Microsoft Volume Licensing Mail Bag: Three Questions on Virtual Desktop Infrastructure (VDI) Licensing

A Microsoft Volume Licensing Expert Answers your Burning Questions on Licensing the Microsoft Virtual Desktop Infrastructure (VDI).

Microsoft VDI offers the ability to rapidly and securely deploy desktops from a data center to users. IT support teams can manage desktops centrally, and VDI can help improve security by centralizing users’ data. VDI also gives end users the flexibility they need to access their work desktops from almost any device that has a reliable network connection.

Louise Ulrick, a UK-based licensing consultant and trainer, has relished taking the opportunity to answer some of your thornier questions on the licensing of VDI. She first began running licensing training courses all the way back in 1995.  Today, Louise continues to love licensing and works all over the world on behalf of Microsoft.

Q: We have an Enterprise Agreement with Windows, Office and the Core Client Access License (CAL) and we’ve always deployed Windows and Office locally on all the users’ desktop PCs.  However, we’re now interested in taking advantage of the benefits of a Virtual Desktop Infrastructure, but our question is – what additional licenses will we need?

Louise: When you start out with VDI licensing it’s helpful to break down the components of the infrastructure and to then work out the licensing requirements for each part.  So, the first part to consider is the desktop PC itself, and in this case Windows and Office running in a virtual desktop on the data center will be delivered to the PCs. From a licensing perspective, those PCs still need to be licensed with Windows and Office – and you already have those licenses as part of your EA.  With a VDI infrastructure there’s the additional requirement to have VDA rights – in essence the rights to choose to run Windows in the data center rather than locally on the device.  And there’s more good news – this is part of Windows Software Assurance which you have as part of the EA already.

The second part is what I’ll call the infrastructure – and here we’re talking about a Microsoft VDI environment which relies on the Hyper-V element of Windows Server to host the virtual desktops, and the Remote Desktop Services (RDS) element to broker connections between the virtual machines running in the data center and the accessing devices. You’ll need Windows Server licenses for the VDI host servers, and then Windows Server CALs and RDS CALs for either users or devices.  From a CAL perspective, you already have the required Windows Server CALs as part of your Core CAL purchase, so it’s likely to just be an additional purchase of RDS CALs.

And the final element is a management element where you could choose to use tools like System Center Configuration Manager to streamline provisioning, and Virtual Machine Manager to configure and deploy new virtual machines (VMs).  These tools would both be licensed through the System Center Configuration Manager CML – and the great news is that this is included in your existing Core CAL purchase too!

So, to answer your original question – your desktop EA gives you the vast majority of licenses you need to deploy the technologies locally as you have done in the past, or to move to a Virtual Desktop Infrastructure by just adding RDS CALs.

Q: We have run VDI for some time and know that we need Windows + SA licenses for the desktop machines accessing the VMs and also Windows Server and RDS CALs for those devices.  Until recently it has been a 1:1 relationship with the number of desktop machines and the number of virtual desktops stored on the server. However, we have taken on more staff who are part time and, as such, we have 350 virtual desktops and just 290 physical devices that these virtual desktops are delivered to.  What additional licenses should we purchase to ensure we’re compliant in this situation?

Louise: Well, there’s some good news for you – you’re already compliant for the scenario you describe!  VDI is a device licensing model – so as long as the physical devices are licensed with the Windows + SA and Windows Server and RDS CALs, then those devices may access any of the virtual desktops on the server and there is no limit (licensing-wise at least!) to the number of virtual desktops that may be stored on the VDI host servers.

Q: We have an Enterprise Agreement with the Enterprise Desktop – so Windows, Office and the Enterprise CAL Suite – and we have additionally purchased RDS CALs for all users so that we can deploy virtual desktops in a Virtual desktop Infrastructure within our offices. However, we now want to give our users the opportunity to work in a more flexible way, and we need to know what additional licenses we would need to allow users to access their virtual desktops on one or more of their personally owned devices at their homes.

