Phase 1a is to introduce device automation layer[1].
Main expected outcome is a transparent and controllable structure around transition from vendor-specific means of device management to vendor-neutral ones. It should be achieved by wider adoption of NETCONF/YANG for device configuration, BGP LS for extracting topology information and PCE-based path computation model.
Figure 4 - phase 1a: Introduce device automation layer (southbound interfaces of bottom-layer SDN controllers)
[1] devices are to be management via southbound interfaces of bottom-layer SDN controller(s)