[Info-vax] Could XRDP be the next graphical interface for VMS?

[Dirk Munk]

Stephen Hoffman wrote:
> On 2015-03-21 13:12:34 +0000, Dirk Munk said:
>
>> I recently had a discussion about VDI. If you don't know what it is,
>> VDI is a virtual desktop PC on a server, and you can connect to it
>> from a PC, or a thin client, or a tablet, or... It is a very expensive
>> way to get the functionality you want.
>
> OpenVMS had a similarly expensive approach with EWS:
> <http://www.digiater.nl/openvms/freeware/v50/ews/>
>
>> The communication between server and client uses the same protocol as
>> with Windows Terminal Server. It is comparable to X-Windows, but of
>> course it is different.
>>
>> In the Unix world there is a project called XRDP to give Unix servers
>> the same kind of interface, so you can connect to a Unix server as if
>> it were a Windows Terminal Server.
>>
>> I guess this could be the best way for VMS as well, no need for
>> special drivers and software on PC's, just standard Windows protocols.
>> Always a good selling point!
>>
>> You can find more about XRDP here:
>>
>> < http://www.xrdp.org/ >
>
> XRDP is a version of an RDP server that is integrated with an X Window
> system environment.  As was stated above.
>
> RDP is arguably comparable to X only in that there are displays around,
> and that there are displays operating over a network.   Being a remote
> transport for an existing physical or virtual GUI, RDP (and xrdp) do not
> provide any application display capabilities, and requires a local X
> Window manager and a local display, or some other local graphical
> display or virtual display.   In other words, RDP has to have something
> running on the RDP server to render remotely.  In OpenVMS
> configurations, the DECwindows X Window client and DECwindows X Window
> server capabilities provide this, either entirely on one server with
> both the client and the server running locally, or remotely with the X
> Window clients on OpenVMS and with the displays available via the X
> Window server.

Yes, I've used it this way.

> This remote server could be Microsoft Windows with xming
> <http://en.wikipedia.org/wiki/Xming> or one of the other available X
> Window server packages installed,

Sure, but the point is that no extra package would be much nicer :-)

> OS X with x11.app installed, or most
> Unix and Linux systems with the respective native X Window servers running.
>
> Something similar to RDP is already available on various Integrity
> servers running OpenVMS, via vKVM.
> <http://h71000.www7.hp.com/openvms/journal/v15/vkvm_ovms.pdf>  vKVM
> displays the DECwindows interface from the X Window software remotely,
> using RDP protocols.
>
> For related information and discussions, search the Google Group
> archives for the comp.os.vms newsgroup for the Sun Ray discussions.
> <http://en.wikipedia.org/wiki/Sun_Ray>
>
> For discussions of a virtual frame buffer for OpenVMS, see
> <http://www.digiater.nl/openvms/freeware/v50/virtcfb/>.  Something
> similar to this would be necessary for a Windows Terminal Server
> implementation on OpenVMS, if you didn't want to install X Window Server
> packages on the remote systems and the associated X network transport.
>

Indeed, that is what I would like to see. No special X-Windows server 
packages on the remote server.

> TL;DR:  RDP would avoid the need for an X Window Server in the target
> box — on the target box, not on the OpenVMS box.

Yes, that was my point exactly.

> As a replacement for
> the OpenVMS graphics system, a configuration with RDP still needs some
> sort of a virtual or physical graphical interface operating on the
> OpenVMS system, and the APIs that applications would necessarily use to
> render display information into the virtual or physical frame buffer. In
> OpenVMS terms, this rendering system is DECwindows, and the DECwindows
> APIs.
>

Yes indeed, that was what I understood about XRDP too. It seems to be 
based on X-Windows.

>
> Does Betteridge's law of headlines apply to comp.os.vms newsgroup
> subject lines?

Not in this case at least.

Recently there was some discussion about X-Windows, Motif etc. in this 
group. I'm not an expert on these matters, but it doesn't stop me 
thinking about good solutions for these problems.

But what is your opinion, could XRDP or a similar OpenVMS package be the 
way for a new graphical interface?