APCN-2: The Backbone of Intra-Asian Internet
APCN-2: The Backbone of Intra-Asian Internet
Cable profile based on GeoCables monitoring data — 100 health checks recorded While transoceanic cables get most of the attention, APCN-2 (Asia Pacific Cable Network 2) quietly carries an enormous share of internet traffic within Asia — connecting China, Hong Kong, Japan, South Korea, Malaysia, Philippines, Singapore, and Taiwan in a regional ring network. At 19,000km, it is one of the longest purely intra-regional submarine cable systems in the world.The Route: Asia's Internet Ring
APCN-2 forms a ring connecting Asia's major internet hubs: Singapore → Malaysia (Mersing) → Philippines (Nasugbu/Balintang) → Taiwan (Toucheng/Tanshui) → China (Shanghai/Shantou/Chongming) → South Korea (Pusan) → Japan (Maruyama/Okinawa) → Hong Kong → back to Singapore This ring topology is crucial: if one segment is cut, traffic can route the other way around the ring. For a region prone to earthquakes (Taiwan, Japan) and fishing anchor damage, redundancy matters enormously.Why Intra-Asian Latency Is Surprisingly Good
APCN-2, combined with cables like EAC-C2C, SJC, and APG, creates a dense mesh of Asian connectivity. The result: - Singapore → Hong Kong: ~30ms (2,600km) - Hong Kong → Tokyo: ~50ms (3,000km) - Seoul → Tokyo: ~20ms (1,200km) - Singapore → Tokyo: ~70ms (5,300km) These numbers approach the theoretical speed-of-light minimum, reflecting how well-optimized intra-Asian routing has become. Compare this to, say, Africa-Europe connections which often run at 3–4× their theoretical minimum.The Taiwan Earthquake Problem
APCN-2 passes through one of the world's most seismically active zones. The 2006 Hengchun earthquake (magnitude 7.1, off Taiwan's southern coast) severed or damaged APCN-2 along with 6 other cables simultaneously. Internet connectivity across East Asia dropped significantly for weeks while repair ships worked through the queue of damaged cables. This event — and subsequent earthquakes in 2009, 2016, and smaller incidents regularly — has driven the development of alternative routing and additional cable systems in the Taiwan Strait corridor.GeoCables Monitoring: 100 Health Checks
Our monitoring covers key APCN-2 segments: - Singapore → Philippines: ~35ms - Philippines → Taiwan: ~25ms - Taiwan → Japan: ~20ms - Japan → South Korea: ~15ms The cable shows consistent performance with occasional anomalies correlating with seismic events or maintenance windows.APCN-2 in 2026: Still Relevant After 20+ Years
APCN-2 entered service in 2001 — making it over 20 years old. In submarine cable terms, this is elderly. The cable uses older 2.5 Gbps wavelength technology compared to modern cables running 100–400 Gbps per wavelength. Yet it remains in active service because: 1. The physical fiber is still functional 2. Upgrades to terminal equipment can improve capacity without replacing the cable 3. The ring topology and geographic diversity remain valuable 4. The cost of a new cable system (typically $300–500M) requires clear business justification Newer cables like SJC2 and JUPITER have supplemented but not replaced APCN-2 on the key Asian routes.GeoCables monitors APCN-2 with 100 recorded health checks across Asian segments. View status →