Connecting a network cable to the DIC-23112 is different than with most other network devices. BEcause the DIC-23112 has no ethernet port, it requires you to connect the network cable manually. This means stripping the cable so that the internal wires are exposed. The wires are then connected to the DIC-23112 by colour coding.
After stripping the network cable with a pair of stripping pliers, you will see many different wires protruding from the network cable. You will only need to connect some of those wires to the DIC-23112. The green wire connects with TD-. The white-green wire connects with TD+. The orange wire connects with RD-. The white-orange wire connects with RD+.