If you go to jmx-console for the jboss instance you're running (using the correct ports offset by your bindings), the click on
1) the link "jboss" on the left hand side
http://localhost:8080/jmx-console/HtmlAdaptor?action=displayMBeans&filter=jboss
2) then the link "service=Naming" on the right side of the page
http://localhost:8080/jmx-console/HtmlAdaptor?action=inspectMBean&name=jboss%3Aservice%3DNaming
It'll take you to the jnp server configurations. Scroll down to the row named "Port" and you'll see "The listening port for the bootstrap JNP service. Set this to -1 to run the NamingService without the JNP invoker listening port." That'll tell you what port jnp is listening to.