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
In computing, virtualization (abbreviated v12n) is a series of technologies that allows dividing of physical computing resources into a series of Virtual machine, virtual machines, Operating system, operating systems, processes or containers.
Vir ...
, 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 checking whether software satisfies expectations.
Software testing can provide objective, independent information about the Quality (business), quality of software and the risk of its failure to a User (computin ...
, 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 and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
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 and physical network interface) is a computer hardware component that connects a computer to a computer network.
Early network interface ...
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 or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve ...
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 198 ...
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 Server (computing), servers in storage area networks (SAN) in ...
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, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...
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, Ethernet switch, 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 destinat ...
comprise the key components. Using this technology, a
system administrator
An IT administrator, system administrator, 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 Server (computing), servers. The ...
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, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...
s (LANs) into a single VLAN spanning segments of a large network.
External network virtualization is envisioned to be placed in the middle of the network stack and help integrating different architectures proposed for next generation networks.
Internal virtualization
Internal network virtualization configures a single system with
software containers, 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, 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 and
Vyatta have built a virtual network
protocol stack
The protocol stack or network stack is an implementation of a computer networking protocol suite or protocol family. Some of these terms are used interchangeably but strictly speaking, the ''suite'' is the definition of the communication protoc ...
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, use ...
(WAN) optimization, and
secure sockets layer
Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network, such as the Internet. The protocol is widely used in applications such as email, instant messaging, and voice over IP, ...
VPN.
OpenSolaris
OpenSolaris () is a discontinued open-source computer operating system for SPARC and x86 based systems, created by Sun Microsystems and based on Solaris. Its development began in the mid 2000s and ended in 2010.
OpenSolaris was developed as ...
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 pri ...
uses virtual machines to make a "network in a box" for
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...
systems. These containers can run different operating systems, such as
Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...
or
Linux
Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...
, 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 and physical network interface) is a computer hardware component that connects a computer to a computer network.
Early network interface ...
(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 and physical network interface) is a computer hardware component that connects a computer to a computer network.
Early network interface ...
(NIC) using
SRIOV extensions of the hypervisor or either using a
fast path Fast path is a term used in computer science to describe a path with shorter instruction path length through a program compared to the normal path. For a fast path to be effective it must handle the most commonly occurring tasks more efficiently tha ...
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 pla ...
, 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 Fast path is a term used in computer science to describe a path with shorter instruction path length through a program compared to the normal path. For a fast path to be effective it must handle the most commonly occurring tasks more efficiently tha ...
are used. The main bypass technologies are either based on a limited set of features such as
Open vSwitch (OVS) with its
DPDK user space
A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware prote ...
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 emulates the hardw ...
*
I/O virtualization
*
Network function virtualization
*
Network Virtualization using Generic Routing Encapsulation
*
Overlay network
An overlay network is a logical computer network that is protocol layering, layered on top of a physical network. The concept of overlay networking is distinct from the traditional model of OSI model, OSI layered networks, and almost always assum ...
*
OVN
*
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 first established across the network between two endpoints. The network, rather than having a fixed data rate reser ...
*
Virtual Extensible LAN
Virtual eXtensible LAN (VXLAN) is a network virtualization technology that uses a VLAN-like encapsulation technique to encapsulate OSI layer 2 Ethernet frames within layer 4 UDP datagrams, using 4789 as the default IANA-assigned destination U ...
*
Virtual firewall
A virtual firewall (VF) is a network firewall service or appliance running entirely within a platform virtualization, virtualized environment and which provides the usual packet filtering and monitoring provided via a physical network firewall. The ...
*
Virtual private network
Virtual private network (VPN) is a network architecture for virtually extending a private network (i.e. any computer network which is not the public Internet) across one or multiple other networks which are either untrusted (as they are not con ...
*
Software-defined networking
Software-defined networking (SDN) is an approach to network management that uses abstraction to enable dynamic and programmatically efficient network configuration to create grouping and segmentation while improving network performance and monit ...
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, s2cid=206584013 , hdl=2117/20996, hdl-access=free
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