Virtualization Technology News and Information
Virtualization – the Next Chapter in Network Management
A Contributed Article by Steve Riley is technical director, Office of the CTO at Riverbed


Computer-generated special effects in feature film date back to 1973, first used in the film Westworld to portray the point of view of an android. Throughout the next two decades computer-animated sequences became more common, until full-length, computer-animated films became inevitable. Some may have questioned whether computer animation was a viable alternative to traditional animation, but the successful release of Disney's Toy Story in 1995 began the full-scale shift to computer animation.

Business data centers today stand at a similar precipice. We have seen a variety of new technologies make their way into the organization over time, including smartphones, cloud computing, and server virtualization. One area that stands to benefit the most from this transition has been the network.

The Next Stage of Network Evolution

While several different aspects of the network have taken advantage of virtualization to some degree, in a way it has been stuck in the same place as early computer animation - nice to have but not embraced as fully necessary. VLANs have provided a degree of logical segregation of network segments, but the underlying hardware has remained fundamentally unchanged - and so have all the headaches involved in managing physical network resources.

At the heart of the network lie two core functions: the forwarding plane, which is responsible for moving traffic from place to place, and the control plane, which gives instructions to the forwarding plane based on network topology and conditions. As a result, advances made in areas such as load balancing and policy enforcement are limited by the abilities of the network hardware.

Given the success of server virtualization and the growth of "devops," the question administrators are now considering is whether a fully virtualized network is possible. Moreover, they are still debating whether it would be useful. Such a network would encompass complete decoupling of the control plane from the forwarding plane, a notion that some network operators have been hesitant to embrace.

A helpful analogy might be to consider a physical server. Typically, individual servers are dedicated to supporting standalone software applications. Supporting a wider variety of needs requires buying more servers, and compute capacity would be isolated and underutilized. If that single server were virtualized, however, multiple virtual servers can coexist in a single space, supporting different configuration needs and more efficiently using resources. The result is a simpler physical environment that offers a great deal of flexibility. The computer becomes a pile of software, managed by software.

SDN and the Virtualized Network

This same approach can be expanded to the corporate network, utilizing software that has been developed for this purpose. Traditional networks are limited by the static nature of their topology and the physical limitations of their individual components. As a result, applications are limited to what will function within relatively narrow bounds, which can have far-reaching effects within the organization.

When more of the network functionality can be moved to software, however, the resulting virtualized network becomes much more flexible. The network controls are freed from the restrictions imposed by physical components and can be much more quickly adapted to changing circumstances than if the physical topology needs to be modified.

Once virtualized, the network appears to applications to be identical to a traditional network, requiring no special configurations of those applications. Applications with differing network requirements can be supported on a single shared physical network, because each virtual network exists as a distinct logical abstraction, based on software. This more flexible approach can handle a wide variety of moment-to-moment needs - such as traffic spikes, QoS alterations, and path selection - more efficiently than a network with traditional hardware limitations.

While several techniques exist for building virtual networks, software-defined networking (SDN) is emerging as one of the most useful methods. SDN can efficiently handle the large number of resulting states in the network, and it can provide businesses with a degree of operational consistency that was not previously possible. This combination of features makes SDN an attractive option for network virtualization.

Futureproofing the Network

Evolution and revolution in business IT show no signs of abating anytime soon. Mobility is eclipsing traditional PC form factors, security concerns are always top of mind as attackers continually invent new tactics, and business groups regularly request new applications to support. Whatever the most likely use case is for tomorrow's data center, however, the ability to quickly adapt to changing circumstances will prove invaluable. The power and beauty of a flexible network may not win an Oscar, but adopting virtualized networks built on software-defined networking will help take the data center into the future.


Published Tuesday, December 17, 2013 10:36 AM by David Marshall
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Kevin Tsang - (Author's Link) - December 23, 2013 3:14 PM

Steve, excellent job explaining the evolution of business technologies while also delving into network virtualization. Clearly, with new networking advancements comes new challenges. Therefore, for professionals interested in future-proofing their networks, I suggest checking out SevOne's software for virtual and cloud systems management.

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