Korea-Japan Cable Network (KJCN)

Korea-Japan Cable Network (KJCN) is a point-to-point submarine cable linking South Korea and Japan. Landing at Busan, Fukuoka, Kitakyushu, it provides a direct fiber-optic path between the two countries, serving as both a primary data route and a redundancy option for neighboring cable systems. Submarine cables in this region contribute to a mesh of redundant paths that keep internet traffic flowing even when individual systems are damaged or under maintenance. GeoCables tracks this cable using RIPE Atlas measurements from four probes in Minsk, Almaty, Tbilisi, and Jerusalem, comparing live RTT against historical baselines to catch performance shifts early.