Most people implement VDI in order to save money, usually by saving management costs of the users. The irony of this, however, is that the users who are the hardest to manage are the users who are outside your office. They're the users who work from home, or from small offices, hotels, or via their mobile phone network air cards.
This is ironic because VDI is a "single user" version of server-based computing (SBC), and SBC and slow WAN connections don't always mix. Unfortunately, as your VDI environment grows, you'll inevitably have to deal with WAN users at some point. Fortunately, there are some proven ways this can be done.
Option 1. Don't use VDI
The easiest way to deal with problem WANs and VDI is simply to not use VDI. I'm not suggesting that you can't virtualize or manage those devices, but remember, VDI is only one type of desktop virtualization. You could also choose to manage remote clients via a bare-metal client hypervisor, or maybe via local app streaming.
Option 2. Pick the right display protocol
Remember that not all remote display protocols are created equal. You might find that the version of RDP that comes with Windows 7 works fine where Windows XP's does not; or perhaps Citrix's ICA or Teradici's PC-over-IP works where others don't. There are about ten different remote display protocols out there today, and since every use case is different, you should try out different protocols if you experience problems along the way.
Option 3. Consider WAN acceleration hardware
There are several companies who make "WAN acceleration" products. Hardware like Citrix's Branch Repeater and products from Riverbed and Expand Networks have always been favorites in the SBC industry. These WAN accelerators are installed in pairs, with one appliance in your central location and another at the remote office. They do all sorts of tricks like intelligent compression, connection multiplexing and traffic deduplication to effectively "accelerate" the WAN connection that's available to your users. A benefit of these product purchases is that they're much cheaper than paying for a faster WAN connection.
Today's WAN accelerator vendors also offer a software version of the "remote office" piece, so you can install a little agent on your users' laptops that lets them get the experience of a faster connection to your office even if they're a mobile worker who doesn't work in the same place every day.
The WAN accelerators are pretty amazing. There have been numerous cases where a CIO was about to throw a VDI pilot out the window because it wasn't performing well for the remote users. After a pair of WAN accelerators was brought in, the user experience switched from "barely usable" to "completely transparent" -- in that the users didn't even know they were connecting to a remote desktop across a WAN.
All the WAN accelerator vendors offer evaluation versions of their equipment, making it an "easy test." Just get a couple of the devices in and see if the problem goes away.
The bottom line is that while WANs have always posed a challenge for SBC environments, there are several proven techniques that can be leveraged to ensure your users get a good work experience over connections that you might not think would be possible.
ABOUT THE AUTHOR:
Brian Madden is known throughout the world as an opinionated, super technical, fiercely independent desktop virtualization expert. He's written several books and over 1,000 articles about desktop and application virtualization. Brian's blog, Brianmadden.com, receives millions of visitors per year and is a leading source for conversation, debate and discourse about the application and desktop virtualization industry. Brian is also the creator of BriForum, the premier independent application delivery technical conference.