Ottawa PC Users' Group, Inc.
Remote Computing with VNC
by Chris Taylor
For years there have been remote control programs available
on the market. Programs such as Symantec's PC Anywhere,
Laplink.com's namesake product, and Microsoft's SMS Remote
Control have helped people run computers from remote
locations as if they were sitting at the console.
These programs work by sending the graphical information
about what is on the screen from the host computer to the
remote computer. In the opposite direction, key-strokes and
mouse movements are transferred from the remote computer to
Although generally pretty slow - there is a lot of data that
has to be transferred so the remote computer can see what is
on the host's screen - they do enable full remote access to
a computer. They can be a godsend to those who need to
remotely administer computers and helpdesk staff who must
try to solve problems without wearing out their shoe
But you don't need to spend any money to get one of the best
remote control packages around - VNC v3.3.3r7. VNC (which
stands for Virtual Network Computing) is available free of
charge under the GNU General Public License. You can
download both the server and viewer portions for 32-bit
Windows from PUB II's file area 2 (Apps-Communications) as
vnc3337.zip. Full source code is available as vnc3337s.zip.
Documentation is available in HTML format as vnc3337d.zip.
You first install the server portion on the machine you want
to be able to control remotely. It uses under 500K of disk
space and less than 5MB RAM. A Start Menu item sets up the
default registry settings. When you first run the program,
you are presented with the configuration screen. About the
only thing you must set is a password. You need to use this
password when you connect to this machine remotely.
You can then go to any other machine and run the viewer. The
viewer portion is a single file under 200K. It doesn't
require any installation routine and uses under 500K of RAM.
You could even run it from a floppy disk. Very slick! When
you run the viewer, you are prompted for the VNC server to
connect to (you can use the DNS name or IP address) and the
password. Once it connects, a window opens displaying the
desktop of the server machine. The mouse and keyboard on
both machines are fully operational.
VNC is available on multiple platforms. In addition to 32-
bit Windows, you can get servers and viewers for Linux 2.x
for x86, Solaris 2.5 (SPARC), Macintosh, and DEC Alpha OSF1
3.2. There is also a viewer for Windows CE 2.x. The viewer
on any platform will work with the server on any platform.
So, for example, you could use a Linux machine to control a
Windows NT server. It is also possible to use any Java-
enabled browser as a viewer. Performance of the browser
viewer is much poorer than the native clients, and there are
fewer configuration options available, but it works.
VNC may be run as a service on Windows, so there does not
have to be a user logged in on the server computer in order
for a viewer to connect. This is particularly useful in
administering remote Windows NT servers. You can always
connect to the server as long as the machine is up and
running and you do not have to worry about security concerns
raised by having someone always logged on at the server.
By default, the VNC server uses port 5900 for the native
client and 5800 for Java browser clients. These may be
changed if they are unsuitable due to issues such as
firewalls or Network Address Translation.
While we have the server and viewer portions, full source
code, and documentation on PUB II for 32-bit Windows, if you
need the binaries for other platforms, you can download them
If you have any need for a remote control package, take a
look at VNC. I think you will be pleasantly surprised at how
well it stacks up against the commercial competition.
VNC (Virtual Network Computing)
from AT&T Laboratories Cambridge
Web site: http://www.uk.research.att.com/vnc
Copyright and Usage
Computer Users' Group (OPCUG), Inc.
3 Thatcher Street,
Ottawa, ON K2G 1S6
The opinions expressed in these reviews may not necessarily
represent the views of the OPCUG or its members
Page created: 02-Nov-00