Unisur

Unisur: A regional submarine cable linking Argentina and Uruguay

The Unisur submarine cable is a 265-kilometer fiber-optic system connecting Las Toninas in Argentina to Maldonado in Uruguay. It is jointly owned by Antel Uruguay and Telxius, and has been listed as in service since 1995 according to GeoCables data. This cable serves as a direct link between the two countries, enabling regional telecommunications and data exchange. What makes Unisur particularly interesting is the scarcity of publicly disclosed technical details about its design capacity, fiber pair count, and supplier. Additionally, its ready-for-service year of 1995 is consistent with GeoCables records, but industry sources occasionally report discrepancies for older systems. This cable operates in a corridor with multiple alternatives, raising questions about its specific role amidst newer systems with potentially higher capacities.

Quick facts

Name	Unisur
Length	265 km
Ready-for-service year	1995 (GeoCables database; no conflicting sources surfaced)
Owners	Antel Uruguay, Telxius
Status	In service
Design capacity	Not disclosed
Fiber pairs	Not disclosed
Supplier	Not disclosed
Technology	Not disclosed
Landing points	Las Toninas (Argentina), Maldonado (Uruguay)

Show Unisur on the interactive cable map

Route

Unisur connects two landing points: Las Toninas, a well-established cable hub in Argentina, and Maldonado, a coastal city in Uruguay. Las Toninas hosts several other submarine cables, including Bicentenario, Firmina, Malbec, South America-1 (SAm-1), South American Crossing (SAC), and Tannat. Maldonado is also a landing site for Bicentenario and Tannat, highlighting its importance in Uruguay's international connectivity. The cable traverses a relatively short distance across the Rio de la Plata, a shallow estuary that separates Argentina and Uruguay. This geography simplifies cable laying and maintenance compared to deeper oceanic routes.

Why it was built and what it carries

Unisur was built to provide direct connectivity between Argentina and Uruguay, supporting regional telecommunications and data traffic. While specific details about its capacity and technology are not publicly disclosed, its role as part of the broader corridor suggests it contributes to redundancy and traffic distribution in the region. Given its age, it is likely that Unisur has undergone upgrades to remain relevant in the face of newer, higher-capacity cables like Bicentenario and Tannat.

History: what can be established

GeoCables records indicate that Unisur became ready for service in 1995. No conflicting dates have been surfaced from industry sources, which is notable given the tendency for discrepancies in older systems. The cable's ownership by Antel Uruguay and Telxius aligns with their broader involvement in regional connectivity projects. The lack of publicly available information about the cable's supplier and technology makes it difficult to trace its construction and upgrade history. However, given its continued operation, it is reasonable to assume that it has been maintained and possibly modernized to meet contemporary demands.

Capacity and technology

Publicly available sources do not disclose Unisur's design capacity, fiber pair count, or technological specifications. Without operator documentation, it is impossible to state these parameters definitively. As a cable commissioned in 1995, it is likely that its original capacity was modest by today's standards, but upgrades may have improved its performance over time. However, attributing specific capabilities without evidence would be speculative.

Latency: the physics

The theoretical one-way light propagation latency for Unisur's 265-kilometer wet segment is approximately 1.3 milliseconds, with a round-trip time (RTT) floor of 2.6 milliseconds. Real-world latency measurements are higher due to additional factors such as land tails, terminal equipment, and network routing. GeoCables live measurements, which reflect the full internet path rather than the cable itself, show an average RTT of 12.7 milliseconds from Las Toninas to Maldonado and 21.3 milliseconds in the reverse direction. The reported minimum RTT of 1.7 milliseconds from Las Toninas to Maldonado is below the physical floor of 2.6 milliseconds, indicating a measurement artifact likely caused by rate-limited ICMP replies from intermediate routers. Such artifacts should not be interpreted as actual cable performance.

Redundancy: what happens if it breaks

In the event of a failure, Unisur's corridor is served by two alternative cables that land at both Las Toninas and Maldonado: Bicentenario and Tannat. These systems provide redundancy and ensure continued connectivity between Argentina and Uruguay. Standard industry practices for submarine cable repair, including the use of specialized cable ships, would apply to Unisur in case of damage.

Bottom line

• Unisur is a 265-kilometer submarine cable connecting Argentina and Uruguay, in service since 1995.
• Its owners are Antel Uruguay and Telxius; technical details like design capacity and fiber pairs are not publicly disclosed.
• The cable's route across the Rio de la Plata is relatively short, simplifying its geography.
• Redundancy is provided by Bicentenario and Tannat, which share the same landing points.
• Theoretical latency is approximately 2.6 milliseconds RTT for the wet segment, with real-world measurements reflecting higher values due to network factors.