Ionian: A submarine cable linking Italy and Greece
The Ionian submarine cable is a 320 km optical fiber system connecting
Crotone in Italy to
Preveza in Greece. Owned by IslaLink and listed as in service, it represents a direct telecommunications link between the two countries across the Ionian Sea. While its design capacity, fiber pair count, and supplier details are not publicly disclosed, the cable's operational status as of 2023 is recorded in the GeoCables database.
What makes the Ionian cable noteworthy is its role in providing an alternative route for data traffic between southern Europe and the eastern Mediterranean. However, there are uncertainties surrounding its technological specifications and latency performance, as live measurements of internet paths involving the cable show significant divergence from theoretical latency floors.
Quick facts
| Name | Ionian |
| Length | 320 km |
| Ready for Service (RFS) | 2023 (GeoCables database) |
| Owners | IslaLink |
| Status | In service |
| Design Capacity | Not disclosed |
| Fiber Pairs | Not disclosed |
| Supplier | Not disclosed |
| Technology | Not disclosed |
| Landing Points | Crotone (Italy), Preveza (Greece) |
| Computed One-Way Latency | 1.6 ms |
| Theoretical Round-Trip Time (RTT) | 3.1 ms |
🗺 Show Ionian on the interactive cable map
Route
The Ionian cable spans the Ionian Sea, connecting the coastal city of Crotone in southern Italy to Preveza, a town in western Greece. These landing points are strategically located to facilitate regional connectivity between Italy and Greece, both of which are key players in the Mediterranean telecommunications network. The corridor serves as a direct link bypassing longer terrestrial or submarine routes that might involve intermediate nodes or detours.
Why it was built and what it carries
The Ionian cable was built to enhance connectivity between Italy and Greece, providing a dedicated link for data traffic between the two nations. This is particularly important for improving latency and reliability in southern European and eastern Mediterranean telecommunications. While the specific data types and traffic volumes carried by the cable are not disclosed, such systems typically support internet, voice, and enterprise data services.
History: what can be established
The GeoCables database records the Ionian cable as ready for service in 2023. No conflicting dates have surfaced from industry sources at this time, but the absence of detailed public announcements or operator documentation makes it difficult to verify the timeline independently. IslaLink, the cable's owner, is known for operating submarine cables in the Mediterranean region, suggesting their expertise in deploying and maintaining systems in this geography.
Capacity and technology
The design capacity, fiber pair count, supplier, and specific technology used in the Ionian cable are not disclosed in publicly available sources. Without operator documentation or reliable third-party reports, attributing these specifications would be speculative. It is likely that the cable employs modern optical transmission technology, given its recent RFS date, but the exact details remain unknown.
Latency: the physics
The computed one-way light propagation latency for the wet segment of the Ionian cable is approximately 1.6 ms, with a theoretical round-trip time (RTT) floor of 3.1 ms. However, live measurements from remote probes show significantly higher latency. For example:
- Crotone to Preveza: minimum 67.1 ms, average 92.1 ms
- Preveza to Crotone: minimum 79.9 ms, average 103.4 ms
These discrepancies arise because live measurements capture the full internet path, including land tails, terminal equipment, and routing inefficiencies, rather than the cable's intrinsic latency. The real-world RTT is influenced by factors such as network congestion, routing policies, and the performance of connected systems.
Redundancy: what happens if it breaks
In the event of a failure, redundancy in the Ionian corridor would depend on alternative submarine cables or terrestrial routes connecting Italy and Greece. Publicly available data does not specify exact alternatives, but other regional systems in the Mediterranean may provide backup, albeit with potentially higher latency or less direct routing. Repairing submarine cables typically involves deploying specialized ships to locate and fix the fault, a process that can take weeks depending on the severity of the issue and weather conditions.
Bottom line
- The Ionian cable is a 320 km submarine system linking Crotone (Italy) and Preveza (Greece).
- Its RFS date is recorded as 2023, with no conflicting information currently available.
- Owned by IslaLink, the cable's design capacity, fiber pair count, and supplier are not publicly disclosed.
- Computed latency for the wet segment is approximately 1.6 ms one-way, but real-world RTTs are significantly higher.
- Redundancy options in the corridor are not specified, and repair logistics follow standard industry practices.