Dunant: Google’s transatlantic submarine cable
The Dunant cable is a private transatlantic submarine cable owned by Google, connecting
Saint-Hilaire-de-Riez in France to
Virginia Beach in the United States. Spanning approximately 6400 kilometers, it is listed as in service and was recorded in the GeoCables database as ready for service in 2021. This cable is part of Google's strategy to enhance its global network infrastructure and improve connectivity between Europe and North America.
While the cable's route and ownership are well-documented, several technical details remain undisclosed in publicly available sources, including its design capacity, the number of fiber pairs, supplier, and specific technologies employed. These omissions make it challenging to fully assess the cable's performance and technical specifications without operator documentation.
Quick facts
| Name | Dunant |
| Length | 6400 km |
| Ready-for-service year | 2021 (GeoCables database; conflicting industry sources not surfaced) |
| Owner | Google |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Saint-Hilaire-de-Riez (France), Virginia Beach (United States) |
🗺 Show Dunant on the interactive cable map
Route
The Dunant cable connects Saint-Hilaire-de-Riez, located on the western coast of France, to Virginia Beach, on the eastern coast of the United States. This transatlantic corridor is a critical route for international data traffic, linking major internet hubs in Europe and North America. Virginia Beach is a well-established landing site for submarine cables, also hosting the
BRUSA,
Confluence-1, and
MAREA cables, which provide additional connectivity options across the Atlantic.
Why it was built and what it carries
The Dunant cable was built to support Google's growing need for high-bandwidth, low-latency connectivity between Europe and the United States. As a private cable, it is likely optimized for Google's internal data traffic, including services like Google Cloud, YouTube, and Gmail. By owning the cable outright, Google gains greater control over its network infrastructure, ensuring reliability and scalability for its operations.
History: what can be established
The GeoCables database records the Dunant cable as ready for service in 2021. Publicly available sources do not indicate any conflicting dates, nor do they provide detailed information about the cable's construction timeline, supplier, or deployment process. Without additional documentation, the history of the cable's development remains largely opaque.
Capacity and technology
The design capacity of the Dunant cable is not disclosed in public sources, nor are details about its fiber pairs, supplier, or the specific technologies employed. Modern submarine cables typically use advanced optical technologies such as wavelength-division multiplexing (WDM) to maximize data throughput, but attributing these features to Dunant without operator confirmation would be speculative.
Latency: the physics
Based on the cable's length of 6400 km, the theoretical one-way light propagation time is approximately 31.4 milliseconds, with a round-trip time (RTT) floor of 62.7 milliseconds over the wet segment. However, real-world latency is higher due to factors such as land tails, terminal equipment, and routing.
GeoCables live measurements, which capture the full internet path rather than the cable itself, report RTTs significantly above the physical floor. For example:
- Saint-Hilaire-de-Riez to Virginia Beach: minimum 111.8 ms, average 115.9 ms
- Virginia Beach to Saint-Hilaire-de-Riez: minimum 96.5 ms, average 114.7 ms
These values reflect the combined latency of the cable, terrestrial networks, and internet routing. One anomalous measurement between Minsk and Saint-Hilaire-de-Riez reports a minimum RTT of 33.2 ms, which is below the physical floor and represents a measurement artifact, likely caused by rate-limited ICMP replies from intermediate routers. This artifact should not be interpreted as the cable's actual performance.
Redundancy: what happens if it breaks
In the event of a failure, redundancy for traffic between Europe and North America is provided by other cables landing at Virginia Beach, including BRUSA, Confluence-1, and MAREA. Additionally, there are numerous other transatlantic cables outside Virginia Beach that could reroute traffic. Repairing submarine cables typically involves deploying specialized cable ships to locate, recover, and repair the damaged section, a process that can take weeks depending on the location and severity of the damage.
Bottom line
- Dunant is a private submarine cable owned by Google, connecting France and the United States.
- Its length is approximately 6400 km, and it was recorded as ready for service in 2021.
- Key technical details, including design capacity and fiber pairs, are not publicly disclosed.
- Measured latencies are higher than the theoretical floor due to land tails and routing.
- Redundancy is available through other cables landing at Virginia Beach and elsewhere in the transatlantic corridor.