Data's Long Journey: Cape Town to Brazil via Atlanta

How often do we think about how data travels thousands of kilometers, connecting continents and countries? The internet, much like air, has become an essential part of our lives, and its complex infrastructure often remains behind the scenes. However, sometimes the routes our data take turn into real "journeys" that are not always logical. GeoCables has documented an interesting case of data routing between Cape Town (South Africa) and Porto Velho (Brazil). At first glance, this should be a direct connection across the Atlantic Ocean, but the reality turned out to be much more complex.

A Detoured Route: What Happened?

A data packet traveling from Cape Town to Porto Velho took 27 hops and deviated 5,168 km from the shortest geographical route. Instead of a direct Atlantic crossing, the data was routed through Atlanta in the United States before returning to Brazil. The resulting round-trip time (RTT) was 362 ms, nearly four times the physical limit (~90 ms) based on the speed of light in fiber optics.

Here are the key points of the route:

• Cape Town, South Africa (AS37153 Xneelo (Pty) Ltd)
• Talatona, Angola (AS37468 Angola Cables)
• Miami, USA (AS1299 Arelion Sweden AB)
• Atlanta, USA (AS4230 CLARO S.A.)
• Brasilia, Brazil (AS4230 CLARO S.A.)
• Cuiabá, Brazil (AS4230 CLARO S.A.)
• Porto Velho, Brazil (AS4230 CLARO S.A.)
• Rio Branco, Brazil (AS4230 CLARO S.A.)

Why Did the Route Go "Through Atlanta"?

The main reason for such a detour lies in the characteristics of the internet at the level of telecommunications operators. Several major network providers were involved in this route:

• Xneelo (Pty) Ltd (AS37153): A South African provider that handed off traffic to Angola Cables.
• Angola Cables (AS37468): A submarine cable operator connecting Africa and the Americas via the South Atlantic Cable System (SACS). However, instead of a direct route to southern Brazil, the data was sent north to Miami.
• Arelion (AS1299): A Swedish global backbone operator that facilitated traffic transit from Miami to Atlanta.
• CLARO S.A. (AS4230): A Brazilian operator that took the traffic in Atlanta and delivered it to its final destinations in Brazil.

Why was this route chosen? The answer lies in the economics and strategies of peering. Direct traffic exchange between Africa and South America is still developing, despite the presence of the SACS submarine cable. Some providers prefer to route data through the United States, where traffic exchange points are well-established and offer more cost-effective routing options.

The Impact of Delays on Users

An additional 272 ms of RTT (beyond the minimum 90 ms) might seem insignificant, but in practice, it has a noticeable impact on service quality:

• Video calls: A delay of 362 ms can lead to significant pauses and echo effects, making natural communication difficult.
• Online gaming: For gamers, every millisecond counts. Optimal latency for such games is less than 50 ms. Here, 362 ms makes player reactions slow and ineffective.
• Financial trading: High latency can cause losses in high-frequency trading, where milliseconds determine the outcome of transactions.
• Cloud services: Working with "clouds" (e.g., Google Drive or AWS) becomes slower, especially when uploading/downloading large amounts of data.

Infrastructure Context: Regional Challenges

At first glance, one might attribute the unusual route to recent events in the region. For example, on October 7, 2026, GeoCables recorded Tropical Cyclone ISAIAS-26, which reached wind speeds of up to 120 km/h, and in July, a 5.6 magnitude earthquake occurred in Peru. However, monitoring data shows that these events did not affect routing. The main issue lies in the region's infrastructural dependence on backbone routes through the United States.

South Africa and Brazil have a limited number of direct connections across the Atlantic. Although the SACS cable system was built to address this issue, the lack of direct peering agreements between providers forces traffic to route through the United States. This not only increases latency but also reduces the overall resilience of the network.

Conclusions

The routing of traffic from Cape Town to Porto Velho via Atlanta is an example of how peering economics and infrastructure limitations can complicate data paths. GeoCables continues to document such anomalies to make the internet more transparent and efficient. This case highlights the need for investments in direct intercontinental connections and route optimization to minimize latency and improve communication quality for users worldwide.