This object reports the optical receive power level measured at this port, encoded as a real number multiplied by 1000, so a raw value of -8500 represents -8.5 dBm. Admins monitor this to detect a degrading or failing fiber link before it causes a complete outage, since receive power dropping over time often signals fiber degradation or a dirty connector. For example, an RxPwr reading around -8000, i.e. -8.0 dBm, within a healthy range would confirm the incoming optical signal strength is adequate for the transceiver.