How Does Citrix Licensing Work?

Citrix licensing has long been a subject of MUCH confusion to Citrix users around the world. In order to alleviate some of that confusion, we'll condense the key aspects of Citrix licensing for XenApp and XenDesktop down to their very essence, and provide a “cheat sheet” that can be referred back to as needed.  

• XenApp is host-based application and server desktop publishing system based on Microsoft’s Terminal Server technology, which was actually written by Citrix and is maintained by Citrix to this day. This product is rarely sold by itself anymore, but is usually purchased as part of XenDesktop Enterprise or Platinum licenses.
• XenDesktop is a combination of XenApp and VDI technology using an individual VM for each user with a copy of desktop Windows as its OS.
• Workspace Suite is XenDesktop Platinum combined with XenMobile Enterprise (with ShareFile) in USER/DEVICE Licenses.
• Workspace Bundle is XenDesktop Platinum combined with XenMobile Enterprise (with ShareFile) in CONCURRENT Licenses.
• Citrix uses USER/DEVICE and CONCURRENT options with XenDesktop. 
  • USER/DEVICE licenses are issued and determined by the Citrix Licensing server. If multiple users LOG IN to the same device, then it is tagged with a device license and any number of users may use that device with that license. If a user LOGS IN to multiple devices (that are not tagged with a device license), then that individual is issued a user license. These licenses may not be reclaimed for 90 days from the last login without running a Citrix utility to manually release them. You can determine how many licenses are needed by using the following formula:
    
    

    A – C + B = Number of USER/DEVICE Licenses Needed

    A= Total Number of Users 
    B= Total Number of Shared Devices
    C= Number of Users that will ONLY use Shared Devices

    
    So, if you have 800 total users, 300 shared devices, and 400 users that will ONLY use shared devices, you will need 700 USER/DEVICE licenses.

  • CONCURRENT Licenses are unlimited and may be used by anyone, anywhere, BUT they are TWICE the cost of USER/DEVICE Licenses, so careful consideration to which model is chosen is very important. If you have 1000 users, but only 400 of them are LOGGED IN at any given time, then CONCURRENT licenses are your best bet. As long as the ration is more than 2-to-1 (since the licenses are twice as much...), then this is the way to go.
  • Other factors to consider are that if both models are chosen, completely separate servers and licenses need to be maintained for each group, making this concept difficult to implement.

• XenApp or XenDesktop VDI or both may be used by a given user simultaneously on one license.
• An unlimited number of hosts are allowed with either product. Citrix only tracks user licenses.
• Citrix used to allow a 10% overage with no other restrictions on licenses as a courtesy to their users. With the implementation of XenDesktop 7.6 this has been eliminated in favor of the start of a 15-day grace period. There is no license count enforcement UNTIL the max number of licenses has been reached for the first time. At that point, extra user will still  be allowed, but only for 15 days from that date, at which time there will be strict enforcement and no users over the purchased license count will be allow to LOGIN.