I downloaded the jta25-src.jar and tried just did a make jar. But the jar file that got created doesn't work.  However, when I changed the jar file back to the one from the website, it works.

This is the error when I tried connecting to a host and port.
I just used port 23 for telnet.
Sorry, Could not connect to: xxx.xxx.xxx.xxx 23
Reason: java.security.AccessControlException: access denied (java.net.SocketPermission xxx.xxx.xxx.xxx:23 connect,resolve)