If possible, remove and reinstall the optical modules to check whether the fault is rectified. If you have physical access to the switch, it can save time to look at the port LEDs which give you the link status or can indicate an error condition (if red or orange). The table describes the LED status indicators for Ethernet modules or fixed-configuration switches: Ensure that both sides have. Before troubleshooting the issue, please look at our 16 tips for troubleshooting your optical transceiver connections. Tip #1: How can we distinguish between the SFP module's RX and TX ports? The triangle indicates the Tx (transmit) port with the pole facing outward on the SFP module, whereas the. When optical modules operate on a switch, it is usually necessary to read the module's internal information to understand its working status—such as connection status and real-time metrics like optical power and temperature. Moreover, these lights signal power status, connectivity, activity, and errors. For network engineers working with fiber optics (SFP, SFP+, QSFP), understanding TX (Transmit) and RX (Receive) signal strength is critical. It is the difference between a stable, high-speed. Usually, the port status failures are manifested as four types: the port is down (link failure), no packets received or sent when the port is up, unstable link, and CRC errors.