Half of Vietnam's international undersea fibre-optic cable network is currently affected by technical faults, significantly impacting internet connectivity between Vietnam and overseas destinations.
Faults on four of the eight submarine fibre-optic cables linking Vietnam to the world have affected network service quality in Vietnam (Illustrative photo: GMN).
Two major submarine cable systems, SJC2 and AAE-1, had already experienced disruptions almost simultaneously, leading to a sharp reduction in international internet traffic carried through the routes.
More recently, a representative of a Vietnamese internet service provider confirmed that two additional cable systems, AAG and IA, had also encountered faults, further affecting international connectivity.
According to industry sources, repair work on the IA cable is not expected to begin until early September, while no restoration timetable has yet been announced for the other three affected systems.
With four of Vietnam's eight undersea cables currently disrupted, internet users may experience slower access to websites, cloud platforms and online services hosted outside the country. Domestic websites and digital services hosted on servers within Vietnam are not expected to be affected.
Following the outages, telecommunications providers have implemented a range of contingency measures, including rerouting traffic across alternative international links, increasing capacity on backup routes and making greater use of terrestrial fibre-optic connections to maintain service quality.
Disruptions to Vietnam's international submarine cable systems have become a recurring issue in recent years, with outages occurring several times annually and often causing inconvenience for businesses and consumers relying on overseas digital services.
One of the most severe incidents occurred in February 2023, when all five of Vietnam's international undersea cable systems operating at the time experienced simultaneous faults, significantly degrading internet service quality across the country.
In addition to submarine cable infrastructure, Vietnam also maintains several cross-border terrestrial fibre-optic routes. Telecommunications companies have increasingly explored ways to shift traffic to land-based networks to reduce dependence on undersea cables.
However, industry experts note that international internet traffic in Vietnam, as well as globally, remains heavily reliant on submarine cable systems because of their vast capacity and efficiency.
Vietnam is currently connected to the global internet through eight international undersea cable systems: AAG, linking Asia and the United States; APG, connecting the Asia-Pacific region; SMW-3, linking Southeast Asia, the Middle East and Western Europe; IA, also known as Intra Asia; AAE-1, connecting Asia, Africa and Europe; TVH, linking Hong Kong, Thailand and Vietnam; SJC2, or Southeast Asia-Japan Cable 2; and ADC, or Asia Direct Cable, which connects Vietnam with China, Hong Kong, Thailand, the Philippines, Singapore and Japan.
Among them, the TVH cable is the oldest system, having entered service in 1996 and carrying relatively low traffic volumes. The newest additions to Vietnam's international network are ADC and SJC2, which began operations in late 2024 and mid-2025 respectively.
