Acceptable dB loss for fiber depends on the component you're measuring: a single mated connector pair should lose no more than 0. 5 dB per kilometer depending on the. Fiber Optic Measurement Units: "dB" and "dBm" Whenever tests are performed on fiber optic networks, the results are displayed on a power meter, OLTS or OTDR readout in units of “dB. The total. Engineers use the decibel-milliwatt (dBm) to quantify the absolute power level of the optical signal on a logarithmic scale, referencing it to one milliwatt (mW). It doesn't measure an absolute quantity; rather, it shows how one value compares to another. As a comparison, here are some typical reflectances: There is a limit to the range of. Hey, Im curious what an ok dBm is for home fiber? I have -16 but all is well. I get no packet loss and advertised speed. But i have read optimal is -6 to -12. I have Telus PureFiber up in Canada if that matters.