The Java^tm Telnet Application/Applet: FAQ

The telnet protocol was developed durin the early stages of the Internet. Actually it was developed by people who set up the ARPA net. It is a protocol to allow a user to remotely log into another computer and perform tasks there as if he would be sitting on a terminal connected to that computer.

SSH or Secure SHell is just like the telnet protocol, but it provided a secure way to log into that remote host. All communication is encrypted, which makes it much harder for third parties to tamper with the information you send over the network or to sniff out your password.

If you try to use an applet that is located outside your firewall you will not be able to use it. This is due to the fact that the applet tries to open a normal connection from your client to the remote host and the firewall is simply in the way. The applet is not firewall enabled!

Even though there are proxy applications that allow such tunneling we do not actively support this. First it breaks the security a firewall establishes and second the http port is not usually thought for tunneling other connections. In contrast to http, telnet is connection oriented, means it holds the connection open for the time of you doing work. http does not!

First, have a look at the Java console of your browser and try to interpret the error message that appears there. Most commen cause for problems with the loading of the applet are:

• insufficient rights of the files (web browser can't read them)
• missing file (make sure all files you need are there)
• wrong path names (the CODEBASE and other tag attributes)

It may happen that you do not see the login prompt. This may have several reasons. First of all the target host may have telnet disabled.
Secondly if you are behind a firewall you will not be able to connect to the remote host as the firewall usually prevents that. The applet is a normal telnet implementation and can't cross firewalls!