There are two licensing models available for XenDesktop customers, User/Device and Concurrent.
User/Device Licenses
XenDesktop User/Device licenses provide customers with the maximum flexibility of assigning a single license to either a user or a device. and supports both license types in the same environment. The license server contains the intelligence to automatically assign these licenses to users or devices based on usage.
- User licensing gives users access to their virtual desktops and apps from an unlimited number of devices.
- Device licensing gives an unlimited number of users access to their virtual desktops and apps from a single device.
- A licensed user simply requires a unique user ID, such as an Active Directory entry. There is no requirement to manage a separate or specific list of authorized users. If a user launches one or more XenDesktop session(s) and/or apps with multiple devices (e.g. desktop PC, laptop, netbook, smartphone and/or thin client), only one XenDesktop user/device license is needed, even if all of the user’s devices are connected to one or more instances of XenDesktop at the same time.
- A licensed device simply requires a unique device ID. Under the device model, a device is any piece of equipment authorized to be used by any individual(s) to access instances of XenDesktop. For a shared device, like a classroom workstation, or a clinical workstation in a hospital, a single XenDesktop device license can support an unlimited number of users.
The license server determines how to minimize license consumption based on the users and devices connected. The license server optimizes every 5 seconds until there are 5000 uses on distinct pairs (user/device) checked out. At 5000 uses, optimization occurs every 5 minutes, which might delay status information until the next optimization.
Examples of uses on pairs:
Optimization occurs every 5 seconds for 1-4999 uses and every 5 minutes for 5000 or more uses.
5000 users * 1 device each = 5000
5000 devices * 1 user each = 5000
2500 users * 2 devices each = 5000
When users or devices connect to an application or desktop, they consume a license for a 90-day license assignment period. The assignment period begins when a connection is made, is renewed to the full 90 days during the life of the connection, and expires (allowing reassignment) 90 days after the last connection terminates. To manually end a license assignment before the 90-day period elapses (for example, an employee consuming a User license leaves the company), an administrator must use the udadmin command line tool.
Concurrent Licenses
A concurrent XenDesktop license is tied to a XenDesktop session, not to a specific user or device. When a user launches a session, a license is checked out to that session. When a user logs off from a session, the license server checks the license back in the pool, making it available for another user. Using this logic, it is important to keep the following scenarios in mind:
- Multiple XenDesktop sessions on the same device use multiple licenses.
- Sessions on multiple devices use multiple licenses. Each time a user launches a XenDesktop session from a different device, a license remains checked out until the user closes the session at that device (at which point the license is checked back in).
More information about the license models can be found here.