An ethernet media converter is a device designed to interconnect incompatible networking media to support ethernet compatible devices. The most common type of ethernet media converter has two cable ports, an RJ45 and a fibre port which enables it to convert copper CAT cable and UTP cable to single mode or multimode fibre. Copper based ethernet connections that use UTP cable are limited to a data transmission distance of 100 metres but when converted from UTP to fibre the link distance can be extended up to 80 kilometers or more. There are also ethernet media converters available that can convert ethernet to VDSL or inject Power over Ethernet (PoE). Most ethernet media converters consist of a small standalone box into which the different network cables are plugged but they can also be built into 19" standard rack systems or DIN rail cabinets. Ethernet media converters allow you to convert link speeds from 10 Mbps to 100 Mbps or from 100 Mbps to 1000 Mbps.