In releases before V5R1, port restrictions were used because Secure Sockets Layer (SSL) support was not available for Telnet. Now you can specify whether SSL, non-SSL, or both are to start. Therefore, there is no longer a need for port restrictions. If you defined port restrictions in previous releases, you need to remove the port restrictions in order to use the SSL parameter. In order to remove port restrictions, follow these steps:
By default, the setting is to start SSL on port 992 and non-SSL on port 23. The Telnet server uses the service table entry for Telnet to get the non-SS port and Telnet-SSL to get the SSL port.