Kardesa: A Black Sea Submarine Cable Connecting Four Nations
The Kardesa submarine cable spans 1,385 kilometers across the Black Sea, linking Bulgaria, Ukraine, Georgia, and Turkey through landing points in
Aheloy,
Odessa,
Poti, and
Sile. Owned jointly by Neqsol Holding and Vodafone, it is listed as in service, although its recorded ready-for-service (RFS) year in the GeoCables database is 2027. This discrepancy raises questions about its operational timeline, as some industry sources may suggest an earlier activation date.
What stands out about Kardesa is its role in connecting countries with diverse geopolitical and economic contexts, including Ukraine and Georgia, which have faced regional tensions. However, many technical details about the cable, such as its design capacity, fiber pair count, supplier, and specific technology, remain undisclosed in public sources, limiting the ability to fully assess its capabilities.
Quick facts
| Cable name | Kardesa |
| Length | 1,385 km |
| Ready-for-service year | 2027 (GeoCables database; potential conflict with industry sources) |
| Owners | Neqsol Holding, Vodafone |
| Status | Listed as in service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing points | Aheloy (Bulgaria), Odessa (Ukraine), Poti (Georgia), Sile (Turkey) |
Route
The Kardesa cable connects four Black Sea nations via landing points strategically located in Aheloy, Odessa, Poti, and Sile. These locations serve as gateways for international connectivity in regions with varying levels of infrastructure development. Notably, Poti is already a landing site for other cables, including the
Caucasus Cable System and
Georgia-Russia cable, making it a hub for regional telecommunications.
Why it was built and what it carries
The Kardesa cable was likely built to enhance connectivity between Eastern Europe, the Caucasus, and Turkey, regions that are increasingly important for international data traffic. By linking Bulgaria, Ukraine, Georgia, and Turkey, the cable provides an alternative route for data transmission, potentially improving redundancy and reducing latency for regional and international communications. However, without disclosed capacity or fiber pair data, the volume of traffic it can handle remains unclear.
History: what can be established
The GeoCables database lists Kardesa's ready-for-service year as 2027, yet the cable is also described as currently in service. This discrepancy could be due to several factors, such as delays in official documentation, phased activation of segments, or differing definitions of "in service" among operators. Without further clarification from Neqsol Holding or Vodafone, the exact timeline remains uncertain.
Capacity and technology
Publicly available information does not disclose Kardesa's design capacity, fiber pair count, supplier, or specific technology used. These unknowns make it difficult to evaluate the cable's performance and scalability. Speculating on these parameters without operator documentation would be inappropriate.
Latency: the physics
Theoretical one-way light propagation latency over Kardesa's 1,385 km wet segment is approximately 6.8 milliseconds, yielding a round-trip time (RTT) floor of 13.6 milliseconds. Real-world latency measurements, however, are higher due to additional factors such as land-based network segments, terminal equipment, and routing inefficiencies.
GeoCables live measurements provide some insights but must be interpreted carefully. For example:
- Tbilisi to Poti shows a minimum of 1.3 ms, which is below the physical floor of 13.6 ms. This is a measurement artifact caused by rate-limited ICMP replies from intermediate routers and does not reflect actual cable latency.
- Sydney to Poti averages 332.2 ms, reflecting the full internet path rather than the cable alone.
- Odessa to Aheloy averages 44.3 ms, which includes both the cable and land-based segments.
These measurements highlight the complexity of isolating cable-specific latency from broader network factors.
Redundancy: what happens if it breaks
In the event of a failure, redundancy in the Black Sea region is supported by other cables, such as the Caucasus Cable System and the Georgia-Russia cable, both of which land at Poti. Repairing submarine cables typically involves specialized ships and equipment to locate, retrieve, and mend the damaged section. However, geopolitical challenges in the region could complicate repair logistics.
Bottom line
- Kardesa spans 1,385 km across the Black Sea, connecting Bulgaria, Ukraine, Georgia, and Turkey.
- Owned by Neqsol Holding and Vodafone, it is listed as in service, though its RFS year of 2027 may conflict with other sources.
- Design capacity, fiber pairs, supplier, and technology details are not publicly disclosed.
- Theoretical latency over the wet segment is ≈13.6 ms RTT, with real-world measurements reflecting higher values.
- Redundancy is supported by other regional cables, but repair logistics could face geopolitical challenges.