Microsoft VECD (Virtual Enterprise Centralised Desktops) is their required licensing offering for companies looking to run Virtual Desktop Infrastructure (VDI) setups. For more general info on VDI, see my posts here and here and my VECD post is here.
VECD licensing can be quite confusing to get right for the various different scenarios that might pop up, so Microsoft have made a handy pdf to show how it works for a variety of different possible situations.
You’ll notice in scenario 2 that although there are 150 VM’s (Virtual Machines) being accessed, you only need to licence the number of machines, in this case 100. You can have an unlimited number of instances (of the OS) stored on the server and each machine can access up to 4 running instances at a time.
This is an interesting scenario and I in fact answered a question about this on Twitter just today :-) VECD is a device based licence BUT it gives Work at Home (WAH) rights to a specific named user of that machine; this mixing of device/user, while perfectly sensible, does lead to some confusion. These WAH rights help make VECD and VDI nice and flexible.
There are more scenarios on the pdf (which is why my scenario 3 is their 4!) as well as a lot more great info, and you can download it from:
For me at least, I had to save the pdf and then open it; if I tried to open it from the site it gave me an error. It’s down near the bottom, the “VDI Licensing Brochure” mentioned 5 lines from the end :-)