This ethernet to mm fiber media converter creates an economical cost effective ethernet fiber link transparently converting tofrom 10base t or 100base tx ethernet signals and 100base fx optical signals to extend an ethernet network connection over a multimode fiber backbone features auto detects halffull duplex transfer mode from the tx port auto negotiation or force 10100 mbps and mdimdi x crossover for tx port auto switching mdi and mdi x support on the rj45 utp connections nbs