High attenuation can lead to signal degradation, which can result in data errors, dropped calls, and slow internet speeds. Understanding it is crucial for anyone involved in data centers, telecommunications, or enterprise networking. This guide will demystify signal loss, explore its causes, and show you how. Attenuation is the reduction in strength of the light signal during transmission. Passive media components such as cables, cable splices, and connectors cause attenuation. It's measured in decibels per kilometer (dB/km), and it determines how far a signal can travel before it becomes too weak to read.