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 the host.

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 leather.

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 from http://www.uk.research.att.com/vnc.

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.

Originally published: November, 2000

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