Remote Desktop Services (RDS), known as Terminal Services in

Windows Server 2008 Windows Server 2008 is the fourth release of the Windows Server operating system produced by Microsoft as part of the Windows NT family of the operating systems. It was released to manufacturing on February 4, 2008, and generally to retail on F ...

and earlier, is one of the components of

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...

that allow a user to initiate and control an interactive session on a

remote computer In computing, the term remote desktop refers to a software- or operating system feature that allows a personal computer's desktop environment to be run remotely off of one system (usually a PC, but the concept applies equally to a server or a ...

virtual machine In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized h ...

over a

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematic ...

connection. RDS was first released in 1998 as ''Terminal Server'' in Windows NT 4.0 Terminal Server Edition, a stand-alone edition of Windows NT 4.0 Server that allowed users to log in remotely. Starting with

Windows 2000 Windows 2000 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It was the direct successor to Windows NT 4.0, and was released to manufacturing on December 15, 1999, and was offici ...

, it was integrated under the name of ''Terminal Services'' as an optional component in the server editions of the

Windows NT Windows NT is a proprietary graphical operating system produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system. The first version of Win ...

family of operating systems, receiving updates and improvements with each version of Windows. Terminal Services were then renamed to ''Remote Desktop Services'' with Windows Server 2008 R2 in 2009. RDS is

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ...

's implementation of

thin client In computer networking, a thin client is a simple (low-performance) computer that has been optimized for establishing a remote connection with a server-based computing environment. They are sometimes known as ''network computers'', or in th ...

architecture, where Windows software, and the entire desktop of the computer running RDS, are made accessible to any remote client machine that supports

Remote Desktop Protocol Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP client software for this purpose, while ...

(RDP). User interfaces are displayed from the server onto the client system and input from the client system is transmitted to the server - where software execution takes place. This is in contrast to

application streaming Application streaming is a form of on-demand software distribution. In these scenarios, only essential portions of an application's code need to be installed on the computer: while the end user performs actions in the application, the necessary c ...

systems, like

Microsoft App-V Microsoft Application Virtualization (also known as App-V; formerly Softricity SoftGrid) is an application virtualization and application streaming solution from Microsoft. It was originally developed by Softricity, a company based in Boston, Ma ...

, in which computer programs are streamed to the client on-demand and executed on the client machine. RemoteFX was added to RDS as part of Windows Server 2008 R2 Service Pack 1.

Overview

Windows includes three client components that use RDS: #

Windows Remote Assistance Quick Assist is a Microsoft Windows feature that allows a user to view or control a remote Windows computer over a network or the Internet to resolve issues without directly touching the unit. It is based on the Remote Desktop Protocol (RDP). It ...

– only Windows 10 and later # Remote Desktop Connection (RDC) #

Fast user switching Fast user switching is a feature of a multi-user operating system which allows users to switch between user accounts without quitting applications and logging out. In Linux The Linux kernel's VT subsystem dates back to 1993 and does not under ...

The first two are individual utilities that allow a user to operate an interactive session on a remote computer over the network. In case of Remote Assistance, the remote user needs to receive an invitation and the control is cooperative. In case of RDC, however, the remote user opens a new session on the remote computer and has every power granted by its user account's rights and restrictions. Fast User Switching allows users to switch between user accounts on the local computer without quitting software and logging out. Fast User Switching is part of

Winlogon In computing, Winlogon (Windows Logon) is the component of Microsoft Windows operating systems that is responsible for handling the secure attention sequence, loading the user profile on logon, and optionally locking the computer when a screensa ...

and uses RDS to accomplish its switching feature. Third-party developers have also created client software for RDS. For example,

rdesktop rdesktop is an implementation of a client software for Microsoft's proprietary Remote Desktop Protocol (RDP). Rdesktop is free and open-source software, subject to the requirements of the GNU General Public License (GPL-3.0-or-later), and is avai ...

supports

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, ...

platforms. Although RDS is shipped with most editions of all versions of Windows NT since Windows 2000, its functionality differs in each version.

