How to extend the Ethernet communication distance

Hi Champs,

My customer is design UART-to-Ethernet module using TM4C129E. During their testing, they found the maximum distance of Ethernet communication was about 70 meters, shorter than other solution. So their question is how to extend the distance, such as configuring the conresponding registers, or how to improve the circuit?

You can find the schematics as follows.

Thanks a lot.

BR,

Young