[Tutorials] [General RDS Information] – Published Jan 2012

An environment built on the concept of virtual desktops or remote desktops is not made up solely of servers. Network infrastructure, communication protocols, and adequate remote clients or endpoint devices play equally important roles.  This chapter is designed to shed more light on the different possible client types and the details of the latest version of the RDP client software for Windows.

What do users and administrators expect from a remote client or an endpoint device?  It’s all about graphical output and user interaction performance when running remote desktops and applications.  Adequate network connectivity of remote clients is mandatory while running local applications is only optional.  Providing a suitable local user interface is, of course, another remote client task.  This interface needs to be as intuitive and ergonomic as possible to optimally support the user.  The client device must also be cost-efficient, which is of vital importance, in particular in corporate environments.  For these reasons, the central administration functions of the client device should be comprehensive and include administration of any local applications.

Such different requirements imply that a wide variety of clients can be used in a remote desktop environment.  The product range begins with Windows-based terminals and works its way up through mobile phones, tablets, notebooks, and desktop PCs all the way to UNIX workstations connected to a network.  There are platforms that are not included in this list because they are based on special hardware or even a particular Web browser – but they may still qualify to be a proper remote desktop client.

It is inadequate to characterize all these platforms as thin clients, because their design objectives are not the same.  This is why they belong to different client types, meaning they cannot be compared directly.  The comparison results would not be realistic.  It is easy to understand that a traditional Windows-based PC is very flexible, but may also produce substantially higher costs of ownership in comparison to a thin client.  However, the different client types can still be reduced to a common denominator through suitable client software.

This is exactly the point where we should start looking at RD Session Host or RD Virtualization Host again, but from a client perspective.  How can a client device take advantage of the service provided by a remote desktop server (RDSH or RDVH)?  One option is to map the user interface of a remote user session completely to the client.  This means that a Windows server’s remote desktop is displayed on top of an existing local client desktop.  In this case, a user needs to know on which of the two desktops the required application is located.  This situation is mitigated only if the local desktop has very limited functionality and the fewest possible local applications are installed.  The remote desktop then becomes the primary user interface.  This scenario is also referred to as virtual desktop infrastructure.

Another option is to directly display RemoteApp programs delivered to the client’s local desktop.  To put this option into effect, a good performing local desktop is required on the client platform.  Yet with this option, the difference between local and remote applications is negligible.

In principle, the potential standard target platforms for remote desktop client software can be divided in the following categories:

• Windows-Based Terminals and smartphones under Windows CE, Windows Mobile or Windows Embedded.
• Apple computers under MacOS X.
• Personal computers under Windows XP, Windows Vista or Windows 7.

When using a computer based on Microsoft Windows, Microsoft Windows Mobile or Apple Mac OS X, connections to remote applications and desktops can be initiated through the standard Microsoft RDP client software called Remote Desktop Connection or RDC (formerly Terminal Services Client).  Other operating system platforms, such as UNIX or Linux, require third-party versions of RDP clients.

Like all RDP clients, RDC initiates connections to RD Session Host servers or RD Virtualization Host servers via TCP port 3389.  In the case of an RD Session Host server, a waiting RDP listener thread receives the connection request and initiates a user session.  The user session control is taken over by a remote desktop thread that handles interaction between client and server.  The RDP listener threads then continue listening for new connection requests on the network.

When connected to remote applications or desktops the user experience is depending on feature set and performance of the RDP client software.  This is why it is obvious that using the latest RDC version is highly recommended.  Remote Desktop Connection 6.1 is compatible to Windows Server 2008 (R2) Remote Desktop Services.  It is available for Windows XP Service Pack 3, Windows Vista and Windows 7.

In May 2010 Microsoft published Remote Desktop Connection Manager, a free RDP client that manages multiple remote desktop connections.  RDCMan is similar to the built-in MMC Remote Desktops snap-in, but more flexible.  It uses the same ActiveX Control like RDC 6.x, making the two RDP clients compatible from a technical perspective.  This is why Windows XP or Windows Server 2003 needs to be updated to version 6 or newer of the Remote Desktop Connection client software.

[Tutorials] [General RDS Information]