In theory:I have a low-power consuption machine: eee pc, ok.I need to run a virtualized windows xp on it. (Because of a windows-only program..)I need to reach it from a smartphone (Android).The smartphone connects with mobile broadband to the internet.Sound is needed too. (The windows-only program gives sound when a notification window comes up from it, and I HAVE to see it a few minutes - my phone is always next to me)So I need to connect to the remote virtualized guest persistently. (all day..)I need this in a secure way.I was thinking about:NetBSD on the eee pc -> XEN -> Windows XP  <-->ConnectBot <- VNC Viewer <- Android phoneAre there any better solutions for this?
SSH tunnel with VNC?
security;vnc;ssh tunneling
Your solution would work, but I think it's a little bit rougher than it needs to be. In particular, the vnc over ssh on android is going to be troublesome. It's possible, but it's not as usable or stable as it could be.I would suggest using RDP instead. There are great RDP clients on Android, the bandwidth consumption is a lot lower so it's more usable and the connection stays up more of the time. Yes, sound works and yes you can use TLS to secure the connection. The one I use is a couple bucks, but there are free ones too.On the host side, do what you know. I would have used Linux and it probably has better support for the EeePC hardware, but if you can make NetBSD go and prefer it, knock yourself out. VirtualBox has the ability to offer RDP access at the virtualized video hardware level which is nice for troubleshooting remote windows, but once windows is up you can use it's own RDP mechanism which is nicer for the screen resolution and layout issues when connecting from a mobile device.