2023 ASR border consolidation: learned IOS-XR l2transport to collapse discrete L2 breakout switch into ASR subinterfaces — eliminated dedicated switch, reduced capex, cleaned stack at LEARN provider

2023 ASR border consolidation: learned IOS-XR l2transport to collapse discrete L2 breakout switch into ASR subinterfaces — eliminated dedicated switch, reduced capex, cleaned stack at LEARN provider boundary (original boundary also personally designed, 2013).