(Posting back to the mailing list...)
On Thu, Jul 26, 2018 at 5:31 AM Martin Ciglan <m.ciglan@sino.sk> wrote:
Thank you.

I would like to connect with RDP to Xen. I guess it's possible without
any major issues?

XenServer itself doesn't support RDP, but you can definitely connect to any guest system running on XenServer that does implement RDP.

If you're looking to connect directly to the console of the guest VMs running on XenServer, you could use VNC as that's the protocol used by XenServer to display the VM consoles.  There is probably some additional configuration required on the XenServer side to expose those VNC connections in a way that Guacmaole could see.