Antminer S9 lan port configuration

Hi just started to take a closer look at how a Antminer S9 works and wanted to know if anyone can help with how the lan port is configured.
When I first set up the S9 I used a RJ45 cable that I had lying around. I connected the miner to the router and it worked fine! 
I have now looked at the cable and it has four live connections in the plug. Does the Antminer use all four wires to transfer data?