[vox-tech] VNC - awesome!

[Karsten M. Self]

on Mon, Jul 26, 2004 at 06:25:24PM -0700, Peter Jay Salzman (p at dirac.org) wrote:
> Hi all,
> 
> After months of procrastinating, I finally got around to installing VNC.
> All I have to say is...  WOW!  Totally and completely neat!  It's a VERY
> impressive piece of software!
> 
> I have a couple of questions:
> 
> 
> 1. A Google search turned up a number of different VNC clients like
>    "realvnc", "ultravnc", and "tightvnc".  The one I downloaded was
>    from:
> 
>       http://www.realvnc.com/
> 
>    The server was installed on a win2k machine and the rpm for my Linux
>    client was converted into a deb from an rpm via alien.  I chose this
>    implementation (realvnc) because it was obviously GPL'd and the first
>    one I found.  I had no way of comparing the different
>    implementations.
> 
>    Is there one implementation that's better than the others?  Why did
>    this piece of software fork so many times?

Try 'em.  I use tightvnc generally myself.

Forking as a result of organizational turmoil:  Olivetti => AT&T =>
divestiture...

I think TightVNC's the most actively developed branch.

There are a number of other tools, including radmin, and NX from
Nomachine.com, which is solidly plugged in the Samba HOWTOs:

    http://www.nomachine.com/

There's also the 'rdesktop' client which is IIRC a terminal services
client for Linux (more below).

> 2. The server is a win2k machine.  When using VNC, the machine is taken
>    over; you can't log in at the console.  

Not quite.  Using VNC, you *are* logged in at the console.

>    Is there a way to make Win2k multi-user?  

I suffered the same illusions of WinNT WS 4.0.  Don't feel bad.

You need Terminal Services + CACLs to come close to what can be
accomplished by an old Pentium-class box serving up X sessions.

>    I was under the impression that this OS is considered by 
>    Microsoft to be a server class OS.  Can't more than one person log
>    in?  Is there a registry setting or something?  Sorry.  I really
>    don't know much about Windows.  This is probably a really dumb
>    question.

I'm going to get this horribly butchered, but basically:

  - The standard login is a single-user affair.  It's possible to
    support multiple users, but only by slathering additional buggy
    software and incomprehensible licensing onto the system.

    VNC grabs the primary "console" display.

  - By contrast, a VNC server session under Linux is a fully independent
    virtual display.  In fact it's difficult to "share" or access an
    existing X session unless you've made arrangements to do so in
    advance.
 
> 
> 3. I'm ashamed to be asking this.  The LAN speed is NEARLY perfect.
>    There are some very slight pauses, but it got me thinking about
>    ethernet speeds.  I've never really thought about it too much before.

Above and beyond your HW tuning:

  - Set compression low (faster compression & lower latency).

  - Set quality low (more jpeg artifacts => smaller framebuffers =>
    faster response).

  - Experiment with polling options.  The client can be set for a number
    of options.  "Full screen" will more accurately portray what's on
    the system, but slows down performance.

  - On systems where it's supported, you want to have mouse actions
    bound on click only.  This means the remote side only has to
    determine where you're clicking, not every mouse movement you make.
 
>    How exactly do I get 100Mb/s = 12.5 MB/s between my local machines?

s/hubs/switches/ will help a lot, looks as if you're doing that.

There's *always* some Ethernet overhead.  At full saturation you'd have
a significant collision problem.  Not sure of the specifics, but I'm
also seeing significantly less than advertised speeds here.

>    For some reason, I've never really thought about the speed on my LAN
>    before.  My switch is a D-Link DSS-5, which also does 100/10 Mb/s.

> Lots of questions.  Thanks for reading down this far!

42.


Peace.

-- 
Karsten M. Self <karsten at linuxmafia.com>        http://linuxmafia.com/~karsten
    Ceterum censeo, Caldera delenda est.