Editing the registry incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.
At the device
HDX uses the computing capacity of user devices to enhance and optimize the user experience. HDX technology ensures that users receive a smooth, seamless experience with multimedia content in their virtual desktops or applications. Workspace control enables users to pause virtual desktops and applications and resume working from a different device at the point where they left off.
On the network
HDX incorporates advanced optimization and acceleration capabilities to deliver the best performance over any network, including low-bandwidth and high-latency WAN connections.
HDX features adapt to changes in the environment. The features balance performance and bandwidth. They apply the best technologies for each user scenario, whether the desktop or application is accessed locally on the corporate network or remotely from outside the corporate firewall.
In the data center
HDX uses the processing power and scalability of servers to deliver advanced graphical performance, regardless of the client device capabilities.
HDX channel monitoring provided by Citrix Director displays the status of connected HDX channels on user devices.
HDX Insight is the integration of NetScaler Network Inspector and Performance Manager with Director. It captures data about ICA traffic and provides a dashboard view of real time and historical details. This data includes client-side and server-side ICA session latency, bandwidth use of ICA channels, and the ICA round-trip time value of each session.
When you're using Windows Media Player and Remote Audio & Video Extensions (RAVE) enabled inside a session, a black screen might display if you right-click on the video content and select Always show Now Playing on top.
When accessing hosted applications or desktops, network interruption might occur. To experience a smoother reconnection, we offer auto client reconnect and session reliability. In a default configuration, session reliability starts and then auto client reconnect follows.
Auto client reconnect
Auto client reconnect relaunches the client engine to reconnect to a disconnected session. Auto client reconnect closes (or disconnects) the user session after the time specified in the setting. If auto client reconnect is in progress, the system sends application and desktops network interruption notification to the user as follows:
During auto client reconnect, sessions relaunch expecting network connectivity. User cannot interact with sessions while auto client reconnect is in progress.
On reconnection, the disconnected sessions reconnect using saved connection information. The user can interact with the applications and desktops normally.
Default auto client reconnect settings:
For more information, see Auto client reconnect policy settings.
Session reliability reconnects ICA sessions seamlessly across network interruptions. Session reliability closes (or disconnects) the user session after the time specified in the setting. After the session reliability timeout, the auto client reconnect settings take effect, attempting to reconnect the user to the disconnected session. When session reliability is in progress, application and desktops network interruption notification are sent to the user as follows:
While session reliability is active, the user cannot interact with the ICA sessions. However, user actions like keystrokes are buffered for few seconds immediately after the network interruption and retransmitted when the network is available.
On reconnection, the client and the server resume at the same point where they were in their exchange of protocol. The session windows lose translucency and appropriate notification area pop ups are shown for applications.
Default session reliability settings
For more information, see Session reliability policy settings.
NetScaler with auto client reconnect and session reliability
If Multistream and Multiport policies are enabled on the server and any or all these conditions are true, auto client reconnect does not work:
By default, any touch enabled device that connects/roams to a Windows 10 VDA starts in tablet mode.
Tablet mode requires a minimum of version XenServer 7.2. XenServer 7.2 integrates with the XenDesktop VDA, changing the hypervisor to enable the virtual firmware settings for 2-in-1 devices. Windows 10 loads the GPIO driver on the target virtual machine based on this updated BIOS. It is used for toggling between tablet and desktop modes within the virtual machine. For more information, see http://docs.citrix.com/content/dam/docs/en-us/xenserver/current-release/downloads/xenserver-release-notes.pdf.
The tablet mode offers a user interface that is better suited to touch screens:
You have access to the File Explorer.
Web Receivers do not support table mode.
Run the XenServer CLI command to allow laptop/tablet switching:
xe vm-param-set uuid=<VM_UUID> platform:acpi_laptop_slate=1
To disable or enable tablet mode, configure this registry setting on XenApp and XenDesktop:
Before starting a session
We recommend that you navigate to Settings >System >Tablet Mode on the VDA before starting a session and set the following options from the drop-down menus:
If you don't set these options before starting the session, set the options after you start the session and restart the VDA.
The following visual display policy settings control the quality of images sent from virtual desktops to user devices.
Several popular video conferencing applications are optimized for delivery from XenApp and XenDesktop through multimedia redirection (see, for example, HDX RealTime Optimization Pack). For applications that are not optimized, HDX webcam video compression improves bandwidth efficiency and latency tolerance for webcams during video conferencing in a session. This technology streams webcam traffic over a dedicated multimedia virtual channel. This technology uses less bandwidth compared to the isochronous HDX Plug-n-Play USB redirection support, and works well over WAN connections.
Citrix Receiver users can override the default behavior by choosing the Desktop Viewer Mic & Webcam setting Don't use my microphone or webcam. To prevent users from switching from HDX webcam video compression, disable USB device redirection by using the policy settings under ICA policy settings > USB Devices policy settings.
HDX webcam video compression requires that the following policy settings be enabled (all are enabled by default).
If a webcam supports H.264 hardware encoding, HDX video compression uses the hardware encoding by default. Hardware encoding might consume more bandwidth than software encoding. To force software compression, add the following DWORD key value to the registry key: HKCU\Software\Citrix\HdxRealTime: DeepCompress_ForceSWEncode=1.
Priorities are assigned to network traffic across multiple connections for a session using Quality of Service (QoS)-supported routers. Four TCP streams (real time, interactive, background, and bulk) and two User Datagram Protocol (UDP) streams (voice and Framehawk display remoting) are available to carry ICA traffic between the user device and the server. Each virtual channel is associated with a specific priority and transported in the corresponding connection. You can set the channels independently, based on the TCP port number used for the connection.
Multiple channel streaming connections are supported for Virtual Delivery Agents (VDAs) installed on Windows 10, Windows 8, and Windows 7 machines. Work with your network administrator to ensure the Common Gateway Protocol (CGP) ports configured in the Multi-Port Policy setting are assigned correctly on the network routers.
Quality of Service (QoS) is supported only when multiple session reliability ports, or the CGP ports, are configured.
Caution: Use transport security when using this feature. Citrix recommends using Internet Protocol Security (IPsec) or Transport Layer Security (TLS). TLS connections are supported only when the connections traverse a NetScaler Gateway that supports multi-stream ICA. On an internal corporate network, multi-stream connections with TLS are not supported.
To set Quality of Service for multiple streaming connections, add the following Citrix policy settings to a policy (see Multi-stream connections policy settings for details):
Explicitly configure the firewalls on VDAs to allow the additional TCP traffic.
For policies containing these settings to take effect, users must log off and then log on to the network.