The fourth undersea fiber optic cable line had a problem, Vietnam's Internet was affected

According to an international undersea cable management unit, the SJC2 route, connecting Vietnam to Asian countries, had an error at section S4 Chung Hom Kok (Hong Kong) on ​​June 25, bringing the total number of undersea cable routes having problems to four and causing international Internet traffic to be "significantly affected".

Previously, the AAE-1 route had problems at section S1.H2 since February and has not yet been resolved. AAG, connecting Southeast Asia with the US, and the IA line are also having problems and are expected to begin repairs in early September.

Internet users in Vietnam connect to the world via marine fiber optic cables, land cables and satellite Internet, in which marine cables play a key role. The failure of many routes causes a significant reduction in the total international bandwidth in the country.

To handle this, Internet service providers said they are balancing load, regulating traffic and adding capacity through other cable routes to limit the impact on users.

A representative of VNPT said that it has deployed load balancing and traffic regulation through the remaining undersea cable transmission directions and especially the VSTN international land fiber optic cable line invested by VNPT to build and put into operation from August 2025, to optimize capacity and thereby commit to ensuring service quality and stable connection for customers.

International services such as web browsing, watching videos or playing games on foreign servers may be slower, but overall the Internet remains stable thanks to redundant infrastructure.

"This is a force majeure event," a VNPT representative said, adding that the situation affects all suppliers in Vietnam.

Responding to VnExpress, Viettel representative also said that this unit is being affected by incidents on two routes IA and AAE-1. In particular, AAE-1 lost all connections, significantly reducing the network's international capacity, but the backup system has not recorded an overload.

To make up for the capacity shortage, on the afternoon of August 26, Viettel added 800 Gbps of international connection via the IA route in the direction of Hong Kong. The network also accelerated the addition of 300 Gbps of capacity via the APG route, expected to be completed on August 31.

A part of international connection traffic is also transferred by Viettel to the mainland cable route, through Laos to Singapore. The network will add an additional 1.5 Tbps of capacity in this direction before August 31.

In case of necessity, the ADC undersea fiber optic cable line owned by Viettel can upgrade its capacity to 50 Tbps to "carry all international Internet traffic". This is a route connecting Vietnam with Asia's three largest international transit points, including Hong Kong, Singapore and Japan, and will be put into operation in 2025.

Vietnam currently uses six undersea fiber optic cables including AAG, IA, AAE-1, APG, ADC and SJC2. Among them, ADC and SJC2 are two new routes put into operation, contributing to increasing international connection capacity.

From 2022 until now, the undersea cable system from Vietnam to internationally has recorded about 40 incidents, an average of 10 errors per year. At one stage, four out of five cable routes had problems, causing international traffic to decline sharply.

Repairing submarine cables usually lasts from a few months to half a year, even a year due to depending on many objective factors. To reduce dependence, in 2025, Vietnam will deploy the VSTN land fiber optic cable line for the first time, and at the same time approve satellite Internet pilots, of which Starlink is the first company to provide services from mid-August.

Trong Dat