Virtual Network Functions (VNFs) Architecture and Components - XenonStack

What is a Virtual Network Function (VNFs)?

The thought behind Network functions virtualization (NFV) with Software-defined networking (SDN) is to achieve agility, flexibility, and dynamic scaling in network infrastructure, which are creating their way towards technology transformation. Basically, with Software-defined networking (SDN), network administrators or operators will get complete control of their Network and with Network functions virtualization (NFV) architecture Virtualized infrastructure replaced the network equipment. Virtual Network Functions (VNFs) will run and host on this virtual infrastructure.

Virtual Network Functions (VNFs) serve as a software implementation of network devices which are virtualized and run on a virtual machine which are movable and scalable. Virtual Network Functions (VNFs) are then hosted on Commercial Off-the-Shelf (COTS) compute, networking infrastructure and storage. Now multiple vendors are offering VNFs as a solution to various network functions.

Virtual Network Functions Components

  • Switching: CG-NAT, BNG, routers.
  • Traffic analysis: QoE measurement, DPI.
  • Edge Devices: Broadband remote access server, IP Edge, vCPE.
  • Tunneling gateway elements: IPSec/SSL VPN gateways.
  • Signalling: IMS, SBCs.
  • Application-level optimization: Load Balancers, CDNs.
  • Security functions: spam protection, virus scanners, firewalls.
  • Set-top boxes and home routers.

In-Network functions virtualization (NFV) environment, there are multiple individual VNFs are joined together to create a single super service. VNFs are built for different network functions can work individually or combined, also allows service providers to develop and deploy services for customers quickly.

Limitation of traditional VNFs

  • A considerable amount of hardware is consumed by VNFs to be able to highly available.
  • VNFs are tested, configured, and developed to use with specified NFV hardware infrastructure.
  • Manual installation, deployment, and configuration are needed for Network functions virtualization infrastructure (NFVi).
  • API is not provided for VNF to enable auto-scaling.
  • Multi-tenancy not supported; therefore, VNFs can’t be easily shared infrastructure to reuse.

Overview of Cloud-Native VNFs

For vendors creating cloud-native VNFs is a solution and to have all cloud-native characteristics to VNFs is a revolution in software development. Features of cloud-native VNFs are microservices-based, containerized functions, designed explicitly for orchestration and dynamically managed. Scalability and self-management capability is the primary differentiator of cloud-native VNFs from traditional VNFs.

Creating cloud-native VNFs solves above-discussed limitations of traditional VNFs and Cloud-native VNFs API enables the following –

  • Automated configuration and installation
  • Scale automatically with the dynamic requirement of Network
  • Fault-tolerant or self-healing
  • VNFs automatic monitoring and analysis for capacity management, errors, and performance
  • Upgrade and update VNFs automatically for applying for new patches and releases
  • Simplified management and standard make less power consumption by reducing unnecessary resources.
  • Process sharing and reusability within VNFs can be achieved.
  • Sharing of VNFs can be done within the NFV environment.

Cloud-Native VNFs Architecture

VNF runs network functions on NFV infrastructure (NFVi). NFV orchestrator does orchestration of VNFs. VNFs are software images created to use as a network function.

EM (Element Management)

Element management performs functional management of VNF i.e., FCAPS ( Fault, Configuration, Accounting, Performance, and Security Management). VNFs manages through proprietary interfaces. There maybe one Element management system (EMS) per VNF or a single Element management system (EMS) manage multiple VNFs. An EMS itself can be a VNF.

VNF Manager

VNF Manager performs the life cycle management of VNF instances. It can manage a single or multiple VNFs. VNF Manager also does FCAPS for virtual components of VNF.The difference between EM and VNFM must be noted that EM does the management of functional components while the VNF Manager does the control of virtual components.

NFVI (Network Function Virtualization Infrastructure)

The environment used to run VNFs is NFVI; it consists of Physical resources, virtualization layer, and virtual resources, described below.

Memory, Compute, and Networking Resources

It is the natural part of NFVI. Any storage server or physical server comes under this category.

Virtual Memory, Virtual Compute, and Virtual Networking Resources

It is the virtual part of NFVI. Virtual resources are abstracted from physical resources that are utilized by VNFs.

Virtualization Layer

This is generally known as “Hypervisor.” This is responsible for abstracting physical resources into virtual resources.

A Holistic Strategy

To understand more about how Enterprise Managed Network Services help Enterprises to enhance Network Security and control Operating Costs, we recommend taking the subsequent steps –


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