Submarine cable redundancy in Africa: Building network resilience beyond more cables

Africa’s digital backbone is no longer defined by capacity alone.

Africa’s digital transformation has accelerated at an unprecedented pace over the past decade. New submarine cable systems, expanding terrestrial fiber networks, growing cloud ecosystems and regional Internet Exchange Points (IXPs) have significantly strengthened the continent’s international connectivity.

Yet recent disruptions have revealed an important reality: capacity and resilience are not interchangeable.

The submarine cable outages that affected large parts of Africa in 2024 demonstrated that multiple international connections do not necessarily translate into uninterrupted service. In several cases, traffic could not be rerouted efficiently because networks shared common physical dependencies or lacked sufficient route diversity.

For network architects, CTOs and peering teams, this marks a fundamental shift in perspective.

The conversation is no longer limited to increasing bandwidth or connecting to additional submarine systems. The focus has expanded to a broader architectural question:

How can international connectivity continue operating when critical infrastructure fails?

Answering that question requires looking beyond submarine cables themselves.

Network resilience now depends on how submarine infrastructure interacts with terrestrial fiber, regional peering ecosystems, Internet Exchange Points and geographically diverse transit routes. Together, these layers form the digital backbone that supports Africa’s growing digital economy.

This evolution is already reshaping infrastructure strategies across the continent. TeleGeography’s 2025 Africa Telecommunications Map identifies 77 submarine cable systems that are active or under construction, illustrating both the scale of investment and the increasing importance of designing networks that can fully leverage this infrastructure.

For carriers, enterprises and digital infrastructure leaders, the challenge is therefore evolving.

Building the next generation of Africa’s backbone is no longer about adding more cables. It is about creating better-connected, more resilient connectivity ecosystems.

Why submarine cable redundancy has become a strategic priority

For years, the resilience of international connectivity was often measured by a simple indicator: the number of submarine cable systems available to a country or region.

That approach made sense when the primary objective was expanding capacity. Every new landing station increased bandwidth, improved competition and created new opportunities to connect African markets with Europe, the Middle East and Asia.

Today’s operating environment is more complex.

Recent disruptions have shown that submarine cable redundancy cannot be measured by the number of cables alone. Multiple systems may still depend on the same coastal corridor, share similar landing areas or converge along common physical routes. When these dependencies remain hidden, additional infrastructure does not necessarily translate into additional resilience.

This distinction has become increasingly important as digital infrastructure supports far more than Internet access. Cloud platforms, financial services, public administrations, content delivery networks and enterprise applications all rely on uninterrupted international connectivity. For many organisations, network resilience has become a business continuity requirement rather than a purely technical objective.

The events of March 2024 clearly illustrated this shift. A single geological incident off the coast of Côte d’Ivoire disrupted several major submarine cable systems simultaneously, including ACE, SAT-3, WACS and MainOne, affecting connectivity across thirteen African countries. The incident exposed a structural weakness: several independent cable systems were vulnerable because they converged around the same physical area.

The consequences extended beyond the directly affected operators.

Traffic had to be rerouted across alternative infrastructures. Networks connected to Google’s Equiano cable or supported by cross-border terrestrial fiber links maintained a higher level of service continuity, while others experienced severe degradation. The Internet Society concluded that geographical diversity, terrestrial interconnections and upstream redundancy played a decisive role in maintaining connectivity during the disruption. The lesson reaches far beyond one outage.

As Africa’s digital economy grows, resilience increasingly depends on the architecture of the network, not simply on the quantity of infrastructure deployed. Redundancy now requires independent physical paths, diversified transit options and the ability to reroute traffic efficiently across regional ecosystems.

For CTOs, Network Architects and Peering Managers, the conversation has therefore evolved. The key question is no longer “How many submarine cables connect my network?” A far more relevant question has emerged: “If one critical route fails, how many truly independent alternatives remain available?“

That shift in perspective is redefining how resilient international connectivity is designed across Africa and the Indian Ocean.

Building network resilience beyond submarine cables

The March 2024 disruptions changed the conversation around international connectivity in Africa.

For years, resilience strategies focused primarily on adding capacity through new submarine cable systems. While this approach improved market access and increased international bandwidth, recent outages demonstrated that infrastructure growth alone does not eliminate operational risk.

Designing a resilient network now requires a broader perspective—one that considers how submarine infrastructure, terrestrial fiber, peering ecosystems and transit architectures interact across the entire connectivity chain.

