Remote Desktop Protocol

from Wikipedia, the free encyclopedia
RDP in the TCP / IP protocol stack :
application RDP
transport TCP
Internet IP ( IPv4 , IPv6 )
Network access Ethernet Token
bus 		Token
ring 		FDDI ...

The Remote Desktop Protocol ( RDP ) is a proprietary network protocol from Microsoft for remote access to Windows computers. It enables the display and control of the screen content of a remote computer . The Remote Desktop Protocol regulates how the Terminal Services ( Remote Desktop Services , formerly Terminal Services ) are addressed and used under Microsoft Windows NT . The service is usually provided on port TCP 3389. From version 8.0 of the Remote Desktop Protocol, UDP 3389 is also used.

history

Microsoft licensed the Multiwin technology from Citrix in order to publish the Windows Terminal Server product based on it in 1998 . Multiwin made it possible to run multiple user sessions at the same time.

The ICA protocol , which Citrix used for its own product, WinFrame , was not part of the licensing agreement. Instead, Microsoft developed the RDP protocol as an extension of the T.Share protocol ( T.Share was the name for the T.128 protocol in its design phase).

functionality

With RDP, one of the two systems acts as a terminal server . This generates screen output on the terminal client. In addition, mouse and keyboard input can be received by the terminal client. There are two possibilities: The remote output on the terminal client can either be the only output that the terminal server generates for this session, or the actual screen output of the session takes place on a local screen of the terminal server and the terminal client only receives a copy of the output. In addition to screen outputs and keyboard and mouse inputs, RDP can also be used to redirect the session audio to the terminal client. It is also possible to use a printer and access the storage media of the terminal client.

Depending on the intended use, the user of the terminal client is able to "observe" the workstation of his terminal server or even to control it remotely. RDP regulates the transmission of screen contents as well as keyboard and mouse inputs over the network.

RDP is based on the ITU protocol T.128 and is a protocol of levels 4–7 of the OSI model . It does not depend on the Transmission Control Protocol or any other lower-level protocol.

Attack opportunities

Due to a design weakness of this protocol in versions prior to 6.1, it is possible that employees in a network can access sensitive data via ARP spoofing . However, it is possible to additionally secure RDP connections using Transport Layer Security (TLS), which guarantees secure authentication.

RDP server

Windows NT 4.0 , Windows Server 2000 , 2003 , 2008 , 2012 , 2016 and 2019 , NetMeeting , Windows XP , Windows Vista , Windows 7 , Windows 8 and Windows 10 are used as servers for RDP . Third-party terminal servers (RDP) for Windows include: B. Thinstuff XP / VS Server, Thinsoft Winconnect Server and AADS Terminal Server. Clients like mstsc.exe exist for almost all operating systems. Since Windows XP, RDP has been used as standard for remote maintenance of Windows computers ( remote support ).

Versions

4.0-5.2

RDP version 5.1 has been available since Windows XP Service Pack 1. Remote Desktop Protocol 5.2 is a component of Windows XP Professional SP2.

6.0

With the introduction of RDP Version 6.0, which is part of Windows Vista, the range of functions has been changed considerably and the encryption has been revised. Among other things were

  • Font smoothing
  • Support of multi-monitor systems with a maximum of 4096 (w) × 2048 (h) pixels , Aero (Glass) and WPF functions
  • as well as a new script system

introduced.

7.0

RDP version 7.0 has been available for Windows XP SP3, Windows Vista SP1 and Windows Vista SP2 since October 2009. This version adds over 10 new functions that are available for connections to Windows 7 or Windows Server 2008 R2. Of these, 4 functions from Windows 7 are available on the client PC. Current client programs are available for Windows XP, Windows Server 2003, Windows Vista, Windows 7 and Mac OS X. The maximum resolution per monitor remains unchanged, but can now add up to 32766 × 32766 pixels.

8.0-8.1

This version appeared together with Windows 8 and Windows Server 2012 . At the end of October 2012, Microsoft published the Remote Desktop Protocol 8.0 updates for Windows 7 SP1 and Windows Server 2008 R2 (also via Windows update and MS download center (KB2592687) and (KB2574819)), which allow the use of the new functions when accessing a Windows Server 2012 as well as on a Windows 8 (pro, enterprise) allowed. The remote desktop application (mstsc.exe) was updated to version 6.2.9200 and thus supports the remote desktop version 8.0. With the update KB2923545 the version was increased to 8.1. The maximum resolution per monitor increases to 8192 × 8192 pixels.

10

This version is included for the first time in Windows 10 1511 Update and in Windows Server 2016 Technical Preview 4, it includes new features such as AutoSize Zoom and improvements in graphics compression with the help of H.264 / AVC.

Support of other operating systems

For Linux , FreeBSD , macOS , AmigaOS , MorphOS , Android , Apple iOS and Chrome OS, there are clients that allow access to Windows RDP servers. There are also commercial Java clients that can be used on different operating systems.

The first RDP Java client ( HOBLink JWT ) was presented at CeBIT in 2000 . This enabled access to RDP servers under numerous operating systems with the aid of the Java platform.

At the CeBIT trade fair in March 2005, the first commercial RDP server for Linux was presented (Thinstuff LX Server ). This software enables the use of RDP clients to connect to X11 servers.

There is also a free RDP server called xrdp available.

The virtualization software VirtualBox from Oracle has its own RDP server, which is compatible with rdesktop and the Microsoft client.

See also

Web links

Individual evidence

  1. ↑ Understanding the Remote Desktop Protocol (RDP) . Microsoft. Retrieved September 28, 2012.
  2. ↑ Dirk Knop: Small eavesdropping against Windows remote maintenance ; Article on heise Security from July 26, 2005.
  3. ↑ Torsten Weber: Terminal Services 6, using authentication options against man-in-the-middle under Vista, XP for servers ; Article on security via TLP for RDP client <> Server 2003 from December 1, 2007.
  4. ↑ thinstuff.com
  5. ↑ thinsoftinc.com
  6. ↑ aads-worldwide.hk
  7. ↑ Remote Desktop Protocol Maximum Supported Resolutions. Microsoft , accessed January 1, 2018 .
  8. ↑ Notes on the Client Update for Remote Desktop Connection 7.0 for Remote Desktop Services (RDS) for Windows XP SP3, Windows Vista SP1 and Windows Vista SP2. Microsoft , September 24, 2011, accessed September 26, 2012 .
  9. ↑ Karri Alexion-Tiernan: Microsoft Desktop Virtualization: Taking another step forward with UE-V and VDI. Microsoft, The Windows Blog, June 20, 2012, accessed September 26, 2012 .
  10. ↑ termserv: Remote Desktop Protocol 8.1 Update for Windows 7 SP1 released to web. (No longer available online.) Microsoft on November 12, 2013, archived from the original on July 25, 2016 ; accessed on July 25, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / blogs.technet.microsoft.com
  11. ↑ Jeroen van Eesteren: Remote Desktop Protocol (RDP) 10 AVC / H.264 improvements in Windows 10 and Windows Server 2016 Technical Preview. Microsoft, January 11, 2016, accessed June 29, 2016 .
  12. ↑ News: HOB at CeBIT 2000. Retrieved on September 24, 2018 .
  13. ↑ Thinstuff 2012: News - Thinstuff. Retrieved September 24, 2018 .