PCoIP put to the test – via T1 link


I recently had the chance to put Teradici documentation to the test in a T1 link scenario. Teridici has a specific recommended deployment for T1 connections. This document can be found on the Teradici website under "PCoIP_Client_WAN_Network_Guidelines.pdf".  A login is required to access the document.

My test consisted of 5 workstations (4 fat clients and 1 zero client), 3 of which had two serial to USB converters attached. One station was the Dell FX100 zero client.

This test was mainly a POC to see if we could deploy this to hundreds of branches for the company. With limited bandwidth in a T1, careful tuning had to take place in multiple different places. This included GPO's for the VDI sessions and performance tuning on the virtual desktops running Windows 7.

For tuning the Windows 7 environment, you putty much just turn off anything graphic intensive. A good general guide can be found on CreedTek. VMware also has a documented guide. Most of these settings can be controlled via GPO, but it's good to build a template with these settings already in place.

There are also some pretty important VMware View GPO's that are provided. On your View connection broker, these can be found under "C:Program FilesVMwareView ManagerServerExtrasGroupPolicyFiles". New to Group Policy Objects? Check out this KB 816662 article from Microsoft. The most important GPO settings I enabled were – no audio in the session and configuring the maximum allowed PCoIP bandwidth to 1MB (which is the lowest setting possible). You can also set the "PCoIPMaxLinkRate", but pay attention to the Teradici recommendations. There are a ton of other good settings in the GPO's you can play around with, but for this test I did not have any graphic intensive screens that needed to be displayed.

Teradici has a basic formula for T1 connections – Bandwidth required – (250Kbps/0.80) * 5  = 1.5Mbps, which comes out to 3 to 5 users per T1 connection. I'm really pushing the limits with my scenario.

Now lets get to the real numbers here. Here is a days worth of normal traffic is for this branch without PCoIP.

So you can see from the charts that utilization for the link stays around 20%. This is a pretty consistent on the history of this link.

Now let's take a look at the PCoIP traffic for a day…

As you can see, the link traffic is off the charts! At one point on the second day we even had a report of 300% utilization on the T1 link, which caused the router to crash and we had to reset it.

So did the Teradici documentation work? Absolutely! But for my user base, I need to stick with 3 users per T1 line. If I was not sending so much USB traffic over UDP 4172 I could possibly have 5 users per T1 link.

What was the user response? They loved it! The users were oblivious to the fact to they were working on a VDI sessions.

My overall impressions of using VMware View with PCoIP over a T1 link? I think it is fantastic, but carful consideration must be giving to how your branch may expand in the future. Pay careful attention to Teradici documentation and make sure you thoroughly test your scenario in a controlled environment before you plan to deploy this to production! Would WAN accelerators help in the scenario? Possibly, but at what point does that become cost effective for 5 (or possibly 10) users.