RX dBm signal should be between -18 to -25 dBm. For example if the RX is -40 dBm that is indicating the port is not sending out any signal. 00dBm, which means the. SFP (Small Form-Factor Pluggable) modules are compact transceivers that allow for high-speed communication between network devices. SFP modules are available in optical and copper variants, and they. In optical communication systems, the transmit power and receive power of an optical transceiver are among the key indicators used to evaluate link quality and module operating status. They play an important role during new link deployment, compatibility testing, and link troubleshooting. These modules, including SFP, SFP+, and SFP28, are widely used in enterprise networks, data centers, and carrier-grade deployments.