NFV architectures enable network functions to be dynamically defined, allowing for the construction and management of function(s) that best support the organization’s environment. Virtual network functions (VNFs) can be deployed and reassigned to share different physical and virtual infrastructure resources to match an organization’s scale, performance and capabilities requirements. This makes it easy for service providers and enterprises to deploy new services faster, while maximizing their investments in existing platforms.
In general, there are three components to an NFV framework:
- Virtualized Network Functions (VNFs) – the software implementation of a network function.
- NFV Infrastructure (NFVI) – the physical resources (compute, storage, network) and the virtual instantiationsthat make up the infrastructure.
- NFV Management and Orchestration – the management and control layer that focuses on all thevirtualization-specific management tasks required throughout the lifecycle of the VNF.
These components each contain a number of different NFV technologies, which organizations can deploy to achieve the flexibility, scalability and efficiencies they require. Let’s look at the technologies/solutions contained within each component (functional block) of an NFV architecture.
A VNF is a virtualized instantiation of a network function that can be deployed in both a virtualized and non-virtualized network. These network functions, which are referred to collectively as a network service, can be deployed in a single virtual machine (VM) or span multiple VMs, depending on the architecture of the organization. In some situations the VNF can run on bare-metal machines and be managed by bare-metal hypervisors or bare-metal provisioning systems.
A VNF is generally managed by an element management system (EMS), which is responsible for setting, monitoring and logging its fault, configuration, accounting, performance and security. The EMS interfaces with the network’s management systems (northbound) and the VNF (southbound). An EMS provides the foundational information required by operations support systems (OSS) in a service provider’s environment. OSS are the overarching management systems that, together with business support systems (BSS), help providers deploy and manage various end-to-end telecommunications services (such as ordering, billing, renewals, troubleshooting, etc.). Note, NFV specifications focus on integration with existing OSS/BSS solutions, not the development of virtualized OSS/BSS capabilities.