Another great write up! Would you say that convergence of packet and circuit networks will become easier as SDN/NFV models become more adaptable to SP's? Smooth interaction between IP & Transport networks have raised a few question marks from operations and management perspective - duplication of functionality, resources, Capex/Opex etc., lack of a common way to use and manage. Solution of bigger router ( e.g., Juniper T640 or TX8 or Cisco CSR-1..) is better may or may not be acceptable for much longer any more in "green" environment.

I once watched a demo with optical Wavelength switches and OpenFlow controllers (SC09) done at Stanford. ..different ISP's with different business models and a "Private Line " adopted a unified Virtualization approach where they all came to the same Flowvisor under t6he Transport service Provider (TSP) control. OpenFlow protocol was used between the ISP's and Flowvisor and Flowvisor and the Client network tiers. The Client networks consisted of a single physical infrastructureof packet and circuit switches.

TSP was shown to virtualize the network with the FlowVisor while maintaining operator control via NMS/EMS:
1) The FlowVisor managing "slices" of the TSP’s network for ISP customers, where { slice = bandwidth + control of part of TSP’s switches }

2) NMS/EMS was used to manually provision circuits for Private Line customers

Of course, as we all know what works in a lab or even in a contained environment, is a far cry from live production networks from more perspectives than we can likely count :-).

Hence, IMHO, great subject to address. SDN/NFV is almost here, at POC stage and about to take off...about time the (I)SP's got in the room too!

Gratitude and Respects,
santanu