This article introduces case studies of failures that have occurred in optical fiber cables as well as some countermeasures against such failures. This is the twenty-third of a bimonthly series on the theme of practical field information on telecommunication technologies. In August of 1999, Boeing Corporation (Boeing) engineers being used on International Space Station flight a defect in the glass fiber (see Figure 1, “Rocket and NASA engineers and managers, Boeing created and reliability of the cable installed in the U. This month's contribution. What are the biggest causes of fi ber-optic network failure in the data center? Study after study shows that they are: In one example, a study conducted by NTT-Advanced Technology, 96% of installers and 80% of network operators have experienced issues with contamination of the connector endface. Fiber-optic cables are the backbone of modern connectivity—powering 5G networks, global internet backbones, and data center interconnections with near-light-speed data transmission. While these cables are engineered for durability (with some rated to last 25+ years), they are not invulnerable.