a significant role. Direct peering between operators requires agreements and costs. If it’s cheaper for an operator to route traffic through a transit hub like Luanda, they will choose that option, even if it increases latency.

Real-world events: a live context

Interestingly, a few months before this route was identified, Brazil experienced a green-level flood warning (June 15, 2026, approximately 615 km from São Paulo). However, GeoCables’ monitoring clearly shows that this event had no connection to the routing issue. The detour’s cause lies solely in infrastructure and network decisions.

This example highlights how the global internet network depends on numerous factors: from physical infrastructure to the economic considerations of operators. GeoCables continues to monitor such cases to shed light on the hidden mechanisms that determine how and why data travels around the world.

This case serves as another reminder of how complex and interconnected modern internet infrastructure is. Even small changes in peering agreements or the deployment of new submarine cables can significantly improve connectivity quality for millions of users worldwide.