ll NC that VNF is installed NC configures the VNFs and notifies the IO&C to configure the IPE/LAN/OVS to the g. IO&C configures the IPE/LAN/OVS 5. NC tells SC network configured graph is complete. 6. SC sets up VPN service (VRFs) to WAN PNF, IPE, VNF. 6.8 SOME USE-CASE EXAMPLES OF SDN CONTROL 6.8.1 BANDWIDTH CALENDARING Bandwidth calendaring is the idea that high bandwidth circuits between end points in the network (like large data centers) could be offered at lower prices during off-peak demand with perhaps special conditions in the event of a network need for the otherwise idle capacity. Implementing this type of feature with its needs for historical traffic analysis and real-time control actions is problematic in a pre-SDN environment. SDN controllers can "listen" to telemetry from the net- work and build up a history of utilization across the nodes and links. The SDN controller can also carve out or virtualize the network to allocate paths and bandwidth for special function via MPLS TE Tunnels using either NetConf or Path Computation Element Protocol (PCEP) signaling [4]. It becomes relatively easy to combine these two aspects of the controller and offer a bandwidth calendaring service. This service would take "orders" for a virtual connection between two end points, with a time, date, duration window, and speed. If there was available capacity expected at that time in the future the controller could accept, schedule, and save the request. At the occur- rence of the identified time slot, the SDN controller can create the virtual tunnel across the net- work, record the start time, and monitor overall network conditions. If nothing abnormal happens at the end of the interval, the virtual connection can be removed and the customer is charged for the use. If something abnormal occurs, depending on what level of service was purchased, the virtual circuit could be removed in real time, making the spare capacity available for resolution of network capacity constraints. This type of service offering has many possible