Saturday, January 6

Remote server

1, principle
2, local drive
3, Multi-login
4, future trend?

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Recently I use the Microsoft Remote Desktop Connection a lot. When I use the Remote Desktop Connection from my laptop, of course there is a Remote Server existed. I am thinking that it can become a big thing in the future, because of its virtues.

I noticed that the principle is quite simple. The Remote Desktop Connection in the local computer (hereby "local") receives keyboard and mouse input, send it through network to the Remote Server. The Server act like the input is "local" by treating the input message the same way as the keyboard and mouse are connected to the server. Then the server send out the display message to the output: the message is sent thought network to the Remote Desktop Connection software in local computer, and this software display the message as it should be.
In a traditional computer, the keyboard message is sent to computer through keyboard cable, the mouse message is sent to computer through mouse cable, and the display output is sent through video cable. In the Remote Desktop/Server framework, user's keyboard message and mouse message is sent to the server through network by the Remote Desktop Connection, and the display output is sent from the server to user by the Remote Desktop Connection too. As to the software in the server, it treats the input/output as normal input/output, because the Remote Server "encapsulate" the details.

Some might say the network input/output might be slow. Correct me if I'm wrong, but I think our keyboard is connected to computer in 1200 bps bond rate, when most of us are using 500k bps broadband network, or 54M wireless network connection.

When I was asked, I asked the same question to several IT guys but didn't get a satisfied answer. The question is: How to transfer file from local computer to remote server? The answer I got was to setup FTP server in the Server site, or use some other software (such as MSN Messenger) to transfer files. Those guys I asked are very good at computers, or at least as good as me. One of them is the network admin of our department. But the answer they gave me is not right. After playing with the option of Remote Desktop Connection for a while, I found an option: You can map your local drive to the server in the "Local Resources" tab. Then from the File Explorer of the Remote Server, you can see your local drives, so that you can copy files between local drive and server's hard drive. I didn't count the transferring speed, but I feel it's the same as FTPing.

The "Local Resources" tab in the options of Remote Desktop Connection also has an option to share the clipboard. I think it is a new feature added in 2007 (I run the Windows Update last week). It is quite useful actually, because we can copy simple text in the local computer, then paste it in the server, or vice versa.

I used Remote Administrator before. I am quite satisfied with this software, actually. It has the two features, file transferring and clipboard sharing. The file transferring function is using a separate application. One special thing about this software is that the monitor of the server computer is actually displaying the same as showing in remote desktop computer. Several people can log in the same server, and see the same session. It can be used to demonstrate how to use a software. The drawback is that if a walk-by see the monitor of the server, he can know what the remote user doing.

One software was very popular. The name might be "Virtual Desktop" or something. I don't like it because it's too big. I think it's more than 20M, while the Remote Administrator is only 2M.

The NetMeeting can also control remote server. I used it to help diagnosed several computers. I like this software so much that I rejected Skype. It's a pity that this software is abandoned. Now Microsoft also has a "Remote Assistant" which can be invoked from MSN Messenger. Although I haven't use it yet.


Two years ago I had a Duron 800 computer and a 486 computer. I wanted to make full use of the 486, but it's hard to keep multiple copies of my file in both computer. The easiest way is to remote-login the Duron 800 using the 486. By that way, my wife can use the Duron 800, while I am sitting in front of the 486 to log in the Duron to access the same files. If both of us only run IE or Word which are not CPU-intensive, we even can't feel the computer is being shared by another person.

That Duron 800 was running Windows 2000. I figured out that this system didn't have remote server built in. So I upgraded it into Windows XP. Yes, the remote connection was established successfully. Then the one who was sitting in front of the server (Duron) was log out. Only one user can log in Windows XP at one time. That is frustrating. The final solution is to install Windows 2003 Server and run the Terminal Service. Thank God, my university is a member of MSDN Academic Alliance, and I can get those Microsoft software for free. This version is quite clean because it's installed in another drive, and it's a clean installation other than an upgrade from previous version. We used this combination (Duron+Windows 2003 Server / 486+Windows NT) for a while, until I got paid as a Teaching Assistant and bought a laptop to my wife.

This month, after I submitted my master thesis, I Googled messages and found that there was a way to enable multi-users logging into Windows XP. Some hacker found the termsrv.dll in Windows XP RC2 (Beta) was an unstricted version. If you replaced the termsrv.dll in the Server following the instruction, you should be able to log in the server concurrently.
I haven't tried this method, because I don't know how to verify the "Digital Signature" of this file, and I don't know if it is a legitimate file. But I do belief this idea, and actually it hasn't been reported with any problem, since this file was discovered in April, 2006.

BTW, I am glad that I didn't spend time to solve this Multi-user login problem 2 years ago. :)

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