TX and RX in SFP refer to the transmission (TX) and reception (RX) of data signals over a fiber optic cable using Small Form-factor Pluggable (SFP) modules. In this article, we will break down the key factors influencing TX/RX power, explain how to calculate the optical power budget, and. In a fiber link, the Rx/Tx power of an optical module is sufficient to ensure the stable operation of the fiber link. They play an important role during new link deployment, compatibility testing, and link troubleshooting. However, in practical use, we adopt the average Tx power. These modules, including SFP, SFP+, and SFP28, are widely used in enterprise networks, data centers, and carrier-grade deployments.