For normal fiber broadband, the ideal range of light attenuation is -20dBm to -25dBm. With light attenuation at -27dBm, speeds are limited to a maximum of 100M, and with light attenuation at -28dBm, speeds are limited to a. The most fundamental parameter for optical fiber is geometry, since the dimensions of the fiber determine its ability to be spliced and terminated to other fibers. Fiber loss, or attenuation, refers to the reduction in optical power as light travels through a fiber optic cable. While some loss is expected, excessive or unexpected loss can lead to poor performance, network downtime, and signal failure. Losses can be introduced by various means such as intrinsic material absorption, scattering, bending, connector loss and more.