I'm joining some pieces of (free) soft in order to assist remotely my parents when they have any doubt/problem (they're using kubuntu 12.04) when using KDE desktop.

My idea is to use an ssh tunnel to add an aditional security layer.
The goal would be to "grab" X session my relatives are using, so I could help her/him a little bit.

I know kde has a built-in vnc server, but I'd like to tweak it a little bit in order to improve performance (as long as ssh will add some overhead).
I tried x11vnc and I think it would fit my needs.

I also tried some others vnc server like tightvncserver ant TurboVNC. My doubts are the following:

1) Can these vncserver (ex. tightvncserver) act like x11vnc? (I mean, "grabbing" an existing X session display:0 and not opening a new one :1)

2) In terms of performance any solution based on NX (NoMachine) would be faster, but these solutions work creating a new X session. Is that correct?

Thanks in advance!

nx can do this, not just new sessions. it's a great bit of kit.

Chris,

Thanks for your reply. In terms of performance nx is just great.
So I'll take a look again on how to "grab" existing X session.

regards,
Matías

I've been testing x2go (http://www.x2go.org/), also based on NX. I like it very much.