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HomeSubmarine Cables › Concerto

Concerto

In Service

550 km · 2 Landing Points · 2 Countries · Ready for Service: 1999

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Specifications

Length550 km
StatusIn Service
Ready for Service1999
Landing Points2
Countries2

Owners

EXA Infrastructure

Landing Points (2)

Location Country Position
Sizewell, United Kingdom GB United Kingdom 52.2071°, 1.6203°
Zandvoort, Netherlands NL Netherlands 52.3704°, 4.5272°

📡 Live Performance

140
measurements
1
probes
129
days monitored
102.9
ms avg RTT
0
anomalies

Monitored from 2026-03-06 through 2026-07-14 - live ICMP round-trip time measurements via our monitoring probes. All values below are recomputed daily from raw probe data. ✓ No anomalies detected in the monitored period.

Measurement sources

Probe Location Samples Avg Min-Max Last seen
#11036 control probe 140 102.9 ms 11.4-2022.0 2026-07-14

About the Concerto Cable System

Concerto: A Submarine Cable Linking the UK and the Netherlands

Concerto is a submarine telecommunications cable connecting Sizewell in the United Kingdom to Zandvoort in the Netherlands. Spanning approximately 550 kilometers, the cable is owned by EXA Infrastructure and has been in service since 1999, according to GeoCables records. It is part of a busy corridor linking the UK and continental Europe, where multiple cables operate. What makes Concerto noteworthy is the lack of publicly disclosed technical details about its design capacity, fiber count, and supplier. This lack of transparency is not uncommon for older cables, especially those built before the industry standardization of open data sharing. Additionally, live latency measurements show significant divergence from theoretical latency, highlighting the complexity of end-to-end internet routing.

Quick facts

NameConcerto
Length550 km
Ready for Service (RFS)1999 (GeoCables database)
OwnersEXA Infrastructure
StatusIn service
Design CapacityNot disclosed
Fiber PairsNot disclosed
SupplierNot disclosed
TechnologyNot disclosed
Landing PointsSizewell (United Kingdom), Zandvoort (Netherlands)

Route

Concerto connects Sizewell, a coastal location in Suffolk, England, to Zandvoort, a seaside town in the Netherlands. The cable traverses the North Sea, a heavily trafficked corridor for submarine communications between the UK and mainland Europe. Zandvoort is also a landing site for other cables, including Circe North and Zeus, making it a hub for international connectivity.

Why it was built and what it carries

Concerto was built to provide additional connectivity between the UK and the Netherlands, addressing the growing demand for international data traffic in the late 1990s. This period saw a surge in internet usage and the expansion of global networks. While specific details about the cable's capacity and technology are not publicly disclosed, its continued operation suggests it plays a role in supporting regional and international telecommunications.

History: what can be established

Concerto was recorded as ready for service in 1999, according to GeoCables data. If any industry sources suggest a different year, such discrepancies could arise from variations in documentation practices, delays in commissioning, or differences in defining the operational start date. However, no conflicting dates have been surfaced in this instance. EXA Infrastructure, the current owner, is known for managing a portfolio of submarine and terrestrial cables across Europe and beyond. Concerto's inclusion in EXA's network underscores its strategic importance in linking the UK and the Netherlands.

Capacity and technology

Publicly available sources do not disclose Concerto's design capacity, fiber pair count, or the technology used in its construction. Without operator documentation, attributing specific technical characteristics would be speculative. Given its age, the cable likely underwent upgrades to remain competitive, but details of such upgrades are not available.

Latency: the physics

The computed theoretical latency for light propagation over Concerto's 550 km wet segment is approximately 2.7 ms one-way, or 5.4 ms round-trip. However, real-world measurements from remote probes show a minimum round-trip time (RTT) of 11.4 ms and an average RTT of 102.9 ms between Sizewell and Zandvoort. This discrepancy reflects the impact of additional factors like land tails, terminal equipment, and internet routing inefficiencies. It is important to note that these measurements capture the full internet path, not the cable itself.

Redundancy: what happens if it breaks

In the event of a failure, redundancy in the UK-Netherlands corridor is provided by other cables landing at Zandvoort, such as Circe North and Zeus. These cables, along with others in the region, help ensure continued connectivity. Standard industry practices for submarine cable repair include deploying specialized cable ships to locate, retrieve, and repair the damaged segment. Repairs can take weeks, depending on the severity of the damage and weather conditions.

Bottom line

  • Concerto is a submarine cable connecting Sizewell (UK) and Zandvoort (Netherlands).
  • Spanning 550 km, it has been in service since 1999, according to GeoCables records.
  • Owned by EXA Infrastructure, its design capacity and technical specifications are not publicly disclosed.
  • Theoretical latency over the wet segment is 5.4 ms RTT, but real-world internet measurements show higher values.
  • Redundancy is provided by other cables in the corridor, such as Circe North and Zeus.

📡 Health

Status✓ Normal
Last checked2026-07-14 12:32

Monitored by our probe network. Open monitoring →

📊 RTT History

Route: #11036 → Zandvoort Measured: 2026-07-14 12:32
0 ms
Min Avg Max #
7 days 13.4 13.4 13.5 3
30 days 13.3 13.4 13.6 15
60 days 11.4 102.9 2022.0 140

Health Timeline

Sun, Jun 14
View full event log →
Zandvoort
RTT Spike
14ms → 33ms (2.42×)
02:31
Fri, Apr 24
View full event log →
🔗
Hop Anomaly
8ms → 45ms (5.41×)
23:00
Thu, Apr 16
View full event log →
🔗
Hop Anomaly
3ms → 29ms (8.39×)
11:00

FAQ

What is the length of the Concerto cable?
The Concerto submarine cable is 550 km long.
Which countries does Concerto connect?
Concerto connects 2 countries via 2 landing points.
Who owns the Concerto cable?
Concerto is owned by a consortium including EXA Infrastructure.
When was Concerto put into service?
The Concerto cable entered service in 1999.
Concerto
  • Length550 km
  • StatusIn Service
  • Ready for Service1999

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