Four subsea cable faults hit Vietnam's Internet

　　Vietnam is currently experiencing significant disruption to its international Internet connectivity due to multiple simultaneous faults in subsea cables. Four out of eight of these cables have reportedly been affected, which has impacted 30% of Vietnam's international Internet traffic.

　　According to local media reports, portions of the Southeast Asia-Japan 2 (SJC2) and Asia-Africa-Europe 1 (AAE-1) cables went down almost simultaneously on August 25, 2026. There were also problems reported with the Asia-America Gateway (AAG), which connects Southeast Asia with the US, and Tata's TGN Intra Asia (IA) cable.

　　The IA cable is expected to start repairs in early September. There is no specific repair schedule yet for SJC2, AAE-1 and AAG. The exact cause of the fault in each subsea cable has yet to be disclosed.

　　Internet users in Vietnam have been warned they could experience localized slowdowns when accessing overseas social media platforms, streaming services and online games during peak periods, due to faults affecting the four subsea cables simultaneously.

　　However, domestic websites and services hosted in Vietnam are not expected to be affected.

　　Contingency measures

　　According to a report by VN Express, Vietnamese telecom operators VNPT and Viettel have put in place contingency measures to deal with the connectivity issues arising from the multiple subsea cable faults.

　　VNPT reportedly rerouted traffic through available connections as soon as problems emerged, making optimal use of its remaining capacity. Meanwhile, Viettel compensated for lost capacity by adding 800 Gbit/s of international connectivity via the IA cable, as well as 300 Gbit/s through the Asia-Pacific Gateway (APG) subsea cable. Further capacity on the APG system is expected to be added today (Monday, August 31).

　　VN Express reported that Viettel had rerouted some international traffic via a terrestrial cable running from Vietnam through Laos to Singapore, and that it planned to increase the capacity of this route by 1.5 Tbit/s by the end of the month. If needed, Viettel could increase the capacity of its Asia Direct Cable to 50 Tbit/s to "handle all international internet traffic."

　　This is not the first time that Vietnam has experienced connectivity issues due to faults affecting multiple subsea cables simultaneously.

　　In 2024, full or partial outages affected the APG, AAE-1 and IA cables, slowing Internet speeds nationwide.

　　The incident prompted the Vietnamese Ministry of Information and Communications (MIC) to approve the construction of at least ten new subsea cables by 2030, bringing the country's total number of subsea cables to 15.