It is very important to check the GPON ONU received optical power, the number xxxx dBm at the back, if it shows -inf dBm, it means that the cable is not connected properly, and when it is connected properly, it usually shows a number within -10 dBm to -24 dBm. The size of the light attenuation will not affect the speed of the Internet, as long as it can be registered, it will not affect the speed of the Internet.
| Rx power value (dBm ) | Healthy |
|---|---|
| -10 to -18 | very good |
| -20 to -24 | generally normal |
| -25 to -26 | working on the edge of danger |
| -27< | disconnect at any time |
| -inf dBm | fiber not connect |