Build robust, resilient internet connectivity to prevent March 2024 service disruption repetition

Internet Provisioning

Almost all these fibre cable sys­tems implement connectivity on a point-to-point basis, linking Afri­can cities individually via fibre optic cable pairs within the cable system to major global internet backbone infrastructure in these European cities.

Thus, Accra, Lagos, etc., on the SAT3 cable system, are linked via point-to-point cable pairs directly to the global internet Backbone located in Sisymbra, Portugal. In other words, all internet traffic from Accra to Lagos, for instance, transit (routed) via Europe before arriving in Lagos.

A fibre pair cable within the SAT3 cable system originates from London and lands in Accra. A redundant fibre optic cable pair continues from Accra to Lagos, Nigeria. That redundant fibre optic cable pairs from Accra to Lagos are usually not engineered to carry traffic.

As a result, any internet traffic from Accra headed to Lagos tran­sitions to London before reaching Lagos, even though both Accra and Lagos are connected via the same SAT3 cable.

African Cites interconnect.

Therefore, despite the many fibre cables, none appear to facilitate fibre pair links point-to-point be­tween African cities. This is typical for most of the cable systems that ring Africa.

This connection topology is crucial in understanding the reasons for the massive disruptions of March 2024, the difficulty in rerout­ing traffic onto alternative fibre ca­ble systems, and the extended mean time to repair and restore service.

Ghana Experience

In the Ghanaian experience, the redundancy strategy for mobile network operators (MNO) and Internet service providers (ISP) was to connect to multiple alternative fibre optic cable systems available in Accra. A case in point is MTN Ghana, which utilised fibre systems from SAT3/WASC, Main One, and WACS. All these cable systems were terminated in Europe, either Sisym­bra, Portugal, or London, UK.

This redundancy strategy was considered adequate since simulta­neous cuts of all three fibre optic cable systems were impossible. However, the events of March 2024 have shown that that scenario was no longer credible.

Notably, at least one MNO, Air­telTigo, (AT) was unaffected by the March 2024 disruptions. Its entire traffic is routed south towards SA via East African cable systems to the global internet as opposed to Europe, where the cable cuts occurred. This can be understood because their previous parent com­pany was Asia-based.

Diversity

Therefore, if the MNO’s and ISP’s redundancy strategy had dic­tated that at least one of the cables routed through SA to Asia, the cataclysmic disruption experienced by all the other significant MNOs would not have occurred or would have been minimised.

Examining the fibre optics cables that terminate in SA illustrates a diversified gateway redundancy strategy. SA takes advantage of its geographical location to have fibre cable systems from both the West Coast, linked to Europe and the East African Cables, connected to the Middle East and Asia.

Therefore, in SA’s case, if the ca­bles from the West failed, the East was always available, and vice versa.

SubmarineNetworks.com states it perfectly when it writes “The SAT-3/WASC and the West Africa Cable System (WACS) are most important international subsea cables in West Coast of Africa. The WACS lands at the Yzerfontein CLS in Western Cape Town, the SAT-3/WASC lands at the Melkbosstrand CLS in Western Cape Town, South Africa, forming alternative gateways to South Africa.”

Multi-Gateway

The experience of AirtelTigo, which did not suffer the March 2024 service disruption, coupled with the diversified gateway re­dundancy strategy of the SA cable architecture, offers the best lessons in proposing a solution for greater internet service resilience, stability, and vulnerability elimination.

The functional key phrase is di­versified multi-gateway redundancy strategy.

Fail Proof Redundancy

A diversified multi-gateway redundancy strategy. Cisco.com defines a multi-gateway setup as a network configuration with multiple exit points or gateways for the data to leave the local (in-country) network and reach other networks or the internet. Besides redundancy and load balancing, multi-gateways’ true benefit in this context is the policy-based routing of internet traffic via different connected FO cable systems.

For a typical MNO operating in Ghana, the imaginary, hypothetical operator called MNO-1, imple­menting the diversified multi-gate­way redundancy strategy would first entail choosing FO cables that best deliver diversified terminations. Thus, the fibre optic cables should typically terminate in Europe but also offer the capability to termi­nate in SA.

Further, the cable should provide terminations directly in the Amer­icas.

Configuration

MNO-1’s internet access archi­tecture, described below, illustrates how a Fail-proof, redundant, resilient internet platform MAY be designed.

MNO-1 chooses three fibre optic cable systems in this configuration to implement its resilient, fail proof internet connectivity and redundan­cy strategy.

The MNO-1 cables are;

1. the WASC, 14.5-terabit bandwidth capacity

2. the ACE cable, 40-terabit bandwidth capacity

3. as the EQUI­ANO,144-terabits bandwidth OR the Pan African Cable system 2AF­RICA, 180-terabits bandwidth

WASC

WASC is the first cable. Configu­ration is as follows;

1. Connect di-directionally on the WASC, terminating direct­ly into London, routing internet traffic to Europe and, by extension, North America.