Windows XP Home Edition Windows XP, which is the next version of Windows NT after Windows 2000 and the successor to the consumer-oriented Windows Me, has been released in several editions since its original release in 2001. Windows XP is available in many languages. In ...

does not accept any RDC connections at all, reserving RDS for Fast User Switching and Remote Assistance only. Other client versions of Windows only allow a maximum of one remote user to connect to the system at the cost of the user who has logged onto the console being disconnected.

Windows Server Windows Server (formerly Windows NT Server) is a group of operating systems (OS) for servers that Microsoft has been developing since July 27, 1993. The first OS that was released for this platform was Windows NT 3.1 Advanced Server. With the r ...

allows two users to connect at the same time. This licensing scheme, called "Remote Desktop for Administration", facilitates

administration Administration may refer to: Management of organizations * Management, the act of directing people towards accomplishing a goal ** Administrative Assistant, traditionally known as a Secretary, or also known as an administrative officer, admini ...

of unattended or

headless computer A headless computer is a computer system or device that has been configured to operate without a monitor (the missing "head"), keyboard, and mouse. A headless system is typically controlled over a network connection, although some headless system ...

s. Only by acquiring additional licenses (in addition to that of Windows) can a computer running

service multiple remote users at one time and achieve virtual desktop infrastructure. For an organization, RDS allows the IT department to install applications on a central server instead of multiple computers. Remote users can log on and use those applications over the network. Such centralization can make maintenance and troubleshooting easier. RDS and Windows authentication systems prevent unauthorized users from accessing apps or data. Microsoft has a long-standing agreement with

Citrix Citrix Systems, Inc. is an American multinational cloud computing and virtualization technology company that provides server, application and desktop virtualization, networking, software as a service (SaaS), and cloud computing technologi ...

to facilitate sharing of technologies and

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

licensing A license (or licence) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another party (licensee) as an element of an agreeme ...

between Microsoft Terminal Services and

Citrix XenApp Citrix Virtual Apps (formerly WinFrame, MetaFrame, Presentation Server and XenApp) is an application virtualization software produced by Citrix Systems that allows Windows applications to be accessed via individual devices from a shared serve ...

(formerly Citrix MetaFrame and Citrix Presentation Server). In this arrangement, Citrix has access to key

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the ...

for the Windows platform, enabling its developers to improve the security and performance of the Terminal Services platform. In late December 2004 the two companies announced a five-year renewal of this arrangement to cover

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

Server components

The key server component of RDS is ''Terminal Server'' (termdd.sys), which listens on TCP port 3389. When a

(RDP) client connects to this port, it is tagged with a unique ''SessionID'' and associated with a freshly spawned console session (Session 0, keyboard, mouse and character mode UI only). The login subsystem (winlogon.exe) and the GDI graphics subsystem is then initiated, which handles the job of authenticating the user and presenting the GUI. These executables are loaded in a new session, rather than the console session. When creating the new session, the graphics and keyboard/mouse device drivers are replaced with RDP-specific drivers: RdpDD.sys and RdpWD.sys. The RdpDD.sys is the device driver and it captures the UI rendering calls into a format that is transmittable over RDP. RdpWD.sys acts as keyboard and mouse driver; it receives keyboard and mouse input over the TCP connection and presents them as keyboard or mouse inputs. It also allows creation of ''virtual channels'', which allow other devices, such as disc, audio, printers, and COM ports to be redirected, i.e., the channels act as replacement for these devices. The channels connect to the client over the TCP connection; as the channels are accessed for data, the client is informed of the request, which is then transferred over the TCP connection to the application. This entire procedure is done by the terminal server and the client, with the RDP mediating the correct transfer, and is entirely transparent to the applications. RDP communications are encrypted using 128-bit

RC4 In cryptography, RC4 (Rivest Cipher 4, also known as ARC4 or ARCFOUR, meaning Alleged RC4, see below) is a stream cipher. While it is remarkable for its simplicity and speed in software, multiple vulnerabilities have been discovered in RC4, ren ...

encryption. Windows Server 2003 onwards, it can use a

FIPS 140 The 140 series of Federal Information Processing Standards ( FIPS) are U.S. government computer security standards that specify requirements for cryptography modules. , FIPS 140-2 and FIPS 140-3 are both accepted as current and active. FIPS 14 ...

