Flight cancellations due to a cut fiber optic cable: The fault lies with Lufthansa

It was a laughing matter: a supposedly careless excavator operator cut through four fiber optic cables with his drill and once again chaos erupted at German airports – especially at Frankfurt Airport. And who is to blame? The excavator operator, of course. But stop. First: Why does he hit the cable at all? Secondly, why does this have such an impact?

Usually excavator operators don’t just dig around in the earth, loosely based on the motto: “Who is digging in the excavator hole so late, it’s the excavator operator who is still digging.” Orders are placed for such work, in the context of which not only responsibilities and liability issues are clarified, but also which information must be made available to the commissioned company. This also includes the plans for the underground lines. Where the client, in this case Bahn AG, gets the plans for the fiber optic lines laid by Telekom is not the responsibility of the construction company – and certainly not that of the excavator operator. So he digs according to the plan, exactly according to the plan that his superior has.

Not an isolated case: excavators versus fiberglass

And yet this cable damage is not an isolated case. Would you like a few examples? Just a few days earlier, an excavator in Düsseldorf had severed several fiber optic cables. 15,000 DSL connections from Telekom, ten cell phone stations in downtown Düsseldorf and numerous online services from the North Rhine-Westphalian state government were offline. In April 2021 there had already been a similar incident in NRW. A few years earlier, an excavator had severed the internet line of the driver’s license and vehicle registration office in Hanover. But she was able to get by temporarily by resorting to paper and analogous processes. Sometimes it is an advantage that digitization has not yet really penetrated German authorities – one might think.

So what triggers the smile? That excavator operators no longer only encounter duds, boulders and archaeological finds when digging, but more and more frequently and completely unexpectedly recently and intentionally buried communication lines? Or that it hit air traffic again?

There is a reason why disruptions in air and rail traffic appear so prominently in the news. Both are part of the essential transport infrastructure. That’s why airline reservation systems have long been considered “mission-critical” applications. As the name suggests, the survival of companies, the maintenance of infrastructure, order and emergency systems, such as the power supply or police and fire brigade operations, depend on these applications. That is why they place the highest demands on IT security and availability.

Redundancy – but not in one pipe

However, the meaning of the words “Reliability”, “Availability” – or more recently: “Resilience” – which are often used in IT, does not seem to have really arrived in Germany. After all, applications whose components run from user terminals via cables, switches, routers and even more cables to server farms, storage and backup systems in data centers miles away can be leveraged at any of these components or put out of operation. This is precisely why all components must be designed redundantly, and not just the fiber optic cables within a tube, but also the paths themselves, which lie between the hopefully redundantly designed data centers and the multiple existing user interfaces on site. Incidentally, this rule applies to all critical systems.

Only Lufthansa knows whether in this case only one path led to a data center or whether two data centers were connected to one and the same path and whether cost reasons or other planning errors were the cause. The only thing that is certain is that the responsibility for this lies with those responsible for the “mission-critical” application and with the authorities responsible for the resilience of the critical infrastructure and certainly not with the excavator operator.

(sun)