Tx main hair, Rx main

Near the TX and RX refers to the hair of the fiber and optical fiber,
Different brands have different meanings by the light of the transceiver,
The Link light refers to the connection state (constant) normally, send and receive Data index according to the state (frequently flashing),
Speed refers to the state of 10/100 m, FDDI refers to collect light fault (flashing refers to the failure of single fiber), some Local and Remote, we can see the directions,