Ethernet susceptibility to electric fast transients

The effect of Electric Fast Transients (EFT) phenomena in an Ethernet interface set-up is investigated in order to get more insight in coupling and interference mechanisms, robustness and susceptibility levels of a typical Ethernet installation on board of a naval vessel. It is shown that already a small EFT pulse is capable of disturbing or disrupting Ethernet communication at protocol level, which makes this not just a matter of signal integrity. It seems that the protocol is not designed to handle EFT phenomena in an efficient way. We focused on the quality of the interface, i.e. cables, connectors and feed-thoughs. While affordable high quality cable is readily available, it is more difficult to find low cost and robust connectors without a large variability in performance for EMC, but to decouple data handling electronics from disturbing transients is of paramount importance for interference free data communication. As expected, screened cables help to mitigate the interference, but only when the screens are properly connected on both sides.