About 1 month ago, my ISP replaced my internet box with a newer version, because of instabilities of my old box. I was very pleased to see I was able to put it anywhere at home and get connected, where the older one could only be put in a window at my attic. I could also bring it at church and get connection there, so I can now imagine some internet activities for the little children there. More: the speed was much better.
But there was a drawback. While the speed seemed better, my telnet sessions get disconnected every five minutes of being idle. That issue did not occur with my old box, and I could leave my telnet session open and idle for hours, without any drop. It was a pain to have to reconnect and enter my passwords each time, and mostly when an interactive task stopped because of idle timeout.
These telnet sessions are connections to an AS400 machine, and I used to use the xtn5250 software. xtn5250 is an opensource and "nearly full options telnet 5250 terminal emulator". I was looking at the net to find a possible solution to these session drops, and these searches lead me to fixing it myself.
It's worth noting that in the past, I have contributed an enhancement suggestion for this software, because I had to work with an AS400 where the port 23 was mapped to another port for the outside world, because of ipv4 limitations, and xtn5250 (as the proprietary Client Access on Windows) could only connect to port 23. So, I tried a solution adding
setKeepAlive(true) to the socket and it worked. No more session drops.
I am not a Java programmer, but with some research, I was able to fix an issue, and forked the original project. That's the beauty of opensource.