It is easy to understand the concept of VNF, if you know what is a Virtual Machine. In conventional manner, the network functions are embedded onto dedicated hardware. But, in some way, if we can make the network functions independent of the hardware and install it on any machine that will lead to the concept of VNF.
Virtualized network functions or VNFs are the software realisations of the various network functions that can be deployed on a Network Functions Virtualization Infrastructure and needed to enable the network to operate. In this way, a VNF handles a specific network function that run on one or more virtual machines on top of the hardware networking infrastructure.
The individual VNF, can be considered to be building blocks and they can be connected or combined together, providing all the capabilities required to provide a complete networking communication service.
some examples of virtual network functions are
- Switching: BNG, CG-NAT, routers.
- Tunnelling gateway elements: IPSec/SSL VPN gateways.
- Traffic analysis: DPI, QoE measurementI.
- Signalling: SBCs, IMS.
- Application-level optimisation: CDNs, load Balancers.
- Home routers and set top boxes.
- Mobile network nodes: HLR/HSS, MME, SGSN, GGSN/PDN-GW, RNC.
- Network-wide functions: AAA servers policy control, charging platforms.
- Security functions: firewalls, intrusion detection systems, virus scanners, spam protection.
Later we will focus on Network Function Virtualization (NFV).
-Thanks
