It's kinda close to what happens with the VDSL products. What are you hoping to get from the protocol stacks?
For information, your traffic when it reaches the ISP is IP over PPP over L2TP over UDP over IP over Ethernet. Just before it reaches your ISP there may also be MPLS encapsulation, with the label removed before presentation to the ISP.
Your PPP session leaves your modem running as IP over PPP over Ethernet over xDSL, the xDSL encapsulation is removed at the MSAN, the PPP session sent to a BRAS via IP, where it is enclosed in L2TP for transport to the ISP. On the way it may be decapsulated and re-encapsulated by an arbitrary number of L2TP Access Concentrators.
You see none of these hops as your visibility ends with the BRAS terminating your PPP at that level and the IP traffic is never native so at no point is the hop counter decremented, hence no signs of hops in traceroutes - these rely on setting ascending hop counts starting at 1 and nodes sending ICMP time expired messages when TTL, a counter that decrements at each IP hop, hits zero. While being transported to the ISP the IP traffic is always encapsulated in something.
Obvious question - how does the BRAS know where to send you? It pre-auths you based on the domain in your username and then forwards the full authentication material to the ISP's authentication servers. The ISP servers can populate Attribute Value pairs in the response that tell the BRAS which LNS the ISP wants your traffic to go to, and can use round-robin DNS to balance both authentication and LNS too.
This was all from memory. It may be wrong. I just got out of an MSc exam in Digital Forensics so brain is somewhat cooked.