Fiber-optic is generally considered more reliable than cable. A fiber-optic network is a passive system, which means that during power outages, a fiber-optic network is less likely to be interrupted or go down. Also, because the conductor is glass, it does not generate electricity, so fiber is immune to interference that can be caused by nearby power lines or high-voltage electrical equipment. Plus, with fiber-optic, there is less chance of your computer sustaining lightning-related damage.