Desktop Replacement on WAN

Updated: March 23, 2011

Applies To: Windows Server 2008 R2 with SP1

A WAN network is a low bandwidth (<10Mbps) or high latency (>20ms) network. Organizations typically invest in Remote Desktop Services infrastructure for desktop delivery over a WAN, for the following reasons:

  • Provide individual applications and full corporate desktops to branch offices. These offices are typically on low bandwidth and high latency networks connections that deliver their desktop from a remote centralized datacenter.

  • Provide full corporate desktops to employees who work from home, either occasionally or full time. This enables the enterprise to provide full-function, secure application delivery to an unmanaged workstation or a thin client without being concerned about the maintenance and security of the user’s device.

  • Provide individual applications and desktops to external off-site locations. This could include third parties such as vendors and suppliers.

  • Combine their computing resources and users after a company merger or acquisition. Combine computing resources in a central location to standardize desktops and applications for users to access remotely.

Design Decisions

Once the organization has decided to use Remote Desktop Services infrastructure for desktop delivery over the WAN, the organization must determine whether session-based or virtual desktop-based infrastructure will meet their needs. The key items that impact this decision are in the table below.

Design Decision RD Session Host Virtual Desktop Infrastructure

Can the application run on Windows Server 2008 R2 with SP1?

Verify that the application can run on Windows Server 2008 R2. If not, use the Application Compatibility Toolkit (ACT), available at, to verify if the application works in compatibility mode.

The application only runs on a client operating system.

Does the application cause problems in a multi-user server environment?

An RD Session Host server runs applications that have run separately on individual client operating systems/workstations together in a server environment. This requires that applications that will be delivered using RD Session Host co-exist and run in that environment without interfering with each other. The applications must also behave in a way that does not degrade their scalability and performance in this environment to the point that it is no longer cost effective.

The application does not work well in a multi-user environment.

Does the user require administrative rights on the machine?

In the RD Session Host server environment, that uses shared sessions; administrative rights cannot be granted to individual users.

The user requires administrative rights on the machine.

Does the user require the desktop to be highly available?

The user does not require the desktop to be highly available.

Organizations that require high availability should consider implementing VDI.

Administrators can use Hyper-V live migration, to move virtual machines from one host server to another without interrupting running workloads.

Does the user need to use local USB devices in the centralized desktop?


Windows Server 2008 R2 with SP1 only supports USB device redirection using RemoteFX on RD Virtualization Host.

RD Session Host does not support USB redirection.

The user requires local USB devices be available in the centralized desktop.

Finally, when investing in a Remote Desktop Services infrastructure, organizations need to determine whether RemoteFX will deliver the experience their end users expect.

The RemoteFX out of box experience is optimized for LAN environments where the bandwidth is >10Mbps and the latency is <20ms. For WAN environments that experience low bandwidth or high latency. RemoteFX can be used with a Microsoft partner WAN solution to deliver the RemoteFX experience over WAN networks. For a list of RemoteFX partners, see

In conjunction with a Microsoft partner WAN solution, RemoteFX can be used to meet the following benefits.

  • Users expect the full rich Windows desktop application experience to be delivered. Organizations expect many applications including Multimedia, Silverlight, Flash, 3D applications work as well over a WAN connection to a centralized desktop compared to a local rich client. RemoteFX enables the efficient delivery of this rich multimedia and graphics experience over the WAN by providing a 3D virtual adaptor and intelligent codecs.

  • Users expect a full rich Windows desktop device experience to be delivered. Organizations require all local devices including USB devices such as scanners, multi-function printers, webcams and more to be usable within the centralized desktop environment. RemoteFX for RD Virtualization Host enables the usage of USB devices over the WAN.

  • Organizations expect the cost of end points accessing the centralizing the desktop environment to be lowered. In addition to the cost of the client end point device, this includes the cost of managing the end point device (cost of applying security updates, other software updates) and the cost of power for the end point device. RemoteFX for RD Virtualization Host, and RemoteFX for RD Session Host leverage the 3D virtual adaptor and intelligent codecs to deliver the best experience in a highly compressed form so that both rich clients and thin clients can deliver the full Windows experience. New ultra-thin clients that have the RemoteFX decoder hardware built in will provide an even lower cost option for end point devices and minimal maintenance (software updates).