compliant encryption schemes. Once a client initiates a connection and is informed of a successful invocation of the terminal services stack at the server, it loads up the device as well as the keyboard/mouse drivers. The UI data received over RDP is decoded and rendered as UI, whereas the keyboard and mouse inputs to the Window hosting the UI is intercepted by the drivers, and transmitted over RDP to the server. It also creates the other virtual channels and sets up the redirection. RDP communication can be encrypted; using either low, medium or high encryption. With low encryption, user input (outgoing data) is encrypted using a weak (40-bit RC4) cipher. With medium encryption, UI packets (incoming data) are encrypted using this weak cipher as well. The setting "High encryption (Non-export)" uses 128-bit RC4 encryption and "High encryption (Export)" uses 40-bit RC4 encryption.

Terminal Server

Terminal Server is the server component of Terminal services. It handles the job of authenticating clients, as well as making the applications available remotely. It is also entrusted with the job of restricting the clients according to the level of access they have. The Terminal Server respects the configured software restriction policies, so as to restrict the availability of certain software to only a certain group of users. The remote session information is stored in specialized directories, called ''Session Directory'' which is stored at the server. Session directories are used to store state information about a session, and can be used to resume interrupted sessions. The terminal server also has to manage these directories. Terminal Servers can be used in a

cluster may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Asteroid cluster, a small asteroid family * Cluster II (spacecraft), a European Space Agency mission to study th ...

as well. In

, it has been significantly overhauled. While logging in, if the user logged on to the local system using a

Windows Server Domain A Windows domain is a form of a computer network in which all user accounts, computers, printers and other security principals, are registered with a central database located on one or more clusters of central computers known as domain controll ...

account, the credentials from the same sign-on can be used to authenticate the remote session. However, this requires Windows Server 2008 to be the terminal server OS, while the client OS is limited to Windows Server 2008, Windows Vista and

Windows 7 Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on July 22, 2009, and became generally available on October 22, ...

. In addition, the terminal server may be configured to allow connection to individual programs, rather than the entire desktop, by means of a feature named

RemoteApp Remote Desktop Services (RDS), known as Terminal Services in Windows Server 2008 and earlier, is one of the components of Microsoft Windows that allow a user to initiate and control an interactive session on a remote computer or virtual machine ...

. Terminal Services Web Access (TS Web Access) makes a RemoteApp session invocable from the

web browser A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used o ...

. It includes the TS Web Access Web Part control which maintains the list of RemoteApps deployed on the server and keeps the list up to date. Terminal Server can also integrate with

Windows System Resource Manager Windows System Resource Manager (WSRM) is a component of Windows Server operating systems that enables the allocation of resources, including CPU and memory resources, among multiple applications based on business priorities. An administrator sets ...

to throttle resource usage of remote applications. Terminal Server is managed by the ''Terminal Server Manager''

Microsoft Management Console Microsoft Management Console (MMC) is a component of Microsoft Windows that provides system administrators and advanced users an interface for configuring and monitoring the system. It was first introduced in 1998 with the Option Pack for Window ...

snap-in. It can be used to configure the sign in requirements, as well as to enforce a single instance of remote session. It can also be configured by using

Group Policy Group Policy is a feature of the Microsoft Windows NT family of operating systems (including Windows 7, Windows 8.1, Windows 10, Windows 11, and Windows Server 2003+) that controls the working environment of user accounts and computer accounts. G ...

Windows Management Instrumentation Windows Management Instrumentation (WMI) consists of a set of extensions to the Windows Driver Model that provides an operating system interface through which instrumented components provide information and notification. WMI is Microsoft's im ...

. It is, however, not available in client versions of Windows OS, where the server is pre-configured to allow only one session and enforce the rights of the user account on the remote session, without any customization.

Remote Desktop Gateway

The Remote Desktop Gateway service component, also known as RD Gateway, can

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the RDP session using a

HTTPS Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP). It is used for secure communication over a computer network, and is widely used on the Internet. In HTTPS, the communication protocol is enc ...

channel. This increases the security of RDS by encapsulating the session with

Transport Layer Security Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in securi ...

