(my) guideline to microsoft licensing for VDI

The list does not claim to be comprehensive. Use this information at own risk!

User or device CALs

• Take user CALs when user uses more than one device to access the desktop.
• Take device CALs when there are more or equal devices than users.
• Microsoft licenses the physical person (named user) NOT an Active Directory-User!

RDS CALs and VDA licenses

• VDA license includes the license for the virtual desktop.
• If you use a Windows Server OS instead of a Client OS to present to a user, you need a RDS-CAL instead of a VDA license to allow a user to connect to this server. The price are almost the same for server-CAL and VDA. Anyway this is just a good idea if a Windows Datacenter license is mapped to the Host.
• Virtual desktop (no Software Assurance) accessed by Linux/Windows embedded/Windows Home/… –> VDA license
• Virtual desktop (with Software Assurance) accessed by any client –> already licensed
• A windows device with active Software Assurance that connects to a virtual desktop –> virtual desktop and connection is licensed by Software Assurance
• To use RDS (Applications or Desktops) you need RDS-CALs.

Additional server CALs

• Connection Brokers needs also windows CALs for users or devices.
• If external user are not countable, you can license them with an External Connector license for Windows. If you know how many, you need CALs for users or devices.
• Licenses for SQL Server based on CPUs are bases on core number NOT socket number.