Unfortunately I don't have Oracle and my experience with it is limited to my very limited exposure to it while taking a database class in college. However, I do have a few ideas.

The first thing that I would test is to see if the Oracle client can connect from the same system that you're running your Perl code from. If that can't connect, you probably won't be able to connect via Perl or any other language. Also, that test will help verify that you have the Oracle driver installed on your OS.

Second, make sure that you don't have a firewall blocking the desired port.

Other than that, I'm not sure what other suggestions that I could offer.