With this API, the VID sends a series of service instantiation API requests to MSO to build an infrastructure Service. A Service consists of one or more related VNFs, with each VNF deployed as one or more VF Modules. A VF Module may have an optional Volume Group, which would be orchestrated first. A Volume Group is a collection of one or more Volumes that will persist beyond the life of the VM it is attached to. This allows for persistent data if so required. The MSO interface also supports orchestration of external networks that could span tenants.
The VID-MSO Service Instantiation Interface Design specification describes the VID-MSO interface in more detail.