(TLS). This also allows the option to use

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems (in ...

as the RDP client. The official MS RDP client for

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and la ...

supports RD Gateway as of version 8. This is also available for iOS and Android. This feature was introduced in the Windows Server 2008 and Windows Home Server products. In October 2021, Thincast, the main contributor of the FreeRDP project, published the first Remote Desktop Gateway solution running natively on Linux.

Remote Desktop HTML5 Web Client

In late 2018 Microsoft released the Remote Desktop HTML5 Web Client. The client allows users to connect to their remote apps or to their remote desktops without using an installed remote desktop client. The web client uses the TLS secured port 443 and does not use the RD Gateway to transport traffic, instead relying solely on the remote desktop session host aspect of remote desktop services.

Roles

;Remote Desktop Gateway: Enables authorized users to connect to virtual desktops, Remote-App programs, and session-based desktops over a private network or the Internet. ;Remote Desktop Connection Broker Role: Allows users to reconnect to their existing virtual desktop, RemoteApp programs, and session-based desktops. It enables even load distribution across RD Session Host servers in a session collection or across pooled virtual desktops in a pooled virtual desktop collection, and provides access to virtual desktops in a virtual desktop collection. ;Remote Desktop Session Host: Enables a server to host RemoteApp programs as session-based desktops. Users can connect to RD Session Host servers in a session collection to run programs, save files, and use resources on those servers. Users can access Remote Desktop Session Host server by using the Remote Desktop Connection client or by using RemoteApp programs. ;Remote Desktop Virtualization Host: Enables users to connect to virtual desktops by using RemoteApp and Desktop Connection. ;Remote Desktop Web Access: Enables users to access RemoteApp and Desktop Connection through the Start Menu or through a web browser. RemoteApp and Desktop Connection provides users with a customized view of RemoteApp programs, session-based desktops, and virtual desktops. ;Remote Desktop Licensing: Enables a server to manage RDS client access licenses (RDS CALs) that are required for each device or user to connect to a Remote Desktop Session Host server. RDS CALs are managed using the Remote Desktop Licensing Manager application.

RemoteApp

RemoteApp (or TS RemoteApp) is a special mode of RDS, available in Windows Server 2008 R2 and later, where remote session configuration is integrated into the client operating system. The RDP 6.1 client ships with Windows XP SP3, KB952155 for Windows XP SP2 users, Windows Vista SP1 and Windows Server 2008. The UI for the RemoteApp is rendered in a window over the local desktop, and is managed like any other window for local applications. The end result of this is that remote applications behave largely like local applications. The task of establishing the remote session, as well as redirecting local resources to the remote application, is transparent to the end user. Multiple applications can be started in a single RemoteApp session, each with their own windows. A RemoteApp can be packaged either as a .rdp file or distributed via an .msi Windows Installer package. When packaged as an .rdp file (which contains the address of the RemoteApp server, authentication schemes to be used, and other settings), a RemoteApp can be launched by double clicking the file. It will invoke the Remote Desktop Connection client, which will connect to the server and render the UI. The RemoteApp can also be packaged in a Windows Installer database, installing which can register the RemoteApp in the

Start menu The Start menu is a graphical user interface element used in Microsoft Windows since Windows 95 and in other operating systems. It provides a central launching point for computer programs and performing other tasks in the Windows shell. It is name ...

as well as create shortcuts to launch it. A RemoteApp can also be registered as handler for file types or URIs. Opening a file registered with RemoteApp will first invoke Remote Desktop Connection, which will connect to the terminal server and then open the file. Any application which can be accessed over Remote Desktop can be served as a RemoteApp.

includes built-in support for RemoteApp publishing, but it has to be enabled manually in registry, since there is no RemoteApp management console in client versions of Microsoft Windows.

