Every day we try our best to do our job. To maintain our clients’ networks. When something is down, we fix it. But sometimes, this is out of our hands and all we can do is wait. And that is frustrating.

The other day our monitoring tool warned me about a problem. All of a sudden there was a loss of light on a dark fibre stretch between two of our Points of Presence. It caused some wavelengths to stop working, though not all. Throughout the night our monitoring tool was giving warning signs about the loss of light on the fibres. And not just ‘some’ loss, a real loss of almost 10 dB was suddenly introduced. Knowing that a loss of 3 dB means that only half of the light’s power is running through the fibre, you can see how big of a loss it was.

This was not just an optic module that wasn’t working properly – especially since there were many waves going down at the same time. This was something bigger. It probably had to do with the cable itself. Perhaps someone hit it during maintenance work. A lot of these cables run next to the railroad tracks and the Dutch railroads do a lot of their maintenance at night. Either way, it had to be checked. In our tool we could only roughly see where the problem was located. We could see that there was a problem on the fibres between Amsterdam and Rotterdam.

In this kind of situation all I can do is give that information to the emergency crew of the company that owns the cables. They then go out and try to find where the problem is. They check the cables using a so called Optical Time-Domain Reflectometer (OTDR) tool, which shows them the loss in the cable with a precision of less than a meter. Once the exact location of the problem is detected, they can dispatch their crew there to fix the problem. In this case it turned out that there was a severe bend in the cable in one of the manholes along the route, probably caused by work that night done there by a third party.

At Fusix we do not have the possibility to check these fibre cables ourselves, since we don’t own them. So we have to rely on others, which we know do an excellent job. All I can do at moments like these is wait, until there is news, which I can relay then to our clients. And hope that they will quickly find and fix the loss location. Then we can continue doing what we do best: maintaining the networks that run over these fibres.