The Network Functions Virtualization (NFV) is a disruptive innovation in the RAN market!
It created a break between the close link hardware and software actually used by technology vendors to manage their equipments. This split will allow all developers to create functionalities & network services such as software applications, in a flexible and agile way.
ETSI Industry Specification Group NFV is leading the standardization of the NFV model, receiving great attention from the Industry. Furthermore, other parties started activities on the NFV theme and the OPNFV project has released the first Open Source NFV Platform
What is NFV?
NFV is basically splitting the network functions, both fixed and mobile, in fact software applications, called VNF (Virtual Network Function), and hardware servers, called COTS (Commodity Off-The-Shelf), such as the classic blade system HP, IBM or other vendors, using virtualization technologies
This is technically achieved by using each server of an abstraction software level, called virtualization layer or hypervisor, which allows to create more virtual machines, called VMs (Virtual Machine), on the same physical machine, able to perform different applications born for different operating systems. The VNF functionalities are than realized through software modules running on one or more VMs. Any of them can perform different tasks (e.g. load-balancing, signal processing, data traffic routing, etc.) and be instantiated on one or more physical servers.
The mechanism is similar to what happens today for IT services running on Cloud Computing platforms, with the difference that VNFs can require appropriate hardware optimization to meet the low delay, scalability, geographic redundancy and manageability requirements of networks telecommunications.
This independence between software and hardware allows to:
- optimize the use of resources, such as CPU, memory, storage and network, activating multiple VMs that implement different types of services on the same physical server, in order to fully exploit available capacity and reduce energy consumption (hardware consolidation)
- expand or dynamically reduce the capacity allocated based on the actual load (elasticity)
- ensure high reliability, since in the face of a hardware malfunction the VMs can be easily migrated from one server to another
- reconfigure the network topology almost in real time to optimize performance and/or extend penetration
- reduce Total Cost of Ownership (TCO) and improve Time-to-Market, taking advantage of NFV’s increased agility and flexibility in deploying services
NFV, the Disruptive RAN Innovation
NFV will provide more efficiency for Network Deployment & Costs Optimization
The NFV architecture can be split in three domains, each one includes a set of components and basic specific elements:
- Virtualized network functions : VNFs
- Network virtualization infrastructure: NFVi
- Network functions virtualization management and orchestration: MANO
The term NFV refers to some component of a network infrastructure that provides a well-defined functional behavior. These physical network functions need to be manually installed into the network, creating operational challenges and preventing rapid deployment of new network functions
A VNF, on the other hand, refers to the implementation of a network function using software that is decoupled from the underlying hardware. This can lead to more agile networks, with significant Opex & Capex Savings
So, VNF allows to realize the EM (Element Manager) that realize the typical telecommunication management features of the VNF
NFVi (network functions virtualization infrastructure) includes all of the networking hardware and software needed to support, and connect, virtual network functions on MNO networks
NFVi resources can include operating systems, servers, hypervisors, virtual switches, virtual machines, virtual infrastructure managers and any other physical or virtual assets that enable NFV
NFVI is composed of NFV infrastructure points-of-presence (NFVI-PoPs) which are where the VNFs, including resources for computation, storage, and networking, are deployed by a network operator. NFVI networks interconnect the computing and storage resources contained in an NFVI-PoP. This may include specific switching and routing devices to allow external connectivity.
MANO, is an architectural framework for managing and orchestrating virtualized network functions (VNFs) and other software components, with the target of enabling the management of network services on the virtualized infrastructure.
MANO has three main functional blocks: NFV orchestrators, VNF managers and virtualized infrastructure managers (VIMs). Together, these blocks are responsible for deploying and connecting functions and services when they are needed throughout the network.
- NFV orchestrators consist of two layers — service orchestration and resource orchestration — which control the integration of new network services (NS)and VNFs into a virtual framework. NFV orchestrators also validate and authorize NFV infrastructure (NFVI) resource requests.
- VNF managers oversee the lifecycle of VNF instances.
- VIMs control and manage NFV infrastructure, which encompasses compute, storage, network resources.
