Which main difference between lean core and hollow core architectures is true?
A. The hollow core model defines two models of operation peering and overlay. The lean core model adapts only the peering operation.
B. Hollow core addresses challenges associated with isolated packet, optical TDM, and DWDM layer control planes. Lean core ignores these challenges.
C. In the lean core model, switches create a dense mesh of circuits between each of the edge and peering nodes. The hollow core model uses less-sophisticated NPUs.
D. Hollow core uses a transport switching function, whereas lean core adapts full IP architectures by using MPLS to forward subscriber traffic instead of IP.
