Network functions virtualization (NFV) defines standards for compute, storage, and networking resources that can be used to build virtualized network functions. The virtual network functions manager (VNFM) is a key component of the NFV management and organization (MANO) architectural framework.
The VNFM works in concert with the other two NFV-MANO functional blocks, the virtualized infrastructure manager (VIM) and the NFV orchestrator (NFVO), to help standardize the functions of virtual networking and increase the interoperability of software-defined networking elements.
These components, as standardized by the European Telecommunications Standards Institute (ETSI) can help lower costs and increase the speed and frequency of new feature deployment by providing a standard framework for building NFV applications. The scalability and speed of service deployments inherent in turning a physical network into a virtual one creates new challenges for network management and orchestration that a VNFM helps solve.
How a VNFM Fits Into NFV
The VNFM can be seen in the center of the NFV-MANO architecture. Source: ETSI
The VNFM is a key component of NFV-MANO, the standards of which allow for interoperability of software-defined networking elements that use network function virtualization. The VNFM is responsible for the lifecycle management of VNFs. VNFM operations include:
- Instantiation of VNFs
- Scaling of VNFs
- Updating and/or upgrading VNFs
- Termination of VNFs
All VNF instances ideally have an associated VNF manager. A VNFM can be assigned to either a single VNF instance or multiple.The managed VNFs can be of the same or different types. VNFMs can be applied to any VNF(s) because they are typically generic.
Importance of NVFMs
VNFs are critical to realizing the business benefits outlined by the NFV architecture. They deliver the actual network functions that create value. But they aren’t autonomous. They require VNFMs. VNFMs are necessary for scaling, changing operations, adding new resources, and communicating the states of VNFs to the NFVO. The NFVO coordinates with the VNFM to instantiate VNFs, and manages the deployment of network services, which are made up of VNFs.
An example of the importance of a VNFM is key performance indicator (KPI) monitoring. During the lifecycle of a VNF, the VNF management functions may monitor defined KPIs of a VNF. The management functions can use this information for scaling operations. Ultimately, the VNFM maintains the virtualized resources that support the VNF functionality without interfering with the logical functions performed by the VNFs.
The VNFM Market
Large players in the VNFM market include Nokia, Cisco, Ericsson, Huawei, and NEC (through its subsidiary Netcracker). Their VNFM offerings are sometimes offered as a component of an overall NFV-MANO service, as they are tightly related.
Of course, the entire NFV market has accrued strong interest from the open source community. OpenStack offers Tacker, which consists of an open NFV orchestrator with a built-in, general-purpose VNF manager to deploy and operate VNFs on an NFV platform. The technology follows ETSI MANO standards and utilizes VNFs for its end-to-end network service orchestration.
The ETSI-associated Open Source MANO (OSM) project is another example of such an open source product. Their stack has worked on interoperability, error handling, multiple VIM integration, and fault and performance management of network services. This technology also uses ETSI MANO standards.
Updated March 2019