MANO works with templates for standard virtual network functions so users can pick from existing network functions virtualization infrastructure (NFVi) resources to deploy their NFV platform. For MANO to be effective, it must be integrated with application program interfaces (APIs) in existing systems in order to work with multivendor technologies across multiple network domains. Telecommunications providers’ operations and billing systems (OSS/BSS) also need to interoperate with MANO and the next steps needed in NFV evolution is to include SDN controllers in the MANO architecture.
Open Source, the key of NFV development
“Network functions virtualization (NFV) is at the heart of some major transformations for telecom operators, but it’s only going to work if it remains as open as possible…vendors enthusiasm for NFV is leading to “a zoo of orchestrators,” where each vendor proposes its own variety of NFV management. What’s needed is a unified approach, one where all services are managed end-to-end.”
Axel Clauberg, Vice president of IP architecture and design at Deutsche Telekom
The NFV is transforming the way networks are conceived, implemented and managed, but in order to achieve it requires the support of the entire ecosystem of standards up to embrace the world of Open Source.
NFV technology is already proposed in applications in current networks, but its application on a large scale requires exceeding the boundary of the specific NGF ISG, designed to be independent of the specific context of application of the network, and to progressively decline them on different contexts of network.
For mobile networks, 3GPP has launched a specific in-depth analysis on the management of “mixed” networks, with both physical and virtualized components; it started a first step on the evolution of virtualized mobile architectures and the prospect is that it will welcome the evolution expected in the next release that will be oriented to the fifth generation (5G) of the mobile radio. The 5G will be the first natively virtualized mobile radio technology leveraging NFV and SDN technologies.
NFV has generated a great deal of attention in the industry and has progressively achieved a paradigm shift in industry in relation to how the networks of the future will be built. One of the ways that have been identified by the NFV community to facilitate and accelerate the introduction and deployment of NFV is through participation in open source projects. the open source allows to govern reference realizations in an ‘agile’ way with the potential advantage of defining a possible ‘de facto’ standard.
Open source for NFV is also attractive because several of the communities that develop core components of the project already exist, such as the OpenStack community.
The ETSI NFV Standardization
Starting from July 2012, a group of operators, including Telecom Italia, started the discussion on the potential application of cloud technologies to the network, coining the term NFV, and recognized the need to guide the entire industrial community to bring it forward. introduction into their own networks.
This gave rise, in November 2012, to the publication of a White Paper  which explained the reasons for this necessity and called for the creation of a standardization group to carry out the specification work necessary to have interoperable virtualization solutions and shared. In January 2013, a new ISG (Industry Specification Group) was created within ETSI on Network Functions Virtualization, with the aim of defining a reference architecture and dictating the guidelines for the development and deployment of nodes. virtualized network.
During the period January 2013 – January 2015 the work of the ISG’s first two-year term, called Phase 1, took place, which led to the definition of the set of GS specification documents (Group Specification), which today constitute the reference for the Industry on the path to virtualization. The interest in these issues by the entire industry is evidenced by the number of companies that over the years have become part of the group, from the 52 initial participants in January 2013 up to the 272 participants in May 2015.
Of the documents developed, four are of a general nature [4-7] as they relate to the application Use Cases, the General Requirements, the Architecture and the Terminology, while the rest relate to the architectural domains
Virtualization is increasingly demonstrating the innovation that will change telecommunications networks in the coming years, allowing operators to improve the processes of development and deployment through which they offer their services. Thanks to the initiative of a group of operators Verizon, BT, Deutsche Telekom and TIM, it was possible to intercept the nascent opportunity allowing to define a reference architecture that was shared by builders and operators and to launch a standardization activity that allowed to obtain interoperable products and a multi-vendor environment that is progressively consolidating
The success of the initiative is not only demonstrated by the large number of companies involved in ETSI NFV (more than 250) but also by the numerous related activities that have in some way originated from the group’s work, above all the OPNFV initiative for the creation of an open source platform able to meet the requirements of telecommunications operators
The BIG challenge for MNO will be to change, not only to a new technologies and solutions, but also to adapt their employees skill and their own processes (engineering and operation) in a modern key. Basically, all MNO will have to move their organization in a different way, they will become more similar to web companies, derived from the world of Big Data or Cloud computing…