NFV for dummies - Understanding the MANO framework

This article is an attempt to explain the basic concept of NFV (Network function virtualisation) and the MANO (Management Orchestration) framework the way I have understood it. I would be delighted if you can identify any errors and suggest correction.

To start with, let us understand the structure of a physical network device and why was there was a need to change that.

Current Internal structure of a network device

The diagram explain the internal structure of a physical device.

The management plane handles external user interaction and administrative tasks like authentication, logging, and configuration via a Web interface or CLI.

The control plane administers the internal device operations, providing the instructions used by the silicon engines to direct the packets; it also runs the routing and switching protocols and feeds operational data back to the management plane.

The data plane is the engine room that moves packets through the device, using the forwarding table supplied by the control plane to determine the output port.

(Reference: http://www.infoworld.com/article/2606200/networking/111753-Software-defined-networking-explained.html#slide2)

An Analogy to our desktop and laptop using X86 hardware

The way we handle various application on our desktop and laptop is entirely different.

In the network devices, the hardware and software are tightly coupled. We can not use the same hardware for handling different network functions such as firewall, router or accelerator. We need to have three different devices, each with their own hardware and software coupled together, to give us each network function.

However, in case of our laptop and desktop, on the same X86 hardware, it is possible to run different application from different vendors on the same hardware. This is possible because of the operating system. The application vendor will have to make the application compatible with the Operating system without worrying about the underlying hardware. Would it not be wonderful if we can have something similar in network device space?

We would need something equivalent to Operating system in the network space to make this possible. This "Something" is a hypervisor.

The Hypervisor allows creation of different virtual devices on which we can then run the required network function as software applications.

VM : Virtual machine

The hypervisor creates illusion of actual hardware. and the network functions can now be installed on the virtual machines as software packages. Virtual Network Function (VNF) are the software package which perform the function of various network function such as firewall, router, accelerator etc.

EM : Element Manager.

We also need to manage the life-cycle of these devices, First of all, we need a software application to create and manage the life-cycle of the virtual devices. These software applications are called VIM (Virtual Infrastructure manager). Openstack is an example of VIM.

We also need to manage the life-cycle of the VNF themselves. The software applications which manage the VNF life-cycle are called VNF manager.

Finally, we need to Integrate all these application to the traditional OSS/BSS system of a telecom company. The integration is facilitated by the VNF orchestrator.

This complete framework to handle the VNF (Virtual network function) is called the MANO (Management and Organisation) framework and it explains how the network functions virtualisation (NVF) can be achieved.

More formally, the following diagram from ETSI shows the MANO framework. (Reference:gs_NFV002v010201p.pdf) 

The diagram above shows the components we discussed above as well as the interfaces between them.

The MANO framework provides the guidelines for a VNF deployment and live-cycle management. More details can be found on ETSI publication gs_NFV002v010201p.pdf

I would repeat that this article is an attempt to explain the basic concept NFV and the MANO framework the way I have understood it. I would be delighted if you can identify any errors and suggest correction.

List of acronyms used in his article

VM : Virtual Machine

VIM : Virtual Infrastructure manager

VNF : Virtual Network Function

NFV : Network function Virtualisation

NFVI : Network function Virtualisation Infrastructure

MANO : Management and Orchestration