The ABCs of WAN Virtualization

Andy Gottlieb, a leading expert in WAN/LAN switching and routing, is the founder and CEO of Talari Networks.

Virtualization – server virtualization, and to a lesser extent desktop virtualization – is driving IT savings. This, of course, is self-evident to anyone paying attention to what’s going on at the leading edge of computing these days. Virtualization technology from companies like VMware has taken us from single CPU with single operating system (OS) to single CPU with multiple virtual machines, towards cloud computing/utility computing. Virtualization leverages the efficient pooling of an on-demand server infrastructure, to scale to run an almost arbitrary set of applications – be it public cloud computing or a private cloud.

A recently introduced technology for the enterprise Wide Area Network (WAN), WAN Virtualization, promises to revolutionize the economics of the enterprise WAN, making it affordable for businesses to deploy virtual desktop infrastructures (VDIs), VoIP, videoconferencing, private clouds, and other modern technologies that support today’s remote office/telecommuter environment, adding bandwidth and reducing monthly WAN spending while increasing network availability and application performance predictability.

About WAN Virtualization

At its core, WAN Virtualization enables network managers to use multiple WAN connections– existing private WANs, such as MPLS, as well as any kind of Internet WAN links, be they DSL, cable, fiber, Metro Ethernet, etc.— to augment or replace individual private WAN connections. Well designed WAN Virtualization two-ended appliance solutions use end-to-end algorithms to do dynamic, real-time, traffic engineering. Because they react sub-second to not just link failures, but also congestion-related network problems, WAN Virtualization enables businesses to build a WAN that is simultaneously less expensive, much higher bandwidth, much lower cost and with lower ongoing operational costs than today’s proprietary, single-vendor WANs.

The cost of MPLS bandwidth at a typical U.S. remote office ranges from $400 - $600/Mbps per month, while the cost of Internet bandwidth is roughly $3 - $15/Mbps per month. This 30 – 100 times cost differential is enormous! Internationally, the cost deltas tend to be wider still. In a carrier-pricing environment where a price/bit factor of 2x is enormous, WAN Virtualization brings Moore’s Law and Internet economics to Enterprise WAN buyers, allowing enterprises to augment and/or replace their very expensive private WAN connections, as it solves the reliability and performance predictability problems associated with Internet connectivity, which have prevented enterprises from fully leveraging the Internet.

Best Practices

One of the advantages of WAN Virtualization is that it can be added seamlessly into existing networks, rather than requiring a forklift upgrade. If desired, WAN Virtualization can be rolled out not just a site at a time, but an application, user, or server at a time, until its reliability has been proven to the enterprise WAN manager.

Just as with WAN Optimization, WAN Virtualization deployments are typically done as a network overlay; the appliances can be deployed either in-line or out-of-line, and support both fail-to-wire capability and high-availability redundancy options for ease of deployment and maximum reliability.

Complements WAN Optimization

WAN Optimization technology, from companies like Riverbed, Blue Coat and Silver Peak, has been widely deployed for the benefits it brings to server centralization/data center consolidation projects. WAN Optimization’s disk-based data deduplication, application-specific help for Microsoft’s CIFS protocol for file access, and some other TCP optimization techniques save network bandwidth, but especially provide application acceleration which enable centralized server environments to deliver acceptable application performance.

WAN Virtualization is highly complementary to WAN Optimization. The bandwidth aggregation and loss mitigation capabilities of WAN Virtualization deliver further benefits to WAN Optimization deployments, providing better end-user performance for first-time data transfers, and reliable voice and videoconferencing, as well as more predictable performance for all applications when any part of the private WAN becomes congested.

WAN Virtualization enables enterprise WAN managers to deploy more bandwidth at substantially lower monthly costs, with greater network availability and application performance predictability. For many businesses, this fundamental network technology is an important step toward enabling the IT flexibility, efficiency and cost-saving promises of cloud computing.