Port 23 Inactive

Question

I periodically need to access my employer's mainframe from home to provide production support. We can access the company servers that use Aventail Remote access software from clients via the Internet, logging in with a user id, pin plus a randomly generated code from an RSA token. I can log into the company servers, access my email and the company's intranet, but I cannot connect to the mainframe computers. To connect, I need ports 23 and 10023 to be active. Using Mozilla Firefox, the diagnostics from the failed connect indicate that port 23 is inactive and 10023 is active. Using Safari, ports 23 and 10023 are both inactive.
I am just conducting a test of accessing my company's mainframe on my son's MacBook Pro because I would like to switch from Windows to OS X. After connecting, I would use TN3270 to work. How can I make the required ports to be active when I need them to connect to my company's mainframe without having to install Windows XP on a Mac?

Answer 1

You're welcome. Please keep me up-to-date with your
progress.
Mahalo for the
It turns out that I don't need port 23 after all, just port 10023. The latter port was successfully activated during the mainframe connection attempt in the Firefox browser. Port 23 was not. I then configured the TN3270 emulator to use port 10023 instead of 23, and the emulator successfully connected.
The Safari browser, however, cannot connect to the mainframe. The very first connection attempt with this browser displayed the status window but failed to open ports 23 and 10023. Subsequent connection attempts fail to even display the status window. Block pop-ups must be unchecked for this to happen but it is unchecked. The browser just hangs on the connection attempt. But, since Firefox works, so what.