Network functions virtualization (NFV)

Network functions virtualization (NFV) is a procedure that increases and improves network function by managing networks. NFV is an architectural framework providing a reference model where network functions are delivered through software…. The NFV framework was first developed by the ETSI (European Telecom Standards Institute) NFV Industry Specification Group set up in 2012. [1]

There’s a lot of info on the internet about NFV and we culled together some sources through this post. Also, included is a great series of videos on YouTube giving a quick intro to telecommunication cloud basics. The videos feature Vikas Shokeen and are available in short 4-video series, with the second video below.

NFV

Benefits of virtualization include:

• Better communication
  • NFV transforms how the network architects generate network services. “This process is performed by using an architectural and creatively designed method to link together different network nodes to produce a communication channel that can provide freely accessible information to users.” [5]
• Reduced costs; lower capital expenses
  • One often used case of NFV is for decoupling network services from their hardware, so NFV can also be used as an alternative to dedicated physical routers, firewalls and load balancers. “One of the appeals of NFV over routers, firewalls and load balancers is that it doesn’t require network proprietors to purchase dedicated hardware devices to perform their work or generate service chains or groups. This benefit helps to reduce the cost of operating expenses and allows work to be performed with fewer potential operating issues.” [5]
• Quick provisioning–allowing for accelerated time to market for new products and updates
• Improved flexibility
  • NFV gives organizations the ability to quickly adapt without having to change an entire physical infrastructure environment.
    • “NFV helps organizations update their infrastructure software when network demands change, starkly reducing the need for physical updates. As business requirements change and new market opportunities open, NFV helps organizations quickly adapt. Because a network’s infrastructure can be altered to better support a new product, the time-to-market period can be shortened.” [5]
• Improved scalability
  • “NFV allows networks the ability to quickly and easily scale their resources based off of incoming traffic and resource requirements. And software-defined networking (SDN) software lets VMs automatically scale up or down.” [5]
• Better resource management
  • “Once a data center or similar infrastructure is virtualized, it can do more with fewer resources because a single server can run different VNFs simultaneously to produce the same amount of work. It allows for an increased workload capacity while reducing the data center footprint, power consumption and cooling needs.” [5]
• Greater mobility; reduced vendor lock-in
• Reduced operating expenses

IBM has NFV described as follows on their website:

SDxCentral notes that NFV is defined by “the decoupling of network functions from proprietary hardware appliances” and using these functions as virtual machines (VMs).  A network architecture concept, NFV uses IT virtualization technology to virtualize networks into building blocks that can connect or link up to produce communication services.

Techopedia defines NFV as a procedure that “increases and improves network function [and] managing networks”. NFV, which is sometimes referred to as network function virtualization, functions by changing how architect networks deliver network services, chaining together disparate classes of network nodes. It then creates a form of communication or makes certain information widely available to specific or general users.

It’s important to note that although networks are meant to be virtualized using NFV, network functions aren’t meant to be virtualized. Firewalls, traffic control and virtual routing are three of the most common virtual network functions (VNFs). Other functions include working as an alternative to load balancers and routers.

via IBM [5]

Mobile Network Functions

So, first, what are the functions that we are referring to? Here’s a list of some:

• Switches
• Routers
• HLR (Home Location Register)
• SGSN (Serving GPRS Support Node)
• GGSN (Gateway GPRS Support Node)
• CGSM (Combined GPRS Support Node)
• RNC (Radio Network Controller)
• SGW (Serving Gateway
• PGW (Packet Data Network Gateway)
• RGW (Residential Gateway)
• BRAS (Broadband Remote Access Server)
• CGNAT (Carrier Grade Network Address Translator)
• DPI (Deep Packet Inspection)
• PE (Provider Edge) Router
• MME (Mobility Management Entity)
• EMS (Element Management System)

NFV Architecture

ETSI (The European Telecommunication Standards Institute) proposed the NFV architecture, in order to bring standards which could improve stability and interoperability.

Components of the NFV architecture include:

• VNFs–Software applications that generate network functions, including file sharing, Internet Protocol (IP) configuration and directory services.
• Network functions virtualization Infrastructure (NFVI)–Made up of the following infrastructure components:
  • Compute
  • Storage
  • Networking

These components work from a platform to support software that’s needed for running networking apps.

• MANO (Management, automation and network orchestration)–Supports the framework for provisioning new VNFs and controlling the NFV infrastructure

NFV Layers

• VNF
  • NFVI (NFV Infrastructure)–The hardware and software required to deploy, manage, and execute VNFs.
  • NF (Network Function)–Functional building block with well defined interfaces and well defined functional behavior.
  • VNF (Virtualized Network Function)–Software implementation of NF that can be deployed in a virtualized infrastructure.
  • Container–VNF is independent of NFVI but needs a container software on NFVI to be able to run on different hardwares.

• Also see:
  • 1). Intro to Telco (Telecommunications Company) Cloud Basics, NFV, SDN, Architecture of Cloud Networks [VIDEO]
  • 3). Intro to SDN (Software Defined Networking) Basics–SDN & Openflow Architecture [VIDEO]
  • 4). Intro to Hypervisor, Docker & Container Basics–(VMs) Virtual Machines [VIDEO]

• Biblio:
  • [1] vCloud NFV Reference Architecture
  • [2] Tech Tutorial–Introduction to NFV: Network Function Virtualization
  • [3] Introduction to Network Function Virtualization (NFV)–Washing University in Saint Louis
  • [4] ETSI Network Functions Virtualisation (NFV); Architectural Framework
  • [5] What is NFV and what are it benefits?–IBM