In future releases Orchestration process flows will be defined in the Service Design and Creation subsystem (SDC). These process flows start with a template that may include common functions such as homing determination, selection of Infrastructure, network and application controllers, consultation of policies and interrogation of Active and Available Inventory (AAI) to obtain information needed to guide the process flows. MSO does not provide any process-based functionality without a workflow for the requested activity (in the current release the process flows are designed directly in MSO using BPMN flows).

MSO interrogates AAI to obtain information regarding existing Network and Application Controllers to support a service request. AAI provides the addresses of candidate controllers that are able to support the service request. MSO may then interrogate the controller to validate its continued available capacity. MSO and the controllers report reference information back to AAI upon completion of a service request to be used in subsequent operations.

Application, Network, and Infrastructure Orchestration

As previously stated, orchestration is performed by various components, primarily the MSO and the Application and Network Controllers.  Each will perform orchestration for:

•  Service delivery or changes to an existing service
•  Service scaling, optimization, or migration
•  Controller instantiation
•  Capacity management

For infrastructure orchestration, ONAP interfaces with the cloud provider's infrastructure control interface. Regardless of the focus of the orchestration, all workflows must include steps to update AAI with configuration information, identifiers and IP Addresses.

Network Controller Orchestration

Network Controllers are constructed and operate in much the same manner as Application Controllers. New service requests will be associated with an overall procedure for instantiation of that service. MSO obtains compatible Network Controller information from AAI and in turn requests LAN or WAN connectivity to be established and configured. This may be done by requesting the Network Controller to obtain its resource procedure from SDC. It is the responsibility of MSO to request (virtual) network connectivity between the components and to ensure that the selected Network Controller successfully completes the network configuration workflow. A service may have LAN, WAN and access requirements, each of which must be included in the procedure and configured to meet the instance specific customer or service requirements at each level. Physical access might need to be provisioned in the legacy provisioning systems prior to requesting MSO to instantiate the service.

Application Controller Orchestration

MSO sends requests to Application Controllers to obtain the application-specific component of the service procedure from SDC and execute the orchestration workflow. MSO ensures that the Application Controller successfully completes its resource configuration as defined by the procedure.  As with Network Controllers, all workflows, whether focused on Instantiation, configuration or scaling, will be obtained or originate from SDC. In addition, workflows also report their actions to AAI as well as to MSO.

Note that not all changes in network or service behavior are the result of orchestration.  Policies and rules (in the Policy subsystem) inform the controller such that the Controller can enable service behavior changes.