# Connecting fiber-optic cables to the network

| If your cables are not labelled Rx and Tx, they may have red and black sleeves at either end. If so, the red cable is the Tx connector, and the black one is the Rx connector. If your cables are not marked in any way that indicates the Rx and Tx connectors at each end, label them first.

Connect the Ringnode to a working token-ring network consisting of at least one concentrator. To do this:

1. Remove the dust caps from the connectors on your Ringnode. Insert one end of the cable labelled Rx into the Rx connector of your Ringnode. Insert the other end of the cable into an Tx connector on your concentrator.

2. Insert one end of the cable labelled Tx into the Tx connector of your Ringnode. Insert the other end of the cable into the corresponding Rx connector on your concentrator.