By Cliff Potts
CSO and Editor-in-Chief, WPS News
B.S., Telecommunications Management

Baybay City, Leyte, Philippines — Tuesday, May 12, 2026 (12:35 p.m. Philippine Time)

Why undersea cables are both strength and liability

For an archipelago, undersea fiber is unavoidable. It is the only way to move large volumes of data between islands and to the global network. At the same time, it introduces some of the highest-impact single points of failure in the entire data communications grid.

Undersea cables are not fragile in the abstract. They are fragile in context—when landing choices, backhaul routing, and restoration assumptions are poorly engineered.

Landing stations are the real choke points

The most critical risk is not the wet cable itself. It is the landing station and its immediate backhaul.

Common failure patterns include:

  • multiple international systems landing in the same coastal corridor,
  • landing stations clustered near urban infrastructure without geographic separation,
  • domestic backhaul converging on a single inland aggregation node,
  • and power or flooding risks at coastal sites.

When multiple cables share a landing or exit path, diversity on paper becomes dependency in reality.

Physical threats are predictable

Undersea cable faults are not rare anomalies. They result from:

  • anchor drags,
  • fishing activity,
  • seabed movement,
  • storms,
  • and earthquakes.

These risks are well understood and largely unavoidable. What is avoidable is allowing one fault to isolate an entire region.

Engineering assumes faults will occur. Design must assume when, not if.

International diversity does not equal domestic resilience

Adding new international cable systems improves capacity and geopolitical diversity. It does not automatically improve national resilience.

If multiple international systems:

  • land in the same region,
  • feed the same domestic corridors,
  • or rely on the same aggregation nodes,

then domestic outages will negate international diversity.

A country can have world-class international connectivity and still experience nationwide outages if domestic integration is weak.

Restoration timelines matter more than headline capacity

Undersea cable repairs are slow by nature. Mobilizing a repair ship can take days. Repairs can take weeks.

This reality makes domestic failover essential. National design must assume:

  • prolonged loss of one or more international systems,
  • degraded capacity for extended periods,
  • and prioritization of critical traffic during repair windows.

If the domestic backbone cannot absorb these conditions, international capacity becomes irrelevant during crises.

Landing diversity must be geographic, not nominal

True landing diversity requires:

  • separation across different coastlines,
  • distinct seismic and storm exposure profiles,
  • independent power and access routes,
  • and multiple inland backhaul paths.

Two landing stations ten kilometers apart on the same coast do not constitute diversity. They constitute shared risk.

Backhaul from landing stations is the silent failure domain

Even when landing stations are diverse, their inland connections often are not.

Common weaknesses include:

  • single fiber routes inland,
  • shared river crossings,
  • co-located regeneration huts,
  • and dependence on the same regional aggregation facility.

In these cases, the undersea cable survives, but traffic still fails to reach the national backbone.

Over-centralization magnifies cable failures

Highly centralized architectures—where most traffic must pass through a single metro region—turn cable faults into national events.

Resilient design assumes that:

  • Manila may be unreachable,
  • international traffic may be partially unavailable,
  • and regional networks must continue operating locally.

Any architecture that collapses without the capital online is inherently brittle.

What competent undersea integration looks like

A resilient Philippine integration strategy would include:

  • multiple, geographically separated landing regions,
  • independent domestic backhaul from each landing,
  • regional traffic localization to reduce dependency on international paths,
  • predefined traffic prioritization during capacity loss,
  • and documented failover behavior tested under real conditions.

This is not exotic engineering. It is standard carrier practice applied consistently.

Why landing-station risk persists

Landing-station risk remains high because:

  • coastal real estate is cheaper and easier to permit,
  • inland routing is expensive and politically complex,
  • outages are episodic rather than continuous,
  • and accountability for national-scale failure is diffuse.

The incentives favor concentration. Physics punishes it.

What this establishes for the series

This essay establishes another non-negotiable principle:

Undersea cables multiply resilience only when landing and backhaul diversity are enforced.

In the next essay, the focus will move inland—to interconnection, IXPs, and traffic locality, examining how domestic peering decisions determine whether failures remain regional or become national.

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