When deploying Horizon 6, there are three different versions:
Standard: This provides core functionality with access to persistent and non-persistent desktops running Windows 7/8x Enterprise.
Advanced: This provides all the features of standard, but also adds VSAN capability, RDSH and image management
Enterprise: This provides all the features of advanced but also includes vCOps, Orchestrator, and App Volumes
Once the Horizon version is chosen, then the number of users needs to be identified. The vSphere Desktop license that come with horizon provides the equivalent of Enterprise Plus licensing on unlimited hosts. However, it is per powered on desktop. So you initially get 100 powered on desktop VMs. For additional desktops, you can get license packs of 10 or 100.
Next, the desktop version OS needs to be chosen. These options are:
Windows XP, Vista, 7, 8, 8.1 and Windows Server 2008R2
For RDS Hosts, the options are:
Windows Server 2008R2 and Windows Server 2012
This is interesting because the license model for the server OS is very different than the desktop OS. In some instances it can be cheaper to license Windows Server 2008R2 datacenter as a desktop than a desktop OS.
Here are the desktop licensing options:
Software Assurance (SA): This is the most common type of licensing that allows VDI use of a desktop, local install on a PC or tablet and the use of “Windows to Go” on a USB drive. The primary user’s primary device must be licensed for Windows 7/8/8.1 Pro or Enterprise
Virtual Desktop Access (VDA): This licensing is for access to VDI desktops from non-windows devices, such as Macs, phones, thinclients, etc.
As another twist in the licensing puzzle, these two types were based on device connectivity. If a user had a bunch of devices that they connect with, then they could use a companion subscription license for the other devices.
As of Nov. 3rd 2014, Microsoft has also added user based licensing to simplify things. Below is the comparison:
So now if device licenses were deployed and the customer wants to add per user functionality, then a per user add on license can be purchased. This effectively replaces the CSL.
So at the end of the day the licensing model depends on the use case, number of users and type of users. One caveat of using Windows Server 2008R2 as a desktop OS is that there were some issue with sound redirection as of Horizon 5.3, though I have not seen any revisions on this or have tested it on 6.
If you have Windows Server 2008R2 Datacenter, you license it per physical core on the underlying host. So if you have a powerful host with a ton of memory that is dual socket with 12 cores, then you only need to buy 1 datacenter license per host. This may be cheaper than using SA or VDA user licensing depending on the number of users.
Or if you want to reduce the number of VMs so you don’t have to buy more Horizon license packs, then you may want to have some users on RDSH instead of on their own desktop. Just remember that you need Horizon advanced to do that.