"usbredir" - sending USB device traffic over a network connection


usbredir is the name of a network protocol for sending USB device traffic over a network connection. It is also the name of the software package offering a parsing library, a usbredirhost library and several utilities implementing this protocol.


  • The protocol is documented here, this document also explains what is meant with a usbhost and a usbguest.
  • The usbguest side is currently only implemented for qemu, and shipped as part of qemu (enabling this in qemu requires the libusbredirparser library to be available when building qemu).
  • usbredir supports USB device filtering configurable by a filter string.


usbredir was created for use with Spice, which is why it is hosted on spice-space.org, but the protocol and the usbredirhost are completely independent of spice, they could for example also be used to create a vnc extension for redirecting USB devices over a vnc connection to a qemu virtual machine.