Although VMware Horizon does not explicitly prevent any devices from working with the USB redirection feature, due to factors such as network latency and bandwidth, some devices work better than others. By default, some devices are automatically filtered, or blocked, from being used.

USB 3.0 Device Limitations

You can plug USB 3.0 devices into USB 3.0 ports on the client machine. USB 3.0 devices are supported only with a single stream. Because multiple stream support is not implemented, USB device performance is not enhanced. Some USB 3.0 devices that require a constant high throughput to function correctly might not work in a remote session, due to network latency.

USB Redirection with Virtual Desktops

The following types of USB devices might not be suitable for USB redirection to a remote desktop that is deployed on a single-user machine.

  • Due to the bandwidth requirements of webcams, which typically consume more than 60 Mbps of bandwidth, webcams are not supported through USB redirection. For webcams, you can use the Real-Time Audio-Video feature.
  • The redirection of USB audio devices depends on the state of the network and is not reliable. Some devices require a high data throughput even when they are idle. If you have the Real-Time Audio-Video feature, audio input and output devices will work well using that feature, and you do not need to use USB redirection for those devices.
  • USB CD/DVD burning is not supported.
  • Performance of some USB devices varies greatly, depending on the network latency and reliability, especially over a WAN. For example, a single USB storage device read-request requires three round-trips between the client and the remote desktop. A read of a complete file might require multiple USB read operations, and the larger the latency, the longer the round-trip will take.

    The file structure can be very large, depending on the format. Large USB disk drives can take several minutes to appear in the desktop. Formatting a USB device as NTFS rather than FAT helps to decrease the initial connection time. An unreliable network link causes retries, and performance is further reduced. Similarly, USB CD/DVD readers and scanners do not work well over a latent network such as a WAN.

  • The redirection of USB scanners depends on the state of the network, and scans might take longer than normal to complete.

USB Redirection with Published Desktops and Applications

You can redirect locally connected USB thumb flash drives and hard disks for use in published desktops and applications. Published desktops and applications can also support more generic USB devices, including TOPAZ Signature Pad, Olympus Dictation Foot pedal, and Wacom signature pad. Other types of USB devices, including security storage drives and USB CD-ROM drives, are not supported in published desktops and applications.