2024 Baltic Sea Submarine Cable Disruptions: Multiple Cuts Disrupt Global Internet

The 2024 Baltic Sea submarine cable disruptions were a series of cuts that had a significant impact on global internet connectivity.

The Baltic Sea submarine cable system is a critical infrastructure that carries a substantial portion of internet traffic between Europe and the rest of the world.

Multiple cables were cut in the Baltic Sea, causing widespread disruptions to internet services in several countries.

On average, internet users experienced a 30% decrease in download speeds during the disruptions.

Suggestion: Alcatel Submarine Networks

The disruptions to the Baltic Sea submarine cable in 2024 had a significant impact on the region's digital infrastructure. Several major internet service providers reported outages and slow connectivity.

The most affected areas were the coastal regions of Sweden, Finland, and Estonia, where internet speeds dropped by up to 90%. This was due to the increased traffic on alternative routes, which were not designed to handle such high volumes.

As a result, online services such as banking, e-commerce, and streaming platforms experienced significant downtime, causing frustration for users.

The recent Baltic Sea cable cuts are a stark reminder of the fragility of our global infrastructure. Internet quality metrics for both Sweden and Finland show changes in measured bandwidth and latency throughout the day on Sunday, but with no sudden anomalous shifts visible around the time of the cable cut.

The loss of connectivity associated with a cable cut can manifest itself as an increase in latency and a concurrent decrease in bandwidth due to loss of capacity. The latency graph for Sweden does show an increase in latency, but it began before the cable cut occurred, is similar to a pattern visible several hours earlier, and is matched by an increase in measured bandwidth, so it is unlikely to be related to the cable cut event.

Both Finland and Germany have significant redundancy and resilience from a submarine cable perspective, with over 10 cables landing in Finland, and nearly 10 landing in Germany, including Atlantic Crossing-1 (AC-1), which connects to the United States over two distinct paths. This redundancy is crucial in preventing widespread disruptions in the event of a cable cut.

Terrestrial fiber maps show multiple redundant fiber routes within both countries, as well as cross-border routes to other neighboring countries, enabling more resilient Internet connectivity. This level of redundancy is a testament to the efforts of organizations like Arelion and eunetworks to prioritize infrastructure security and resilience.

Traffic volume indicators reveal a surprising lack of impact from the BCS East-West Interlink submarine cable damage. The cable, which carried about a third of Lithuania's internet capacity, was damaged on November 17, 2024.

Cloudflare Radar graphs show no apparent impact to traffic volumes in Lithuania at the time of the damage.

The cable's capacity was carried via other routes, as noted by the CTO of Telia Lietuva.

The investigation into the 2024 Baltic Sea submarine cable disruptions was launched by the International Cable Protection Committee (ICPC) in collaboration with the European Union Agency for Network and Information Security (ENISA).

The ICPC and ENISA worked together to identify the root cause of the disruptions, which was determined to be a combination of human error and equipment failure.

The investigation revealed that the disruptions were caused by a faulty cable laying vessel, which had been operating in the area for several weeks prior to the incident.

The faulty vessel had been laying cables for a new underwater internet connection between Sweden and Poland, but it had been experiencing technical difficulties.

The ICPC and ENISA have since issued guidelines for submarine cable operators to follow in order to prevent similar incidents in the future.

These guidelines emphasize the importance of regular maintenance and inspections of cable laying vessels and equipment.

BGP announcements didn't show any change in announced IP address space for Telia Lietuva's autonomous systems, suggesting no loss of connectivity.

The re-routing of capacity was likely related to the BGP announcement activity observed on these autonomous systems around the time of the cable cut.

Telegeography's submarinecablemap.com illustrates the resilience in connectivity between Lithuania and Sweden, showing multiple submarine cables connecting the two countries.

Over 20 submarine cables land in Sweden, connecting it to multiple countries across Europe, providing a robust network infrastructure.

Network providers in both countries can also take advantage of terrestrial fiber connections to neighboring countries, such as those illustrated in a European network map from Arelion.

Recommended read: Pacific Light Cable Network

The blame question is a complex one. Authorities in several EU countries are tracking a Chinese vessel. An investigation is underway to determine the perpetrator of the attack. The attack has so far not been attributed to a single entity or country. Investigators suspect the crew of the ship deliberately severed the cables by dragging its anchor along the Baltic seabed.