▁General ized ▁M PL S ▁( G MP LS ) ▁to ▁allow ▁the ▁creation ▁of ▁label - switch ed ▁paths ▁( L SP s ) ▁also ▁in ▁non - native ▁IP ▁networks , ▁such ▁as ▁S ON ET / SD H ▁networks ▁and ▁w avel ength ▁switched ▁optical ▁networks . ▁ ▁Compet itor ▁protocol s ▁M PL S ▁can ▁exist ▁in ▁both ▁an ▁IP v 4 ▁and ▁an ▁IP v 6 ▁environment , ▁using ▁appropriate ▁routing ▁protocol s . ▁The ▁major ▁goal ▁of ▁M PL S ▁development ▁was ▁the ▁increase ▁of ▁routing ▁speed . ▁This ▁goal ▁is ▁no ▁longer ▁relevant ▁because ▁of ▁the ▁usage ▁of ▁newer ▁switching ▁methods ▁( able ▁to ▁forward ▁plain ▁IP v 4 ▁as ▁fast ▁as ▁M PL S ▁label led ▁packets ), ▁such ▁as ▁AS IC , ▁T C AM ▁and ▁C AM - based ▁switching . ▁Now , ▁therefore , ▁the ▁main ▁application ▁of ▁M PL S ▁is ▁to ▁implement ▁limited ▁traffic ▁engineering ▁and ▁layer ▁ 3 ▁/ ▁layer ▁ 2 ▁“ service ▁provider ▁type ” ▁V PN s ▁over ▁IP v 4 ▁networks . ▁ ▁Besides ▁G MP LS , ▁the ▁main ▁compet itors ▁to ▁M PL S ▁are ▁Short est ▁Path ▁Br id ging ▁( SP B ), ▁Pro vider ▁Back bone ▁Br id ges ▁( P BB ), ▁and ▁M PL S - TP . ▁These ▁also ▁provide ▁services ▁such ▁as ▁service ▁provider ▁layer ▁ 2 ▁and ▁layer ▁ 3 ▁V PN s . ▁▁ ▁As ▁an ▁example ▁of ▁N PL C , ▁consider ▁two