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 other NFV-MANO functional blocks, such as the virtualized infrastructure manager (VIM) and NFV orchestrator (NFVO), to help standardize the functions of virtual networking and increase the interoperability of software-defined networking elements.
These standard components can help lower costs and increase new feature deployment and velocity by providing a standard framework for building NFV applications. In the virtualized network world of NFV, scalability and speed of service deployments create new challenges in the areas of network management and orchestration.
How a VNFM Fits Into NFV
NFV-MANO was defined by a working group of the European Telecommunications Standards Institute (ETSI). This framework consists of three major functional blocks: VIM, NFVO, and the virtual network functions manager.
The VNFM is a key component of the NFV-MANO that helps standardize the functions of virtual networking and increases interoperability of software-defined networking elements. The VNFM is responsible for the lifecycle management of VNFs under the control of the NFVO, which it achieves by instructing the VIM. VNFM operations include:
- Instantiation of VNFs
- Scaling of VNFs
- Updating and/or upgrading VNFs
- Termination of VNFs
All VNF instances are assumed to have an associated VNF manager. A VNFM may be assigned the management of a single VNF instance or multiple VNF instances. The managed VNFs can be of the same or different types. VNF manager functions are assumed to be generic and can be applied to any VNF.
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 critical for scaling, changing operations, adding new resources, and communicating the states of VNFs to other functional blocks in the NFV-MANO architecture.
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 services provided by the VNFM can be employed by authenticated and properly authorized NFV management and orchestration functions (e.g., functions that manage network services).
The VNFM Market
The VFNM market can still be characterized as being relatively young, with both new entrants and established players competing to secure their places in it. Large players such as Alcatel-Lucent (Nokia), Cisco, Ericsson, Huawei, and NEC/Netcracker all have VNFM offerings, which are sometimes offered as a component of an overall NFV-MANO since these services are tightly related. Other companies are betting on interoperability as a route to operators.
Of course, the entire NFV market has accrued strong interest from the open source community. OpenStack has Tacker, which is an OpenStack project that consists of an open NFV orchestrator with a built-in, general-purpose VNF manager to deploy and operate virtual network functions on an NFV platform. It is based on the ETSI MANO architectural framework and provides a full functional stack to orchestrate VNFs end-to-end.