Support for Windows Terminal Server (WTS) and Citrix MetaFrame

This document provides a brief overview of the Windows Terminal Server (WTS) and Citrix XenApp (formerly MetaFrame) technology, discusses ArcGIS Desktop and ArcInfo Workstation, support for this technology, and documents the current software limitations. Latest Update 02/15/2006: Document has been updated with information regarding ArcGIS Licensing Support on Citrix or Windows Terminal Server (WTS) Platforms.

Below is information regarding the Windows Terminal Server (WTS) and Citrix XenApp (formerly MetaFrame) technology, ArcGIS Desktop and ArcInfo Workstation support for this technology, and current software limitations or known issues:

Updated 7/22/2005: Document has been updated for WTS working with ArcGIS 9.1 and Seat Licensing, as well as ESRI_SOFTWARE_CLASS variable issues with ArcMap.

Updated 8/03/2005: Document has been updated to reflect recent changes in Digitizer support.

Updated 09/20/2005: Document has been updated to reflect changes in ESRI Support of WTS / Citrix configurations.

Updated 01/03/2006: Document has been updated with information regarding a Microsoft 'Font Smoothing' limitation

Updated 02/16/2006: Document has been updated with added a section regarding the Licensing Support of ArcGIS running on Citrix or Windows Terminal Server (WTS) Platforms

Technology Overview

Windows Terminal Server is a multi-user server operating system that provides the ability to host multiple simultaneous thin-client sessions on remote client devices. All client processing is performed locally at the Terminal Server and only display, keystroke, and mouse commands are transmitted over the network to the client device. Two types of thin-client protocols are supported with WTS:

1. The Remote Desktop Protocol (RDP) from Microsoft and

2. The Independent Computing Architecture (ICA) protocol from Citrix.

RDP is an International Telecommunications Union's T.120 based multi-channel protocol developed originally by Microsoft for such applications as Microsoft NetMeeting. It utilizes TCP/IP as its transport protocol and is designed to use low network bandwidth and supports multi-level data encryption. With RDP, clients can either be a Windows-based terminal with RDP built-in, or a personal computer running Windows 95/98/ME/NT/2000/XP.

Citrix Presentation Server enables applications to be centrally deployed and managed while providing easy, secure, instant access for any user anywhere—for lower total cost of ownership (TCO), security, availability, and performance for client/server applications. This application virtualization solution—used by more than 180,000 customers worldwide—provides a secure, centralized architecture that makes it easy to handle the complexities of application delivery across business-critical environments. Presentation Server extends the Microsoft Windows Terminal Services base-level functionality by enhancing the end-user experience, manageability, compatibility, security and control, and scalability. Presentation Server relies on the Independent Computing Architecture (ICA) protocol and can be used in place of or in conjunction with RDP. One of the key aspects of ICA is that it allows non-Windows clients to access Terminal Services. Examples of this are X-terminal (Unix) clients, Macintosh clients, Windows CE clients, etc. Therefore, ICA allows for the efficient use of existing hardware in a heterogeneous environment.

With Windows NT 4.0, a separate version of the operating system is utilized called Windows NT 4.0 Server, Terminal Server Edition. With Windows 2000 Server and Windows Server 2003, terminal server functionality is integrated into the core operating system as Terminal Services.

Windows Terminal Server and Citrix implementations have a number of advantages:

• Applications and data access are moved to the computer room, reducing network bandwidth requirements
• Relieves the need to regularly upgrade client workstations to keep up with increasing software system demand
• Administration is centralized resulting in a reduction in administration costs
• Ability to rapidly deploy applications, including Web based deployment options
• Since the applications run on a powerful central server, end-client performance increases are often observed
• Provides a secure computing environment since all data can be protected in the server room while only displays are sent to the client device.

ESRI Support for WTS / Citrix configurations

Windows Terminal Server and/or Citrix configurations and ESRI software have been successfully implemented at several GIS sites. However, there are some software limitations that should be considered prior to implementing such configurations. To assist in troubleshooting ArcGIS software issues within a WTS (RDP) or Citrix (ICA) environment, the issue should be reproducible within the WTS server environment only. See ArcGIS WTS Troubleshooting Procedures (Related Information link at bottom of page) for details.

