i recently purchased an 877 router
configuring the ATM0 interface cannot find Annex M there is only A and L
C877(config-if)#dsl operating-mode ?
adsl2 ITU G.992.3 Annex A and L
adsl2+ ITU G.992.5 Annex A
ansi-dmt ANSI T1.413
auto auto detect mode
itu-dmt ITU G.992.1 Annex A