When an undersea cable breaks, international traffic from South Africa is rerouted through alternative submarine paths. This increases routing distance, raises latency, and can introduce congestion-related packet loss. Locally hosted games remain mostly unaffected if traffic stays within South Africa.
What Undersea Cables Do in Gaming
Undersea cables carry international internet traffic between continents. When you play a game hosted outside South Africa, your data leaves the country, travels across submarine fibre, lands in Europe, the Middle East, or Asia, and reaches the game server. This international routing adds unavoidable latency due to physical distance. If the cable is operating normally, latency is predictable. If a cable is damaged or under maintenance, routing behaviour changes.
Normal International Routing Path
When cables are healthy, international gaming traffic typically flows as: Your PC/Console → Your Router → ISP Core Network → International Transit Provider → Undersea Cable → Foreign Internet Exchange → Game Server. Latency is determined by distance, cable route, and congestion levels. For many international games, this means 120–180ms baseline latency.
What Happens During a Cable Break
When an undersea cable fails, traffic is rerouted automatically. Alternative submarine cables are used, and remaining cables carry increased load. The new routing path becomes: Your PC/Console → Router → ISP Core → Alternative Transit Provider → Different Undersea Cable → Different Landing Station → Foreign Exchange → Game Server. This rerouting usually causes higher latency, increased jitter, temporary packet loss, and evening congestion amplification. The issue is not fibre at your home. It is international capacity pressure.
Why Latency Increases During Rerouting
There are two main causes. First, longer physical route: alternative cables may land in different countries, increasing total travel distance. Distance equals increased propagation delay. Second, congestion on remaining capacity: when one cable fails, traffic shifts to others. Higher load can cause queuing delay, packet loss, and increased jitter. Even if routing remains technically stable, congestion adds delay variability.
Why Local Games Are Less Affected
If a game is hosted inside South Africa, traffic stays local. It routes through peering exchanges such as NAPAfrica and remains inside infrastructure often concentrated in Johannesburg. See: What Is NAPAfrica and Why It Matters for Gamers Because traffic does not depend on international transit, cable failures have minimal impact. However, games without South African servers remain exposed to submarine instability. See: Why Some Games Don't Have South African Servers
JHB vs CPT Impact During Cable Issues
For international routing, both JHB and CPT players are affected. Geographic difference inside South Africa becomes insignificant because the international path dominates total latency. For locally hosted games, JHB players remain lowest latency, CPT players still experience slight geographic delay, and cable breaks typically do not affect local routing performance.
How to Detect Cable-Related Latency Spikes
- Use traceroute or WinMTR during the issue
- Look for a sudden latency jump after leaving South Africa
- Check for a different international hop sequence than normal
- Note higher than usual baseline ping
- Watch for increased jitter on mid-route hops
- If routing remains entirely local and latency is high, the cause is elsewhere
Definition
A submarine fibre optic cable that connects countries and continents to carry international internet traffic. When damaged or congested, international routing is forced onto alternative paths, increasing latency and potential packet loss.
What Cannot Be Fixed Locally
If a game server is hosted internationally and cable rerouting is occurring: fibre speed upgrades will not reduce latency, router reboots will not fix propagation delay, and Ethernet vs WiFi does not eliminate international distance. The latency floor is determined by physical geography and available submarine capacity.
Performance Expectations During Cable Outages
Typical behaviour: international latency increases by 10–40ms, jitter becomes more noticeable, packet loss may appear intermittently, and evening peak periods worsen impact. Once cable repair or load redistribution stabilises, latency returns to normal routing levels.