A resilient backbone is therefore built on multiple, independent layers rather than on a single category of infrastructure.

Route diversity goes beyond cable redundancy

Route diversity is often confused with infrastructure redundancy.

The distinction matters.

Connecting to two submarine cable systems does not automatically provide two independent paths. If both systems converge at the same landing station, follow the same coastal corridor or rely on identical terrestrial backhaul infrastructure, a single physical incident may affect both simultaneously.

The West Africa outages of March 2024 illustrated this vulnerability. Multiple cable systems were disrupted because they converged within the same geographical area, reducing the effectiveness of traditional redundancy strategies.

For network architects, route diversity should therefore be assessed across several dimensions:

• physical separation of submarine routes;
• diversity of landing stations;
• independent terrestrial backhaul;
• diversified upstream transit providers;
• geographically distributed Points of Presence (PoPs).

Viewed this way, submarine cable redundancy becomes an architectural principle rather than simply an infrastructure count.

Terrestrial fiber creates independent connectivity paths

A resilient international backbone does not stop at the coastline.

Once traffic reaches a cable landing station, terrestrial infrastructure determines how efficiently it can reach regional markets or bypass an affected area.

Cross-border fiber networks increasingly provide those alternative paths.

Rather than concentrating traffic around a single coastal gateway, operators can redirect flows through neighboring countries and regional hubs, reducing dependence on one physical corridor.

Google’s Umoja project reflects this evolution. By combining a new subsea segment with terrestrial infrastructure across Southern and Eastern Africa, the project illustrates how future international connectivity will rely on complementary infrastructure layers rather than isolated assets.

The broader lesson extends well beyond Umoja itself.

Future resilience will increasingly depend on independent terrestrial paths capable of complementing submarine infrastructure during large-scale disruptions.

Regional peering has become a resilience layer

Network resilience is not determined solely by international connectivity. It also depends on where traffic is exchanged.

For many operators, unnecessary international routing still introduces avoidable latency, additional transit costs and greater exposure to external failures.

Regional Internet Exchange Points (IXPs) and stronger African peering ecosystems address these challenges by allowing more traffic to remain within the continent whenever possible.

During the 2024 disruptions, several operators relied on regional rerouting strategies, terrestrial cross-border fiber and unaffected cable systems such as Equiano to preserve service continuity. These examples demonstrated that resilience is strengthened when multiple interconnection options are available rather than when networks depend on a single international path.

For CTOs and Peering Managers, peering has evolved from a performance optimisation tool into a strategic resilience capability.

Regional hubs are becoming the new anchors of Africa’s backbone

As connectivity ecosystems mature, the strategic role of regional hubs continues to expand.

Cities such as Johannesburg, Lagos, Nairobi, Djibouti and Dakar increasingly combine several critical infrastructure layers:

• submarine cable landing stations;
• terrestrial fiber corridors;
• carrier-neutral data centres;
• cloud on-ramps;
• regional peering exchanges.

Their value lies less in the quantity of infrastructure they host than in the diversity of connections they enable.

Egypt provides another illustration of this trend. By combining numerous submarine cable landings with extensive terrestrial corridors linking the Mediterranean and the Red Sea, the country demonstrates how physical diversity can reinforce international transit resilience. While every market has unique geographic constraints, the underlying principle applies across the continent: interconnected ecosystems offer greater operational resilience than isolated infrastructure assets.

For carriers operating across Africa and the Indian Ocean, future competitiveness will increasingly depend on the ability to orchestrate these ecosystems rather than simply access them.

A resilience framework for CTOs and network leaders

Network resilience is no longer a procurement exercise focused on selecting additional capacity.

It has become an architectural discipline that requires a comprehensive understanding of how international, regional and local infrastructure interact.

For CTOs, Network Architects and Peering Managers, the objective is no longer simply to secure backup connectivity. The challenge is to identify hidden dependencies before they become operational risks.

A resilient international connectivity strategy should therefore be evaluated across five complementary dimensions.

1. Assess physical route diversity, not Just provider diversity

Working with multiple carriers does not automatically eliminate infrastructure risk.

Different providers may ultimately rely on the same submarine cable system, the same landing station or the same terrestrial corridor before traffic reaches its destination.

