VIRTUAL NETWORK COMPUTING

Contributor:Sreedish P.S.

Virtual Network Computing (VNC) is a graphical (GUI) desktop sharing system which uses the RFB (Remote FrameBuffer) protocol to remotely control another computer. It transmits the keyboard and mouse events from one computer to another, relaying the graphical screen updates back in the other direction, over a network.VNC was originally developed at AT&T.It is, in essence, a remote display system which allows us to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. VNC consists of two types of component. A server, which generates a display, and a viewer, which actually draws the display on your screen. So, to get started with VNC we need to run a server, and then connect to it with a viewer. . The
important factors which distinguish VNC from other remote display systems such as X are as follows:

No state is stored at the viewer. This means we can leave our desk, go to another machine, whether next door or several hundred miles away, reconnect to our desktop from there and finish the sentence we were typing. Even the cursor will be in the same place.

With a PC X server, if your PC crashes or is restarted, all the remote applications will die. With VNC they go on running. It is small and simple. The Win32 viewer, for example, is about 150K in size and can be run directly from a floppy. There is no installation needed. It is truly platform-independent. A desktop running on a Linux
machine may be displayed on a PC. Or a Solaris machine. Or any number of other architectures. The simplicity of the protocol makes it easy to port to new platforms. We have a Java viewer, which will run in any Java-capable browser. We have a Windows NT server, allowing us to view the desktop of a remote NT machine on any of these platforms using exactly the same viewer. And other people have ported VNC to a wide variety of other platforms. It is sharable. One desktop can be displayed and used by several viewers at once.


REFERENCES

http://en.wikipedia.org/wiki/VNC2)
http://www.cl.cam.ac.uk/research/dtg/attarchive/vnc/index.html
(Archive of AT&T Laboratories)3) AT&T Laboratories Cambridge (1999). X-based VNC server. Virtual Network Computing.4)
Tristan Richardson - "Virtual Network Computing”