There are three general redirection policies selectable, with preconfigured settings for different device classes:

1. No redirection – no peripheral devices other than system keyboard and mouse will be redirected.
   
2. Default – preferred redirection settings for the thin client device model will be used.
   
3. Custom – devices will be redirected or blocked according to granular selections.
   

Two redirection types (methods) are possible: Native redirection and Generic USB redirection. The availability of the redirection methods varies between device classes and terminal session protocols.

Generic USB redirection, in contrast to native redirection, does not require any special device support on the client-side. With the generic USB redirection the low-level USB communication between the virtual USB hub created on the server-side and the USB device physically connected to the thin client gets redirected. The USB peripheral device connected to thin client’s USB port gets detected by a virtual USB host controller or hub assigned to the user’s terminal session on the server-side. The Windows device driver software necessary for using the connected peripheral device must be installed on the terminal server hosting the user session. The peripheral device forwarded with generic USB redirection always appears in the Device Manager inside user’s terminal session. If the terminal server hosting the user sessions is a multi-user system then it must be able to appropriately handle (filter) the USB devices redirected in the generic way. If that fails then it can happen that the redirected device will interact with the Console session, not with user’s terminal session.

Note: In Windows Server 2019, Windows Server 2016 and Windows 10 the ‘Do not allow supported Plug and Play device redirection’ Group Policy setting is enabled by default (when not configured), which prevents the Generic USB redirection of peripheral devices to the above mentioned operating systems. This Group Policy setting can be found under ‘Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Device and Resource Redirection’. To be able to use the Generic USB redirection of peripheral devices in RDP sessions running on operating systems mentioned in this note this group policy setting must be explicitly disabled. In Windows Server 2012 R2, Windows Server 2012, Windows 8 and Windows 8.1 the Remote Desktop Services by default allow the redirection of supported plug and play devices, thus the ‘Do not allow supported Plug and Play device redirection’ Group Policy setting does not need to be altered.

Customizing  peripheral devices redirection

When the Custom radio-button will be selected as the general redirection policy, then the following redirection type selections are available for different USB device classes:

Default redirection types on RX-series and LEAF OS devices: