Surge Protection on Ethernet

https://www.bourns.com/pdfs/bourns_ethernet_poe_article.pdf

http://www.akrossilicon.com/home/component/jdownloads/finish/3-whitepapers/29-ethernet-esd-compliance-w-as1602-wp12-rev1-3-pdf

PCB Spark Gaps

http://www.youtube.com/watch?v=vfP_65gSSBU

Breakdown voltage = (3000 * air_pressure_atm * distance_mm) + 1350

0.1mm = 1650V

0.2mm = 1950V