Network function virtualization: Difference between revisions

Revision as of 12:51, 7 December 2021

Revision as of 06:28, 9 December 2021

Line 47:

==Relationship to SDN==

Network Functions Virtualisation is highly complementary to [[Software-Defined Networking]] (SDN).<ref name="white">{{cite web |title=Network Functions Virtualization— Introductory White Paper |publisher= ETSI |date= 22 October 2012 |url= https://docbox.etsi.org/isg/nfv/open/Publications_pdf/White%20Papers/NFV_White_Paper1_2012.pdf |access-date= 20 June 2013 }}</ref>. In essence, SDN is an approach to building data networking equipment and software that separates and abstracts elements of these systems. It does this by decoupling the control plane and data plane from each other, such that the control plane resides centrally and the forwarding components remain distributed. The control plane interacts both [[Northbound interface|northbound]] and [[Southbound interface|southbound]]. In the northbound direction the control plane provides a common abstracted view of the network to higher-level applications and programs using high-level APIs and novel management paradigms, such as Intent-based networking. In the southbound direction the control plane programs the forwarding behavior of the data plane, using device level APIs of the physical network equipment distributed around the network.

Thus, NFV is not dependent on SDN or SDN concepts, but NFV and SDN can cooperate to enhance the management of a NFV infrastructure and to create a more dynamic network environment. It is entirely possible to implement a virtualized network function (VNF) as a standalone entity using existing networking and orchestration paradigms. However, there are inherent benefits in leveraging SDN concepts to implement and manage an NFV infrastructure, particularly when looking at the management and orchestration of Network Services (NS), composed of different type of Network Functions (NF), such as Physical Network Functions (PNF) and VNFs, and placed between different geo-located NFV infrastructures, and that's why multivendor platforms are being defined that incorporate SDN and NFV in concerted ecosystems.<ref>{{cite web|url=http://www.cisco.com/go/esp|title=Platform to Multivendor Virtual and Physical Infrastructure}}</ref>

Line 53:

An NFV system needs a central orchestration and management system that takes operator requests associated with an NS or a VNF, translates them into the appropriate processing, storage and network configuration needed to bring the NS or VNF into operation. Once in operation, the VNF and the networks it is connected to potentially must be monitored for capacity and utilization, and adapted if necessary.<ref>{{Cite book|url=http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1118900286.html|title=Software Defined Mobile Networks (SDMN): Beyond LTE Network Architecture.|last=Liyanage|first=Madhusanka|publisher=John Wiley|year=2015|isbn=978-1-118-90028-4|___location=UK|pages=1–438}}</ref>

All network control functions in an NFV infrastructure can be accomplished using SDN concepts and NFV could be considered one of the primary SDN use cases in service provider environments .<ref name="eve005">{{cite web |title=Report on SDN Usage in NFV Architectural Framework |publisher= ETSI |date= December 2015 |url= https://www.etsi.org/deliver/etsi_gs/NFV-EVE/001_099/005/01.01.01_60/gs_nfv-eve005v010101p.pdf |access-date= 7 December 2021 }}</ref>. For example, within each NFV infrastructure site, a VIM could rely upon an SDN controller to setup and configure the overlay networks interconnecting (e.g. VXLAN) the VNFs and PNFs composing an NS. The SDN controller would then configure the NFV infrastructure switches and routers, as well as the network gateways, as needed. Similarly, a Wide Area Infrastructure Manager (WIM) could rely upon an SDN controller to setup overlay networks to interconnect NSs that are deployed to different geo-located NFV infrastructures. It is also apparent that many SDN use-cases could incorporate concepts introduced in the NFV initiative. Examples include where the centralized controller is controlling a distributed forwarding function that could in fact be also virtualized on existing processing or routing equipment.

==Industry impact==