VirtualBox中的USB over RDP或者叫Remote USB

VirtualBox的二进制发行版中具有usb over rdp，可是一直不知如何使用。
最近把virtualbox-bin升到1.5.6，到安装目录看到了rdesktop-vrdp。
运行一下

rdesktop: A Remote Desktop Protocol client.
Version 1.5.0. Copyright (C) 1999-2005 Matt Chapman.
Modified for VirtualBox by innotek GmbH.
See for more information.

Usage: /opt/VirtualBox/rdesktop-vrdp [options] server[:port]
   -u: user name
   -d: domain
   -s: shell
   -c: working directory
   -p: password (- to prompt)
   -n: client hostname
   -k: keyboard layout on server (en-us, de, sv, etc.)
   -g: desktop geometry (WxH)
   -f: full-screen mode
   -b: force bitmap updates
   -L: local codepage
   -A: enable SeamlessRDP mode
   -B: use BackingStore of X-server (if available)
   -e: disable encryption (French TS)
   -E: disable encryption from client to server
   -m: do not send motion events
   -C: use private colour map
   -D: hide window manager decorations
   -K: keep window manager key bindings
   -S: caption button size (single application mode)
   -T: window title
   -N: enable numlock syncronization
   -X: embed into another window with a given id.
   -a: connection colour depth
   -z: enable rdp compression
   -x: RDP5 experience (m[odem 28.8], b[roadband], l[an] or hex nr.)
   -P: use persistent bitmap caching
   -r: enable specified device redirection (this flag can be repeated)
         '-r comport:COM1=/dev/ttyS0': enable serial redirection of /dev/ttyS0 to COM1
             or      COM1=/dev/ttyS0,COM2=/dev/ttyS1
         '-r disk:floppy=/mnt/floppy': enable redirection of /mnt/floppy to 'floppy' share
             or   'floppy=/mnt/floppy,cdrom=/mnt/cdrom'
         '-r clientname=': Set the client name displayed
             for redirected disks
         '-r lptport:LPT1=/dev/lp0': enable parallel redirection of /dev/lp0 to LPT1
             or      LPT1=/dev/lp0,LPT2=/dev/lp1
         '-r printer:mydeskjet': enable printer redirection
             or      mydeskjet="HP LaserJet IIIP" to enter server driver as well
         '-r sound:[local|off|remote]': enable sound redirection
                     remote would leave sound on server
         '-r usb': enable USB redirection
         '-r clipboard:[off|PRIMARYCLIPBOARD|CLIPBOARD]': enable clipboard
                      redirection.
                      'PRIMARYCLIPBOARD' looks at both PRIMARY and CLIPBOARD
                      when sending data to server.
                      'CLIPBOARD' looks at only CLIPBOARD.
   -0: attach to console
   -4: use RDP version 4
   -5: use RDP version 5 (default)

这就是usb over rdp的rdesktop修改版。试验一下，可以在远程的VirtualBox上的VM后，本地的USB设备都会重定向到远程的VM上。

这是LINUX版的，WINDOWS版的不知如何使用。不过我有LINUX版就可以了。