Windows Desktop Sharing

onwards, Terminal Services also includes a multi-party desktop sharing capability known as Windows Desktop Sharing. Unlike Terminal Services, which creates a new user session for every RDP connection, Windows Desktop Sharing can host the remote session in the context of the currently logged in user without creating a new session, and make the Desktop, or a subset of it, available over RDP. Windows Desktop Sharing can be used to share the entire desktop, a specific region, or a particular application. Windows Desktop Sharing can also be used to share multi-monitor desktops. When sharing applications individually (rather than the entire desktop), the windows are managed (whether they are minimized or maximized) independently at the server and the client side. The functionality is only provided via a public API, which can be used by any application to provide screen sharing functionality. Windows Desktop Sharing API exposes two objects: RDPSession for the sharing session and RDPViewer for the viewer. Multiple viewer objects can be instantiated for one Session object. A viewer can either be a passive viewer, who is just able to watch the application like a

screencast A screencast is a digital recording of computer screen output, also known as a video screen capture or a screen recording, often containing audio narration. The term ''screencast'' compares with the related term ''screenshot''; whereas screensho ...

, or an interactive viewer, who is able to interact in real time with the remote application. The RDPSession object contains all the shared applications, represented as Application objects, each with Window objects representing their on-screen windows. Per-application filters capture the application Windows and package them as Window objects. A viewer must authenticate itself before it can connect to a sharing session. This is done by generating an Invitation using the RDPSession. It contains an authentication ticket and password. The object is serialized and sent to the viewers, who need to present the Invitation when connecting. Windows Desktop Sharing API is used by

Windows Meeting Space Windows Meeting Space (codenamed Windows Shared View and formerly Windows Collaboration) was a peer-to-peer collaboration program developed by Microsoft for Windows Vista as a replacement for Windows NetMeeting and it enables application sharing, ...

and

for providing application sharing functionality among network peers.

Client software

Remote Desktop Connection

Remote Desktop Connection (RDC, also called Remote Desktop or just RD, formerly Microsoft Terminal Services Client, mstsc or tsclient) is the client application for RDS. It allows a user to remotely log into a networked computer running the terminal services server. RDC presents the desktop interface (or application GUI) of the remote system, as if it were accessed locally. In addition to regular username/password for authorizing for the remote session, RDC also supports using smart cards for authorization. With RDC 6.0, the resolution of a remote session can be set independently of the settings at the remote computer. With version 6.0, if the ''Desktop Experience'' component is plugged into the remote server, remote application user interface elements (e.g., application windows borders, Maximize, Minimize, and Close buttons etc.) will take on the same appearance of local applications. In this scenario, the remote applications will use the Aero theme if the user connects to the server from a Windows Vista machine running Aero. Later versions of the protocol also support rendering the UI in full 32-bit color, as well as resource redirection for printers, COM ports, disk drives, mice and keyboards. With resource redirection, remote applications can use the resources of the local computer. Audio is also redirected, so that any sounds generated by a remote application are played back at the client system. Moreover, a remote session can also span multiple monitors at the client system, independent of the multi-monitor settings at the server. RDC can also be used to connect to Windows Media Center (WMC) remote sessions; however, since WMC does not stream video using RDP, only the applications can be viewed this way, not any media. RDC prioritizes UI data as well as keyboard and mouse inputs, as opposed to print jobs or file transfers. so as to make the applications more responsive. It redirects plug and play devices such as cameras, portable music players, and scanners, so that input from these devices can be used by the remote applications as well. RDC can also be used to connect to computers which are exposed via Windows Home Server RDP Gateway over the

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, p ...

. Finally, few shortcuts that will be handy * To achieve effect on remote desktop, you can use the key combination. * To alternate between the full screen and window mode of remote desktop, you can use ( on certain HP laptops).

Other clients

Microsoft produces an official client for a variety of non Windows platforms: * Windows Mobile * MacOS: Microsoft Remote Desktop for Mac * Android: Microsoft Remote Desktop * iOS and iPadOS: Microsoft Remote Desktop There have been numerous non-Microsoft implementations of clients that implement subsets of the Microsoft functionality for a range of platforms. The most common are:
FreeRDP
- Open Source under Apache license *

for Linux/Unix and Microsoft Windows * Remmina for Linux (based on FreeRDP) * CoRD for macOS (Discontinued in April 2020)
Thincast Client
for Linux, macOS and Windows

References

External links

Welcome to Remote Desktop Services

Download Chrome Remote Desktop
{{remote administration software Microsoft server technology Remote desktop Windows communication and services Windows remote administration software Windows components