The Management and Organization Working Group of the European Telecommunications Standards Institute (ETSI) has defined the network functions virtualization management and orchestration (NFV-MANO) architecture, comprising three major functional blocks: VIM manager, VNF manager, and NFV orchestrator. The virtualized infrastructure manager (VIM) is a key component of the NFV-MANO architectural framework. It is responsible for controlling and managing the NFV infrastructure (NFVI) compute, storage, and network resources, usually within one operator’s infrastructure domain.
These functional blocks help standardize the functions of virtual networking to increase interoperability of software-defined networking elements. VIMs can also handle hardware in a multidomain environment or may be optimized for a specific NFVI environment.
The VIM is responsible for managing the virtualized infrastructure of an NFV-based solution. VIM operations include:
- It keeps an inventory of the allocation of virtual resources to physical resources. This allows the VIM to orchestrate the allocation, upgrade, release, and reclamation of NFVI resources and optimize their use.
- It supports the management of VNF forwarding graphs by organizing virtual links, networks, subnets, and ports. The VIM also manages security group policies to ensure access control.
- It manages a repository of NFVI hardware resources (compute, storage, networking) and software resources (hypervisors), along with the discovery of the capabilities and features to optimize the use of such resources.
The VIM performs other functions as well – such as collecting performance and fault information via notifications; managing software images (add, delete, update, query, copy) as requested by other NFV-MANO functional blocks; and managing catalogues of virtualized resources that can be consumed from the NFVI. In summary, the VIM is the management glue between hardware and software in the NFV world.
Virtual infrastructure managers are critical to realizing the business benefits enabled by the NFV architecture. They coordinate the physical resources necessary to deliver network services. This is particularly visible for infrastructure-as-a-service (IaaS) providers. The IaaS providers have to ensure that their servers, networks, and storage work smoothly with those onsite. They must ensure that resources can be dynamically allocated based on requirements, which is a key feature of cloud computing.
VIMs address this need. Some consider it a morphing of a traditional OS, but it is not. It doesn’t work with a single node, but collects information from many machines simultaneously and uses that information for management functions. So, even if multiple machines are working in concert at the NFVI layer, applications and users are ensured of a good, uniform experience.
The VIM Market
Many vendors offer VIMs. VMware offers vSphere, a proprietary, yet market-proven VIM that delivers one of the widest ranges of features. VMware is trying to utilize its VIM to help customers transform existing IT infrastructures into private clouds.
And then there is OpenStack. Some industry users point out that OpenStack provides more functionality than simply VIM services. But if you look at what OpenStack does, you’ll see why it is often deployed as a VIM: It controls pools of compute, storage, and networking resources that can be managed through OpenStack API. Many vendors have created OpenStack implementations of their own, including Red Hat, Mirantis, Oracle, and VMware.
Based on the popularity of OpenStack and the functions the VIM provides it is clear that the role of a virtual infrastructure manager is a very critical component of the NFV-MANO architecture – necessary to realize the increased value promised by NFV-based solutions.
Many other vendors supply VIM solutions as well as add-ons to OpenStack. The NFV market is evolving rapidly as technology and service providers alike uses pieces of open source and add them to their existing software solutions to provide the full complement of NFV functions.