Group policy settings for HTML Access are specified in the template file vdm_blast.adm. This template is for the VMware Blast display protocol, which is the only display protocol that HTML Access uses.

For HTML Access 4.0 and Horizon 7.0, the VMware Blast group policy settings are described in "VMware Blast Policy Settings" in the Setting Up Desktop and Application Pools in View document.

If you have HTML Access 3.5 or earlier and Horizon 6.2.x or earlier, the following table describes group policy settings that apply to HTML Access. Note that starting with Horizon 7.0, more VMware Blast group policy settings are available.

Table 1. Group Policy Settings for HTML Access 3.5 and Earlier

Setting

Description

Screen Blanking

Controls whether the remote virtual machine can be seen from outside of View during an HTML Access session. For example, an administrator might use vSphere Web Client to open a console on the virtual machine while a user is connected to the desktop through HTML Access.

When this setting is enabled or not configured, and someone attempts to access the remote virtual machine from outside of View while an HTML Access session is active, the remote virtual machine displays a blank screen.

When this setting is disabled, under the preceding conditions, the remote virtual machine displays the active View desktop session to the second remote accessor.

Session Garbage Collection

Controls the garbage collection of abandoned remoting sessions. When this setting is enabled, you can configure the garbage collection interval and threshold.

The interval controls how often the garbage collector runs. You set the interval in milliseconds.

The threshold determines how much time must pass after a session is abandoned before it becomes a candidate for deletion. You set the threshold in seconds.

Audio playback

Controls whether audio playback is allowed on the remote desktop. By default, this setting is enabled.

Image Quality

Controls the image quality of the remote display. There are three image quality profiles, low, medium, and high. The encoder tries to use the best quality level possible, given the constraints of available bandwidth, recent frame-rate, and the size of the region that has recently changed in the current frame. The encoder keeps track of which regions of the client screen are currently low- or medium-quality and incrementally improves those areas to high quality.

When this setting is enabled, you can separately change the low-, medium-, and high-quality JPEG settings to different values. The actual JPEG quality levels used at low, medium, and high settings are individually configurable as numbers between 0 and 100.

Chroma subsampling is enabled according to the JPEG quality level chosen. Whenever JPEG quality set to 80 or higher, chroma-subsampling is turned off and the ratio is set to the highest available value, YUV-4:4:4. For JPEG quality set to 79 or below, the ratio is set to YUV-4:2:0.

  • Low JPEG Quality. By default, this value is 25. You can also set the low JPEG chroma subsampling to various ratios. By default, the low ratio is set to the lowest available value, 4:1:0.

  • Mid JPEG Quality. By default, this value is 35. You can also set the low JPEG chroma subsampling to various ratios. By default, the low ratio is set to the lowest available value, 4:2:0.

  • High JPEG Quality. By default, this value is 90.You can also set the high JPEG chroma subsampling to various ratios. By default, the low ratio is set to the highest available value, 4:4:4.

Configure clipboard redirection

Determines the direction in which clipboard redirection is allowed. Only text can be copied and pasted. You can select one of these values:

  • Enabled client to server only (That is, allow copy and paste only from the client system to the remote desktop.)

  • Disabled in both directions

  • Enabled in both directions

  • Enabled server to client only (That is, allow copy and paste only from the remote desktop to the client system.)

This setting applies to View Agent or Horizon Agent only.

When this setting is disabled or not configured, the default value is Enabled client to server only.

HTTP Service

Allows you to change the secured (HTTPS) TCP port for the Blast Agent service. The default port is 22443.

Enable this setting to change the port number. If you change this setting, you must also update settings on the firewall of the affected remote desktops (where View Agent or Horizon Agent is installed).