Always check your BBU is plugged in correctly and the lights are on. If the AC or OUTPUT lights are not glowing, call your internet service provider. These lights can be useful to help you troubleshoot problems with your. Resetting your ONT box can often resolve connectivity problems, but it's essential to do it correctly to avoid any unintended consequences. Not sure if you have an ONT? The video below can help you identify if you have one. What is an ONT? Are you a fiber customer? Learn how to identify your Optical Network. Fiber optic networks are celebrated for their speed and reliability, but even the best systems can encounter problems.