There are several possibilities for sending IP over ATM.
For example, I know this possibility in the local loop between the client modem and the DSLAM. I'm trying to be accurate :
IP > MAC 802.3 > RFC 2684 bridged LLC > AAL-5 > ATM
This is in the local loop. Is it the same protocol architecture between the DSLAM and the BAS. I would suppose it is the same in this WAN subnetwork.
What is pleased your advice?