2. On the same WASC, con­nect southbound to Yzerfontein, SA.

In SA, the WASC is cross-con­nected to East Africa cable systems such as DARE1 or PEACE, each with a 60-terabit bandwidth capaci­ty. SA proper, the Middle East, and the Asia-bound internet use this route.

3. A third cable connection is possible on WASC, which links directly from Accra to Sangano, Angola. This facilitates a cross-con­nect to the SACS, a 40-terabit cable system that terminates in Brazil and the Americas.

Thus, a diversified set of routed gateways is achieved on the single WASC: Europe, the Middle East, Asia, and South America.

ACE

ACE is the second fibre optic ca­ble system deployed in the MNO-1 network architecture. Similar to the WASC, it connects di-directionally, terminating in Penmarch, France, and Melkbosstrand, South Africa, where it cross-connects with East Africa cable systems as described above.

Thus far, the MNO-1 network architecture results in 2 indepen­dent, mutually exclusive connec­tions to Europe: London on WASC and Penmarch on ACE. The SA x2 independent connection terminates at Yzerfontein for WASC and Melk­bosstrand for the ACE cable.

The architecture includes a direct link to the American continent’s internet backbone via Brazil.

EQUIANO/2AFRICA

MNO-1 may deploy connectivity to the latest, most advanced fibre optic cable systems, EQUIANO or 2AFRICA. It must be observed that, in the MNO-1 network archi­tecture, neither of the three fibre optic cable systems is set up in a primary and redundancy role. All cable systems are at a PEER level, and routing algorithms or poli­cy-based routing are implemented to route internet traffic automatical­ly to their final destinations based on route efficiency. Route efficiency is determined by route latency, hop count, etc.

EQUIANO or 2AFRICA cable systems are the latest, newest, and most advanced cable systems cir­cumventing the African Continent. While global tech giant Meta backs the 2AFRICA cable system, Google backs EQUIANO. Their respective web pages state that these new cables deploy the latest technolo­gies for submarine cable systems, such as Space-Division Multiplex­ing (SDM), Optical switching at the fibre-pair level, and branching Units for connectivity extension. These technology features enhance capacity and flexibility, significantly advancing Africa’s and global inter­net infrastructure.

Unfortunately, Ghana does not land the Equiano cable directly but via land-based fibre optic cables from Lome, Togo. Research currently does not indicate whether 2AFRICA lands directly in Ghana.

Disruption Analysis

An analysis of the architecture and configuration above, in light of the March 2024 disruptions, would result in near-zero downtime for internet traffic.

March 2024 disruption scenarios would play out as follows. With both WASC and ACE cables cut towards Europe, Europe-bound traffic would reroute for both cables via SA cross-connecting to East African cable systems to the Global Internet, albeit with slightly higher latency and route hops. All other traffic, i.e., SA, Middle East, and Asia internet traffic, would not be affected.

American-bound traffic would also not be affected, as it is routed to the Americans’ backbone inter­net resources via Sangoro, Angola, which is cross-connected to Brail.

Similarly, should there be disrup­tions on the East Coast cable sys­tems, Middle East and Asia traffic will be rerouted via the West Coast cable systems through the Europe­an internet backbone network.

So far, in this article, we have examined the African continental fibre optic cable systems, leveraging that to achieve a more robust, reli­able, and resilient internet architec­ture for the Ghana-based hypothet­ical operator herein referred to as MNO-1.

We have examined the current redundancy configuration before the March 2024 disruption and illustrated the more resilient and technically superior multi-gateway routing architecture in contrast to the default single gateway routing, primary, and redundant cable con­figuration.

Of course, the Multi-Gateway architecture results in a much more complex implementation and programming of master border routers, switches, etc. However, these complexities are quickly re­solved using Cisco’s AI tools set or similar tools.

Continental Perspective

The proposed hypothetical solu­tion for MNO-1 will be typical for any operator in any other African country looking to implement a more robust, resilient, and fail proof internet architecture for its people. However, what is clear is the failure of the numerous fibre optic cable providers to facilitate direct connectivity between the various African countries where their cable terminates. This situa­tion is even more exasperating for landlocked countries.

Such connectivity guarantees resilient, robust internet to every single African country, facilitating seamless connectivity between each country without recourse to the global internet infrastructure. An Africa-centric Internet infrastruc­ture, hypothetically named RingA­frica-1.

Therefore, the push for better internet provision on the continent should be a fundamental pursuit of an Africa-centric organisation such as the African Union for all Africans.

The writer is an ICT

Consultant

BY LESLIE MENSAH TAMAKLOE