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A virtualized server requires a dynamic WAN optimization controller

Server virtualization changes a wide area network's ability to deliver applications with adequate security, storage access and QoS configurations and policies.

Server virtualization changes a wide area network's ability to deliver applications with adequate security, storage access and QoS configurations and policies. However, in environments with virtualized servers, a flexible WAN optimization controller can support the dynamic movement of virtual machines (VMs).

How WAN optimization controllers help virtualized servers

There are many challenges and solutions associated with the next generation of application delivery (Application Delivery 2.0), but the primary challenge and the primary solution involves virtualization. For example, the cost savings associated with deploying virtualized servers are well known, but virtualized servers present the IT organization with a range of challenges. One management challenge associated with virtualized servers stems from the fact that IT organizations typically leverage the management functionality in their physical LAN switches to manage the traffic flows between their physical servers. Unfortunately, in most instances, the virtual switch (vSwitch) that resides in a virtualized server provides little if any management insight. As such, IT organizations lose insight into the traffic flows between and among the virtual machines (VMs) on the same physical server.

Another of the benefits associated with virtualized servers is that a production VM can be transferred to a different physical server -- either to a server within the same data center or to a server in a different data center -- without service interruption. While this capability provides significant value, it can be challenging for IT organizations to ensure that the migrated VM retains the same optimization functionality, security, storage access, and QoS configurations and policies. As we enter the first phase of Application Delivery 2.0, IT organizations are just beginning to realize that in order to support the dynamic movement of VMs, the IT infrastructure itself, including the WAN optimization controller (WOC), has to become dynamic.

One key step toward implementing a dynamic IT infrastructure is to integrate its components more tightly. As discussed in a companion document, Evaluating WAN optimization controllers (WOCs), most WOC vendors have begun the process of integrating their products with other components of the IT infrastructure. However, based in part on their lineage and in part on their long-term strategy, the WOC vendors are taking notably different approaches to integration. For example, some WOC vendors are tightly integrating WOC functionality with security. Others are integrating WOC functionality with other IT functionality such as switches and routers, application delivery controllers and/or storage.

As noted, the issue of an integrated, dynamic IT infrastructure is important in the data center in order to support the dynamic movement of VMs. It is also important in the branch office as IT organizations try to figure out what platform they will leave in their branch offices and what integrated functionality should reside on that platform. It is also important on the access device used by mobile workers who do not want to use -- or cannot cope with using -- multiple clients in order to perform a simple transaction.

As part of Application Delivery 2.0, applications are becoming more complex. An example of that is an application that is supported in part by functionality provided by the IT organizations and in part by one or more cloud computing service providers. In order to manage these complex applications, IT organizations need WAN optimization solutions with more detailed visibility into the end-to-end performance of these applications. That visibility can be provided either by the WOC or by functionality that is tightly integrated with the WOC. They also need more granular control over the network so that, as discussed in the virtualized applications section of this guide, they can distinguish interactive traffic from bulk file transfer traffic within a single ICA stream. In some cases, IT organizations will require the ability to optimize new protocols such as PCoIP, and in some cases, they will also require new application-specific optimization similar to what is available today from some WOC vendors for applications such as SharePoint.

Continue reading this guide to learn how WAN optimization controllers are used in Application Delivery 2.0:

Or view sections of this companion guide on WAN optimization vendor products to learn more:

About the author:
Dr. Jim Metzler, principal at Ashton Metzler and Associates, is a widely recognized authority on network technology and its business applications. In more than 28 years of experience, Jim has helped numerous vendors refine product and service strategies and has helped enterprises evolve network infrastructures. He has directed and conducted market research at a major industry analyst firm and run a consulting firm. Jim holds a Ph.D. in numerical analysis from Boston University. He is co-author of the book Layer 3 Switching: A Guide for IT Professionals (Prentice Hall).

This was last published in June 2010

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