Thank you very much for your attention, but it is not only telnet, is an others services, like rpc and other, or what ports do you open in my case if you want to public the directiona and rpc, telnet ???
Guess my question is what are you trying to open it up to? Just 5250 Telnet connections?
You will need to open up a few more ports up from 23. Client Access is far more complex.
Follow this Link.
I will caution you from just opening up your System i to the internet. You had better have that sucker locked down and done right. People ,hackers, are savey to the system your about to place on the internet and you also had better be on top of who is hitting it and who has access to it via a real account. While I know the System i is very secure and Client Access is encrypted it can still be hacked and detroyed in minutes. I would offer you that for free that I could get into your system in a matter of minutes if I needed to.
I would place it behind a firewall and make it only accessable after you have a VPN connection.
The System i is very secure but it can’t beat social hacking.
As David asked, the key is to identify what services you need to access. To get the general idea of what applications and ports might be useful, use the command WRKSRVTBLE SERVICE(*ALL).