Step 1: Physically connect the loopback adapter to the transceiver port at the near end of a fiber link. A fiber loopback module is a compact diagnostic tool that allows engineers to verify whether an optical port is functioning properly. By looping the transmitted signal (Tx) directly back to the receiving end (Rx), it enables a closed test without requiring a live network connection. It can be performed internally via network management software, known as a soft loopback, or externally via a physical loopback adapter, known as a hard loopback.
