▁connections ▁between ▁hosts ▁for ▁file ▁transfer . ▁The ▁data ▁transport ▁service ▁may ▁use ▁any ▁number ▁of ▁modes ▁to ▁implement ▁the ▁transfer ▁to ▁include ▁parallel ▁data ▁transfer ▁where ▁two ▁or ▁more ▁data ▁streams ▁are ▁used ▁over ▁the ▁same ▁channel ▁or ▁strip ed ▁data ▁transfer ▁where ▁two ▁or ▁more ▁ste ams ▁access ▁different ▁blocks ▁of ▁the ▁file ▁for ▁simultane ous ▁transfer ▁to ▁also ▁using ▁the ▁underlying ▁built - in ▁capabilities ▁of ▁the ▁network ▁hardware ▁or ▁specifically ▁developed ▁protocol s ▁to ▁support ▁faster ▁transfer ▁spe eds . ▁The ▁data ▁transport ▁service ▁might ▁option ally ▁include ▁a ▁network ▁overlay ▁function ▁to ▁facil itate ▁the ▁routing ▁and ▁transfer ▁of ▁data ▁as ▁well ▁as ▁file ▁I / O ▁functions ▁that ▁allow ▁users ▁to ▁see ▁remote ▁files ▁as ▁if ▁they ▁were ▁local ▁to ▁their ▁system . ▁The ▁data ▁transport ▁service ▁h ides ▁the ▁complexity ▁of ▁access ▁and ▁transfer ▁between ▁the ▁different ▁systems ▁to ▁the ▁user ▁so ▁it ▁appears ▁as ▁one ▁un ified ▁data ▁source . ▁ ▁Data ▁access ▁service ▁Data ▁access ▁services ▁work ▁hand ▁in ▁hand ▁with ▁the ▁data ▁transfer ▁service ▁to ▁provide ▁security , ▁access ▁controls ▁and ▁management ▁of ▁any ▁data ▁trans fers ▁within ▁the ▁data ▁grid . ▁Security ▁services ▁provide ▁mechan isms ▁for ▁authentication ▁of ▁users ▁to ▁ensure ▁they ▁are ▁properly ▁identified . ▁Common ▁forms ▁of ▁security ▁for ▁authentication ▁can ▁include ▁the ▁use ▁of ▁passwords ▁or ▁Ker ber os ▁( protocol ). ▁Author ization ▁services ▁are ▁the ▁mechan isms ▁that ▁control ▁what ▁the ▁user ▁is ▁able ▁to ▁access ▁after ▁being ▁identified ▁through ▁authentication . ▁Common ▁forms ▁of ▁authorization