In computing, network virtualization is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves
platform virtualization
Hardware virtualization is the virtualization of computers as complete hardware platforms, certain logical abstractions of their componentry, or only the functionality required to run various operating systems. Virtualization hides the physic ...
, often combined with resource virtualization.
Network virtualization is categorized as either external virtualization, combining many networks or parts of networks into a virtual unit, or internal virtualization, providing network-like functionality to software containers on a single network
server.
In
software testing
Software testing is the act of examining the artifacts and the behavior of the software under test by validation and verification. Software testing can also provide an objective, independent view of the software to allow the business to apprecia ...
, software developers use network virtualization to test software which are under development in a simulation of the network environments in which the software is intended to operate. As a component of
application performance engineering, network virtualization enables developers to emulate connections between applications, services, dependencies, and end users in a test environment without having to physically test the software on all possible hardware or system software. The validity of the test depends on the accuracy of the network virtualization in emulating real hardware and
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
s.
Components
Various equipment and software vendors offer network virtualization by combining any of the following:
* Network hardware, such as switches and
network adapter
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
E ...
s, also known as network interface cards (NICs)
* Network elements, such as firewalls and load balancers
* Networks, such as
virtual LANs (VLANs) and containers such as
virtual machine
In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized har ...
s (VMs)
* Network storage devices
* Network machine-to-machine elements, such as telecommunications devices
* Network mobile elements, such as laptop computers, tablet computers, and smartphones
* Network media, such as
Ethernet
Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in ...
and
Fibre Channel
Fibre Channel (FC) is a high-speed data transfer protocol providing in-order, lossless delivery of raw block data. Fibre Channel is primarily used to connect computer data storage to servers in storage area networks (SAN) in commercial data c ...
External virtualization
External network virtualization combines or subdivides one or more
local area network
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
s (LANs) into virtual networks to improve a large network's or data center's efficiency. A virtual local area network (VLAN) and
network switch
A network switch (also called switching hub, bridging hub, and, by the IEEE, MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device.
A netw ...
comprise the key components. Using this technology, a
system administrator
A system administrator, or sysadmin, or admin is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems, especially multi-user computers, such as servers. The system administrator seeks to en ...
can configure systems physically attached to the same local network into separate virtual networks. Conversely, an administrator can combine systems on separate
local area network
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
s (LANs) into a single VLAN spanning segments of a large network.
Internal virtualization
Internal network virtualization configures a single system with
software container
OS-level virtualization is an operating system (OS) paradigm in which the kernel allows the existence of multiple isolated user space instances, called ''containers'' ( LXC, Solaris containers, Docker, Podman), ''zones'' (Solaris containers), '' ...
s, such as
Xen hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called ...
control programs, or pseudo-interfaces, such as a
VNIC
In virtualization, input/output virtualization (I/O virtualization) is a methodology to simplify management, lower costs and improve performance of servers in enterprise environments. I/O virtualization environments are created by abstracting the ...
, to emulate a physical network with software. This can improve a single system's efficiency by isolating applications to separate containers or pseudo-interfaces.
Examples
Citrix
Citrix Systems, Inc. is an American multinational cloud computing and virtualization technology company that provides server, application and desktop virtualization, networking, software as a service (SaaS), and cloud computing technologies. C ...
and
Vyatta have built a virtual network
protocol stack combining Vyatta's routing, firewall, and VPN functions with Citrix's Netscaler
load balancer, branch repeater
wide area network
A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits.
Businesses, as well as schools and government entities, u ...
(WAN) optimization, and
secure sockets layer
Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in sec ...
VPN.
OpenSolaris
OpenSolaris () is a discontinued open-source computer operating system based on Solaris and created by Sun Microsystems. It was also, perhaps confusingly, the name of a project initiated by Sun to build a developer and user community around t ...
network virtualization provides a so-called "network in a box" (see
OpenSolaris Network Virtualization and Resource Control).
Microsoft Virtual Server
Microsoft Virtual Server was a virtualization solution that facilitated the creation of virtual machines on the Windows XP, Windows Vista and Windows Server 2003 operating systems. Originally developed by Connectix, it was acquired by Microsoft ...
uses virtual machines to make a "network in a box" for
x86 systems. These containers can run different operating systems, such as
Microsoft Windows or
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...
, either associated with or independent of a specific
network interface controller
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
E ...
(NIC).
Use in testing
Network virtualization may be used in application development and testing to mimic real-world hardware and system software.
In
application performance engineering, network virtualization enables emulation of connections between applications, services, dependencies, and end users for software testing.
