A Virtual Router, or vRouter, is a software function that replicates in software the functionality of a hardware-based Layer 3 Internet Protocol (IP) routing, which has traditionally used a dedicated hardware device. It is often used as a generic term for virtual routing, but it is also included in the name of several brand-name commercial products.
Virtual routing is a form of Network Functions Virtualization (NFV), in which the functions of traditional hardware-based network appliances are converted to software than can be run on standard Commercial Off-the-Shelf (COTS) hardware. This has advantages of lowering hardware costs and allowing more hardware interoperability, rather than requiring a proprietary hardware platform.
Because virtual routing liberates the IP routing function from specific hardware, that means that routing functions can be more freely moved around a network or data center. In basic software routing function, routing software is added to commodity server and that piece of hardware becomes a router. In a more sophisticated distributed routing environment, pieces of the routing software can be moved around entire networks while managed with a centralized control plane.
This evolution means that routing functions can be dynamically configured or adapted to the network needs. Emerging open-source technologies such as OpenStacks’s Neutron include ways for routing functionality to morph into software that is distributed through the network or data center.
Brocade Starts a Trend
Although vRouters have been around a while, Brocade Communications stepped up the marketing of virtual routing after acquiring startup Vyatta in 2012. Brocade has since used Vyatta, which it now calls the Vyatta 5600 vRouter, as one of the linchpins of its Software Defined Networking (SDN) and NFV strategy. The Vyatta 5600 is a 10Gbps+ virtual router with many IP routing features.
As SDN and NFV have gained popularity, other major networking hardware players have developed vRouter strategies. For example, Juniper Networks has a module called vRouter, which is part of its Contrail product line, which provides IP-based data forwarding. This can be used to create an IP-based tunnel by encapsulating traffic. This is an approach known as “overlay” in SDN. Cisco markets the Cloud Services Router 1000V series, designed for Wide Area Networking (WAN) applications. And Alcatel-Lucent, another big routing player, in 2014 introduced its Virtualized Services Router (VSR). The same approach is used by VMware in its NSX gateway. Many other large networking vendors, including Ericsson, are taking routing technology and virtualizing it as a software solution.
Use Cases from WAN to WiFi
The major networking players have created virtual routing products to offset competition from SDN in and NFV, which puts more emphasis on software functionality that can be applied to industry-standard hardware.
Each company has a slightly different spin on the vRouter, but generally the use cases mimic those of commercial hardware-based routing solutions. This might include VPN, traffic engineering, route reflectors, BGP routing, firewalls, and virtual Customer Premises Equipment (CPE) for the WAN. Another use case includes network virtualization (i.e. VMware NSX).
In addition to the commercial products designed for larger enterprise or service-provider networks, there are also lightweight freeware versions of vRouters for uses such as creating a virtual WiFi routers on a Windows Personal Computers (PCs).
In general, the vRouter has gained momentum as a replacement for hardware-based routing in certain use cases, especially the WAN. However it is still not regarded as a replacement for heavy-duty core IP routers, which help control the core of the Internet. Many industry experts question how virtual routing will effect some of largest IP router companies, Cisco and Juniper, because it threatens their existing hardware-based routing revenue streams.
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