After looking at the countries most impacted by the cable cut in our first blog on this topic, we now turn our attention to the Internet service providers in the region and how they fared. Due to differences in network architecture, cable ownership, and transit purchasing, carriers in the same country may not all experience the same degree of outage. For all of the following, we consider a network to be “outaged” when it is unreachable from the perspective of the broader Internet—as represented by Renesys’s 250 peering sessions.
The following two tables provide the top 15 providers with the largest number of outaged networks. We list the provider’s name, the country in which most of their unreachable networks are located and their autonomous system number (ASN), an assigned number that uniquely identifies their organization on the Internet.
In the first table, we list the providers in decreasing order by total number of outaged networks. In the second table, we list them by decreasing order of the percentage of their networks that are unreachable.
Not surprisingly, the hardest hit providers are located primarily in the hardest hit countries: Egypt, Kuwait, India and Pakistan. One local provider in each of Egypt and Kuwait lost essentially all of their Internet connectivity.
After totaling up the damage to the local providers, we wondered if any of harder hit ones managed to regain connectivity for some of their networks via alternate paths. We often hear statements like “the Internet is good at routing around damage”. Well, that can be true, but only when there are available alternatives. Looking at hard-hit Egypt and Kuwait, we plotted the number of outaged networks per provider over the past day in the following stacked graph, where the width of each color represents the number of unreachable networks for a given provider. If any of the providers had choices, we would expect to see the width of their color decrease over time as they shifted traffic to alternative paths. Except in one case, that didn’t happen. The exception was the Egyptian provider, LINKdotNET (ASN 24863), which did regain connectivity for most of their unavailable networks for about one hour at 20:00 UTC, only to lose more than twice as many after that time. Whatever backup routes they used obviously didn’t hold up. The others had essentially the same number of networks out all day, the typical shape of a prolonged catastrophic failure.
To make this last point perhaps more forcefully, we next plot the total number of outaged networks for the region as a whole for 24 hours, excluding the Indian subcontinent. As shown, there was no immediate relief for the large swath of the Internet cut off by this disaster.
Next up, we’ll look at the global Internet providers and who won and lost in the battle to retain their regional customers or acquire new ones.