Understanding USB devices connected to a PCoIP zero client

Trying to sort out why webcams and USB headsets work for some customers and not others is very time consuming as we have to understand the use case. When using a PCoIP zero client to connect to a software host such as HP Anyware Agent or VMware Horizon Agent, you need to ensure USB redirection is enabled when installing the host agent. With USB redirection installed we can now troubleshoot from the zero client side. Some Tera2 PCoIP zero clients have an internal USB hub and some do not. This is determined by the manufacture at time of manufacture and not by our PCoIP firmware.

In the screenshot below the PCoIP zero client does not have an internal hub so you cannot separate the USB devices to different controllers - OHCI / EHCI. It is important to separate USB devices as each controller is capable of a specific amount of bandwidth and that bandwidth is shared by each USB device enumerated on the controller regardless if the USB device is being used. When using a webcam it is important to only have the webcam using the OHCI controller.

In the above screenshot notice I have USB Root ports 0 to 3 and all devices connected are using the OHCI controller. In this scenario if you try to use the webcam and headset the user experience will be very poor.

In the below screenshot I have connected an external USB hub to Root 0 and moved my USB receiver, my Plantronics C510-M headset and the USB keyboard (RFideas Prox card reader) to the external hub. I left the Microsoft Life Cam connected to Root1. In this scenario the user experience will be much better. NOTE: this will depend on available network bandwidth and latency, the lower the available bandwidth and the high the network latency the poorer the user experience.

In the below screenshot my PCoIP zero client has an internal USB hub however I have not enabled EHCI and you can see all USB devices are sharing the OHCI controller. Again if using the webcam the user experience will be very poor as the available OHCI bandwidth is being shared by all enumerated USB devices.

If I go to Configuration > USB and enable EHCI this will allow me to separate the USB devices between OHCI and EHCI controllers.

Now when we look at the Attached Devices we can now see the Microsoft Life Cam is the only USB device using OHCI all other USB devices are plugged into the internal USB hub of the zero client which happens to be Root3.

If I now go into session the only device showing will be my webcam as all other devices are now on the EHCI controller. The user will have the best possible experience when using their webcam.