By default, Windows Media MMR adapts to network conditions on single-user desktops that run on Windows 8 or later and published desktops that run on Windows Server 2012 or 2012 R2 or later. If the network latency between Horizon Client and the remote desktop is 29 milliseconds or lower, the video is redirected with Windows Media MMR. If the network latency is 30 milliseconds or higher, the video is not redirected. Instead, it is rendered on the ESXi host and sent to the client over PCoIP.
This feature applies to Windows 8 or later single-user desktops and Windows Server 2012 or 2012 R2 or later published desktops. Users can run any supported client system, Windows 7 or Windows 8/8.1.
This feature does not apply to Windows 7 single-user desktops or Windows Server 2008 R2 published desktops. On these guest operating systems, Windows Media MMR always performs multimedia redirection, regardless of network latency.
You can override this feature, forcing Windows Media MMR to perform multimedia redirection regardless of the network latency, by configuring the RedirectionPolicy registry setting on the desktop.