xrdp without xorgxrdp

In my role as a tutor I often have to set up test Ubuntu installations to help students that use Ubuntu - I myself use Windows (sorry!).

For convenience I always install xrdp, and I found out by Googling and lots of experiment that I need to also install xorgxrdp. Then I can RDP to the test installations from my Windows workstation and this all works very well.

If I don't install xorgxrdp my RDP session just shows a blank screen. There are lots of questions about this already, and I vaguely grasp that xorgxrdp is an interface between xrdp and xvnc, so I'm not asking how to fix the blank screen. Instead I would be interested to know what exactly has happened if I make the connection without installing xorgxrdp. The connection has obviously established some form of graphical session because the mouse works, and I see the Ubuntu cursor in my RDP window not the Windows cursor. Can I do anything with this connection? Is there any way of running a graphical application?

Basically, afaik, if you want to have working remote desktop solution using xrdp software, you have to install xrdp + xorgxrdp. If you install xrdp from command line on your Ubuntu system using the following command in a Terminal console

sudo apt-get install xrdp 

xorgxrdp package will be installed along since this package will be marked as dependencies

To answer your question about what xorgxrdp is, Please have look at the maintainer github page at https://github.com/neutrinolabs/xorgxrdp.. On this link they provide some explanation on what xorgxrdp is....

Extrat From https://github.com/neutrinolabs/xorgxrdp

xorgxrdp is a collection of modules to be used with a pre-existing X.Org install to make the X server act like X11rdp. Unlike X11rdp, you don't have to recompile the whole X Window System. Instead, additional modules are installed to a location where the existing Xorg installation would pick them.

xorgxrdp is to be used together with xrdp and X.Org Server. It is pretty useless using xorgxrdp alone.

Hope this help Till next time See ya

I will post an answer to my own question because with help from Griffon's answer and some Googling I think I understand what is happening.

Firstly I had not realised that Xrdp contains a window manager. When you open the RDP connection you are presented with this login screen:

And then on entering my username and password I see this blank screen:

Although it doesn't show in the screen grab the screen shows a cursor that isn't the standard Windows cursor so I thought the RDP session had connected, but actually this output is coming from the Xrdp server and the connection is still in progress.

The second confusion is that the timeout connecting to Xorg is very long (3½ minutes!) and I had thought the blank screen after entering my credentials meant I had successfully established an RDP session and for some reason the desktop hadn't started. In fact I am still looking at output generated by the Xrdp server, and if I wait long enough I eventually see an error message from Xrdp saying it cannot connect to Xorg:

So the answer to my question is I am seeing only the graphical elements drawn by the Xrdp server, and there is no way of running anything because when the screen is blank the RDP connection is still in progress.