Unmask the fake backup

1 · The double cut

Beginner

An excavator cuts one conduit, and a company loses its main link and its backup, bought from two providers. Why did the route check not see it coming?

It missed a network the two shared It cannot see shared trenches It only checks the main link

2 · Same region, same buildings

Intermediate

Average overlap of interconnection buildings: 0.094 between two operators of the same region, 0.024 between two operators of different regions. If your main link and your backup come from the same region, by how much is that overlap multiplied, on average?

By about 2 By about 40 By about 4

3 · Two cables, two shores

Expert

Your main link and your backup use two transatlantic cables that do not land within 25 km of each other. What can you conclude about their independence?

Independent, the 25 km rule guarantees it Dependent, 31% of such pairs fail together Undetermined, the rule sees only shores

4 · Count the operators in Marseille

Expert

The sample has 47 operators, forming 1,081 pairs. The Digital Realty campus in Marseille hosts 153 of those pairs. How many of the sample's operators are present there?

12 operators 18 operators 24 operators

Fake backup unmasked

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