This schematic figure shows the recommended solution for intra-building exposed 10BaseT and 100BaseT systems. This is a solution for non PoE systems only. The SP03-3.3 is a grounded TVS diode array. It is very robust with a 150A, 8x20 surge current rating which is currently 50% higher than other available offerings on the market. A TeleLink® fuse provides the power cross overcurrent protection which is needed by some customers. While only one fuse is shown per data pair, engineers will find that putting a fuse in each line improves the line balance.  Some designs have been granted a waiver that allows them to do without the fuses.