connect to jboss on a Fedora Linux System from external network

This week I had the problem, that from an external WebSphere portal server, I wanted to connect to a manually started jboss on port 8080.

After some time I recognized, that Fedora 17 has a firewall, which prevented
the connection.

How to enable such a port?

There is a command line system-config-firewall:

This GUI allows to add new ports and apply the changes to the system.