If the procedural criterion is met, please contact ESRI Technical Support, ESRI Technical Support for assistance. If the problem cannot be reproduced at the local console, then it is most likely not an ESRI software issue. For these cases, please contact Microsoft or Citrix technical support. In cases that appear to be a Citrix/ESRI integration issue, you can contact ESRI Enterprise Systems Lab personnel at sihelp@esri.com and they can potentially assist. Past experience has shown that most problems encountered are not related to WTS or Citrix directly, but are related to either a configuration issue, such as system permissions, or software issues that can also be reproduced in a non-WTS environment.

Color depth limitation
Certain application functionality requires more than 256 colors to function properly.  Examples are the use of transparency and raster imaging/printing within ArcGIS.  ArcGIS ArcMap transparency functionality does not work in a standard WTS environment and high-resolution imagery such as color ortho-photos may not display properly.

To ensure that color depth sensitive applications function properly with Windows 2000 Terminal Services, either Citrix MetaFrame 1.8 with Feature Release 1, or Citrix MetaFrameXP must be utilized.  These products allow for color depth increases to 65K high color and 16M true color, which provide adequate color depth for almost all applications.Windows Server 2003 Terminal Services supports color depth up to 65K colors.  
NOTE: Increasing the color depth can significantly increase the amount of network bandwidth utilized during raster-based operations and this may not be feasible for WAN users. Vector data performance is not typically affected by the added color depth.

Font Smoothing Limitation
Windows 2000 and Windows Server 2003 Operating Systems have a visual effect setting to help the display environment appear crisper when enabled called 'font smoothing'. This functionality is not supported for the Citrix ICA protocol or the Remote Desktop Protocol with Windows Server 2003. Users with complex text and annotation may find the text drawn on their map at an angle to be a bit more blurry than the text that draws horizontal to the page when using a thin-client protocol. This is a limitation of the Windows Server 2003 Operating System (MS KB302555) inherited by the ICA and RDP protocols and is not an issue that could be resolved at the ArcGIS application level. This setting is found under control panel >display > appearance tab >effects.

Graphics Intensive Applications Limitation
Extremely graphic intensive applications such as those involving fly-by 3D, etc., may not perform well under Terminal Services/Citrix and should be tested prior to deployment. Network bandwidth utilization can be extremely high with these types of applications and should be limited to LAN environments. Further, tasks involving constant display movement consume a CPU on the terminal server resulting in quick depletion of system resources with only a few users.

Digitizer support:

• ArcGIS Desktop: ArcMap digitizing using a digitizer table in a WTS session via a remapped client COM port is supported with a Wintab compliant driver. Not all Wintab compliant drivers work in a WTS/Citrix environment. Contact your digitizing tablet manufacturer to verify that there is a Wintab compliant driver that works in a WTS/Citrix environment.
  Update 8/03/05: The GTCO CalComp Wintab driver for WTS/Citrix has been replaced by the TabletWorks driver. The TabletWorks for Citrix and Terminal Services driver has been successfully tested with ArcGIS 9.x desktop. Refer to GTCO Calcomp's website (http://www.gtcocalcomp.com) to download driver.
  
• ArcView 3.x: ArcView GIS 3.x requires Wintab features that are not available in the GTCO CalComp WinTab driver for WTS/Citrix. Therefore it is currently not possible to digitize in a Citrix environment using ArcView 3.x. For thin-client digitizing it is recommended to upgrade to ArcGIS Desktop.
• ArcInfo Workstation: Digitizer support does work with Workstation ArcInfo (i.e., ArcEdit) via a Citrix session using the 32-bit ICA Client. Digizting in ArcInfo Workstation uses its own driver and therefore does not require a Wintab driver to communicate with the digitizer. Digitizing in ArcEdit has been successfully tested in a WTS environment.

Printing considerations:
There are several issues such as number of users, plot file size, location of clients, etc... to consider when designing a printer solution for a WTS / Citrix environment. Please review the following documents from Citrix to get details on a Citrix Printing solution:

Printing Architecture Solution

MetaFrame XP Printing Optimization Techniques

The Ultimate Guide to Terminal Server Printing - Design and Configuration

ArcGIS Licensing Support on Citrix or Windows Terminal Server (WTS) Platforms

Customers who need to use Citrix or WTS to provide access to GIS applications can do so using ArcGIS Concurrent Use Licenses (ArcView CU, ArcEditor CU, ArcInfo and CU Extensions). ESRI does NOT allow deployment of Single Use Licenses on Citrix or WTS platforms.

Accordingly, customers who develop applications using ArcGIS Engine can run their applications with standard Concurrent Use ArcGIS Desktop Licenses (ArcView CU, ArcEditor CU, ArcInfo and CU Extensions) on Citrix or WTS platforms. These ArcGIS Engine applications must specifically request an ArcView CU, ArcEditor CU, or ArcInfo license.