Wireless network virtualization
Wireless network virtualization can have a very broad scope ranging from spectrum sharing, infrastructure virtualization, to air interface virtualization. Similar to wired network virtualization, in which physical infrastructure owned by one or more providers can be shared among multiple service providers, wireless network virtualization needs the physical wireless infrastructure and radio resources to be abstracted and isolated to a number of virtual resources, which then can be offered to different service providers. In other words, virtualization, regardless of wired or wireless networks, can be considered as a process splitting the entire network system. However, the distinctive properties of the wireless environment, in terms of time-various channels, attenuation, mobility, broadcast, etc., make the problem more complicated. Furthermore, wireless network virtualization depends on specific access technologies, and wireless network contains much more access technologies compared to wired network virtualization and each access technology has its particular characteristics, which makes convergence, sharing and abstraction difficult to achieve. Therefore, it may be inaccurate to consider wireless network virtualization as a subset of network virtualization.
Performance
Until 1 Gbit/s networks, network virtualization was not suffering from the overhead of the software layers or hypervisor layers providing the interconnects. With the rise of high bandwidth, 10 Gbit/s and beyond, the rates of packets exceed the capabilities of processing of the networking stacks. In order to keep offering high throughput processing, some combinations of software and hardware helpers are deployed in the so-called "network in a box" associated with either a hardware-dependent
network interface controller
A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network.
E ...
(NIC) using
SRIOV extensions of the hypervisor or either using a
fast path technology between the NIC and the payloads (virtual machines or containers).
For example, in case of
Openstack
OpenStack is a free, open standard cloud computing platform. It is mostly deployed as infrastructure-as-a-service (IaaS) in both public and private clouds where virtual servers and other resources are made available to users. The software platfo ...
, network is provided by Neutron which leverages many features from the Linux kernel for networking: iptables, iproute2, L2 bridge, L3 routing or OVS. Since the Linux kernel cannot sustain the 10G packet rate, then some bypass technologies for a
fast path are used. The main bypass technologies are either based on a limited set of features such as
Open vSwitch (OVS) with its
DPDK
The Data Plane Development Kit (DPDK) is an open source software project managed by the Linux Foundation. It provides a set of data plane libraries and network interface controller polling-mode drivers for offloading TCP packet processing from ...
user space
A modern computer operating system usually segregates virtual memory into user space and kernel space. Primarily, this separation serves to provide memory protection and hardware protection from malicious or errant software behaviour.
Kerne ...
implementation or based on a full feature and offload of Linux processing such as
6WIND virtual accelerator.
See also
*
Application performance engineering
*
Hardware virtualization
Hardware virtualization is the virtualization of computers as complete hardware platforms, certain logical abstractions of their componentry, or only the functionality required to run various operating systems. Virtualization hides the physic ...
*
I/O virtualization
*
Network function virtualization Network functions virtualization (NFV) is a network architecture concept that leverages the IT virtualization technologies to virtualize entire classes of network node functions into building blocks that may connect, or chain together, to create an ...
*
Network Virtualization using Generic Routing Encapsulation
Network Virtualization using Generic Routing Encapsulation (NVGRE) is a network virtualization technology that attempts to alleviate the scalability problems associated with large cloud computing deployments. It uses Generic Routing Encapsulatio ...
*
Overlay network
*
OVN
OVN (Open Virtual Network) is a system to support virtual network abstraction. OVN complements the existing capabilities of Open vSwitch to add native support for virtual network abstractions, such as virtual L2 and L3 overlays and security grou ...
*
Virtual circuit
A virtual circuit (VC) is a means of transporting data over a data network, based on packet switching and in which a connection is established within the network between two endpoints. The network, rather than having a fixed data rate reservation ...
*
Virtual Extensible LAN
Virtual Extensible LAN (VXLAN) is a network virtualization technology that attempts to address the scalability problems associated with large cloud computing deployments. It uses a VLAN-like encapsulation technique to encapsulate OSI layer 2 ...
*
Virtual firewall
*
Virtual private network
References
*
Further reading
*
*
*
* {{cite journal, last1=Fischer, first1=Andreas, last2=Botero, first2=Juan Felipe, last3=Beck, first3=Michael Till, last4=de Meer, first4=Hermann, last5=Hesselbach, first5=Xavier, title=Virtual Network Embedding: A Survey, journal=IEEE Communications Surveys & Tutorials, year=2013, pages=1–19, issn=1553-877X, doi=10.1109/SURV.2013.013013.00155, volume=15, issue=4
External links
NetworkVirtualization.com , Newsretrieved 3 June 2008
VMware Virtual Networking Conceptsretrieved 26 October 2008
Network functions Virtualization(NFV) Benefits
Virtualization
Internet Protocol based network software