[Summary] Widespread Damage from KT Communication Outage... "Cause is 'Configuration Error,' Not 'DDoS'"

[Asia Economy Reporter Seulgina Jo] As KT's wired and wireless internet networks were paralyzed, causing numerous cases of damage nationwide, it was confirmed that the cause of the connection failure was a routing (network path setting) error, not a DDoS attack.

On the 25th at around 2:30 PM, KT issued an official statement saying, "We apologize for the inconvenience caused to the public due to the communication failure," and added, "Initially, we suspected a DDoS attack due to traffic overload, but after careful verification, we identified a routing error as the cause."

The connection failure occurred nationwide, including Seoul, the metropolitan area, Chungcheong and Honam regions, as well as Jeju Island, from around 11:20 AM for about 40 minutes. It was restored around noon, but instability remains.

In this regard, the Ministry of Science and ICT issued an information and communication accident crisis alert at the 'caution' level at 11:56 AM. The ministry explained, "We are conducting an in-depth investigation into the cause of the incident and have instructed KT to investigate the status of user damages," and added, "After investigating the cause, we plan to prepare follow-up measures such as recurrence prevention."

Damage due to communication outages occurred across the country. Not only internet access but also mobile phone calls were disrupted in some areas. Especially before lunchtime, restaurants and stores using the KT network experienced malfunctions in payment systems and QR code authentication, causing many citizens to express inconvenience.

Mr. Park, who runs a restaurant near Dangsan Station, said, "The system went down during the busiest time when orders were pouring in," and expressed frustration, "There was no guidance on what the problem was or when it would be restored, which was even more frustrating." He added, "The number of orders during lunchtime was about one-tenth of usual," and "Since card payments were not possible, we barely accepted payments via bank transfer or cash." Another person who tried to order food through a delivery app before lunchtime also complained, "Orders could not be placed due to the restaurant's system paralysis."

Confusion was also confirmed as QR authentication, required for restaurant entry, did not work properly, causing lines to form on the streets. Some restaurants that had not prepared handwritten entry logs hurriedly provided logs for customers to write down their contact information. Even phone calls for entry registration were not smooth. Mr. Jung, a KT wireless subscriber living near Sungshin Women's University, said, "I tried to make several calls, but only received a message saying 'This is not a serviceable area.'"

Work paralysis also occurred in offices. Some office workers practically stopped working and headed to restaurants early for lunch. Some connected to tethering via other carriers such as SK Telecom and LG Uplus for urgent work, but if the company system they needed to access was based on KT servers, even this was difficult. Articles from media outlets using the KT network were also not exposed on portals during this time.

Voices expressing dissatisfaction about the KT outage flooded the internet. Especially stock traders, for whom transactions by the second and minute are crucial, expressed confusion, saying, "It became a forced holiday," "A good time for manipulation," and "I was supposed to sell just now but couldn't." Korea Investment & Securities posted a notice on their application stating, "Due to KT internet connection failure, customers using KT as their carrier may experience connection issues." Mr. Bae, who runs an online shopping mall, said, "I chose KT because it was the most stable and cheapest package, but this is frustrating," and added, "As an internet-based business, there was nothing I could do without internet."

Among those using bundled products from personal smartphones to home internet, some considered switching providers. One netizen said, "I've used KT for a long time, but it seems the time has come," and shook their head, saying, "I don't know if the follow-up measures will be properly implemented."

This outage incident was evaluated as showing how heavily our society depends on the internet. Especially with many working from home and remote classes due to COVID-19, the impact was even greater. A university student posted online, "I was in a Zoom class when the professor and classmates all disappeared at the same time," adding, "They are all KT subscribers." KT also held an online AI briefing via Zoom for reporters until around 11 AM, just before the internet network was paralyzed that day.