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Does Microsoft CDL provide the same VDI access as Windows RT devices?

The language surrounding Microsoft's Companion Device License for non-Windows devices accessing VDI isn't exactly clear on what kind of access you'll get.

Windows 8 VDI licensing won't change much for regular PCs, but licensing for tablets gets a bit more confusing.

In part one of this two-part series, I explained the old Microsoft VDI licensing rules and how these will change for Windows 8, particularly when it comes to Windows RT devices. But for non-Windows devices, users will need the Companion Device License (CDL). The problem is the language Microsoft uses to describe the CDL rights raises some important questions.

Are Microsoft CDL rules for real VDI?

When discussing Windows RT rights on The Windows Blog, Microsoft's Erwin Visser talks about access to "a full VDI image running in the data center." He doesn't use the same language to describe the Microsoft CDL. It would have been easy to say that the CDL offers the same rights that Windows RT companions get for free, but Microsoft doesn't do that. Instead, the CDL will license access to "a corporate desktop, either through VDI or Windows To Go." (Windows To Go is an instance of Windows 8 stored on a flash drive.)

Part one of this series:

What's new in Windows 8 VDI licensing: Free ride for Windows RT

To the casual reader, that may appear to be a lot like virtual desktop infrastructure (VDI) access, but to a licensing nerd, it's not. When Microsoft talks about accessing a corporate desktop, it could mean accessing a remote physical machine, such as the PC sitting on your desk at work. But that's not a new right. If you are the primary user, you already have the right to access that PC from any other device, including your iPad.

This is an often-overlooked but very powerful right. Remote access products such as GoToMyPC, LogMeIn and TeamViewer already rely on this "primary user right," which can eliminate all additional licensing requirements for remote access. Someone with a corporate PC licensed for Windows and Microsoft Office, which both include the primary use right, can access his PC from any other device without requiring SA, VDA or other licenses. The user can also access any servers he needs by virtue of Client Access Licenses (CALs) assigned to himself or to his work PC.

If Microsoft now plans to put primary use rights under the CDL (which, in turn, is locked up behind SA), we have a serious diminution of remote access rights. Microsoft will begin charging a substantial fee for what is now free to anyone with a physical workstation licensed for Windows and Office.

No corporate devices

Who owns the device is rarely important for Microsoft, but Visser's description of Microsoft CDL specifies that it can be assigned to "up to four personally owned devices." So, if a company buys iPads for its employees, the Microsoft CDL doesn't apply. In that case, every device needs full licensing, which can mean, at least, a VDA subscription, a full Office license and possibly CALs, as well. That can run more than $1,000.

But if the company buys Windows RT devices for employees instead, it would not require a VDA subscription, and it's possible Office will also be excused.

The big picture of Windows 8 VDI licensing

You should be able to see where this is headed. The final Windows 8 VDI licensing rules could not only generate more revenue for Microsoft but create real competition for the iPad, particularly in corporate environments, which are Microsoft strongholds.

Microsoft is rumored to be asking as much as $100 for a Windows RT license, but iPad and Android tablet OS licenses are virtually free. The royalty for RT will let Microsoft recoup all the OS revenue that it's now losing every time someone buys a tablet rather than a regular PC, but it will also drive up the cost of Windows RT devices relative to the competition.

That disadvantage could be easily overcome, however, by giving Windows RT devices preferred remote access to Office and VDI scenarios, while adding $1,000 or more to do the same thing with a non-RT device. Couple that with stricter enforcement and auditing around access to Microsoft products from non-Windows devices, and Microsoft could put a heavy fist on the scale that balances the total cost of ownership of Windows RT devices versus non-RT devices.

This guessing game won't be over until the official rules are published, which probably won't be until October 2012 at the earliest. But at a minimum, organizations should make sure they have a handle on who is using which devices to access remote instances of Windows and Office. They may need to apply a heavy hand themselves to use such devices to avoid some very big bills once Windows RT is released.

Paul DeGroot is Principal Consultant at Pica Communications, an independent firm focused on optimizing Microsoft customers' license spending and agreements.

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