Q: Because I'm using a Citrix solution, do I need a Remote Desktop Services Client Access License?

A:A Remote Desktop Services (RDS) Client Access License (CAL) is needed whenever any component of the Remote Desktop Service (or formally, TerminalServices) role is used. This could be an actual Remote Desktop Session Host (via Terminal Server), it could be RemoteFX running on Hyper-V attached toa virtual machine (VM), the RD Connection Broker, any component.

The two main Citrix solutions I want to focus on are XenApp and XenDesktop.

XenApp is a session virtualization technology that delivers either a desktop or just an application that's running on a remote server OS. BecauseXenApp is built on RDS, the RDS CAL is required for every device or user that uses XenApp.

XenDesktop is Citrix's Virtual Desktop Infrastructure (VDI) solution that uses pure Citrix components. No RDS role services are used, which means thatfor a pure XenDesktop solution, the RDS CAL isn't required.

But there is a caveat. While XenDesktop doesn't require the RDS CAL, it's very common thatXenDesktop deployments also use XenApp to deliver applications to the VDI desktops. If the XenApp capability is used with XenDesktop, then once againthe RDS CAL is required.

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