My 877 routers dsl mode is set to ADSL2+ and a sh dsl int atm0 displays 2 downstream channels and 2 upstream rather than the usual Fast and Interleave that i'm used to. Can anyone tell me the difference between the two channels and if there is any differences between adsl2+ showing channels only and dsl that shows fast and interleaving.
ADSL2+ can use alternative/overlapping bands depending by detected cross-talk from adjacent pairs in the binder. The details are contained in the official standard but require specialized knowledge to be fully understood.
In your case the router is simply indicating which band(s) are being used and everything appears OK.