Chapter 7 - Network Functions Virtualization: Concepts and Architecture

Network Attached Storage (NAS)

File and database servers attached to the network

Network Function Virtualization Infrastrucutre

Hardware and software infrastructure with an environment where virtual network functions are deployed.

Container Virtualization

In this approach, software, known as a virtualization container, runs on top of the host OS kernel and provides an execution environment for applications. Unlike hypervisor-based VMs, containers do not aim to emulate physical servers. Instead, all containerized applications on a host share a common OS kernel.

Se-Ma

Interface between the orchestrator and a data set that provides informationregarding the VNF deployment template, VNF forwarding graph, service-relatedinformation, and NFV infrastructure information models

Nf-Vi

Marks interfaces between the NFVI and the virtualized infrastructure manager. This interface can facilitate the specification of the capabilities that the NFVI provides for the VIM.

NFV Requirements - Automation

NFV will scale only if all the functions can be automated.

NFV Requirements - Integration

Network operators need to be able to "mix and match" servers fromdifferent vendors, hypervisors from different vendors, and virtual appliances fromdifferent vendors without incurring significant integration costs and avoiding lock-in

OSS/BSS

Operational and Business Support System

NFV Requirements - Migration and coexistence with respect to legacy equipment

The NFV architecture must support a migration path from today's proprietary physical network appliance-based solutions to more open standards-based virtual network appliance solutions.

NFV infrastructure (NFVI)

The NFVI performs a virtualization function on thethree main categories of devices in the network service environment: computerdevices, storage devices, and network devices.

NFV Requirements - Portability/Interoperability

The capability to load and execute VNFs provided bydifferent vendors on a variety of standardized hardware platforms.

Virtualized network functions (VNF)

The collection of VNFs, implemented in software,that run over the NFVI

Element Management System

The manager of VNF

Virtualization

running multiple systems simultaneously on one physical computer

NFV Distributed architecture

A VNF may be made up of one or more VNF components (VNFC), each of which implements a subset of the VNF's functionality. Each VNFC may be deployed in one or multiple instances. These instances may be deployed on separate, distributed hosts to provide scalability and redundancy.

deep packet inspection

Analyzing network traffic to discover the type of application that sent the data. Inspecting the packets all the way up to the application layer, it can be used to analyze anything within the packet that is not encrypted. For example, it can determine not only that the packets contain the contents of a web page but also which website the page is from

NFV Requirements - Performance trade-off

Because the NFV approach is based on industry standardhardware, a probable decrease in performance has to be taken into account.

Virtualized infrastructure manager

Controls and manages the interaction of a VNF with computing, storage, and network resources under its authority, in addition to their virtualization.

EMS

Element Management System

NFV management and orchestration

Encompasses the orchestration and lifecycle management of physical/software resources that support the infrastructure virtualization, and the lifecycle management of VNFs. NFV management and orchestration focuses on all virtualization-specific management tasks necessary in the NFV framework.

NFV Requirements - Network stability

Ensuring stability of the network is not impacted when managingand orchestrating a large number of virtual appliances between different hardwarevendors and hypervisors.

NFV Requirements - Simplicity

Ensuring that virtualized network platforms will be simpler to operatethan those that exist today.

VNF manager

Oversees lifecycle management of VNF instances

NFV Benefits

Reduced CapEx and OpEx Roll out services quickly Ease of interoperability (less vendor-specific management)

NFV orchestrator

Responsible for installing and configuring new network services(NS) and virtual network function (VNF) packages, NS lifecycle management, globalresource management, and validation and authorization of NFVI resource requests.

Hypervisor

Software that enables a single computer to run multiple operating systems simultaneously.

Type 2 hypervisor

Software to manage virtual machines that is installed as an application in an operating system.

Type 1 hypervisor

Software to manage virtual machines that is installed before any operating system is installed.

Network-related compute devices

Such as firewalls, intrusion detection systems,and network management systems

Network Function Devices

Such as switches, routers, network access points,customer premises equipment (CPE), and deep packet inspectors

Network Function Virtualization (NFV)

The principle of separating network functions from hardware they run on by using virtual hardware abstraction

NFV Requirements - Security and resilience

The security, resilience, and availability of their networks should not be impaired when VNFs are introduced

Vn-Nf

These interfaces are APIs used by VNFs to execute on the virtual infrastructure.

NFV Management and Orchestration

This involves deploying and managing the lifecycle of VNF instances. Examples include VNF instance creation, VNF service chaining, monitoring, relocation, shutdown, and billing. MANO also managesthe NFV infrastructure elements

Or-Vnfm

This reference point is used for sending configuration information to the VNF manager and collecting state information of the VNFs necessary for network service lifecycle management.

Os-Ma

Used for interaction between the orchestrator and the OSS/BSS systems.

Ve-Vnfm

Used for requests for VNF lifecycle management and exchange of configuration and state information.

Or-Vi

Used for resource allocation requests by the NFV orchestrator and the exchange of resource configuration and state information.

Vi-Vnfm

Used for resource allocation requests by the VNF manager and the exchange of resource configuration and state information.

NFV Service Chaining

VNFs are modular and each VNF provides limited functionalityon its own. For a given traffic flow within a given application, the service providersteers the flow through multiple VNFs to achieve the desired network functionality

NFV framework's three domains

Virtualized network functions; NFV infrastructure; NFV management and orchestration