key scenarios, requirements, and reference designs. Orchestration functionality is enabled for element discovery, lifecycle management, fault management (FM), and performance management (PM) for both physical network functions (PNFs) and VNFs that run on a cloudified RAN. Management of a cloudified RAN requires a vendor-neutral approach to the above functions, as well as scale-out, slice management, fault tolerance, and hitless software upgrades. 6.2 Virtualization Orchestration Cloudification Flexible All RAN modules Orch. Inventory, Discovery, H/W abstraction layer Support 10,000s Registration of distributed Blackbox Policy, Cloud stack (containers/VMs), OS, cloud m-plane cloud sites Metrics Common LCM mechanisms Multitude of silicon across VNF & accelerators ((g)) Multitude of deployment models: CloudRAN, CU-DU split, Centralized CU/DU CU/DU split Distributed dRAN on whitebox or DC (C-RAN) CU/DU (D-RAN) Figure 6.2.10 O-RAN cloudification and orchestration work (Source: Reproduced by permission of © O-RAN). A common orchestration interface 01 is defined for the network management system (NMS) APIs across all the managed elements that support a disaggregated RAN. Figure 6.2.10 shows the efforts being undertaken in O-RAN for cloudification and orches- tration of the virtualized RAN. 6.2.7 Virtualization Challenges While NG-RAN virtualization has significant benefits, as described above, there are certain challenges that need to be overcome in order to realize its full potential. 6.2.7.1 Accelerator Integration Traditional virtualization does not include hardware accelerators, that is, it assumes that everything is implemented in software. However, with the compute-intensive workloads in 5G, accelerators may be needed to provide real-time support, reduce latency, and improve CPU utilization. Most container frameworks provide a container network interface (CNI), which enables multiple containers to talk to FPGA via a single root input-output virtualization (SR-IOV) interface in a low latency and high throughput man