Louise: The situation you’ve described is licensed with Roaming Use Rights.  These rights allow users to access their VDI desktops on third party devices outside of the office with no limit to the number of different devices that they can use. So, the question is – how do you acquire Roaming Use Rights?  They’re actually a Software Assurance (SA) benefit when you acquire SA on Windows and Office licenses and are conferred on the primary user of a licensed machine.  You already have all of your company-owned devices licensed with Windows and Office + SA under your Enterprise Agreement, so all of the primary users are already licensed to access their VDI desktops at home.

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Have a follow-up question on VDI? Write us a note in the comments below or visit the Microsoft virtualization licensing page. Need additional assistance? Visit the Contact Us page for additional support or check out the TechNet Forums for more insight.

Feedback welcome: This is our third rendition of the “mailbag” feature and we would love your input. Do you have suggestions to make this more useful for you? Perhaps you have a question you would like to see in a future mailbag? Feel free to provide them in the comments section.

Editor’s Note: Remember, always check with your account representative or partner on any terms, restrictions or other that may apply within VDI licensing. The answers and examples provided above make assumptions that may not apply to your unique situation and are primarily designed to serve as a guide.

Comments (11)

  1. KensterVibe says:

    Microsoft – I thought you would welcome questions in the comments section and actually post answers to them?

    So Matt – yes you can run Hyper-V as the Virtualization Host for the VDI Server farms hosting the virtual Windows desktops without the full Windows Server OS, however, you do need the full Windows Server OS's for the RDS Roles such as the RD Web Access, RD Connection Broker, etc.  These require the full Windows Server OS to function.  The Windows Server RDS Roles are what will play a crucial role in a Microsoft RDS VDI solution such as publishing Apps and Virtual Desktops via a Web Interface over https, Connection Brokering, etc.  

    And so then that is why RDS CALs are needed.  You only need 1 RDS CAL per device or per user and with that you can access however many RDS Server roles you have or need in your infrastructure.  

    Hopefully that helps.

    Kenny | CDW

  2. DonPick says:

    thanks for this scenario-based write-up, it is so very much easier to point people to these examples, rather than the complex array of PURs and MSLTs and Briefs and whitepapers and…. 🙂

    Could you cover a mixed scenario, where a company has a mixture of on-premise devices/servers and is looking at O365? e.g. some on-premises VDI/RDS + O365, so will likely need to consider some Office via Select in addition to O365?

  3. Matt says:

    You mention that you require Server licensing for the Virtualization Hosts.  Couldn't you run Hyper-v Server 2012 as a free virtualization host?

    Do you require a special license to add the RDS role to the hyper-v server so it can be part of the collection/RDS broker setup?

  4. JonathanG says:

    If the VDI solution uses a 3rd party broker, i.e. Quest vWorkspace, rather than the Microsoft RDS broker, do you still need the RDS-CAL for each VDI session provisioned from Hyper-V?

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  6. Sagari Website says:

    This blog is all about the cloud computing and virtual desktop hosting.The desktop is a unique beast within the data center.Thank you so much for this post.

  7. Jess says:

    I have the following VDI deployment:
    1 x server Microsoft RDS Connection Broker, RDS Gateway, RD Web Access – Licensed with Windows 2012 R2 Standard (No remote applications programs published)

    2 X server Hyper-V core 3 (total of 90 VMs)
    90 x Repurposed Computer – Licensed with 90 Windows 7 + SA
    90 x Office 2013 Professional Licenses

    Each VM are installed with Windows 7 and Office 2013 Prof.

    Do I still need RDS CAL?

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  9. Kevin says:

    Could you explain the usage rights of the Core CAL in regards to SCVMM? I know you mentioned using it to manage VMs, but is it just client OSE VMs? Or is it compliant to use it for the Hyper-V hosts and RDS VMs as well? If so are other SCVMM licensing
    requirements needed if I run other VMs such as server OSEs on the same Hyper-V hosts?

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