Cause : Severed fiber, dead transceiver, or failed switch. Clean connectors and test signal. Industrial fiber optic networks typically use either multimode fiber (OM3/OM4, 50/125 micron) for short distances within a facility (up to 550 meters at 10 Gbps) or single-mode fiber (OS2, 9/125 micron) for long distances between buildings or facilities (up to 80+ km with appropriate transceivers). However, in real-world installations, whether underground, aerial, or in harsh industrial environments, fiber cables can and do fail. Understanding the common causes of. Fiber optic communication uses pulses of light to transmit data along thin strands of glass or plastic. Configuration Errors : IP conflicts, incorrect routing, or firmware bugs. The NMS can visualize network delay in real time, which is better than the manual delay evaluation method of SDH.