VNC

Introduction

VNC stands for Virtual Network Computing.

VNC is a client/server program. Put a VNC server on your office PC computer and activate it with a password. Then, from any other PC, UNIX system or handheld computer, you can connect to your office PC with the same password and control the keyboard and mouse inputs and see the desktop display output. It's like a remote control device. It's ideal for times when you need the same office desktop environment when you can't get to the office. Work at home when the snow is too deep. Work from a research lab on another campus.

VNC works well because most of the work to control your office PC is done on the server side software, leaving the client side software to access your remote office PC simple and small, usually with one executable file. The executable size for both Windows computers and Sun/Solaris computers are less than 200KB. Both of these would fit on a floppy. So access from a remote campus computer wouldn't require any software installations to mess it up. Just pop in the floppy, type in to the Run... prompt a:\vncviewer.exe and the program is ready to connect.

Installation

The VNC software, both server and client sides, is available from the Real VNC. The software is freeware, so licensing is not a problem. There are many versions available, including Windows (Windows 95, Windows 98, Windows NT and Windows 2000), Macintosh, Sun/Solaris, Linux, Alpha/OSF and Windows CE. Each download contains both the client and server versions in a single package. You'll need to download all packages needed to provide both client and server access. For example, if you're going to operate your Windows 98 computer in your office, but access it from Sun/Solaris, you'll need to download both the Windows and Sun/Solaris versions, even though only the client of Sun/Solaris will be used out of the Sun/Solaris package, and only the server of the Windows package. Check the web side for available packages as they may change over time.

Caveats

VNC is not perfect. It has a few flaws that keep it from being the end-all solution for remote access computing. For example, windows often does not update all the way. VNC tries to optimize display updates to reduce network traffic, and sometimes misses an update. Network latency sometimes causes delays in showing the status of the screen or a mouse movement. Sounds are not propagated at all. And certainly, displaying live video won't come across. There are settings in the control panel for VNC to enable it to make more aggressive updates of the screen at the expense of higher network traffic.

An additional problem is differences in screen resolution or sizes. Most people will have a high-powered computer on their desktop, but have a modest system at home. If your office desktop is displaying at 1280 by 1024 pixels, and your home system is only at 800 by 640 pixels, you will only see a partial desktop in the VNC viewer. There are scrollbars to account for the difference in size; however, it will make operating the remote desktop difficult.

On a slightly different type of problem, I had access to the new line of Microsoft Pocket PCs, a Compaq IPAQ 3650. Microsoft Pocket PC is the same as saying Windows CE version 3.0. While AT&T has VNC available for the Windows CE computers, they only had versions for the processor types MIPS and SH3. The Compaq IPAQ 3650 uses the Strong-ARM processor. Neither the MIPS nor SH3 versions work on this processor type. Be sure to check your Windows CE version 2 or 3 computer for processor type before downloading software from the VNC web site.

Personal Experience

I have used VNC for over two years in different configurations. For a while, I would rather have a UNIX desktop because that's where I do most of my work. However, no one can get away from the dreaded Microsoft monster for long. If someone sends me a Microsoft Word document, I used to have to switch to a PC running Windows and look at the document from there. However, with VNC, I could have a second office PC running Windows, and just display the Windows desktop onto of my UNIX desktop. I no longer had to switch between computers.

Another VNC solution is to access a program on my office PC that I did not have access to at home. At one time I had a big Microsoft Access database. Even if I had Access on my home computer, I really couldn't push all of the data in the database over the dialup line. Using VNC to display Microsoft Access from my office computer to my home computer's desktop display was enough to get at the data that I needed.

My experiences with VNC are generally positive. The software is well designed and easy to install and operate. I've never noticed it to ever fail or hang, on either side of the client or server. Be sure to ask your local computer support personnel about their willingness to help should problems arise ahead of time before installing this software on your office computer.

An Alternative

Just to let you know, there are alternatives to running VNC. The Distributed Academic Computing Service (DACS) is another type of remote access Windows system. WTS is a single, usually large, usually multi-processor computer running a special version of Microsoft Windows 2003. This special version allows for multiple users to connect remotely and all keyboard and mouse inputs are sent in and a desktop display output is sent back. It also uses a special program to do the input and output called an ICA client. More information is available at the Distributed Academic Computing Service web site.

WTS has the advantage that it is a separately maintained system and always operating. It contains a lot of prebuilt software, updates the display correctly, propagates sounds and is probably more efficient at networking traffic. It doesn't require that you have a PC computer at all - for those folks that only have UNIX computers in their offices. On the other hand, the client software is not as simple as VNC's one executable and that the software available on WTS is specified by a steering committee.

VNC Server

Note to self: When building VNC server for FreeBSD, it cannot detect the operating system in the X windows imake configuration files. I put in an additional statement in Xvnc/config/imake/imake.c at line 596 that says:

	AddCppArg("-D__FreeBSD__");

before doing the make World command.