The latest version of Remote Desktop Services, available in Windows Server 2012, improves longstanding capabilities -- and adds new ones -- that can help you deliver desktops and applications and still maintain a good user experience.
Remote Desktop Services (RDS), formerly Microsoft Terminal Services, is a group of server-based computing technologies that offer much of the same functionality as virtual desktop infrastructure (VDI), but there are differences.
RDS gives end users the ability to access their applications and desktop images remotely. End users can access their remote sessions from myriad physical platforms via a client or through an HTML5 browser. Because remote desktop sessions are delivered from a pool of generic desktop images, RDS is best suited for employees who don't need personal desktops, such as call center workers. VDI, on the other hand, can be used by knowledge workers who need personalized desktops. RDS' CPU and memory requirements are often lower than more robust VDI implementations because there are fewer Windows instances running.
You can build RDS to be downtime resistant by using clusters or server farms. This lets you scale infrastructure up or down based on demand. RDS instances also have the advantage of running on local storage. This keeps storage costs down, compared with full-fledged VDI which is notorious for increasing storage costs.
Here's a quick overview of the RDS Windows Server 2012 components:
Remote Desktop Connection Broker connects users with their remote desktops. If the connection to the remote desktop drops, the Broker lets the user re-establish the connection without resetting the virtual desktop's state. The Broker is aware of both remote and VDI sessions, which has not been the case in past iterations of RDS in Windows Server.
Remote Desktop Gateway assigns end users to a desktop or RemoteApp program over the WAN or Internet.
Remote Desktop Session Host (RDSH) lets a server host session-based desktops or RemoteApps.
Remote Desktop Virtualization Host is the server that hosts the virtual desktops.
Remote Desktop Web Access lets users access remote desktops or RemoteApps from the Start menu or a browser.
RemoteApp lets you deliver virtual applications to users instead of (or in addition to) full desktops. RemoteApp integrates with the desktop and makes applications appear as if they're running locally on users' devices. RemoteApp can bridge application compatibility issues that may come from using RDS to host sessions.
RemoteFX is a suite of improvements to the Remote Display Protocol (RDP) that enhances the display experience for remote users, even on bandwidth-constrained networks. RemoteFX also improves access to peripherals such as those attached by USB port.
In Windows Server 2008 R2, RemoteFX only used TCP, but in Server 2012 it can also use UDP to deliver packets. TCP ensures the connection while it's delivering data, and it resends any data that may not make it the first time. UDP doesn't confirm when packets are sent, which means it's faster for sending media messages. And if you have DirectX 11-capable GPU cards, you can use RemoteFX vGPU to virtualize graphics-intensive applications. This works in Windows Server 2012 and Windows 8, but not Server 2008 R2 or Windows 7.
Session shadowing lets you remotely monitor or control another user's active session on an RDSH server in Windows Server 2012 R2. Shadowing was removed in Windows Server 2012, but it returned in Server 2012 R2.
Quick reconnect for Remote Desktop Clients improves connection performance in Windows Server 2012 R2 because it lets users quickly reconnect to their existing virtual or session-based desktops, as well as their applications if the network drops.
Online data deduplication lets you reduce disk size on collections of desktops with virtual hard disks stored on a Windows Server 2012 R2 file server.
Should you use RDS?
When it comes down to choosing a way to deliver desktops and applications to users, simplicity is a major factor to consider. Microsoft RDS is fairly simple to manage and maintain, and rarely requires third-party products to achieve the desired end-user experience.
Another important consideration when weighing RDS is licensing cost. A Standard edition Windows Server 2012 license costs $882 per server. To use RDS, you need RDS Client Access Licenses (CALs) for each device or user who accesses the server. The per-device CAL for RDS in Windows Server 2012 R2 costs $102 per year and the per-user CAL comes in at $118 per year.