Windows Telnet "Duplicates" Characters - KB Article #1771Related Articles --
AllegroSurf features a "Telnet Proxy Server" which allows clients to connect to other machines via telnet. Any telnet client can be used to connect, including PuTTY, TeraTerm, ZOC, and the Windows command-line telnet client.
AllegroSurf's Telnet Proxy Server is configured to echo characters back to the client so that the client can see what has been sent to AllegroSurf. This process developed as an improvement to original telnet servers which offered no way of knowing if a user had committed a typographical error. Later telnet clients (such as the ones offered today) typically echoed characters locally to cut down on traffic and increase accuracy. When both the client and the server echo characters, the result appears as duplicated charcters.
This duplication ceases as soon as a connection is opened to a remote server through AllegroSurf, at which point it is simply passing data back and forth between the destination server and client. However, if necessary this graphical duplication (which does not actually impact the characters the server receives) can be turned off. The telnet program's documention should indicate how to do this. In Windows telnet, use the following command: