CI ▁or ▁P CI e ). ▁ ▁Pro tocol s ▁ ▁There ▁are ▁numerous ▁protocol s ▁for ▁E ther net - style ▁networking ▁over ▁USB . ▁The ▁main ▁motiv ation ▁for ▁these ▁protocol s ▁is ▁to ▁allow ▁application - in dependent ▁exchange ▁of ▁data ▁with ▁USB ▁devices , ▁instead ▁of ▁special ized ▁protocol s ▁such ▁as ▁video ▁or ▁M TP . ▁Even ▁though ▁USB ▁is ▁not ▁a ▁physical ▁E ther net , ▁the ▁networking ▁stack s ▁of ▁all ▁major ▁operating ▁systems ▁are ▁set ▁up ▁to ▁transport ▁IE EE ▁ 8 0 2 . 3 ▁frames , ▁without ▁car ing ▁much ▁what ▁the ▁underlying ▁transport ▁really ▁is . ▁ ▁The ▁main ▁industry ▁protocol s ▁are ▁( in ▁chron ological ▁order ): ▁Rem ote ▁N DIS ▁( R ND IS , ▁a ▁Microsoft ▁vendor ▁protocol ), ▁E ther net ▁Control ▁Model ▁( EC M ), ▁E ther net ▁Em ulation ▁Model ▁( E EM ), ▁and ▁Network ▁Control ▁Model ▁( NC M ). ▁The ▁latter ▁three ▁are ▁part ▁of ▁the ▁larger ▁Communic ations ▁Device ▁Class ▁( CD C ) ▁group ▁of ▁protocol s ▁of ▁the ▁USB ▁Im plement ers ▁Forum ▁( U SB - IF ). ▁They ▁are ▁available ▁for ▁download ▁from ▁the ▁USB - IF ▁( see ▁below ). ▁The ▁R ND IS ▁specification ▁is ▁available ▁from ▁Microsoft ' s ▁web ▁site . ▁Regarding ▁de ▁fact o ▁standards , ▁some ▁standards , ▁such ▁as ▁EC M , ▁specify ▁use ▁of ▁USB ▁resources ▁that ▁early ▁systems ▁did ▁not ▁have . ▁However , ▁minor ▁modifications ▁of