Deployment Best Practices for Citrix XenApp over Galaxy Managed Network Services Table of Contents

Transcription

1 Table of Contents Executive Summary... 1 Best Practices & Recommendations... 2 Appendix A Lab Environment Detailed Diagram... 6 Appendix B Citrix WAN Policy Configuration Instructions... 7 Appendix C SpeedScreen Configuration Instructions Appendix D Sample DEFAULT.ICA FILE with SpeedScreen Settings G

2 Executive Summary Broadband networks offer high-bandwidth but can often exhibit high-latency and/or higher jitter with certain wireless technologies. The unique nature of high-latency networks causes poor performance amongst latency-sensitive applications. Citrix XenApp, when used with, can provide an effective application delivery experience over satellite connections. Utilizing Citrix policies to regulate and optimize XenApp features in conjunction with proper implementation of SpeedScreen Latency Reduction provides a desirable end-user experience for satellite network subscribers. This article will provide an overview on how to optimize Citrix XenApp to effectively deliver applications to broadband satellite users.

3 Best Practices & Recommendations General High-Latency Network Considerations In a low-latency, high-bandwidth environment, administrators rarely have to take latency into account. Administrators utilizing satellite (and in some circumstances other wireless) based Galaxy Managed Services for IT service delivery can improve end user experience by reducing client-to-server round trip times, caching data, batching records and packets, and leveraging compression and acceleration technology. Here are some general best practices on how to optimize network communications over high- latency networks: Limit the number of client to server round trips - Every round trip from a remote client, through the satellite network and back will typically take between milliseconds, and occasionally more. While the approximate one second round trip seems almost trivial, a process that makes multiple round trips will become an issue. On a LAN this is not a concern. It is definitely a problem when multiple transactions must take place sequentially over a satellite or other high latency wide area network. Cache Infrequently Changing Data Locally - Cached data does not have to be fetched over the network, thus decreasing total network traffic and making the user experience better increasing user productivity: clients will not have to wait on an operation to complete before performing another one. Batch Data Records Together - Multiple records transfer, either upload or download, to/from a server over the network are almost always best batched together rather than sent individually. This may seem like antithetical advice to keep network payload small, but pushing on a record by record basis will entail a heavy price in communication overhead involving multiple server requests and round trips. The real saving is in reducing these round trips. Leverage Galaxy Performance Enhancing Protocol (PEP) and TurboPage - Galaxy s comprehensive package of acceleration and compression technologies is embedded in every HN router. The result is dramatically improved throughput and response time through mitigation of satellite delay, meaning Hughes customers experience wire-line or better performance of broadband IP applications. Galaxy routers utilize Galaxy s patented Performance Enhancing Proxy (PEP) to optimize the performance of many widely used Internet protocols. Citrix XenApp Recommendations The SpeedScreen Latency Reduction and Citrix Policy features of Citrix XenApp provide an effective solution to Galaxy Managed Services by effectively delivering applications over high-latency networks. The following diagram depicts the testing environment used for this engagement:

4 Figure 2 Lab Environment Layout Citrix XenApp was tested to evaluate the delivery of bandwidth-demanding applications over high-latency connections for several different application types, including productivity, client/server, and browserbased applications. EdgeSight for Load Testing was scripted with Microsoft Office (Productivity), Internet Explorer (Browser), and Hyperion (Enterprise Client/Server) applications to ensure a consistent experience when using a LAN-based connection versus a satellite-based link. Visual observation of enduser experience and performance metrics from EdgeSight for Load Testing from both types of network connections were gathered and analyzed. Results from integration testing show that Citrix policies optimized for satellite communications in conjunction with the SpeedScreen Latency Reduction features of XenApp provided the best end user experience for Galaxy Managed Network subscribers. Other features, such as the Citrix Access Gateway, were also tested to measure their effectiveness when used with XenApp server.

5 The following provides an overview of the results and related recommendations: Access Gateway (Secure Gateway Mode/Secure Access Client) For configurations that require SSL VPN Access or utilize the Secure-Gateway functionality of Access Gateway, there was no significant loss in performance or functionality when used in conjunction with XenApp published applications using default configurations. Network Administrators and engineers should design an appropriate access strategy in accordance with their company s security policies. XenApp WAN Policies During the testing, the default WAN Citrix policy for satellite communications was configured and enforced. This policy will ensure applications delivered by XenApp servers are optimized. In addition, administrators should disable any ICA virtual channels that are not required (i.e. audio, client drive mappings, etc.) or limit any virtual channel functionality (i.e. default printers, printing bandwidth, etc.). Managing the ICA virtual channels will minimize any unnecessary communications overhead between the XenApp server and client. Configuration instructions for implementing Citrix policies can be found in Appendix B of this document. SpeedScreen Latency Reduction - Network latency and bandwidth availability can impact the performance of connections to published applications and content. SpeedScreen technology allows administrators to configure several features to improve connection speed and responsiveness. SpeedScreen Latency Reduction Manager helps reduce a user s perception of latency with mouse click feedback and local text echo. Enabling mouse and local text echoing on several applications improved the end user experience with applications delivered by XenApp. Server-side and client-side instructions for configuring SpeedScreen Latency Reduction can be found in Appendices C and D sections of this document. Session Reliability/ICA Keep-Alive Session reliability allows a client to reconnect and avoid inconvenience to a user during a short network interruption. Instead of removing all unresponsive applications and desktops from the client workbench, they are kept open until the connection is re-established. ICA Keep-Alive enables a server to detect broken sessions. If the server loses connectivity to the client, the connection is placed into a disconnected state, allowing a user to re- connect to a dropped session. These settings can be implemented at the farm-wide/server- default level or at an individual server level. Figure 3 Farm-Wide Session Reliability Settings

