Broker Vendors Still Don’t Get USB

On 25 January 2013 by Pete Petersen


Most articles on VDIenterprise have been written around helping you get a better idea of what’s out there, what the choices are, and how to better implement a VDI solution with happy and productive users.

This is a departure. This will come across as an issue review. But it’s done to illustrate a point: Broker vendors–including the big three: Citrix, Quest, and VMware–still don’t get USB well enough.

Recently for a point of sale customer, there was a solid study of all of the major broker vendors’ ability to handle USB cameras. This includes Citrix (XenDesktop/XenApp), VMware (View), and Dell/Quest (vWorkspace). This particular point of sale customer used the camera to take a picture of the customer on-site who would purchase a season pass. Then as the customer would go through entry points, the RFID device in their pass would signal the gate agent, who would then see a picture of the person who should be holding the pass. This prevented re-use of the pass. In addition, there were seven other USB devices attached to the point of sale device (two of which were the keyboard and mouse).

But the results of the testing were not impressive.

With all the products, many USB devices pass through flawlessly, including printers, keyboards, mice, thumb drives, external USB drives, etc. and even webcams that come pre-installed in laptops and other user devices. All of the devices we tested on this particular project worked perfectly–except the USB camera.

In order to solve the issue, we purchased several different types, brands, and models of cameras, including IP-based cameras, basic webcams, and business-class cameras that had more sophisticated features such as digital panning and zooming, and robotic cameras with physical pan/zoom features.

All had one thing in common: performance degradation.

Both VMware View and Citrix XenDesktop/XenApp had issues with buffer-building. The static image would keep getting further and further behind, until the image wouldn’t update for up to two minutes, then the device would finally time out and become useless until the user logged out of the session (not disconnected), and started over again. Not good for point of sale in front of customers.

Finally, a configuration was found that worked with Dell/Quest vWorkspace. The vWorkspace client includes much more granular control over the USB device sharing and pass-through. The results are still not seamless–and not great–but at least the users can get a still shot. (Note that full-motion video would be unbearable in any of the scenarios.) The physical pan and zoom is also pretty clunky. But the point of sale desk agents can tolerate the performance of the pan/zoom features, and the still shots are very do-able.

Although this may seem like a rant on one particular technical issue–and we all have hundreds of such stories–it needs to be understood that the customer spend months on this particular issue with their broker environment, before ever bringing in the the consultant organizations–even so much that they were willing to throw the whole existing solution out the window if something else could be found that worked. And the consultant also spent more time on this issue than will ever be recovered in the actual project, plowed through support tickets with the vendors, traveled a dozen times on-site, and devoted POC equipment for far more time than was worthwhile..

This indicates above all one thing: USB devices (and cameras in particular) are difficult at best for the broker vendors to master. When virtualizing/centralizing the desktop session, passing through that device’s USB port when it’s created, is shaky at best.