ArcGIS Seat Type Licensing
ArcGIS is built on a shared application architecture where only one application type is registered and used at any given time on a computer system. The application types are ArcInfo, ArcEditor, and ArcView. Since a WTS is a single system, the chosen application type determines which type of license is checked-out and will affect all users on that system. If you use the Desktop Administrator tool to switch between different license types, all users are affected and must be using the same desktop license mode to continue being operational.

ArcGIS Versions prior to Version 8.3: There is no software-based solution to this limitation in ArcGIS versions prior to Version 8.3. Therefore, if you have ArcInfo and ArcView users, for example, then the highest-level license would be required on the server (i.e., ArcInfo) to support all user needs. Or, separate servers would be required to run the applications, one for ArcInfo and one for ArcView, in this case.

ArcGIS Version 8.3 and higher: The ESRI_SOFTWARE_CLASS environment variable can be used on a per-user basis to dynamically change the desired application type and work around this limitation. It overrides the SOFTWARE_CLASS registry key for the user that sets the environment variable before launching ArcGIS. For example,when you launch ArcMap.exe it will become ArcView, ArcEditor or ArcInfo (and checkout the appropriate license too).

ESRI_SOFTWARE_CLASS=Viewer | Editor | Professional

NOTE: The values for the ESRI_SOFTWARE_CLASS are case sensitive. The first letter for each setting must appear with a capital letter followed by lower case (i.e . Viewer, Editor and Professional). If the values are set to all capital or lower case letters the ESRI_SOFTWARE_CLASS will not function properly.

The use of this variable overrides the currently configured license type configured in the Desktop Administrator, therefore allowing any user of a WTS/Citrix configuration with a single installation of ArcGIS desktop to switch to any desktop license mode. This variable can be set either in the user's profile or in a batch file that first sets the variable then launches ArcMap. The batch file can then be published as an application.

This is a list of issues with the ESRI_SOFTWARE_CLASS variable. In some instances the issues have been resolved in a subsequent version of ArcGIS and is noted where applicable:

1. ArcToolBox: During an ArcGIS installation, the ArcToolBox DLLs get registered based on the seat type of the installation (ArcInfo, ArcEditor, or ArcView) to restrict certain capability access. When you use the ESRI_SOFTWARE_CLASS variable to override the current license type, the DLLs associated with configuring ArcToolbox do not get re-registered. The user is therefore restricted to the original installation capability for ArcToolBox.
   Workaround: For ArcGIS 8.3, it is recommended that either the initial ArcGIS Desktop installation or the Desktop Administrator be configured to support the highest license type used by your organization to ensure that the ArcToolbox menus are configured correctly prior to using the ESRI_SOFTWARE_CLASS variable to change your seat type. Resolved at ArcGIS 9.0.
2. ArcMap: When using the ESRI_SOFTWARE_CLASS variable to change ArcGIS application type, the ArcMap title bar does not reflect the ArcGIS application type you are now using. Instead, the title bar stays the same as the originally installed product. This will be confusing to customers who need to validate what mode of operation they are currently in and the switching to different ArcGIS application type and desktop license mode has occurred.
   Workaround (Update 07/22/05): No workaround existed at 8.3, however problem has been resolved at ArcGIS 9.0.
3. ArcMap (Update 07/22/05): If the software product is set to "ArcINFO" in Desktop Administrator, and then the ESRI_SOFTWARE_CLASS variable is set to "Viewer", the versioning toolbar is erroneously still available when going to view->toolbars. If the software product is set to "ArcView" in Desktop Administrator, and then the ESRI_SOFTWARE_CLASS variable is set to "Professional", the versioning toolbar is NOT available in view->toolbars even though it should be.
   Workaround: Both issues are existing bugs with ArcGIS 9.0/9.1.

License Manager
Citrix MetaFrame allows the system administrator to remap the server system drive (C:) to a different drive letter during MetaFrame installation for the purpose of distinguishing the server C: drive from the client C: drive when client drives are remapped within a thin-client session. If the server system drive is remapped, the ESRI License Manager will not be able to run on the server.

Related Information

Currently no install issues have been identified with Windows Server 2003 Terminal Services. Although dated, some information in the WTS Installation Tips document may still apply to Windows 2000 Server Terminal Services environments.

• ArcGIS WTS Troubleshooting Procedure - PDF - 16 kb