enable rmi port?

Hello,

I hope I am at the right place for asking a question.
I set up a JBoss eap 5.1.2 server on RHEL 6.3 .
I took the production profile and altered this to my needs.
To be able to monitor it we wanted to use the rmi interface. So I altered the port in bindings-jboss-beans.xml this way:

jboss.remoting:service=JMXConnectorServer,protocol=rmi
30390
true
RMI/JRMP socket for connecting to the JMX MBeanServer

and restarted the server.
I thought it was enough, But when I check with lsof -i or with telnet 30390 (from the same system) I find no listening port.
Do I need to alter other things to be able to use and reach this rmi port?

Kind regards