This is a good talk about decomposability of control plane and creating proper abstractions for it.

PS. "The ability to master complexity is not the same as the ability to extract simplicity" is a good takeaway. PPS. This is a part of EE 122: https://inst.eecs.berkeley.edu/~ee122/fa12/class.html PPPS. PDF for SDN lecture: https://inst.eecs.berkeley.edu/~ee122/fa12/notes/25-SDN.pdf