Microsoft Windows Server 2008 R2 Remote Desktop Services

1. Overview and History

Posted by Benny Tritsch on December 11, 2009

 

Microsoft Server 2008 was developed as the successor to the popular Microsoft Windows Server 2003 operating system, with special emphasis on use by IT professionals in corporate networks.  A computer system running Windows Server 2008 supports simultaneous execution of an almost unlimited number of processes.  Such a server system provides, of course, supports to use several processors simultaneously and large amounts of memory to increase scalability.

By default the Windows Server operating system allows multiple users to log on interactively, creating a scenario called either multi-user operation or presentation virtualization.  Redirecting input and output operations to remote computers is possible in the core Windows Server 2008 system using Remote Desktop Services.  Consequently, Remote Desktop Services allow remote devices to access and use Windows desktops and applications.

Windows Server 2008 and Windows Server 2008 R2 introduce many new Remote Desktop Services features if compared to their predecessors.  Some changes can only be seen when looking at system level, while other enhancements are rather obvious.  Here is a very short overview of the most spectacular new features:

• RemoteApp allows users to launch a remote application hosted on a server and interact with it on the local desktop.  The remote application is displayed without the surrounding remote desktop including start menu and Explorer shell.  This means that from a local desktop perspective remote application windows are integrated seamlessly, which makes it harder to distinguish which application runs locally on the workstation and which application runs on the server.
• Terminal Services / Remote Desktop Session Broker is a load balancing and session reconnection mechanism developed specifically for the requirements of server groups hosting remote desktops or remote applications.
• Terminal Services / Remote Desktop Web Access allows individual remote applications or complete remote desktops to be launched from a webpage.
• Terminal Services / Remote Desktop Gateway enables users to connect to remote desktops or remote applications by tunneling RDP over HTTPS (HTTP with SSL encryption).

Before going into the details of these features and other enhancements of Windows Server 2008 R2 Remote Desktop Services, it is advisable to learn about some basic things and know about the history leading to the development of the underlying technology.  Essentially, Remote Desktop Session Host servers – previously called Terminal Servers – allow administrators to install, configure, manage and maintain applications on central servers.  In many cases this is more efficient than deploying applications on local client computers.  Remote Desktop Session Host servers enable client devices – often referred to as thin clients and sometimes even called terminals – to connect to a desktop running on the central server.  Such a Remote Desktop Client can be either a physical device or remote client software executed on a computer in the network.  Each client is assigned a separate interactive user session on the server.

While being logged into such an interactive session, a user performs all operations on the server except operations directly related to physical local devices such as keyboard, mouse and monitor.  This concept opens up interesting and powerful options for the Windows Server platform because it can be used for the deployment of centrally managed desktops and applications in corporate environments with computer networks that may even be widely dispersed geographically.

The multiple-user function of a Remote Desktop Session Host server should not be confused with the function that allows multiple users to be connected to server resources through the network in a more general sense.  Multi-user service without interactive logon to the server's user interface is frequently used for file, print, or directory services.  In contrast, RD Session Host servers allow multiple interactive user sessions in parallel, with each of the sessions providing a full user desktop or another kind of graphical user shell.

But why are people using RD Session Host servers?  Historically the primary design objective of remote desktop servers was to redirect the display of interactive user sessions and many kinds of Windows-based applications to multiple client hardware platforms.  To function properly, the applications had to be able to run as is on Windows Server with Terminal Services or Remote Desktop Services activated.  The objective was to reduce operating costs, especially in corporate environments, implying that RD Session Host servers provide a powerful option for delivering and updating software.

In a nutshell, an RD Session Host server is a host computer on which several users can work simultaneously while their screens can be displayed remotely.  Now the question is if an RD Session Host server behaves more like a server or a workstation.  The answer is far from being simple; an application server for several simultaneous users, who are logged on interactively to a single machine, acts both as a server and as a workstation, depending on one's point of view.

That being said the central question is still not answered adequately.  Why would small, medium and large enterprises want to introduce or maintain RD Session Host servers?  In the past the answer was quite simple; the reasons were economics and quality of service.  Enterprises wanted to reduce costs based on usage and apply management based on policies.  Both worked very well with remote desktop servers.  This didn’t mean that IT managers and users particularly liked these servers for what they are; they only turned out to be very effective in reaching the goals mentioned previously.  Besides that, RD Session Host servers were mostly regarded as being unattractive, static and old-fashioned as host computers.

The advantages of RD Session Host servers in corporate environments started to vanish as new system management concepts and products were introduced for standard Windows applications.  Microsoft System Center Configuration Manager and other system management products allowed deploying and managing standard workstations almost as efficiently as RD Session Host servers, even if the workstations were geographically distributed.  Infrastructure and operations maturity had improved, apparently leaving remote desktop servers behind.  This was particularly true in agile environments where both infrastructure and application sets are very dynamic.  While RD Session Host servers still were able to provide high stability, good manageability and relatively low costs in traditional medium and large enterprises, they seemed not to be suitable for smaller or more agile environments.

However, common practices show that RD Session Host servers were and still are particularly useful for many organizations.  The following scenarios outline a collection of typical use cases:

• Delivering line-of-business applications from a data center, in particular if the application requires frequent updates or maintenance activities.
• Providing applications that rely on access to a centralized data source.
• Hosting applications or even full desktops for users in remote locations with bandwidth constraints, preventing large amounts of application data to be transmitted over the network connection.
• Delivering a highly standardized and controlled application environment to users.
• Allowing traveling users access to their line-of-business applications from mobile devices.
• Supporting heterogeneous client platforms, for example a mixture of Windows and Apple Macintosh workstations.

With Windows Server 2008 and Windows Server 2008 R2, Remote Desktop Services finally became a commodity.  Combined with other technologies, such as hardware virtualization and application isolation and streaming, RD Session Host servers are a lot more agile and adaptable to increased business requirements than ever before.  In combination with the typical RD Session Host server advantages in terms of stability, manageability and costs, such a technology mix has a bright future in many organizations.