▁without ▁change ▁to ▁other ▁software . ▁ ▁Message ▁Ab stra ction ▁ ▁To ▁provide ▁implementation ▁language ▁and ▁message ▁transport ▁independence ▁all ▁operations ▁of ▁a ▁service ▁must ▁be ▁defined ▁by ▁a ▁language / platform / encoding ▁ag nost ic ▁specification . ▁The ▁M AL ▁defines ▁this ▁set ▁of ▁basic ▁data ▁types ▁and ▁how ▁they ▁must ▁be ▁used ▁to ▁build ▁up ▁the ▁messages ▁that ▁make ▁up ▁the ▁operations ▁of ▁a ▁service . ▁This ▁only ▁then ▁has ▁to ▁be ▁mapped ▁once , ▁in ▁an ▁MO ▁standard , ▁to ▁a ▁specific ▁implementation ▁language ▁or ▁transport ▁encoding ▁to ▁apply ▁to ▁all ▁services ▁that ▁are ▁defined ▁in ▁terms ▁of ▁the ▁M AL . ▁In ▁addition ▁to ▁the ▁patterns ▁of ▁interaction ▁and ▁the ▁abstract ▁API ▁the ▁M AL ▁provides ▁support ▁for ▁the ▁following : ▁– <0x09> generic ▁concepts , ▁such ▁as ▁domain , ▁session ▁and ▁zone ; ▁– <0x09> generic ▁facilities ▁such ▁as ▁access ▁control ▁( authentication ▁and ▁author isation ) ▁and ▁Qu ality ▁of ▁Service . ▁ ▁Pattern s ▁of ▁interaction ▁ ▁An ▁operation ▁of ▁a ▁service ▁can ▁be ▁decom posed ▁to ▁a ▁set ▁of ▁messages ▁ex changed ▁between ▁a ▁service ▁provider ▁and ▁consumer ▁and ▁form ▁a ▁pattern ▁of ▁interaction . ▁Analysis ▁of ▁the ▁services ▁given ▁in ▁reference ▁shows ▁that ▁there ▁are ▁a ▁limited ▁number ▁of ▁these ▁patterns ▁of ▁interaction ▁that ▁can ▁be ▁applied ▁to ▁all ▁currently ▁identified ▁services . ▁Standard ising ▁a ▁pattern ▁of ▁interaction , ▁which ▁defines ▁the ▁sequence ▁of ▁messages ▁passed ▁between ▁consumer ▁and ▁provider , ▁makes ▁it ▁possible ▁to ▁define ▁a ▁generic ▁template ▁for ▁an