6 Figure 4 Server-Defualt ICA Keep-Alive Settings For this testing scenario, setting the ICA keep-alive (utilizing TCP port 1494) or Session Reliability (utilizing TCP port 2598) values to 180 seconds allowed sufficient time for reconnection in the event a session would become interrupted. Before implementing either option, administrators should consider the benefits of either session reliability or ICA Keep-Alive specific to their environment and determine whether these settings should be applied to farm-wide/server defaults or to specific servers. All settings should be well-tested before implementing them in a production environment. Refer to the Citrix XenApp Server Administrator s Guide for information on Session Reliability and ICA Keep-Alive features.

7 Appendix A - Lab Environment - Detailed Diagram

8 Appendix B - Citrix WAN Policy Configuration Instructions

9 Citrix WAN Policy Settings

10 Citrix WAN Policy Settings (cont d)

11 Appendix C - SpeedScreen Configuration Instructions To configure SpeedScreen Latency Reduction for a XenApp Server: Launch the SpeedScreen Latency Reduction Manager from the ICA toolbar. Click on NEW to launch the SLR wizard to add an application / process. The wizard will launch - click next. Browse to the process/executable that you wish to enable for SpeedScreen. Alternatively, you can use the pointer to select the application window if it is already open. When completed, click next.

12 Choose the local text echo, and click next. Select whether this will be applied to ALL installations or selected installations of the application, then click next. Click Finish. Click Apply / OK to save/exit the SpeedScreen Latency Reduction Manager.

13 To configure SpeedScreen Latency Reduction for an ICA Client connection (Program Neighborhood Client): In Program Neighborhood window, select the custom ICA connection or Application Set to configure. In the Program Neighborhood toolbar, click the Properties icon. Click the Options tab in the dialog box to display the Options page. In the SpeedScreen Latency Reduction section, set the mode to On to decrease the delay between user input and screen display. Turn on both local text echo and mouse click feedback. To ensure SpeedScreen Latency Reduction is enabled, the following Web Interface (version 4.x) settings are required for the Citrix Web Client and Program Neighborhood Agent: Edit the default.ica file located \Inetpub\wwwroot\Citrix\Web Site Name\conf for a Web Interface site, or \Inetpub\wwwroot\Citrix\PNAgent\conf for Program Neighborhood Agent sites (NOTE: These paths reflect a default installation of Web Interface). In the [Application] section, add: ZLKeyboardMode=1 ZLMouseMode=1

14 Appendix D - Sample DEFAULT.ICA FILE with SpeedScreen Settings ; ICA Override File ; ; Add ICA file settings that you want to be sent to client devices ; to this file. Settings contained in this file override any ; settings generated by Web Interface. This file is only used when ; no bandwidth profile is selected. When a bandwidth profile is ; selected bandwidth_xxx.ica is used. ; ; NOTE: The format of this file has been changed from previous ; versions of Web Interface. For backwards compatibility, you may ; continue to use legacy files. All lines containing a tag of ; the form [NFuse_XXX] will be ignored. ; [WFClient] Version=2 RemoveICAFile=yes ProxyTimeout=30000 ProxyFavorIEConnectionSetting=Yes ProxyUseFQDN=Off [ApplicationServers] Application= [Application] Launcher=WI TransportDriver=TCP/IP DoNotUseDefaultCSL=On BrowserProtocol=HTTPonTCP LocHttpBrowserAddress=! WinStationDriver=ICA 3.0 ProxyTimeout=30000 AutologonAllowed=ON ZLKeyboardMode=1 ZLMouseMode=1 [EncRC5-0] DriverNameWin16=pdc0w.dll DriverNameWin32=pdc0n.dll [EncRC5-40] DriverNameWin16=pdc40w.dll DriverNameWin32=pdc40n.dll [EncRC5-56] DriverNameWin16=pdc56w.dll DriverNameWin32=pdc56n.dll [EncRC5-128] DriverNameWin16=pdc128w.dll DriverNameWin32=pdc128n.dll [Compress] DriverNameWin16=pdcompw.dll DriverNameWin32=pdcompn.dll