Orchestration process flows are 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. The MSO does not provide any process-based functionality without a recipe for the requested activity.

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. The MSO may then interrogate the controller to validate its continued available capacity. The 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 Controller Orchestration

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

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

Regardless of the focus of the orchestration, all recipes must include a way to update AAI with configuration information, identifiers and IP Addresses.

Infrastructure Controller Orchestration

Like the MSO, the Application, Network and Infrastructure Controllers obtain their orchestration process and payload (templates/models) from Service Design and Creation (SDC). For service instantiation, the MSO maintains overall end-to-end responsibility for ensuring that a request is completed. As part of that responsibility, the MSO selects the appropriate controllers (Infrastructure, Network, or  Application) to carry out the request. Because a service request is often comprised of one or more Resources, the MSO will request the appropriate controllers to obtain the recipe for the instantiation of a Resource within the scope of the requested controller. After service placement is determined, the MSO may request the creation of a virtual machine (VM) at one or more locations depending on the breadth of the service being instantiated and whether an existing instance of the requested service can be used. If new VM resources are required, the MSO will place the request to the Infrastructure Controller for the specific cloud location. Upon receipt of the request, the Infrastructure Controller can obtain its resource recipe from SDC. The Infrastructure Controller will then begin orchestrating the request. For infrastructure controllers, this typically involves execution of OpenStack requests for the creation of virtual machines and for the loading of the Virtual Function (VF) software into the new VM container. The resource recipe will define VM sizing, including compute, storage and memory. If the resource level recipe requires multiple VMs, the MSO will repeat the process, requesting each infrastructure controller to spin up one or more VMs and load the appropriate virtual functions (VFs), as specified by the resource recipe of the specific infrastructure controller. When the infrastructure controller completes the request, it passes the virtual resource identifier and access (IP) information back to the MSO to provide to the Network and Application Controllers.  The MSO might write identifier information to AAI for inventory tracking during the entire process.

Network Controller Orchestration

Network Controllers are constructed and operate in much the same manner as Application and Infrastructure Controllers. New service requests will be associated with an overall recipe for instantiation of that service. The 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 recipe from SDC. It is the responsibility of the 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 recipe 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 the MSO to instantiate the service.

Application Controller Orchestration

The MSO sends requests to Application Controllers to obtain the application-specific component of the service recipe from SDC and execute the orchestration workflow. The MSO ensures that the Application Controller successfully completes its resource configuration as defined by the recipe. As with Infrastructure and 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 the MSO.

Note that not all changes in network or service behavior are the result of orchestration. For example, application virtual functions can change network behavior by changing rules or policies associated with controller activities. These policy changes can dynamically enable service behavior changes.