One of the earliest implementations of network virtualization were virtual local area networks<\/strong> (VLANs). VLANs make it possible for devices physically in different geographical locations to appear as if they were in a single local area network, with a unique broadcast and multicast domain.<\/p>\n VLANs can support multiple networks on the same hardware infrastructure, such as multiple IP addresses on the same switch, meaning that VLANs are adept at scaling network traffic.<\/p>\n Network virtualization<\/strong> enables network functions usually run on hardware to be delivered as software and managed as a single entity.<\/p>\n To understand what is virtualized in a virtual network, we refer to the OSI model. The Open Systems Interconnection<\/strong> (OSI) model defines the standards for networking. OSI describes a network in seven layers, from the electrical hardware of the physical layer<\/strong> at the bottom to the end-user interface of the application layer<\/strong> at the top.<\/p>\n Network virtualization \u201csoftwarizes\u201d functions on the first three layers of the OSI model:<\/p>\n Software-defined networking (SDN) and network functions virtualization (NFV) are complementary approaches to managing networks. What is \u201cvirtualized\u201d in each case varies. The two concepts were introduced in 2008 and 2012 respectively, and their technologies are governed by standards bodies: the Open Networking Foundation<\/a> and European Telecommunications Standards Institute<\/a>.<\/p>\n Software-defined networking<\/strong> involves separating the control plane of a network from the data plane. In a network, the control plane <\/strong>is responsible for guiding how packets should move through a network whereas the data plane<\/strong> (or forwarding plane) is responsible for sending packets to their destinations. Traditionally, the control and data planes are packaged together in a network device. By separating the control and data planes, SDN makes a network programmable, that is, it frees a network from relying on the rules set in a routing table. Instead with SDN, an administrator can program rules in a switch. Switches must be programmed through an SDN controller<\/strong> which uses protocols such as OpenFlow. OpenFlow<\/strong> was introduced around the same time as software-defined networking and is a protocol that allows for the control of switch data planes.<\/p>\n Software-defined networking was originally designed to work on local area networks (LANs). The technology has led to the development of software-defined wide area networks<\/strong> (SD-WANs) for enterprises. SD-WANs connect geographically isolated data centers together.<\/p>\n Mobile carriers and internet service providers use software-defined networking to scale bandwidth during increases in usage. Because network provisioning is programmable, administrators can assign bandwidth to servers at will. Additionally, cloud service providers utilize SDN to support multi-tenant cloud architecture. In multi-tenancy, administrators manage switches to funnel traffic into segregated networks for different tenants.<\/p>\n While SDN abstracts physical network infrastructure so that networks can be programmable, NFV deploys the functions of a network without the use of physical network devices. Network functions virtualization<\/strong> happens when proprietary network devices such as routers and firewalls are replaced with software versions that deploy on commercial off-the-shelf<\/strong> (COTS) hardware such as ARM and x86.<\/p>\n Key to network functions virtualization are virtual network functions<\/strong> (VNFs). Virtual network functions are the namesake virtualized instances of network functions. These are the virtual routers and virtual firewalls for example. Most VNFs operate inside hypervisors<\/a>.<\/p>\n Although VNFs (the components) are integral to NFV (the architecture), NFV architecture also consists of a framework that oversees the management, automation, and orchestration <\/strong>(MANO) of VNF components, as well as both the hardware and software-based compute, storage, and networking components that enable network functions to be virtualized. Therefore, NFV architecture isn\u2019t restricted to VNFs or software alone.<\/p>\n Both network functions virtualization and software-defined networking, mentioned in the previous section, decouple hardware and software. The difference to remember between the two network virtualization methods is that NFV imitates the network function on a physical device, so that the function can run on a server, while SDN separates the control and data planes of a network in order for both planes to be programmable.<\/p>\n At their conception, network virtualization technologies brought about data center modernization. They have been an accelerator for the adoption of cloud computing. Cloud computing<\/strong> permits organizations to access and use shared computing resources located in a public data center via the internet. Network virtualization helped move infrastructures to the cloud since they gave rise to remote administration of networks.<\/p>\n Yet the centralized management of networks in cloud computing has exacerbated an already existing latency problem. While delays in data transmissions were already happening inside local networks, the phenomenon is worse over the internet. Latency worsens in cloud computing because data must travel for longer geographical distances.<\/p>\n A new decentralized approach is on the rise, focusing on reducing the impact of latency for scenarios involving mobility and real-time processing of data.<\/p>\n Network virtualization applies to mobile networks as much as data networks. In mobile telecommunications, network virtualization can partition resources so that different users can transmit data on a single network.<\/p>\n The practice of network slicing<\/strong> uses NFV to overlay multiple virtual networks on a shared physical infrastructure. Because of the plethora of wireless internet devices available (think IoT, smartphones, mobile broadband, etc.), mobile networks need to run applications with different bandwidth requirements. Network slicing configures the optimum grouping of network traffic in order to decrease latency. In this way, network slicing is vital to upcoming 5G mobile networks and mobile edge computing. By now, you should know what is virtualized in a network, the differences between two common approaches to network virtualization, and how network virtualization helps decentralization. Ormuco\u2019s r\u00e9gionales et globales d\u2019infrastructure-service<\/a> and PaaS P\u00e9riph\u00e9rique<\/a> solutions for cloud and edge computing come equipped with software-defined network (SDN) and network functions virtualization (NFV) capabilities. With Ormuco<\/a>, enterprises can create and manage virtual data networks, routers, load balancers, and virtual private networks (VPNs). For more details, consult our product features<\/a>.<\/a><\/p>\nApproaches to Network Virtualization<\/h2>\n
What Is Network Virtualization?<\/h5>\n
![\"OSI](\"https:\/\/ormuco.com\/wp-content\/uploads\/2019\/06\/OSI-Model-1024x768.jpg\")
<\/p>\n\n
Software-Defined Networking (SDN)<\/h5>\n
Network Functions Virtualization (NFV)<\/h5>\n
Network Virtualization Moves from the Cloud to the Edge<\/h2>\n
From Data Networks to Mobile Networks<\/h5>\n
\n<\/a><\/p>\nNetwork Virtualization Recapped<\/h2>\n
![\"\"](\"https:\/\/ormuco.com\/wp-content\/uploads\/2019\/06\/5G-Person-336x280.png\")
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