How Microsoft RDP 8.0 addresses WAN, graphics shortcomings

Microsoft's Remote Desktop Protocol improves the user experience with the release of RDP 8.0 in Windows Server 2012, but there are some limitations.

With the release of Windows Server 2012 and Windows 8, Microsoft introduced version 8.0 of its Remote Desktop Protocol (RDP), which tackles many of the shortcomings when compared with other leading protocols.

Remote display protocols are tasked with transmitting data over the network from the data center to the visual display on an end user's device; some of the most popular ones on the market include Citrix HDX and VMware's PC over IP from Teradici. Microsoft RDP 8.0, part of the RemoteFX set of protocol technologies, comes with major changes from its previous incarnation, RDP 7.1 (introduced with Windows Server 2008 R2 SP1 and Windows 7 SP1). Namely, it boosts graphics delivery and supports more underlying protocols -- both in an effort to improve the end-user experience.

Be aware that the new RDP 8.0 protocol can be used with Windows 7 SP1 hosts, not Windows Server 2008 R2; in this case, the host has to be upgraded to Windows Server 2012.

Here are the benefits you'll get with Microsoft RDP 8.0 in Windows Server 2012:

RemoteFX for WAN. This is a group of features to enhance RDP and virtual desktop performance over the WAN. It added the ability to rely on both the TCP and UDP underlying protocols, whereas the previous version only supported TCP. Improvements in RDP 8.0 include:

  • UDP transport to maximize performance over lossy network conditions (by using Forward Error Connection techniques to eliminate retransmissions);
  • A TCP fallback mechanism in case UDP cannot be used; and
  • Support for UDP connections over Remote Desktop Gateway

RemoteFX Network Autodetect. Microsoft RDP 8.0 is capable of adapting to the initial and changing network conditions to provide a better user experience in all scenarios.

RemoteFX Adaptive Graphics. RDP detects what type of content is being delivered and applies different encoding techniques to optimize performance for that particular content. It is intelligent to detect the content on any region of the screen, applying the most effective techniques to each of these, which greatly enhances the user experience.

RDP now also supports progressive rendering, where the quality of the graphics being delivered can be increased in steps, adapting to the available bandwidth and network conditions.

RemoteFX Media Streaming. Video and audio content are encoded on the server side using common codecs (H.264, AAC, RDP Progressive) and sent to the client for decoding. This provides a much better experience at the client side regardless of the media content being viewed (e.g., Flash, QuickTime, HTML5 Video, etc.) while reducing the bandwidth utilization by up to 90% when compared with RDP 7.1.

RemoteFX USB redirection for non-RemoteFX vGPU virtual desktops. USB redirection is now much improved when compared to RDP 7.1.

First, Microsoft RDP 8.0 works without the RemoteFX virtual GPU. This means it is now available to any Remote Desktop Virtualization Host deployment, regardless of the RemoteFX vGPU being available.

Plus, dynamic in-session USB redirection allows you to plug in any USB device in the middle of a session and it will be dynamically detected and made available, even allowing users to switch the USB device between the local and the remote computer -- on the fly! Compared with its previous incarnation, RDP 8 now supports many more types of USB devices (e.g., CD writers, phones, etc.).

More on Windows Server 2012 RemoteFX

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Finally, you can do USB redirection for RD Session Hosts with isolation. Users connected to a terminal server can have their USB devices redirected and completely isolated from each other.

Support for nested RDP sessions. Microsoft added official support for running RDP sessions within RDP sessions.

Performance counters for user experience monitoring. Several counters are now available to allow administrators to closely monitor RDP performance for troubleshooting purposes.

Watch out for these RDP limitations

RDP 8 has a few limitations as well, including:

Aero Glass support. RDP 8.0 does not support Aero Glass, so if you require it for certain applications, such functionality will be broken if you update your Windows 7 SP1 hosts or start delivering Remote Desktop Session Host sessions using Windows Server 2012.

Remote Control. This common feature, used by administrators to remote control a user session for troubleshooting, is not available with RDP 8.0. The official answer from Microsoft is to use Remote Assistance, which unfortunately requires the user to initiate the support request or to use a third party tool.

UDP ports required. This may not be obvious, but to deliver the best end-user experience with RDP 8.0, it will require UDP in certain conditions. To use UDP, that may require not only UDP ports to be opened at the firewall level, but a new Remote Desktop Gateway to support RDP 8.0 UDP traffic.

Windows XP Clients. If you have Windows XP somewhere, just be aware all these great new enhancements for RDP 8.0 are not available for XP clients. They will be able to connect to Windows 8 and Windows Server 2012 hosts (or Windows 7 SP1 hosts with the RDP 8.0 update installed), but will fall back to the feature set available on RDP 7.X.

RDP 8.0 is a must-have feature for any Remote Desktop Services or VDI deployment. If you can work around some of the drawbacks and new RemoteFX requirements, your users will certainly notice the improved user experience.

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