The ACE (African Coast to Europe) submarine cable runs along the west coast of Africa between France and South Africa, connecting 22 countries. It extends over 17,000 km, and has a potential capacity of 5.12 Tbps. The cable system is managed by a consortium of 19 telecommunications operators & administrations, and the first phase entered service in December 2012. While it may not have been completely problem-free over the last 5+ years, online searches do not return any published reports of significant outages caused by damage to the cable.
However, on March 30, damage to the cable disrupted Internet connectivity to a number of connected countries, with reported problems posted to social media over the next several days. These posts indicated that the ACE submarine cable was cut near Noukachott, Mauritania, but did not provide any specific information about what severed the cable.
Of the 22 countries listed as having landing points for the ACE Submarine Cable, 10 had significant disruptions evident in Oracle's Internet Intelligence data. The graphs below show the impact of the cable cut to Internet connectivity within the affected countries, with the countries shown grouped by the number of submarine cable connections each country has, based on information found on TeleGeography's Submarine Cable Map.
This first figure, immediately above, includes graphs for the six affected countries (Sierra Leone, Mauritania, Liberia, Guinea-Bissau, Guinea, and the Gambia) that only have a single submarine cable connection (to ACE). While the disruption begins at the same time across all six countries, it is interesting to note that the duration and severity of impact varied widely. The most significant, and longest-lasting disruption was seen in Mauritania, with a complete outage lasting for nearly 48 hours, followed by partial restoration of connectivity. Sierra Leone also saw a significant impact as a result of the cable cut, followed by a complete outage on April 1. However, we believe that the April 1 outage may have been government-directed, related to recent national elections. The differences in duration and severity may be related to the other international Internet connections, via terrestrial cable or satellite, that the providers in these countries have in place, resulting in varying levels of reliance on the ACE cable system.
The second figure, immediately above, illustrates the impact of the cable cut on Internet connectivity in Benin, which is connected to two submarine cables - ACE and SAT-3/WASC, which follows a similar path along the west coast of Africa, up to Portugal. The impact on Benin appeared to be nominal, affecting less than a tenth of the regularly available networks, with nearly all coming back after a little more than a day. The redundant connection to SAT-3/WASC, as well as other terrestrial/satellite connections, may have helped to mitigate the overall impact on Benin's connectivity.
The third figure, immediately above, highlights the impact of the cable cut on three affected countries, each of which is connected to three submarine cables -- Senegal (ACE, SAT-3/WASC, and Atlantis-2), Ivory Coast (ACE, SAT-3/WASC, and the West African Cable System), and Equatorial Guinea (ACE, Ceiba-1, and Ceiba-2). The duration of the disruption in Senegal is longer than the other surveyed countries, but may be related to its proximity to the cable cut, which took place near Mauritania. And although Equatorial Guinea is connected to three submarine cables, the Ceiba-1 cable provides no international redundancy, while the Ceiba-2 cable is only connected internationally to Cameroon. (However, Cameroon is connected to four other submarine cables, in addition to Ceiba-2 and ACE.) And while Ivory Coast (Côte d'Ivoire) is connected to ACE, the observed disruption begins several hours after the other affected countries, and lasts significantly longer, which could indicate that it is actually unrelated to the reported cable cut.
With multiple submarine cables landing in Western African countries that provide connectivity between countries, as well as to landing points in Europe, network providers in these countries have an opportunity to take advantage of this redundancy to mitigate the potential impact of problems such as the ACE submarine cable cut discussed above. Internet Intelligence data showed that in this case, there was a somewhat limited impact to Internet connectivity in connected countries, but problems with other cables in the past (2008, 2012, 2013, 2014) have resulted in much more significant issues.