A resilience assessment should therefore answer questions such as:

• Are primary and backup routes physically independent?
• Do they land at different cable stations?
• Do they cross different terrestrial corridors?
• Can traffic bypass a regional failure without converging on another single point of failure?

Physical route diversity has become one of the strongest indicators of submarine cable redundancy.

2. Identify concentration risks across the entire connectivity chain

Every international network contains critical dependency points. 

These may include: 

• submarine landing stations;  

• terrestrial aggregation nodes;  

• metropolitan fiber rings;  

• carrier hotels;  

• Internet Exchange Points;  

• upstream transit providers.  

The objective is not to eliminate every dependency, that is rarely possible. 

The objective is to understand where dependencies accumulate and whether alternative paths remain available when one element fails. 

This level of visibility allows resilience planning to move from reactive incident management to proactive network design. 

3. Integrate peering and IP transit into the resilience strategy

Resilience cannot rely exclusively on physical infrastructure. 

Routing policies play an equally important role. 

A diversified IP transit strategy, combined with regional peering, provides greater flexibility when international routes experience disruption. 

Instead of concentrating traffic through a single upstream provider, operators can balance connectivity across multiple transit partners while keeping regional traffic within Africa whenever appropriate. 

This combination improves: 

• operational flexibility;  

• routing efficiency;  

• latency;  

• business continuity.  

As African digital ecosystems continue to mature, peering is becoming as strategic as international transport itself. 

4. Test the architecture before an incident occurs

A backup route that has never been exercised remains an assumption. 

Resilient networks are validated through regular testing. 

This includes: 

• failover simulations;  

• routing policy validation;  

• capacity verification;  

• recovery time measurement;  

• operational coordination between network teams.  

The March 2024 disruptions demonstrated that organisations already familiar with their alternative routing options recovered more effectively than those discovering their dependencies during the incident itself.  

Testing therefore transforms resilience from a design principle into an operational capability. 

5. Think in ecosystems rather than individual assets

Perhaps the most significant shift concerns mindset. 

Traditional infrastructure planning often evaluates assets independently: 

• one submarine cable;  

• one terrestrial route;  

• one data centre;  

• one transit provider.  

Modern network resilience requires a broader perspective. 

The most robust architectures combine multiple infrastructure layers into an interconnected ecosystem where no single component determines service continuity. 

This evolution is already visible across Africa, where new submarine systems, expanding terrestrial networks, regional IXPs and strategic connectivity hubs are creating increasingly diverse routing options. TeleGeography’s latest Africa Telecommunications Map reflects this transition, with 77 submarine cable systems active or under construction, supported by growing regional interconnection and terrestrial expansion.  

For network leaders, the strategic objective is no longer to deploy more infrastructure. 

The objective is to orchestrate infrastructure more intelligently. 

The next chapter of Africa’s backbone

Africa’s digital infrastructure is entering a new stage of maturity. 

The conversation is gradually moving away from capacity expansion alone toward a broader objective: designing networks that can adapt, recover and continue operating in an increasingly interconnected environment. 

Submarine cable systems will remain the foundation of international connectivity. Their strategic importance will only continue to grow as cloud adoption, artificial intelligence, digital financial services and cross-border data exchanges accelerate across Africa and the Indian Ocean.  

The differentiator, however, will no longer be access to infrastructure alone. 

Competitive advantage will increasingly come from the way infrastructure is combined. 

Networks designed around geographical route diversity, independent terrestrial connectivity, regional peering and resilient IP transit architectures will be better positioned to absorb disruption while maintaining service continuity. 

This evolution also changes the role of wholesale carriers. 

Beyond delivering international connectivity, carriers are expected to help operators and enterprises design architectures that reduce concentration risks, improve operational flexibility and strengthen business continuity across multiple infrastructure layers. 

That is where the concept of Backbone takes its full meaning. A backbone is not defined by a single submarine cable, a single terrestrial network or a single regional hub. It is defined by the intelligence of the architecture connecting them. 

For Africa, this represents more than an infrastructure challenge. 

It is an opportunity to build a digital ecosystem where resilience becomes a competitive advantage rather than a contingency plan. 

For Silver Links, this vision shapes the way international connectivity is approached across Africa and the Indian Ocean: connecting infrastructure, routes and regional ecosystems into architectures designed not only for performance, but also for long-term resilience. 

Because tomorrow’s strongest networks will not necessarily be those with the greatest capacity. 

They will be the networks designed to keep moving when the unexpected happens.