Ill tell you what I use MPLS for.
I still use OSPF for route distribution.
I create VPLS tunnels from each PoP to a core router, bridge in the APs or what-have-you that are going to be customer interfaces to the VPLS tunnel, then a core router does all the PPPoE termination. I use bridge horizons to keep traffic from flowing back out of the core router.
Your L2MTU is important for MPLS networks.
You do not need to use MPLS for pppoe, ospf works for that, but if you want central termination, then MPLS is definitely an option to look at.--
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