For multimode fiber, the loss is about 3 dB per km for 850 nm sources, 1 dB per km for 1300 nm. 5 dB/km max per EIA/TIA 568) This roughly translates into a loss of 0. 5. At TREND Networks, we are frequently asked how much loss is allowed when conducting testing on fiber optic cabling. If this information is not available, the maximum allowable fiber loss per TIA-568. Table 1 below provides th e values tor pairs. The connector pair count includes the connectors (patch panels) at the end of the system that you plug into f r testing. While some loss is expected, excessive or unexpected loss can lead to poor performance, network downtime, and signal failure. First, you should be aware of the fiber loss formula: The Total Link Loss = Cable Attenuation + Connector Loss + Splice Loss Cable Attenuation (dB) = Maximum Cable Attenuation. The EIA/TIA standards clearly state that maximum attenuation is one of the most important parameters in measuring fiber optic loss.
[PDF Version]