What on Earth is Session Zero?

James Weatherall jnw "at" realvnc.com
Tue Nov 1 14:19:00 2005


Hi Stephen,

My exact reply to your (somewhat abusive) enquiry via our trial-feedback
form was:

--
Stephen,

Thanks for your comments.

FYI, error 10061 means that the address to which you attempted to connect
actively refused the connection.  This can mean that the computer using that
address isn't running VNC Server (perhaps because it's not the computer you
meant to connect to), that it's running VNC Server on a different port
number to the one you're using, or that it has a firewall in place that
refuses connections rather than ignoring them.

Error 10061 does not relate to Fast User Switching nor Remote Desktop in any
way.

It is not necessary to disable Fast User Switching nor Remote Desktop in
order to use VNC Server on a Windows XP system.  It is the case that current
releases of VNC Server will only allow session zero to be accessed remotely,
however, and this may best be ensured by disabling those features in some
cases.  Disabling these features is described in the Windows XP
documentation, which may be accessed via the "Help and Support" entry in the
Start Menu of your Windows XP system.

Regards,

Wez @ RealVNC Ltd.
--

As you will notice, I have specifically pointed out that the problem you are
seeing is NOT related to Fast User Switching, nor to Remote Desktop.  The
problem you are seeing indicates that the computer that is using the IP
address that you specify to VNC Viewer is NOT listening for VNC connections.
This may be because:

1.  You are using the incorrect IP address for the server computer.
2.  There is no VNC Server running on the server computer.
3.  There is a firewall in place around/on the server computer that is
rejecting the connections.
4.  You are testing connecting via a NAT router from a machine on the same
LAN as the server - many new NAT routers are broken and won't allow this.

The fact that you say "no, I am not using the same port number" suggests
that perhaps your router's port forwarding configuration at the server end
is the problem - you'll need to make sure that you are specifying the
correct external port number to VNC Viewer, and having that forwarded to the
port number on which your VNC Server is listening for connections.

Are you testing connections using VNC Viewer for Java, or a native VNC
Viewer?

VNC Server works fine on Windows XP Home Edition.

Cheers,

Wez @ RealVNC Ltd.



> -----Original Message-----
> From: vnc-list-admin "at" realvnc.com 
> [mailto:vnc-list-admin "at" realvnc.com] On Behalf Of Stephen
> Sent: 01 November 2005 11:50
> To: vnc-list "at" realvnc.com
> Subject: What on Earth is Session Zero?
> 
> I am getting really really fed up with RealVNC. All it will 
> ever ever do is
> say Connection Refused Eror 10061, and yes I have checked 
> every single thing
> to do with firewalls over and over again, all firewalls are 
> completely off,
> RealVNC viewer and server are exceptions in Windows Firewall 
> list anyway.
> The exact same system works with a Windows ME PC on the same 
> router, and no
> the other PC is not switched on, and no I do not use the same 
> port number,
> yes the server is running on the XP PC, yes I am accessing 
> the right PC.
> 
> It DOES work if I phone someone at the other end and get them 
> to initiaite
> the connection with "Add New Client", but it is never 
> possible to connect
> from my end with RealVNC viewer, or http in Internet 
> Explorer. Because "Add
> New Client" is the only thing that has ever worked, it means 
> that the full
> extent of the usefulness of RealVNC is that it can be used if there is
> someone at the other end 24 hours a day who can be contacted 
> by phone to Add
> New Client manually to initiate the connection. This is not 
> how we want
> remote control software to work.
> 
> I e-mailed Real VNC's help and support explaining the reality 
> of Real VNC
> for the ordinary (XP Home) user, "it is a piece of software 
> which can and
> does do only one thing: put a message on the screen which 
> says "Connection
> Refused" - in the REAL world RealVNC does not work." Their reply was,
> "current releases of VNC Server will only allow session zero 
> to be accessed
> remotely, and this may best be ensured by disabling Fast User 
> Switching nor
> Remote Desktop in some cases. Disabling these features is 
> described in the
> Windows XP documentation, which may be accessed via the "Help 
> and Support"
> entry in the Start Menu of your Windows XP system."
> 
> I have disabled Fast User Switching and Remote Desktop, and 
> it has made no
> difference at all. What difference should it make? How is 
> anyone supposed to
> know what SESSION ZERO is? What is it? I see no mention of 
> session zero in
> Real VNC or in Windows XP Help. If attempting to get RealVNC 
> to work relies
> on an understanding of the meaning of "Session Zero", then no ordinary
> computer user can ever be expected to
> use RealVNC.
> 
> Can someone please point me in the direction of a remote 
> control Server
> which DOES work on Windows XP Home Edition? NOT Real VNC Server, NOT
> TightVNC Server (I have been down the same path with this and it also
> refuses to connect), NOT Windows Remote Desktop Server (deliberately
> disabled by Microsoft in XP Home Edition), NOT Microsoft 
> Netmeeting Server
> (also deliberately disabled by Microsoft in XP Home Edition.) 
> Is my problem
> because this deliberate disabling also disables Real VNC Server?
> 
> It seems to me that RealVNC IS NOT COMPATIBLE WITH WINDOWS XP 
> HOME EDITION
> and should not be advertised as though it is. Has anyone EVER 
> had the remote
> control Server running correctly and accepting connections on 
> Windows XP
> HOME Edition?
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